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High Power Rocketry Certification Program The NAR was created in
1957 as an advocate of the model rocketry hobby. Over the past four
decades the hobby has grown to encompass rocket motor types and
performance unavailable to the modeler at the NAR's inception. In
response to this growth the NAR offers a certification process,
which permits individuals to purchase and use rocket motors whose
physical constraints and performance exceed traditional model
rocket boundaries. Rocket motors which exceed model rocketry motor
definitions and the models that use these motors are collectively
referred to as high power rocketry. The following pages provide the
following:
1. A copy of the NAR High Power Certification Application for
Level 1, 2 and 3 (Which may be photocopied for use of your
members.)
2. A description of the High Power Certification Program
3. The current "Pool of Test Questions" used in the written
test. (Latest revision of March,
1999) Not all of the questions from the pool are used, but all
questions in the test are chosen from the Test Question Pool. This
section will probably be the most frequently updated section of
this manual.
Steve Lubliner is in charge of maintaining the question pool. In
the 1995 December issue of The Model Rocketeer, Steve offers the
following:
Please contact me if you have issues with the questions or are
seeking other information about the NAR High Power Certification. I
can be reached at (520)-296-1689, or by mail at 9968 E. Domenic
Lane, Tucson, AZ 85730. (e-mail: [email protected])
Editor's note: Suggest you contact Steve before a test session
to make sure that this question pool is still in effect. If not,
Steve can get you a more current list. Also, a practice area is
available on the NAR Web Site ( http://www.nar.org). Certification
for high power rocketry consists of three progressive levels:
Level 1 allows the purchase and use of H and I impulse class
motors.
Level 2 allows the purchase and use of J, K, and L impulse class
motors and hybrid rocket motors.
Level 3 certification allows the purchase and use of M, N, and O
impulse class rocket
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motors. The procedures for Level 1 and Level 2 certification are
documented below. Level 3 certification requires in-process reviews
of the certification model design and construction prior to flight.
Level 3 certification is covered in an application separate from
the Level 1 and Level 2 paperwork. Please note that the NAR high
power certification is only one consideration when purchasing and
using high power rocket motors. Compliance with local and state
laws as well as federal regulations (e.g. FAA FAR Part 101) is also
required. High power certification is intended to provide a measure
of the modeler's competence to avoid gross violations of good
modeling practice and safe model operation. The program is not
foolproof. A single demonstration of a modeler's skills does not
guarantee consistent safe performance. The certification program
does not replace competent range personnel (note that high power
range safety officers will require high power certification per
NFPA 1127) to provide assurance of safe models and operating
practices. Levels 1 and 2 1. Minimum Requirements
1. 1.1 The individual seeking high power certification must be a
minimum of 18 years old at the time of certification. A driver's
license or a birth certificate is an acceptable proof of age. Note:
Other requirements, e.g. 21 years old minimum age, U.S.
citizenship, and/or no felony convictions, are imposed by federal,
state, or local authorities. Federal requirements for a Low
Explosives Users Permit (LEUP) are not satisfied by NAR high power
certification. This document does not supersede any requirements
imposed by the authorities having jurisdiction.
1.2 The individual must be a member in good standing with the
National Association of
Rocketry (NAR) at the time of certification. Evidence of NAR
membership will be requested prior to the certification attempt.
Acceptable evidence of membership includes the NAR membership card,
a canceled check indicating payment of membership fees, or
participation in a NAR event where membership status is verified
and indicated on the event materials.
1.3 Motors used for certification attempts must be currently
certified by either the NAR or
other organizations (e.g. Tripoli) with a recognized
certification program. Manufacturer's designations, not
certification test data, will be used to identify suitability for
the certification level being attempted (e.g. an H128 is an H, a
G75 is a G).
2. Certification Teams
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2.1 The certification team consists of two individuals who are a
minimum of 18 years old and are members in good standing in the
NAR. The certification team members must be unrelated to the
applicant. Members of Tripoli, unless they are also members of the
NAR, cannot participate on a certification team.
2.2 At least one of the team members must be already certified
to a level equal to the
certification level being attempted, e.g. a team member must be
certified at Level 1 to judge another individual's Level 1
certification attempt.
2.3 Level 1 certifications, may be administered by a single NAR
Level 2 certified individual.
The two certified individuals requirement is waived in this
case.
2.4 Certification attempts and written tests must be witnessed
in person by the certification team.. Video recordings of a
certification flight are not acceptable.
3. Certification Process and Documentation
3.1 Certification may be accomplished at any launch where
sufficient individuals meeting the requirements of paragraph 2 are
available.
3.2 FAA regulations requiring notification or waivers must be
complied with. The launch
site must have a FAA waiver for high power models (greater than
3.3 pounds launch weight and/or 4.4 ounces of propellant) in effect
at the time of launch. All conditions and restrictions imposed by
the FAA must be satisfied and followed.
3.3 The individual attempting certification must complete a NAR
High Power Certification
Application prior to his certification attempt. If Level 2
certification is desired the individual must provide proof of
previous Level 1 certification. Proof of previous certification
includes the high power certification card or a NAR membership card
showing the Level 1 certification level.
3.4 The model will be subjected to a safety inspection prior to
flight. The safety inspection
form is on the back of the NAR High Power Certification
Application. During the safety inspection the modeler will be
expected to orally answer technical questions related to the safety
and construction of his model. The questions may include (but not
limited to) identification of the model's center of gravity and
center of pressure, methods used to determine model stability, and
interpretation of the rocket motor's designation. The certification
team will initial (or check) the blocks indicating that model
safety, motor certification, and the existence of a FAA waiver (if
required) in effect were verified prior to flight.
3.5 The individual will fly his model. The flight must be
witnessed by the certification team
members. Stability, deployment of the recovery system, and safe
recovery should be considered when evaluating safety of the flight.
Models experiencing a catastrophic failure of either the airframe,
rocket motor and/or recovery system (e.g. shock cord
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separation) will not be considered as having a safe flight. 3.6
The model must be returned to the certification team after flight
and be inspected to
verify engine retention and for evidence of flight induced
damage. The certification team will initial the blocks indicating
that a safe flight was made and that the post-flight inspection was
satisfactory.
3.7 The certification team will sign the certification sheet to
indicate that the certification
attempt was successfully completed. Both the certification sheet
and the certification card must be signed. The certification card
and the certification sheet are normally returned to the certifying
individual after the flight. At club launches or NAR sponsored
activities (e.g. NARAM, NSL) the certification sheets may be
retained by the event sponsors to be sent to NAR Headquarters as a
group. In that event, only the certification card is returned to
the certifying individual.
3.8 The certification sheets and Level 2 written tests (if
applicable) are returned to NAR
Headquarters. No fees are required. The certification sheets
with tests must be returned by the certified individual or the
event sponsors to NAR Headquarters to allow updating the NAR
database. A new NAR membership card will be issued showing the
certification level upon receipt of the certification
paperwork.
3.9 The certification card is valid for one year after the
certification date or until the end
the NAR member's membership, which ever comes first. The card is
recognized as proof of the certification level. The certification
card should be destroyed upon receipt of a new NAR membership card,
which shows the certification level.
3.10 Falsification of data or statements by the certifying
individual will result in revocation of
the high power certification. Falsification of data or
statements by the certification team, e.g. failure to secure a FAA
waiver, can result in revocation of the team members' NAR
memberships.
4. Level 1 high power certification (160.01 to 640.00
Newton-seconds impulse)
4.1 The modeler must demonstrate his ability to build and fly a
rocket containing at least one H or I impulse class motor. Cluster
or staged models used for certification may not contain over 640.00
Newton seconds total impulse. Single use or reloadable (no hybrids)
technology motors are permitted. The modeler must assemble the
reloadable motor, if used, in the presence of a certification team
member.
4.2 No written examination is required.
4.3 Certification at this level permits single or multiple motor
rocket flights with motors
having a maximum total impulse of 640.00 Newton seconds. 5.
Level 2 high power certification (640.01 to 5120.00 Newton-seconds
impulse)
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5.1 The modeler must demonstrate his ability to build and fly a
rocket containing at least
one J, K, or L impulse class motor. Cluster or staged models
used for certification may not contain over 5120.00 Newton seconds
total impulse. Single use, reloadable, and hybrid technology motors
are permitted. The modeler must assemble the reloadable or hybrid
motor, if used, in the presence of a certification team member.
5.2 A written examination is required to demonstrate knowledge
of the regulations and laws
pertaining to high power rocketry. Questions concerning basic
rocket technical knowledge, e.g. center of pressure and center of
gravity relationships, will also be included.
5.2.1 The examination will contain 33 questions in the multiple
choice format.
5.2.2 The questions will come from a 50 to 100 question pool of
previously published
questions and answers.
5.2.3 The passing grade is 88%.
5.2.4 The test may be taken only once in a 30 day period.
5.2.5 The test must be completed prior to the flight attempt.
The flight attempt should be made as soon as reasonably and safely
possible after successful test completion. The written test will
not have to be repeated if the flight attempt is completed within 1
year of taking the written test. Tests should be retained until the
completion of the certification flight and sent with the
application form to NAR Headquarters.
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5.2.6 Tests are available from: Stephen Lubliner 9968 E. Domenic
Lane Tucson, AZ 85730 (520) 296-1689 (home)
[email protected]
Tests will typically be provided to a certification team member
or to a Section officer (e.g. advisor, president). Tests can be
provided to the individual on a case by case basis to be evaluated
when the test is requested. The tests are sealed to prevent
accidental disclosure of the questions. The tests should remain
sealed until taken. Allow one week minimum prior to a certification
attempt to receive the test in the mail.
Section advisors or officers can request a supply of tests
(typically three to 12 tests) in advance of launches or Section
events. Address requests to the above address.
5.3 Certification at this level permits single or multiple motor
rocket flights with motors
having a maximum total impulse of 5120.00 Newton seconds. 6.
Administrative Items
6.1 NAR members who are currently Tripoli members and are
Tripoli Level 1 certified may grandfather at the NAR Level 1 by
completing a NAR high power application and attaching proof of
Tripoli certification.
6.2 NAR members who are currently Tripoli members and are
Tripoli Level 2 certified may
grandfather at the NAR Level 2 by completing a NAR high power
application and attaching proof of Tripoli certification.
6.3 Tripoli certifications will be honored at NAR launches.
6.3.1 A current Tripoli consumer confirmation card is required
as evidence of Tripoli high
power certification at launches.
6.4 Lapses in the NAR membership over one year will void all
certifications. Certifications will have to be repeated starting
with Level 1.
Revision of 4 May, 1999
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Formal Certification Procedure Level 3 1. Flyer Requirements
1.1 Any individual attempting NAR Level 3 Certification must be
a Level 2 high power certified NAR member in good standing.
2. Rocket Requirements
2.1. The certification rocket must be substantially built by
certifying flyer. Individuals using rockets with substantial
"prefabricated" components will be required to demonstrate suitable
construction knowledge to the satisfaction of the Certification
Committee. Only the builder of the rocket may use that rocket for a
certification attempt. Rockets built by other than the certifying
flyer are specifically disallowed. Certification rockets may be
built from commercially available kits and may contain components
built to the specifications of the certifying flyer but fabricated
by others.
2.2. Multiple stage rockets are specifically disallowed for
certification flights.
2.3. The rocket must contain a redundant mechanism for
performing the initial recovery
event. For single event recovery, the main parachute must have
redundant mechanisms for ejection. For drogue-main recovery
systems, the drogue parachute must have multiple mechanisms for
ensuring drogue deployment. Motor ejection charges may be used as a
redundant ejection mechanism, but rockets depending primarily on
motor ejection for any recovery event are specifically
disallowed.
2.4. The capability must exist to externally disarm all
pyrotechnic devices in the rocket. In
this context, "disarm" means the ability to physically break the
connection between a pyrotechnic device and the power source to its
igniter. Simply turning off the device controlling the
pyrotechnic(s) is not sufficient.
2.5. The rocket must conform in all respects to any restrictions
imposed by the NAR High
Power Safety Code and NFPA 1127. 3. Certification Procedures
3.1. The flyer must obtain and fill out a NAR Level 3
Certification Form. This form documents the certification procedure
steps. The flyer must also prepare a Certification Package as
defined in these requirements.
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3.2. During the construction of the rocket, the flyer must
complete the Rocket Construction section of the Certification Form.
This package will consist of one of the following three
options:
a. The flyer may present the rocket for inspection to one member
of the Level 3
Certification Committee (L3CC) prior to its final assembly. The
purpose of the inspection is to verify, to the satisfaction of the
L3CC member, that the rocket is being constructed in a manner
suitable for the stresses encountered in a Level 3 flight. The L3CC
member performing the inspection will sign his/her approval on the
Certification Form.
b. The flyer may prepare a construction packet with descriptions
of the construction
techniques, and including photos and/or diagrams. If a
construction packet is used in lieu of a physical inspection, this
package must be approved and signed by one member of the L3CC.
c. The flyer may build and document a test flight of the rocket.
The test flight must utilize
a Level 2 motor with thrust characteristics similar to the
intended Level 3 certification motor. The flyer must be able to
show that the rocket received stresses approaching that anticipated
in the Level 3 flight (either by flight simulation or by recording
altimeter or accelerometer).
3.3 The L3CC member accepting the Construction Package will sign
the Level 3
Certification Form at the indicated location.
3.4. Prior to the certification flight, the flyer must present a
Recovery Systems Package to one L3CC member. This document package
must contain the following components:
a. A description of the recovery system components, including
the type of electronics,
where redundancy is employed, the type and size of pyrotechnic
devices, and the sizes of parachutes or streamers being
utilized.
b. A schematic/wiring diagram of the ejection control system.
This diagram should show
the wiring between the ejection devices, disarming "switches"
and controlling electronics/power source(s).
c. Description of expected descent rate with the main recovery
device deployed and
explanation of how the descent rate was determined, or other
description explaining why the main recovery device is suitably
sized for the certification rocket (manufacturer's recommendation,
etc.).
d. Documentation describing how the basic functioning of the
recovery electronics has
been demonstrated prior to the certification flight (use of
untested ejection control electronics is not permitted). This may
be accomplished by either of two methods:
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The flyer may document a Level 2 test flight utilizing the
recovery components intended
for use in the Level 3 certification flight, including the
primary ejection electronics to be used in the certification
flight.
The flyer may document the ground testing of the recovery
electronics.
3.5. The L3CC member accepting the Recovery Systems Package will
sign the Level 3
Certification Form at the indicated location.
3.6. At the time of the Certification Flight, the flyer will
present a completed Certification Package for approval as described
in the Certification Package Guidelines.
3.7. Upon approval of the Certification Package, the flyer must
make a successful
certification flight as described in Certification Flight
Requirements.
3.8. Upon successful completion of the certification flight, the
completed, approved certification package will be sent to NAR
headquarters for final processing as described in Final Procedures
After Certification.
3.9. If the certification flight fails or is disallowed, one of
the Flight Witnesses will complete
and send in the Certification Form as described in Failed
Certification Procedures. 4. Certification Package Requirements The
Level 3 Certification Package will contain all of the
following:
1. The certification rocket Construction and Recovery
packages.
2. A scale drawing of the certification rocket showing major
dimensions, calculated center of pressure, and expected center of
gravity in Level 3 certification flight configuration.
3. A description of the expected flight profile using the
intended certification motor(s). This
profile should include at a minimum estimates for the following:
Maximum expected altitude Maximum expected acceleration Maximum
expected velocity Velocity as the rocket leaves the launch
system
4. A pre-launch checklist covering rocket and motor preparation
and setup.
5. A post-recovery checklist for "safing" the rocket in case of
a failure. This would include
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steps required for disarming pyrotechnics, removal of unfired
igniters, etc. 5. Certification Flight Requirements
5.1. Prior to the Certification Flight, the flyer will present
the certification rocket and Certification Package to two senior
members of the NAR, who will act as Flight Witnesses, for
pre-flight inspection. Both of the Flight Witnesses must be at
least Level 2 high power certified. One of the Flight Witnesses
must be a member of the L3CC. Both Flight Witnesses must approve
the rocket for flight.
5.2. The actual flight must meet all of the following
requirements:
The rocket must use at least one motor with total impulse
greater than 5120NS. The flight must be made while a suitable FAA
waiver is in effect. The rocket must make a stable, safe flight.
The rocket must fully deploy its recovery system. The rocket must
remain intact, with no separation of parts that do not deploy their
own
recovery device(s). The rocket must be returned for post-flight
inspection.
5.3. If the recovered rocket is plainly visible but not
retrievable (such as hung in high power lines or in an inaccessible
location) the flyer may direct the Flight Witnesses to the location
of the rocket for visual inspection at that location.
5.4. By signing for final approval on the Certification Package,
the Flight Witnesses are also
certifying that they have looked over the entire Certification
Package and to the best of their knowledge, it is complete and
acceptable.
5.5. Different Certification Committee members may be used for
Construction/Recovery
Package approval and Flight witnesses.
5.6. Either Flight Witness may disallow the certification
attempt if, in his or her opinion:
a. The flight did not demonstrate the flyer's ability to
successfully fly a Level 3 High Power rocket.
b. The rocket did not fully meet all of the flight requirements
for Level 3 certification. 6. Final Certification Procedures
6.1. The flyer will remove and keep the signed, lower section of
the Certification Form. This may be used as temporary proof of
Level 3 certification.
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6.2. One of the Flight Witnesses will return the completed
Certification Form to NAR Headquarters.
6.3. The flyer will receive an updated NAR membership card,
showing the new Level 3
certification level, by return mail. 7. Failed Certification
Procedures
7.1 One of the Witnesses shall fill out the Failed Certification
Flight section on the Level 3 Certification Form. The form shall
then be mailed to NAR headquarters, in its entirety.
7.2. These forms will not be used to track failures by
individuals. Failed certification attempts
do not count against an individual. The forms will be used to
track the effectiveness of the NAR Level 3 certification
procedures. They will also be used to track the frequency and types
of failures. This information is needed in order to improve the
certification procedures over time.
Revision of 4 May, 1999
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National Association of Rocketry Level 2 ("J"/"K"/"L")
Certification Test Question Pool
Section A - Applicable Regulations (11 questions) A1) Which of
the following National Fire
Protection Association standards provides a code for high power
rocketry?
A) NFPA 1122 B) NFPA 1127 C) NFPA 1123 D) NFPA 1124
The answer is "B". NFPA 1127 is the Code for High Power
Rocketry. NFPA 1122 is the Code for Model Rocketry; NFPA 1123 is
the Code for Outside Display of Fireworks; NFPA 1124 is the Code
for the Manufacture, Transportation, and Storage of Fireworks.
A2) What part of the Federal Aviation
Administration Federal Aviation regulations govern rocket
activity?
A) Part 95 B) Part 97 C) Part 101 D) Part 125
The answer is "C". Rocket activity is codified in Part 101,
Moored Balloons, Kites, Unmanned Rockets, and Unmanned Free
Balloons.
A3) What is the maximum launch weight
allowable for a rocket which does not require FAA notification
or waiver?
A) 4 ounces (113 grams) B) 4.4 ounces (125 grams) C) 1 pound
(453 grams)
D) 3.3 pounds (1500 grams) The answer is "C". Part 101 does not
govern the operation of model rockets weighing under 16 ounces (1
pound).
A4) What is the maximum propellant
weight allowable for a rocket which does not require FAA
notification or waiver?
A) 4 ounces (113 grams) B) 4.4 ounces (125 grams) C) 1 pound
(453 grams) D) 3.3 pounds (1500 grams)
The answer is "A". Part 101 does not govern the operation of
model rockets using not more than 4 ounces of propellant.
A5) What is the maximum total impulse
allowable for a rocket which does not require FAA notification
or waiver?
A) 80 Newton seconds B) 160 Newton seconds C) 320 Newton seconds
D) There is no impulse limit.
The answer is "D". Part 101 does not specify any impulse
limits.
A6) What is the maximum launch weight
allowable for a rocket when complying with the FAA notification
requirements?
A) 4 ounces (113 grams) B) 4.4 ounces (125 grams) C) 1 pound
(453 grams) D) 3.3 pounds (1500 grams)
The answer is "D". Part S101.22 allows
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operation of rockets weighing no more than 1500 grams (3.3
pounds) provided an individual complies with the notification
requirements in part S101.25.
A7) What is the maximum propellant
weight allowable for a rocket when complying with the FAA
notification requirements?
A) 4 ounces (113 grams) B) 4.4 ounces (125 grams) C) 1 pound
(453 grams) D) 3.3 pounds (1500 grams)
The answer is "B". Part S101.22 allows operation of rockets
using not more than 125 grams (4.4 ounces) of propellant provided
an individual complies with the notification requirements in part
S101.25.
A8a) High power rocket motors, motor
reloading kits, and pyrotechnic modules shall be stored at least
____ away from smoking, open flames, and other sources of heat.
A) 10 feet B) 25 feet C) 50 feet D) 75 feet
The answer is "B". Refer to paragraph 2-18.1 of NFPA 1127, 1998
edition.
A9a) Which of the following is a
requirement for high power certification:
A) The ability to understand written English instructions B) A
minimum of 18 years of age C) A citizen of the United States of
America D) No felony convictions
The answer is "B". Refer to paragraph 5-4.1 of NFPA 1127, 1998
edition.
A10) Deleted A11) What is the maximum total impulse
permitted in a high power rocket per NFPA 1127?
A) 81920 Newton seconds B) 40960 Newton seconds C) 20480 Newton
seconds D) There is no limit provided the FAA altitude waiver
requirements are not exceeded.
The answer is "B". Refer to paragraph 2-8.2 of NFPA 1127, 1998
edition.
A12) What is the maximum allowable weight
for a high power rocket permitted per NFPA 1127?
A) 30 pounds B) 60 pounds C) 120 pounds D) There is no limit
provided the rocket weighs less than the rocket motor
manufacturer's recommended liftoff weight for the rocket motor(s)
used for flight.
The answer is "D". Refer to NFPA 1127, 1998 edition paragraph
2-8.1.
A13) What is the minimum age for user
certification?
A) 16 years old B) 18 years old C) 21 years old D) 25 years
old
The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph
5-4.1.
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A14) Which of the following is not a
required feature of a rocket motor ignition system?
A) A removable interlock device is in series with the launch
switch. B) The system is electrically operated. C) The launching
switch will return to the "off" position when released. D) An
audible or visual indicator shows continuity through the rocket
motor ignitor.
The answer is "D". Refer to NFPA 1127, 1998 edition, paragraphs
2-12.1 and 2-12.2.
A15) Which of the following statements are
true concerning the definition of a High Power Rocket Motor?
A) Total impulse is more than 160 Newton seconds B) The motor
uses a "composite" propellant C) Both A and B above D) The motor
must use either fiberglass or metal case materials
The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph
1-3, for the definition of a high power rocket motor.
A16) Which of the following is (are) true of a
complex high power rocket per NFPA 1127?
A) The rocket is multi-staged or propelled by a cluster of
rocket motors B) The rocket contains electrical or electronic
devices intended for control of the rockets functions, e.g.
staging, recovery initiation C) The rocket uses other than
parachute or streamer recovery, e.g. helicopter or glide recovery
D) Both "A" and "B" above
The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph
1-3, Definitions.
A17) A launch site is defined as containing
areas for which of the following activities? A) Launching B)
Recovery C) Parking D) All of the above
The answer is "D". Refer to NFPA 1127, 1998 edition, paragraph
1-3, for the definition of a launch site.
A18) A person shall fly a high power rocket
only in compliance with:
A) NFPA 1127 B) Federal Aviation Administration Regulations,
Part 101 C) State, and local laws, rules, regulations, statutes,
and ordinances D) All of the above
The answer is "D". Refer to NFPA 1127, 1998 edition, paragraph
2-2.
A19) Which of the following statements is
always true concerning the definition of a hybrid rocket
motor?
A) The fuel component is composed of either paper or plastic. B)
The fuel is in a different physical state (solid, liquid, or
gaseous) than the oxidizer. C) The oxidizer component is nitrous
oxide. D) Both "A" and "C" above"
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The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph
1-3, for the definition of a hybrid rocket motor.
A20) Per the ATF-Explosives Law and
Regulation (Orange Book) what kind of explosive material is
Thermalite fuse:
A) High Explosive B) Low Explosive C) Blasting Agent D)
Non-explosive
The answer is "B". Refer to section 55.202 (b) of the
ATF-Explosives Law and Regulation, 6/90 revision.
A21) LEUP stands for:
A) Legal Entitity User Permit B) Liability Evaluation/Uniform
Process C) Low Explosive User Permit D) Low Explosive Uniform
Process
The answer is "C".
A22) The minimum age for an explosive
permits applications is:
A) 16 years or older B) 18 years or older C) 21 years or older
D) 25 years or older
The answer is "C". Refer to ATF- Explosives Law and Regulation
(Orange Book), Sections 843 (b) (1) and 842 (d) (1).
A23) Which of the following statements are
true concerning the definition of a High Power Rocket Motor?
A) Total impulse is less than 81920 Newton seconds B) The total
impulse is more than 160 Newton-seconds C) Both A and B above D)
The motor must use either fiberglass or metal case materials
The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph
1-3, for the definition of a high power rocket motor.
A24) Which of the following are
prohibited activities for participants prepping or launching
high power rockets?
A) Consumption of alcohol B) Use of medication that could affect
judgement, movement, or stability C) Both "A" and "B" above D) None
of the above
The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph
6-1 "l".
A25) Which of the following are prohibited
activities for spectators in high power rocket prepping areas
?
A) Consumption of alcohol B) Use of medication that could affect
judgement, movement, or stability C) Both "A" and "B" above D) None
of the above
The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph
6-1 "l".
A26) An certified individual wants to
purchase a "L" motor reload kit at a launch in a state other
than his residence. Which of the following is true?
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Section 8, Page 21
A) He must possess a Low Explosives User's Permit. B) He does
not require a Low Explosives User's Permit. C) He must pay in
advance for the motor purchase. D) He must use the reload kit on
the same day as purchase.
The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph
5-2 "a".
A27) A certified individual wants to
purchase a "L" motor reloadable casing at a launch in a state
other than his residence. Which of the following is true?
A) He must possess a Low Explosives User's Permit. B) He does
not require a Low Explosives User's Permit. C) He must pay in
advance for the motor purchase. D) He must use the reload kit on
the same day as urchase.
The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph
5-2 "a". Note the difference from question A26 (casing versus
reload kit).
Section B - Storage Requirements (2 questions) B1) What is the
maximum net propellant
weight that may be stored in a indoor Type 3 or Type 4
magazine?
A) 10 pounds B) 25 pounds C) 50 pounds D) 100 pounds
The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph
2-18.2.
B2) Which type of storage magazine is
referred to as a "day-box"?
A) Type 1 B) Type 2 C) Type 3 D) Type 4
The answer is "C". A Type 3 magazine is a "day-box" or other
portable magazine per page 51 of the ATF - Explosives Law and
Regulations (6/90).
B3) Which of the following are
requirements for Type 3 magazine construction?
A) Steel structure B) Wood lined C) Lockable D) All of the
above
The answer is "D". A Type 3 magazine is constructed from steel,
no thinner than 12 gauge, and lined with 1/2" thick plywood or
hardboard. Provisions for 1 lock, no hood, are required.
B4) Which of the following is not a
requirement for an indoor magazine?
A) The magazine will be painted red. B) The magazine will bear
the words "EXPLOSIVES-KEEP FIRE AWAY". C) The magazine will bear
the words "EXPLOSIVES-50 POUND MAXIMUM" D) The words
"EXPLOSIVES-..." are printed in white letters at least 3 inches
high.
The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph
2-18.2.
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Section 8, Page 22
B5) In which of the following locations can a Type 3 or Type 4
magazine be properly located?
A) In the attached garage of a single family residence B) In the
utility or laundry room of a multi-family residence C) In the
bedroom closet for a non-smoker resident D) Anywhere inside the
house at least 10 feet away from flame producing appliances (stove,
water heater, etc.)
The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph
2-18.2.3.
B6) In which of the following locations can
a Type 3 or Type 4 magazine be properly located?
A) In the utility or laundry room of a multi-family residence B)
In the attached garage of a multi- family residence if the garage
is surrounded on all sides by a 1 hour fire rated barrier C) In the
bedroom closet for a non-smoker resident D) Anywhere inside the
house at least 10 feet away from flame producing appliances (stove,
water heater, etc.)
The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph
2-18.2.4.
B7) In which of the following locations can
a Type 3 or Type 4 magazine be properly located?
A) In the bedroom closet for a non-smoker resident B) In the
attached garage of a multi- family residence C) In a detached
garage substantially removed or segregated from any residence.
D) Anywhere inside the house at least 10 feet away from flame
producing appliances (stove, water heater, etc.)
The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph
2-18.2.2.
Section C - Range and Safety Practices (15 questions) C1) What
is the maximum launch angle,
measured from the vertical, for a high power rocket?
A) 10 degrees B) 20 degrees C) 30 degrees D) 40 degrees The
answer is "B". Refer to section 15 of the NAR High Power Rocket
Safety Code.
C2) What is the maximum wind velocity
allowable for launch operations? A) 20 miles per hour B) 25
miles per hour C) 15 miles per hour D) 30 miles per hour
The answer is "A". Refer to section 13 of the NAR High Power
Rocket Safety Code.
C3) The minimum launch site dimension
for rockets having a maximum installed impulse of 320.00 Newton
seconds is 1500 feet. What is the minimum distance between the
launch site boundary and the launcher?
A) 150 feet B) 375 feet C) 750 feet
D) The launcher may be located anywhere on the launch site
to
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Section 8, Page 23
compensate for wind.
The answer is "C". A person shall not locate a launcher closer
to the edge of the launch site than one half (1/2) the minimum
launch site dimension. Refer to section 9 of the NAR High Power
Rocket Safety Code (revision 7/95).
C4) The minimum launch site dimension
for rockets having a maximum installed impulse of 2560.00 Newton
seconds is 5280 feet. Flights to 10500 feet are anticipated. What
is the minimum distance between the launch site boundary and the
launcher?
A) Approximately 660 feet B) Approximately 1320 feet C)
Approximately 2600 feet D) The launcher may be located anywhere on
the launch site to compensate for wind.
The answer is "C". A person shall not locate a launcher closer
to the edge of the launch site than one half (1/2) the minimum
launch site dimension. Refer to NFPA 1127, 1998 edition, paragraph
2-14.2 and section 9 of the NAR High Power Rocket Safety Code
(revision 7/95). The anticipated altitude is important because the
launch site dimensions may also be determined to be 1/2 of the
maximum altitude expected (see NFPA paragraph 2-13.4). In this case
1/2 of 10500 feet is 5250 feet or about the same as specified in
the safety code launch site table.
C5) The FAA has granted a waiver for high
power rocket flight to 18000 feet for your event. Flights up
tothat altitude are expected. What are the minimum launch site
dimensions?
A) 1800 feet B) 4500 feet C) 9000 feet D) 18000 feet
The answer is "C". The size of the launch site may also be
calculated as no less than one half (1/2) of the maximum altitude
expected, calculated, simulated, or granted (by FAA
waiver/authority having jurisdiction). Note that the minimum launch
site dimensions may even beeven greater depending upon the total
impulse flown. For example, "L" powered models require a minimum
launch site dimension of 10560 feet. Refer to NFPA 1127, 1998
edition, para 2-13.2 and to section 9 of the NAR High Power Rocket
Safety Code (revision 7/95).
C6) The FAA has granted a waiver for high
power rocket flight to 2500 feet for your event. What are the
minimum launch site dimensions?
A) 250 feet B) 500 feet C) 1250 feet D) 1500 feet
The answer is "D". The size of the
launch site may also be calculated as no less than one half
(1/2) of the maximum altitude expected, calculated, simulated, or
granted (by FAA waiver/authority having jurisdiction), however, in
no case shall the minimum launch site dimension be less than 1500
feet. Note that the minimum launch site dimensions may even be even
greater depending upon the total impulse flown. Refer to NFPA 1127,
1998 edition, paragraph 2-13.3 and to section 9 of the NAR High
Power
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Section 8, Page 24
Rocket Safety Code (revision 7/95). C7) In no case shall the
minimum launch
site dimension be less than ______ the estimated altitude of the
high power rocket or _______ .
A) 1/4, 1500 feet B) 1/2, 1500 feet C) 1/4, 2500 feet D) 1/2,
2500 feet
The answer is "B". Refer to NFPA 1127, 1998 edition, paragraphs
2-13.2 and 2-13.3.
C8) Your launch site borders on an
interstate freeway. What is the minimum distance allowable for
location of a high power launch site from the interstate
freeway?
A) 750 feet B) 1500 feet C) 3000 feet D) 5280 feet (1 mile)
The correct answer is "B". Refer to NFPA 1127, 1998 edition,
paragraph 2-14.2.
C9) Your launch site's owner's house is
located in the middle of your site. What is the minimum distance
allowable for location of a high power launch site from the owner's
house?
A) 750 feet B) 1500 feet C) 3000 feet D) The launch site shall
contain no occupied buildings; you cannot launch unless the house
is empty. The answer is "D". Paragraph 2-14.2 of NFPA 1127, 1998
edition, states that
when occupied structures or busy roads border the launch site, a
1500 foot minimum separation is required between the launcher and
the road or building.
C10) What is the minimum safe distance
from a high power rocket containing a single "I" motor?
A) 200 feet B) 100 feet C) 75 feet D) 50 feet
The answer is "B". Refer to Table 2-15 .3 of NFPA 1127, 1998
edition, and the safe distance table in the NAR High Power Rocket
safety code (revised 7/95).
C11) What is the minimum safe distance
from a high power rocket containing two "H" motors?
A) 200 feet B) 100 feet C) 75 feet D) 50 feet
The answer is "A". Refer to Table 2- 5.3 of NFPA 1127, 1998
edition, and the safe distance table in the NAR High Power Rocket
safety code (revised 7/95).
C12) What is the minimum safe distance
from a high power rocket containing two "K" motors?
A) 50 feet B) 100 feet C) 300 feet D) 500 feet
The answer is "D". Refer to the NAR High Power Rocket Safety
Code and Table 2-
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Section 8, Page 25
15.3 of NFPA 1127, 1998 edition. C13) Which of the following
igniters may be
ignited by the continuity test of some launch controllers?
A) Nichrome wire B) Flashbulbs C) Electric match D) Both "b" and
"c" above The answer is "D". Refer to the "Handbook of \Model
Rocketry" by G. Harry Stine, 6th edition, Chapter 6 on "Ignition
and Ignition Systems". Look at page 94.
C14) In the event of a misfire how long
should you wait before approaching the launch pad?
A) 15 seconds B) 60 seconds C) 5 minutes D) No wait is
required
The answer is "B". Refer to paragraph 12 of the NAR High Power
Rocket Safety Code.
C15) Which of the following is most likely to
cause catastrophic failure of a black powder rocket motor?
A) Temperature cycling B) Electromagnetic fields C) Vibration D)
High altitude
The answer is "A". Temperature cycling is the primary cause of
black powder rocket motor catastrophic failure. Temperature cycling
cause expansion and contraction of the black powder grain and motor
casing causing delaminations between the case and propellant grain
and cracks within the
grain. These delaminations and cracks expose additional burning
surface that increases combustion pressures. The result is a motor
failure. Note that shock or vibration can also damage a black
powder rocket motor, however thermal cycling is the most likely
cause of failure. Refer to the May and June 1992 issue of American
Spacemodeling magazine, page 10, the article "A Theoretical
Analysis of Why Black Powder Model Rocket Motors Fail".
C16) Igniters for clustered rocket motors
should be wired together in: A) Series B) Parallel C) Short
Circuit D) Open Circuit
The answer is "B". If the igniters are wired in series the first
igniter to burn out opens the circuit preventing any other igniters
from receiving electrical power. Parallel connections allow all of
the igniters to independently receive electrical power.
C17) When should igniters installed in
rocket motors be checked for continuity?
A) Any time B) Only in an enclosed shelter C) Only on the launch
pad when ready for launch D) Igniters should never be checked for
continuity while installed in a rocket motor.
The answer is "C". Continuity is typically checked by the launch
controller when the rocket is placed on the launch pad. This is
considered safe practice because the number of personnel around the
model is at a minimum and the model is pointed
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Section 8, Page 26
skyward which minimizes the hazard in the event of inadvertent
ignition.
C18) Which of the following is the preferred
method for attaching fins to a high power rocket?
A) Tube surface mounting B) "Wedge" mount C) "Though the wall"
mounting D) All fin mounting methods are all equally strong; it
does not matter.
The answer is "C". Through the wall mounting is stronger because
the model is supported and attached to the rocket at two locations.
The fins are attached to the motor tube and the body tube. In cases
where through the wall mounting is not usable "wedge" mounting may
be possible. Wedge mounting places the fin at the junction of two
tubes; this mounting is typically used in cluster models. Surface
mounting, like that used in most model rocket kits, is not
recommended for high power rockets.
C19) Which of the following adhesives
should not be used on rubber (or elastic) shock cord
components?
A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C)
Aliphatic resin based glues D) White "Elmer's" glue
The answer is "B". Cyanoacrylate glues will chemically attack
rubber or elastic shock cord components allowing them to break when
stretched.
C20) Which of the following adhesives is
most likely to be weakened under humid or wet weather
conditions?
A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C)
Aliphatic resin based glues D) White "Elmer's" glue
The answer is "D". White glues are weakened under high humidity
conditions. Use aliphatic base (wood or carpenter's) glues instead
of white glue.
C21) Which of the following adhesives is the
best choice for engine mount construction?
A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C)
Aliphatic resin based glues D) "Hot melt" adhesives
The answer is "A". Epoxies can be used to easily form fillets at
the bond joints which provides an increase in strength. Epoxies
also bridge gaps in loose fitting parts to improve bond strength.
One caution when using epoxies is that they are relatively heavy;
they can reduce model stability by making the model tail heavy.
Cyanoacrylate glues are not recommended for engine mount
construction because they tend to soak into paper/cardboard body
tube materials and are poor gap fillers. Hot melt adhesives should
never be used for engine mount applications because they weaken
with heat.
C22) The centering rings provided with your
high power kit are a loose fit around the motor tube. Which of
the following adhesives is the best choice for a strong joint?
A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C)
Aliphatic resin based glues D) "Hot melt" adhesives
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Section 8, Page 27
The answer is "A". Epoxies can be used to easily form fillets at
the bond joints which provides an increase in strength. Epoxies
also bridge gaps in loose fitting parts to improve bond strength.
One caution when using epoxies is that they are relatively heavy;
they can reduce model stability by making the model tail heavy.
Cyanoacrylate glues are not recommended for engine mount
construction because they tend to soak into paper/cardboard body
tube materials and are poor gap fillers. Hot melt adhesives should
never be used for engine mount applications because they weaken
with heat.
C23) A small hole is typically recommended
near the top, but below the nosecone or payload section
shoulder, of a high power rocket's booster section. Why?
A) This hole allows excessive ejection charge pressures to vent
to reduce shock cord stress. B) The hole is used to give air
pressure readings for on board altimeters. C) The hole vents
internal air pressure as the rocket gains altitude to prevent
internal air pressure from prematurely separating the model. D) The
hole allows easy verification that a parachute is installed.
The answer is "C". Air pressure external to the rocket decreases
as the rocket ascends. Trapped pressure within the model can
prematurely separate the model. The hole vents this internal air
pressure to prevent separation. Note that the hole size is
dependent on model size; larger models require larger holes. Use
caution in locating the hole such that the nosecone (or stage
coupler) does not block the hole. Also, position the hole such that
ejection
charge pressure is not vented before ejecting the recovery
system from the body tube.
C24) When clustering combinations of black
powder and composite motors, which type of rocket motor should
be ignited first?
A) Composite rocket motors should be ignited first B) Black
powder rocket motors should be ignited first C) It does not matter
which motors are ignited first D) Clusters should never mix
composite and black powder motors The answer is "A". Composite
rocket motors are harder to ignite than black powder motors. The
concern is that the model will leave the launch pad before the
composite motor has ignited.
C25) Why should composite motors be
ignited first in a mixed composite and black powder cluster?
A) Composite motors are more difficult and take longer to
ignite. B) Composite motors are more likely to "cato" than black
powder motors C) The exhaust products from black powder motors
prevent composite motor ignition. D) Composite rocket motors are
more powerful than black powder motors
The answer is "A". Composite rocket motors are harder to ignite
than black powder motors. The concern is that the model will leave
the launch pad before the composite motor has ignited.
C26) If individual igniters are used for
igniting a clustered model's motors which of the following
statements is
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Section 8, Page 28
typically true:
A) The launch control must have an audible as well as visual
indication of igniter continuity. B) The launch control must
provide additional current to ignite the additional igniters. C)
The launch control must provide higher voltage to ignite the
additional igniters. D) The launch control must use a car battery
as a power source
The answer is "B". Parallel wiring used in cluster ignition
models "shares" the current among all the igniters. If the ignition
circuit is marginal those igniters which are slightly more
sensitive will ignite before their mates. The model may leave the
launcher prior to full ignition of the cluster. Common practice is
to use a battery which can deliver higher currents than dry cells;
automotive, motorcycle, and "gell cell" batteries are common.
Increased voltage will not significantly improve cluster ignition
reliability. House voltage, 110 volts AC, should never be used for
ignition systems.
C27) What is (are) the advantages of using a
"relay" type launch control?
A) It is cheaper than a non-relay launch control B) The relay
allows a better indication of igniter continuity C) It can deliver
more power to the rocket motor igniters D) Both "B" and "C"
above
The answer is "C". A relay launch system uses a relay to switch
the power needed for rocket motor ignition. The battery is usually
placed adjacent to the launch pad which allows for shorter
power wires. The shorter power wires minimize the normal loss of
power that occurs over long wire lengths (remember that several
hundred feet of wire may be required to reach a high power launch
pad). The wires going to the launch officer only carry the power
required to operate the relay; this power is typically much less
than that required by an igniter.
C28) Petroleum based lubricants should not
be used with the oxygen or nitrous oxide systems used in
hybrids. Why?
A) They thicken when exposed to oxygen or nitrous oxide. B) They
lose their lubricating properties when exposed to oxygen or nitrous
oxide. C) There is a risk of spontaneous ignition or explosion. D)
The lubricant can promote corrosion of the metal components in the
presence oxygen or nitrous oxide.
The answer is "C". Petroleum lubricants are a fuel. Oxygen rich
environments are more likely t o promote combustion.
C29) Which of the following safety hazards
may be associated with hybrid rocket motors?
A) High pressure gas, low temperatures (frostbite) B) Low
temperatures (frostbite) C) Corrosive materials D) High pressure
gas
The answer is "A". The pressure within a nitrous oxide cylinder
used with hybrid rocket motors is approximately 750 psi. When
filling or venting the nitrous oxide cylinder individuals need to
use caution to avoid having high
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Section 8, Page 29
pressure gas or liquid impinge on skin or eyes. Oxidizer
cylinders need to be inspected after crashes for damage that may
compromise their structural integrity. Nitrous oxide boils at -127
o F. Partially filling and allowing the liquid to drain (boil-off)
from a nitrous oxide cylinder is a technique used to pre-chill the
nitrous oxide cylinder in some motor applications (called shock
chilling). The low temperatures achievable through this method may
present a hazard to exposed skin.
C30) The range safety officer says that your
model is unsafe to fly. Who has the authority to overturn this
ruling:
A) The Launch Control Officer (LCO) B) The individual who
"checked-in" the model C) Three certified high power fliers who
agree the model is safe D) The safety monitor's (RSO) decision
cannot be overturned by anybody
The answer is "D". The range safety officer's decision is final.
If the flier can produce additional information which shows the
safety of the model, e.g. simulations, previous flight data, then
the flier should present the information to the range safety
officer.
C31) Parachute ejection systems that sense
barometric pressure for activation need a outside hole in their
compartment because:
A) This hole allows excessive ejection charge pressures to vent
B) The hole is used to give outside air pressure readings C) The
hole vents internal air pressure as the rocket gains altitude to
prevent internal air pressure from prematurely separating the
model.
D) The hole allows easy verification that the battery is
installed
The answer is "B". Air pressure external to the rocket decreases
as the rocket ascends. Most barometric ejection systems trigger
after detecting a minimal change in the outside barometric pressure
(which happens near apogee). The hole allows the sensor to "see"
the outside pressure. Use caution in locating the hole such that
the nosecone (or stage coupler) does not block the hole.
C32) Which of the following individuals has
the final authority in permitting a high power rocket to
fly?
A) The launch control officer (LCO) B) The range safety officer
(RSO) C) The check-in officer D) The rocket owner
The answer is "B". The range safety officer's decision is
final.
C33) Which of the following individuals has
the ultimate responsibility to ensure that the rocket was built
in a safe manner?
A) The launch control officer (LCO) B) The safety monitor (range
safety officer or RSO) C) The rocket owner/builder D) All of the
above
The answer is "C". Range personnel can do inspections to catch
lapses in construction quality or rocket design errors but the
owner/builder bears all responsibility for the "goodness" and
safety of the model.
C34) Parachute ejection systems that sense
barometric pressure can malfunction
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Section 8, Page 30
during supersonic flight because:
A) Aerodynamic heating changes the values of electronic
components B) The outside pressure distribution is not continuous
around the model C) Static discharges will "zap" sensitive
electronic components D) Both answers "A" and "B" are correct
The answer is "B". During supersonic flight shock waves are
generated off various model features. The pressure distribution
across the shock wave is not continuous. The pressure change across
the shock wave may fool the ejection system logic causing a
premature ejection.
C35) Your rocket was returned from its flight
with "zipper" damage where the shock cord tore through the
model. What is the possible cause:
A) Parachute ejection occurred too soon after motor burnout B)
Parachute ejection occurred too late after apogee C) Parachute
ejection occurred at apogee D) Both "A" and "B"
The answer is "D". "Zippers" are caused when the model is moving
too quickly during parachute deployment. Ejection too soon after
burnout does not allow the model to slow down. Ejection too late
after apogee allows the model to gain velocity. Ejection at apogee
is best because the model velocity is lowest.
C36) Your payload section, with heavy
payload, separated from your model immediately after motor
burnout. What might be the cause?
A) The center of pressure at burnout
was behind the center of gravity for the model B) The payload
shoulder was too loose in the body tube C) The rocket motor had a
failure of its delay system D) Both "B" and "C" are correct.
The answer is "D". Delay train failures do happen and can cause
this problem. More often, though, "drag separation" causes this
problem and is mistaken for a motor failure. Drag separation is
caused by the drag on the aft section of the model being higher
than the drag of the forward section. The difference in drag causes
the aft section to be pulled away from the forward section. This
problem is more pronounced with heavier forward sections because
the momentum of the forward section tends to carry it away.
Preflight inspection should confirm that the forward section cannot
separate under its own weight. More sophisticated models will use
some form of positive retention, e.g. shear pins, to prevent
premature separation.
C37) What is the distance around a launcher
with a "J" powered model that must be cleared of easy to burn
material?
A) 10 feet B) 30 feet C) 50 feet D) 75 feet
The answer is "C". Refer to paragraph 2- 4.1 of NFPA 1127, 1998
edition.
C38) What is the distance around a launcher
with a 2 "J" engine cluster powered model that must be cleared
of easy to burn material? A) 10 feet B) 30 feet
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Section 8, Page 31
C) 50 feet D) 75 feet
The answer is "D". Refer to paragraph 2- 4.1 of NFPA 1127, 1998
edition.
Section D - Rocket Stability (3 questions) D1a) For a rocket to
be stable which of the
following statements is true?
A) The center of pressure (CP) must be behind the center of
gravity (CG). B) The center of pressure (CP) must be in front of
the center of gravity (CG). C) The rocket must have fins. D) The
length of the body tube must be at least 5 times the model
diameter.
The answer is "A". Refer to the "Handbook of Model Rocketry" by
G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note
references on pages 137 and 138.
D2) An unstable rocket can be made stable
by:
A) Adding weight to the nosecone B) Removing weight from the
nosecone C) Moving the fins forward towards the nosecone D) Making
the rocket shorter
The answer is "A". To make the rocket stable the center of
gravity (C.G.) must be moved forward of t he center of pressure
(C.P.). Adding weight to the nosecone moves the C.G. forward.
Removing weight from the nosecone moves the C.G. aft which is
incorrect. Moving the fins forward towards the nosecone moves the
C.P. forward which is also incorrect. Finally, making
the rocket shorter reduces the correcting moments produced by
the aerodynamic forces at the C.P.; the reduced moment makes the
rocket less stable.
D3) Rocket stability can be estimated by:
A) Center of pressure "Barrowman" equations B) "Cardboard
cutout" method C) Determining the relative positions of the center
of pressure and center of gravity D) Stability cannot be estimated
before a test flight.
The answer is "C". Refer to the "Handbook of Model Rocketry" by
G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note Figure
9-6 on page 138. Center of pressure equations and the cardboard
cutout method only allow you to determine the center of pressure of
the model; the center of gravity location must also be known to
determine stability.
D4) A high power rocket's center of
pressure can be estimated by: A) The "Barrowman" method
B) Finding the point where the model balances C) Center of
pressure equations D) Both "A" and "C" above
The answer is "D". The "Barrowman" method is a set of equations
developed by J. Barrowman for estimating modell rocket stability.
More sophisticated methods are available to cover conditions not
covered by the Barrowman method, e.g. supersonic flight. Refer to
the "Handbook of Model Rocketry" by G. Harry Stine, 6th edition,
Chapter 9 on "Stability". Note
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Section 8, Page 32
references on pages 140 and 14, Appendix II, and Appendix
IV.
D5) An unstable rocket can usually be made
more stable by:
A) Using a shorter nosecone B) Increasing the size of the aft
fins C) Using a larger, heavier rocket motor D) Increasing the
rocket diameter
The answer is "B". To make the rocket stable the center of
pressure (C.P.) must be moved aft of t he center of gravity (C.G.).
Adding larger fins on the aft portion of the model moves the center
of pressure aft. A shorter nosecone removes weight from the nose
moving the C.G. aft which is incorrect. A larger, heavier rocket
motor has the same affect of moving the C.G. aft. Finally,
increasing the rocket diameter has essentially no effect on its
stability.
D6) During boost a rocket powered by a
solid rocket motor tends to become:
A) Less stable in flight B) More stable in flight C) No change
in stability D) Unstable
The answer is "B". During powered flight the solid rocket motor
consumes its fuel causing the aft end of the rocket to become
lighter. This moves the C.G. forward and enhances stability. This
can be seen in instances where a unstable rocket becomes stable
partway during the rocket motor burn; this is also particularly
dangerous because the now stable rocket may be pointed in any
direction.
D7) Which of the following is true of an
unstable rocket?
A) The center of pressure (CP) is behind the center of gravity
(CG). B) The center of pressure (CP) is in front of the center of
gravity (CG). C) The rocket has more than 6 fins. D) The length of
the body tube is less than 5 times the model diameter.
The answer is "B". Refer to the "Handbook of Model Rocketry" by
G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note
references on pages 137 and 138.
D8) As a rule of thumb, how far should the
center of pressure be from the center of gravity?
A) The center of pressure should be at the same location as the
center of gravity. B) The center of pressure should be at least 1.0
body tube diameters behind the center of gravity. C) The center of
pressure should be at least 1.0 body tube diameters ahead of the
center of gravity. D) The center of pressure should be 1.0 body
tube diameters ahead of the fin leading edge; the center of gravity
does not matter.
The answer is "B". Refer to the "Handbook of Model Rocketry" by
G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note
references on pages 141 through 146.
Section E - Rocket Motor Designations (2 questions) E1) What
does the "H" in the motor
designation H100-5 stand for?
A) It is the first letter in the manufacturer's name.
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Section 8, Page 33
B) It indicates the total power range or impulse range of the
rocket motor. C) It indicates the total thrust of the rocket motor.
D) It indicates that the motor uses black powder as a
propellant.
The answer is "B". In a rocket motor designation the alphabetic
character indicates the total impulse (or total power) for the
rocket motor. High power rocket motors are rated as follows: "H"
160.01 to 320.00 Newton-seconds "I" 320.01 to 640.00 Newton-seconds
"J" 640.01 to 1280.00 Newton-seconds "K" 1280.01 to 2560.00
Newton-seconds "L" 2560.01 to 5120.00 Newton-seconds "M" 5120.01 to
10240.00 Newton- seconds "N" 10240.01 to 20480.00 Newton-seconds
"O" 20480.01 to 40960.00 Newton-seconds. Note that the total
allowable impulse doubles with each letter class.
E2) What does the "100" in the motor
designation H100-5 stand for?
A) It is the peak thrust in pounds of the rocket motor. B) It is
the rocket motor burn time in seconds. C) It is the average thrust
in Newtons of the rocket motor. D) It is the manufacturer's retail
price code.
The answer is "C". In a rocket motor designation the number
before the dash is the average thrust in Newtons of the rocket
motor. Divide this number by 4.45 for the average thrust in
pounds.
E3) What does the "5" in the motor
designation H100-5 stand for?
A) It is the rocket motor burn time.
B) It is the peak thrust (in kilograms) of the rocket motor. C)
It is the average thrust of the rocket motor. D) It is the ejection
charge delay time.
The answer is "D". In the standard designation system for rocket
motors the number after the dash indicates the delay in seconds
between rocket motor burnout and ejection charge operation. Note
that a "0" (zero) delay indicates a booster rocket motor; the
propellant grain is exposed and no delay or ejection charge is
used. A "P" may also be used; this indicates that the end of the
motor where the ejection charge and delay train normally reside is
plugged.
E4) What are the units of measurement for
the "100" in the motor designation H100-5?
A) Newtons per second B) Newtons C) Newton-seconds D) feet per
second
The answer is "B". In a rocket motor designation the number
before the dash is the average thrust in Newtons of the rocket
motor. Divide this number by 4.45 for the average thrust in
pounds.
E5) What is the maximum total impulse for
a "J" rocket motor?
A) 320.00 Newton-seconds B) 640.00 Newton-seconds C) 1280.00
Newton-seconds D) 2560.00 Newton-seconds
The answer is "C". In a rocket motor designation the alphabetic
character indicates the total impulse (or total
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Section 8, Page 34
power) for the rocket motor. High power rocket motors are rated
as follows:
"H" 160.01 to 320.00 Newton-seconds "I" 320.01 to 640.00
Newton-seconds "J" 640.01 to 1280.00 Newton-seconds "K" 1280.01 to
2560.00 Newton-seconds "L" 2560.01 to 5120.00 Newton-seconds
"M" 5120.01 to 10240.00 Newton-seconds "N" 10240.01 to 20480.00
Newton-seconds "O" 20480.01 to 40960.00 Newton-seconds
E6) Assuming that each motor has the full
allowable impulse, how many "H" motors have the same total
impulse as a single "J" motor?
A) 3 B) 1 C) 2 D) 4
The answer is "D". An "H" motor has a maximum allowable total
impulse of 320.00 Newton-seconds and a "J" motor has a maximum
total impulse of 1280.00 Newton- seconds thus it takes 4 "H's" to
equal 1 "J".
E7) The Department of Transportation
explosives classification "EXPLOSIVES B" indicates what type of
hazard?
A) Mass detonating type explosive B) Mass fire and hot gas
production
C) Shrapnel or projectiles resulting from detonation D) Limited
fire, hot gas production
The answer is "B". Classification "EXPLOSIVES A" indicates a
mass detonation hazard; this class has n o use in high power
rocketry. Classification "EXPLOSIVES B" indicates the production of
large
amounts of fire and hot gas; this is the classification
typically given to high power expendable rocket motors and large
(54mm or greater) reloadable motors. Classification "EXPLOSIVES C"
indicates the production of limited amounts of fire or hot gas;
Class "C" devices typically contain limited amounts of Class "A" or
Class "B" materials. Model rocket motors are sometimes classified
as Class "C" devices.
E8) What classification in the United
Nations (UN) system is similar to t he Department of
Transportation classification "EXPLOSIVES B"?
A) UN Division 1.1 B) UN Division 1.2 C) UN Division 1.3 D) UN
Division 1.4
The answer is "C". UN Division 1.1 is similar to the DOT
"EXPLOSIVES A" classification. UN Division 1.4 is similar to the
DOT "EXPLOSIVES C" classification. UN Division 1.3 is similar to
the DOT "EXPLOSIVES B" classification. (As a note UN Division 1.2
is shrapnel producing; Division 1.1 usually is applied
instead.)
E9) You have an H64-8 rocket motor which
has been certified to have a total impulse of 320.00 Newton
seconds. What is the approximate burn time for this motor?
A) 3 seconds B) 5 seconds C) 8 seconds D) 10 seconds
The answer is "B". Divide the total impulse by the average
thrust to determine the motor burn time. 320
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Section 8, Page 35
(Newton-seconds) = 5 (seconds) 64 (Newtons)
E10) The manufacturer's test data shows a total impulse of 680
Newton-seconds for your motor. What impulse class does your motor
represent?
A) "H" B) "I" C) "J" D) "K"
The answer is "C". Refer to the answer for question E5 above
E11) The manufacturer's test data shows an
average thrust of 100 Newtons for 6 seconds for your motor. What
impulse class does your motor represent?
A) "H" B) "I" C) "J" D) "K"
The answer is "B". The total impulse is calculated by
multiplying the average thrust by time. In this case the total
impulse is 600 Newton seconds. Refer to question E5 above for the
letter versus total impulse class table.
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Section 8, Page 36
NAR SAFETY OFFICER TRAINING PROGRAM Introduction: Model rocketry
was created in the late 1950's as a means by which non-professional
individuals could build and fly their own rocket powered models.
The hobby was structured to safely pursue an activity that has a
potential for personal injury and property damage. The use of
manufactured motors to minimize the mixing and handling of
propellants was a major factor in model rocketry's safety success.
Safety procedures for the construction and operation of the models,
based on aerospace industry practices, were another factor in this
excellent safety record. Hobby maturity and technology advancements
permitted the use of more powerful motors and more sophisticated
models. High power rocketry describes the step beyond model
rocketry. Safety procedures for high power rocketry evolved from
model rocketry. This document augments those safety procedures with
practical guidance for individuals experienced in model rocketry
and familiar with high power rocketry. The intent of this guidance
is to assist individuals in performing safety officer functions on
a high power rocket range. This guidance is based on experience,
regulatory documents (e.g. FAA FAR Part 101), and codified
practices (e.g. NFPA 1127). Note that regulatory or codified
practices shall supercede guidance in this document if conflicts
occur. The primary safety officers are the Range Safety Officer
(RSO) and the safety check-in officer. The RSO is responsible for
safe operation of the rocketry range. The RSO shall have the final
authority to approve or disapprove the launch of a vehicle. The
safety check-in officer is responsible for verification of the
vehicle flight worthiness. He will inspect the vehicles for
structural integrity, systems condition (e.g. recovery system,
motor restraint), motor certification, and dynamic properties (e.g.
center of gravity, center of pressure). Participants in this
program will be required to complete tasks relevant to range
safety. Individuals will share safety critical range positions with
a mentor. Individuals performing mentored RSO or safety check-in
functions must possess a high power certification (Levels 1, 2, or
3). Mentors will be individuals who are both generally acknowledged
to be competent in the safety critical roles and are currently
certified to NAR level 2 or 3 (Proof of Tripoli certification is
not adequate; Tripoli members must have a NAR Membership License
showing their certification level). Mentors will observe and advise
the participants while they apply suggested guidelines to real
world situations. The objective of this program is to educate NAR
members by exposing them, with guidelines and mentors, to “real
world” situations. These members, when acting as safety officers
and instructing other NAR members, will increase the level of
safety awareness at our launches to continue our legacy of safety
in the rocketry hobby. Requirements: 1.0 Specific Safety Check-in
Officer Tasks Description A) 20 check-ins required (Level 1 or 2)
B) A minimum of 6 models must be Level 2 C) 2 cluster model
check-ins D) 1 “staged” high power model check-in E) 4 models w/
electronic recovery deployment systems check-ins F) 3 post flight
failure analyses
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Section 8, Page 37
Requirements called out in C, D, and E above can be met at the
same time as requirements in A and B.
2.0 Range Safety Officer Tasks Description A) 15 launches
required (Level 1 or 2) B) A minimum of 6 models must be Level 2
launches C) 1 cluster model launch D) 1 “staged” high power model
launch E) 2 model launches using electronic recovery deployment
systems F) 1 launch site evaluation required
Requirements called out in C, D, and E above can be met at the
same time as requirements in A and B.
Safety Check-in Officer Guidelines: The items below offer
guidance for the acceptance and rejection of models presented for
inspection. In addition to the inspection, question the modeler
about his model. Ask him if he has any worry areas and what, if
anything, he has done to minimize that worry. Other questions may
be directed towards specific features of the model. Ask if he has
flown the model before with the installed motor and recovery
system. If, for example, electronic recovery or staging are being
attempted for the first time ask the modeler how he tested their
operation prior to flight. If a lack of knowledge or skills is
evident from the conversation then consider performing a more
extensive inspection of the model. Items A1 through A3 provide
administrative guidance. Items A1 and A2 are necessary to assure
compliance with Consumer Product Safety Commission (CPSC) and NFPA
1127 user requirements. Item A3 guidance is intended to assure
compliance with the Federal Aviation Administration (FAA) Part 101
requirements. A1) Is the modeler over 18? If not, the modeler
cannot legally use high power motors, reloadable
motors of any power class, or "G" motors. "G" motors and
reloadable motors may be used if the individual is accompanied by a
parent or legal guardian.
A2) Is the modeler certified to the power level being flown? Ask
to see his membership card to
verify the certification level. Make sure that the membership
card is current. Note that some events will verify the
certification level at registration. In that case, the person will
have event identification showing the certification level.
Individuals flying models meeting the following criteria will
require high power certification:
a) Launches models containing multiple motors with a total
installed impulse of 320.01
Newton-seconds or more, or
b) Launches models containing a single motor with a total
installed impulse of 160.01 Newton-seconds or more, or
c) Launches rockets that weigh more than 53 ounces (1500 grams),
or
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Section 8, Page 38
d) Launches models powered by rocket motors not classified as
model rocket motors per NFPA 1122, e.g.:
• Average thrust in excess of 80.0 Newtons • Contains in excess
of 2.2 ounces (62.5 grams) of propellant • Hybrids Note that some
“F” and “G” motors fall into this category. A3) Does the model fall
within the FAA limitations? Models with less than 4 ounces of
propellant
and weighing less than 1 pound at launch do not require any
additional interface with the FAA. Models with 4 to 4.4 ounces of
propellant or which weigh 1.0 to 3.3 pounds at launch require a
notification to have been previously submitted to the FAA. Verify
with the event director or RSO that the notification has been
submitted prior to accepting these models. Models should be weighed
prior to flight to verify that they fall within the weight limit.
Motor data, typically available on certification lists, must be
consulted to verify compliance with propellant limits.
Models containing in excess of 4.4 ounces of propellant or
weighing over 3.3 pounds can only be flown with a FAA waiver. The
waiver will specify a maximum altitude for flights. Verify with the
event director or RSO that a waiver has been approved prior to
accepting these models. Models must be weighed and motor propellant
weight determined to verify that the model needs a waiver for legal
flight. The performance of the model must be evaluated to determine
compliance with the waiver altitude limit. Tables listing the motor
type and model diameter may be available to indicate a minimum
weight for the model. Models under the minimum weight must add
ballast or reduce power to stay within waiver limits. Computer
software may also be available on the field to estimate
performance.
When estimating performance be conservative by using a lower
value for the drag coefficient (CD ). Most airframes will have a CD
between 0.65 and 0.75. Use a CD value between 0.45 and 0.50 for a
conservative estimate of airframe performance.
Cluster combinations will not be addressed on most performance
tables. A computer simulation will provide the best estimate of
model performance. If a simulation prediction is not available then
total the impulse of all motors and the average thrust of all
motors. Use this number to identify a similar single motor model
for comparison. If the model performance is within 15% of the
waiver altitude limit do not permit it to fly without a higher
fidelity prediction. Staged models have a similar issue. Since
staged models will typically have less drag and higher performance
than clustered models the method described above is less reliable.
Use the method suggested for evaluating clusters but allow a larger
margin for error; if the model is within 25% of the waiver altitude
limit do not permit it to fly without a higher fidelity
prediction.
Items A4 through A7 concern the rocket motor(s). The NAR safety
code requires the use of certified rocket motors. Item A4 addresses
this requirement. Items A5 and A6 are intended to verify the
correctness of the motor choice and to identify potential safety
hazards associated with the igniter. Item A7 addresses a potential
hazard with some reloadable designs. A4) Is the motor certified?
Certification lists are available on the Internet or in
publications from
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Section 8, Page 39
the certifying organizations. Verify the motor certification
status by consulting the certification lists. Note that
certification status may not extend to all delays within a motor
type.
A5) Is the motor or motors adequate to safely fly the model? If
available, consult the
manufacturer's recommended liftoff weight. Model drag and
weather conditions should be considered. High drag models (caused
by basic model design, poor finish) will not go as high as
streamlined models. Low average thrust motors in windy conditions
allow more weathercocking of the model. The altitude may be limited
due to weathercocking and the delay may be too long. Remember that
motors with longer delays have lower recommended liftoff weights
than the same motor with a shorter delay. If still in doubt, ask
the modeler for his performance predictions and the prediction
method for the model.
A6) Is the igniter a low current type? Flash bulbs and electric
match current requirements are low
enough that some launch systems my set them off with continuity
power. Verify with the RSO or LCO whether the launch system is
"flash bulb safe". Annotate flight cards if required to show the
presence of a low current igniter.
A7) Ask the modeler if he is using the motor ejection charge. If
he is, verify that he installed the
black powder. Also, some motors rely on a tape disk to retain
the powder in its cavity. Disks with dry adhesive or lubricant
contamination on the forward face of the cavity may reduce the
paper disk adhesion. Deceleration forces may cause the paper disk
to come free and disperse the black powder. This will cause an
ejection failure. It is suggested that the modeler backup the paper
disk with masking tape around the edge to prevent it from coming
free.
Items B1 through B8 cover the inspection of the basic model
structure and recovery system. The check-in officer will need to
handle the model during this phase of the inspection. Ask the model
builder if there are any safety hazards, e.g. electronic systems,
which may be activated while handling the model. The check-in
officer needs to use his judgement when pulling and pushing on
model parts; the effort needs to be sufficient to find marginal
installations or construction but not so great as to damage a
properly built model. B1) Examine all "slip-fits", e.g. nosecone or
payload shoulder, which are intended to separate in
flight.
Turn the model nose down. It is unacceptable if the nosecone (or
payload) can separate under their own weight. If it does, the
nosecone (or payload) may "drag separate" just after motor burnout.
Drag separation typically occurs at the highest velocity; the
effect is often recovery system failure from excessive loads. A
loose nose cone (or payload) can be tightened by the addition of
tape to the shoulder.
Does the nosecone (or payload) slide free without excessive
effort? A tight nosecone (or payload) can be caused by several
problems. Paint overspray in the tube or on the shoulder may cause
stickiness in the sliding area. A light sanding or a dusting with
talcum powder can reduce the stickiness or remove the overspray. A
burr may also form at the edge of the body tube. Again, a light
sanding can correct the problem.
Check that the nosecone, if used as part of a payload section,
is firmly installed. The object is
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Section 8, Page 40
to prevent loss of the nosecone and the payload contents in
flight.
Consider the comment "it's flown before" with caution.
Temperature and humidity affect the fit of airframe parts (parts
swell or contract, finishes may soften in the heat). A smooth fit
in an Arizona winter may become a test of muscle and patience in an
Alabama summer.
B2) Examine the launch lugs. Are the launch lugs firmly attached
to the model without evidence of
cracking in the joints? Are the lugs adequately sized for the
model?
Suggestions are 1/4" minimum for models up to 3.3 pounds; 3/8"
to 1/2" lugs for models up to 20 pounds, 3/4' or larger lugs for
models over 20 pounds. Single launch lugs should be at least 6
inches long and mounted at the model's CG. 2 lugs, each spaced a
minimum of 2 body tube diameters from the CG are preferred. The
separated lugs are preferred because they better resist rotation
(from winds) of the model on the launch rod. Rotation of the model
on the launch rod may cause binding during launch.
Check the lugs for paint buildup or burrs inside the lug(s).
Paint or burrs may cause binding on the launch rod. A rolled sheet
of sandpaper can be used to remove burrs or paint.
B3) Examine the fins. Are the fins mounted parallel to the roll
axis of the model? Attempt to
wiggle the fins at their tips. There should be no movement and
minimal deflection. If the fins deflect is the fin material
appropriate for the model? Models powered by H, I, or J motors
should use 1/8" plywood or fiberglass at a minimum. Higher powered
models and high aspect ratio fins (large fin span versus fin chord)
require additional strength to resist launch loads and possible
flutter problems. Laminated or built-up fins should be checked for
delaminations. Bubbles mayindicate delaminations. Tapping the fin
with a heavy coin (e.g. half-dollar) will give a "dead" thud if a
delamination is present. Examine the fin roots for cracks; minor
"hairline" cracks may be acceptable if the fins are not loose or if
the fins are mounted using "through the wall" construction. Check
the fins for warpage; their should be little, if any, warpage.
B4) Examine the engine installation. Verify, if possible, that
the engine is what the flight card
indicates. If in doubt, ask that the engine be removed from the
model. Pull on the motor to make sure it is firmly restrained in
the model. If the motor is friction fitted then it should not move
when strongly pulled. A positive means of engine retention, e.g.
motor clip, bolted washers, is preferred. Verify that the motor
cannot deflect the retention device and then eject. A wrap of tape
around motor clip(s) to restrain the them against the motor is
suggested.
B5) Can the motor "fly through" the model? Push on the nozzle
end of the motor. The motor
should not move forward in its mount nor should the mount move
within the model. Try to determine the type and quantity of
adhesive used in construction. Any evidence of "hot melt" adhesives
should make the model suspect. Motor mounts should typically be
mounted with epoxy adhesives with a sufficient quantity to form
fillets at the centering ring to body tube joints.
B6) Is the model stable? Find the CG (center of gravity) of the
flight ready model (motors installed,
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Section 8, Page 41
recovery system packed) by finding the model balance point.
Where is the CG relative to the leading edge of the fins? On a
single staged model with only a rear set of fins the CG should
typically be forward of the forward root edge of the fins.
Canards, wings, forward swept fins, and strakes will require the
CG to be further forward. Multi-staged models must be evaluated for
each stage. Ask the modeler to show the CP (center of pressure)
location on the model (and less each stage for a staged model).
Request to see the calculations if in doubt. The CG must be a least
one body tube diameter forward of the CP in each flight phase. Note
that a subscale model may, in most cases, al