[4910-13-P] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2018-1046; Product Identifier 2018-CE-049-AD] RIN 2120-AA64 Airworthiness Directives; Piper Aircraft, Inc. Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain Piper Aircraft, Inc. (Piper) Model PA-28-140, PA-28-150, PA-28-151, PA-28-160, PA-28-161, PA-28-180, PA-28-181, PA-28-235, PA-28R-180, PA-28R-200, PA-28R-201, PA-28R-201T, PA-28RT-201, PA-28RT-201T, PA-32-260, and PA-32-300 airplanes. This proposed AD was prompted by a report of a fatigue crack found in a visually inaccessible area of the lower main wing spar cap. This proposed AD would require calculating the factored service hours for each main wing spar to determine when an inspection is required, inspecting the lower main wing spar bolt holes for cracks, and replacing any cracked main wing spar. We are proposing this AD to address the unsafe condition on these products. DATES: We must receive comments on this proposed AD by [INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments. • Fax: 202-493-2251. This document is scheduled to be published in the Federal Register on 12/21/2018 and available online at https://federalregister.gov/d/2018-27577 , and on govinfo.gov
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DEPARTMENT OF TRANSPORTATION Federal Aviation ... · AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt
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PA-28RT-201T, PA-32-260, and PA-32-300 airplanes. This proposed AD was prompted by a
report of a fatigue crack found in a visually inaccessible area of the lower main wing spar cap.
This proposed AD would require calculating the factored service hours for each main wing spar
to determine when an inspection is required, inspecting the lower main wing spar bolt holes for
cracks, and replacing any cracked main wing spar. We are proposing this AD to address the
unsafe condition on these products.
DATES: We must receive comments on this proposed AD by [INSERT DATE 45 DAYS
AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and
11.45, by any of the following methods:
• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions
for submitting comments.
• Fax: 202-493-2251.
This document is scheduled to be published in theFederal Register on 12/21/2018 and available online athttps://federalregister.gov/d/2018-27577, and on govinfo.gov
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• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building
Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2018-1046; or in person at Docket Operations
between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains this NPRM, the regulatory evaluation, any comments received, and other information.
The street address for Docket Operations (phone: 800-647-5527) is listed above. Comments will
be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Dan McCully, Aerospace Engineer, Atlanta
ACO Branch, FAA, 1701 Columbia Avenue, College Park, Georgia 30337; phone: (404)
(i) Equipment used must provide impedance plane diagrams. (ii) Probes may be either absolute or differential coil configurations.
(iii) For manual bolt hole probing: use probe collars at an increment of every 1/64 inch to ensure the uniform depth of rotation and to aid in reducing lift-off effects.
(iv) Automated scanning systems may be used. (v) Bolt hole probes must match as closely as possible, but not exceed, the bolt hole
diameter. Split core probes may be expanded to a maximum of 0.050 inch beyond the probe’s
nominal diameter (in accordance with on the probe manufacturer’s instructions). The fill factor must be 80 percent minimum.
(vi) A right angle (90 degree) surface probe may be used for further detail indication, if needed.
2. Equipment Examples
The following optional inspection equipment has been shown to be adequate to conduct this procedure and is provided as examples only. Other equipment meeting the requirements in A.1. may be used.
(i) Nortec 500D Series Portable Eddy Current Flaw Detector – Olympus
(ii) Bolt hole probe, 0.375 inch with 0.062 inch shielded coil – Olympus (iii) Right angle (90 degree) surface probe with 0.062 inch shielded coil – Olympus (iv) Calibration standard (NIST traceable) for bolt holes and surface: Air Force General
Purpose Eddy Current Standard (a) Bolt hole: 0.030 x 0.030 inch corner notch, 0.030 inch radial notch
(b) Surface: 2024-T3: 0.008, 0.020, and 0.040 inch depth EDM notches (c) Frequency 300 KHz, EDM notch set at five (5) divisions screen height
B. Reference Standard
(1) Use a reference standard of the same conductivity 2024 T-3 within +/-15% IACs. It
must have electrical discharge machining (EDM) notches for simulating defects as calibration references.
(2) The surface finish must be 63 RHR or better. (3) The reference standard must have a corner notch size of 0.030 x 0.030 inch (screen set
at minimum of three divisions vertical with a phase signal of between 45 and 120 degrees separation from the horizontal liftoff).
(4) Use a frequency between 100 and 500 kHz.
(5) The calibration must be checked in the beginning and end and every 30 minutes of
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inspections.
C. Personnel Qualifications
Personnel doing the eddy current inspection must have NAS 410 Level II or Level III
certification. D. Material Required
NOTE: Hardware part numbers and torque values are contained in the Aircraft
Maintenance Manual and Illustrated Parts Catalogue for the specific airplane model. For each wing inspected:
(1) Two (2) wing to spar attach bolts
(2) Two (2) wing to spar attach nuts (3) Two (2) wing to spar attach washers (4) Cleaning cloth
(5) Isopropyl alcohol or mineral spirits
E. Conduct Inspection
For each wing to be inspected:
(1) Locate the two (2) lower outboard main spar attach bolts, as shown in Figure 1 of
Appendix 1, installed on the lower cap of the main spar, on the forward and aft sides of the spar web.
CAUTION: The interior surface of the bolts holes can be easily damaged during bolt removal and installation. Do not drive out spar to fuselage attach bolts.
(2) Clean the inspection surfaces using a cloth dampened with isopropyl alcohol or mineral spirits.
(3) Use eddy current surface and bolt hole examinations to detect surface and shallow subsurface cracking and discontinuities on the left and right lower outboard spar bolt holes.
Use SAE ARP4402, “Eddy Current Inspection of Open Fastener Holes in Aluminum Aircraft Structure,” or another FAA-approved eddy current inspection method to do these inspections.
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F. Accept/Reject Criteria
A crack or crack-like indication with an amplitude equal to or greater than 50 percent of the reference level signal must be rejected and documented. Such an amplitude reading indicates
that the spar does not meet type design.
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Figure 1. Main Spar Attach Bolt Locations (RH Side Shown)
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Appendix 2 to this AD
Inspection Results Form
Email completed form to: Or mail to: Federal Aviation Administration