Evaluating - AMU Magazineamumagazine.com/wp-content/uploads/2018/04/AMU-April-May18-1.pdfSR Technics is the first European company to use Invert Robotics technology in a pro-gram that

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Evaluatinga conversion:Evaluating

a conversion:

April - May 2018Volume 16/Issue 6

$7.95

Transport Canada Approved for R/T

Clare Leavens Award Joe Chase Award Aviall High Achievement Award

choosingthe right powerplant

choosingthe right powerplant

providing independent analysis

providing independent analysis

Tracking evidence:Tracking evidence:

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AMU-OFC-IFC.indd 2 4/2/18 11:46 AM

Departments

Features

Published by Alpha Publishing Group (2004) Inc.AirMaintenance UpdatePublication Mail Agreement Number 0041039024and Return Undeliverable Canadian Addresses to:Alpha Publishing Group (2004) Inc.Unit 7, 11771 Horseshoe WayRichmond BC V7A 4V4 Canada

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This publication neither endorses nor confirms the informationcontained within. The appropriate authorities should becontacted prior to commencing work on any aircraft oraircraft part or procedure.

ISSN 1703-2318

Tracking Hard Evidence 10Providing independent, unbiased analysis

Evaluating a Conversion 24Choosing the right powerplant

The Big Four 29Essentials for your helicopter line maintenance toolkit

One Thing Leads to Another 34Raising the Bar:Bell 206B C-GIFV 2004

4 Upcoming Events

6 STCs & New Products

8 Industry Forum

20 AME Association and PAMA News

39 Classifieds

42 AMU Chronicles

AMU is viewable online: subscribe and download at www.amumagazine.com

From the small country that ‘punches above its weight’ in regard to innova-tion and technology, a New Zealand

company has created robots designed to ultimately improve the safety of the world’s multi-billion dollar aviation market.

Considered a ‘disruptor’ in the industry, Invert Robotics’ technology is bringing in-triguing change to the aircraft Maintenance Repair and Overhaul (MRO) sector with its remote-controlled robots that use a patented suction mechanism to adhere to and traverse a range of surfaces including aluminum, glass and carbon fibre, even when surfaces are wet or require an upside down inspection.

Zurich-based aircraft maintenance group SR Technics is the first European company to use Invert Robotics technology in a pro-gram that could possibly change the nature of many aircraft inspection processes.

Equipped with a high definition camera and sensor technology, the robot records and transmits video images to a ground-based screen for real-time analysis by line-mainte-nance staff, enabling efficient visual inspec-tions (GVI and DVI) on the tarmac or in the hangar. Images can be used for more detailed repair assessments and as a record of ‘current state’ for future comparison purposes.

Its technology will soon include ultra-sound and thermographic testing, allowing many labour-intensive and tedious mainte-nance inspection processes to be performed. This frees up skilled aircraft engineers to at-tend to more complex tasks and reduces the time and cost of aircraft maintenance.

“SR Technics is constantly looking for ways to improve the services and reduce the costs to our customers in this highly compet-itive industry,” said SR Technics CEO Jeremy Remacha. “Time savings mean our custom-ers have their aircraft back in service sooner and for airlines that is a huge benefit.”

Neil Fletcher, Managing Director of In-vert Robotics says, “Having developed the world’s first inspection robot of its kind, Invert Robotics has evolved to deliver tools and technologies for difficult-to-access areas, quickly and safely. The opportunity to evolve from inside concave surface to outside con-vex surfaces brought the aviation industry into clear focus as a significant market for Invert Robotics.” n

So Stuck on You

April/May 2018 AIRMAINTENANCE UPDATE 3

Upside-down robots from “Middle-Earth” take on aviation safety

10

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Upcoming Events

Advertisers Index

MRO AmericasApril 10 – 12, 2018

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NBAA Maintenance ConferenceMay 1 – 3, 2018

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CFB Borden AirshowJune 2 – 3, 2018Borden, Ontario

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Great Lakes International Air ShowJune 16 – 17, 2018

St. Thomas, Onatariowww.glias.ca

Farnborough International Air ShowJuly 11 – 17, 2018

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Great New England AirshowJuly 14 – 15, 2018

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Cold Lake Air ShowJuly 21 – 28, 2018Cold Lake, Alberta

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APS Brakes / Aero Incorporated ......... 33Aeroneuf Instruments Ltd ...................... 17BKD Aerospace ...................................... 5Canadian Aero Accessories Ltd ........... 44Canadian Propeller Ltd ......................... 15Casp Aerospace Inc ............................. 29

Concorde Battery .................................. 32Eagle Fuel Cells Inc ............................... 13Gregoarsh Aviation ................................. 9 Hartwig Aircraft Fuel Cell Repair ........... 35JetBed .................................................... 7MARSS ................................................ 32

NAASCO ................................................ 38ProAero Engines Inc. ............................ 16Progressive Air ...................................... 16Propworks Propeller Systems ............... 12Rapco Inc ................................................ 2Schweiss Bi-fold Doors ......................... 37

4 AIRMAINTENANCE UPDATE April/May 2018

BRS Aerospace has added a number of newly authorized Cessna Parachute System Authorized Installation Centers to handle whole aircraft parachute instal-lations on the large Cessna 172 and 182 single-engine piston powered fleets.

“Our growing network of factory-ap-proved installation centers are equipped and qualified to install BRS Aerospace’s whole aircraft parachute recover systems in 172s and 182s,” said BRS Aerospace President Enrique Dillon. “We have add-ed another five centers in the past five months, bringing the network to 13 cen-ters strategically located in the United States, Canada and Spain.”

The newly added centers each have the capability of installing the only FAA/EASA certified aircraft parachute sys-tems for Cessna 172/182s available in the marketplace.

BRS Aerospace expands install network

The level of safety provided by the bal-listic recovery system for owners and operators of Cessna 172s and 182s is comparable to a similar system on the world’s best-selling single-engine piston powered aircraft and new certified aircraft with six seats or less under development today.

BRS Aerospace’s whole aircraft para-chute system design calls for a parachute ballistic launcher to be installed in the air-craft with either a pilot-initiated activator located in the cockpit or an automated activation system. Upon activation, a bal-listic rocket propels a parachute into the airstream to slow the airplane and float it down into a survivable vertical landing. The system has been successfully de-ployed multiple times and the company has documented 376 lives saved as a re-sult of its safety device.

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STCs & new products

Dakota Air Parts has announced a new composite tail rotor blade for the Bell 206A and 206B helicopters. The blade design incorporates a non-symmetrical airfoil section and a swept tip. The blades are primarily fabricated from carbon fibre and Kevlar fibres suspended in an epoxy matrix. The nickel abrasion strip is designed to protect the blade under harsh operating conditions, like those encountered in agricultural work. The abrasion strip is 1 3/8 inches wide and covers 23 percent of the chord, providing protection to all of the blade surfaces exposed during flight, ensuring that erosion doesn’t impact the blade structure. For information visit www.DakotaAirParts.com

Arlington Aerospace has launched a new vending machine, which instantly dispenses cutting tools. The cutting tool vending machine has been designed to disperse a full range of indexible inserts and bodies, Rotary H.S.S and T/Carbide drills, cutters, and more special cutting tools.

For more information visitwww.arlingtonindustriesgroup.com

Binks, a Carlisle Fluid Technologies’ brand, has launched the Binks Trophy AA, air-assisted airless manual spray gun. The Trophy AA is built to maximize spray quality, increase efficiency of product application, reduce downtime and be environmentally responsible. The new gun is available in two pressure configurations: the Trophy AA 1600 (1600 psi - 110bar) and the Trophy AA 4400 (4400 psi - 303bar). It is also available with a wide range of flat, fine-finish and twist tips. For information visit www.carlisleft.com

Kaeser’s AirCenter is a packaged compressed air system with a Sigma rotary screw compressor, refrigerated air dryer, and optional filter, all mounted on a receiver tank. Simply connect the power and air-line for a fully operational compressed air system. Compressor size ranges from three to 30 horsepower with working pressures available from 80 to 217 psig.

For more information visit www.us.kaeser.com

Aviation Management Intl’s new AMI-TW60 and the AMI-TW60AT turbine engine wash system (TEWS) are designed for performing compressor and turbine washes on turbine engines. The AMI-TW60 TEWS are light weight and portable for flexibility and convenience. Benefits include reduced engine maintenance costs, reduced engine fuel consumption, reduced engine downtime and extended engine life.

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Disc brushes finishmachined workpieces

The new Garant disc brushes from Hoffmann Group USA are designed to boost efficiency and create more precision during the finishing process. These brushes are for direct application in a CNC machine or a robot cell, providing an automated way of finishing workpieces immediately after the machining process.

For information visit www.hoffmann-group.com



Industry Forum

MAX 7 COMPLETES FIRST FLIGHT

Boeing’s new 737 MAX 7 successfully completed its first flight during mid-March as the airplane remains on sched-ule and now begins a comprehensive flight test program leading to certifica-tion and delivery in 2019. Piloted by Boeing Test and Evaluation Captains Jim Webb and Keith Otsuka, the airplane completed a successful three-hour, five-minute flight, taking off from Renton Field in Renton, Washington and land-ing at Seattle’s Boeing Field.

The airplane is the third and newest member of Boeing’s 737 MAX family to be produced, with a maximum capacity of 172 passengers. It has a range of 3,850 nautical miles, the longest of any MAX family airplane and is designed for air-line customers flying out of airports at high altitudes and hot climates. The 737 MAX is the fastest-selling airplane in Boeing history, accumulating more than 4,300 orders from 93 customers world-wide. BRAKING SYSTEM TARGETS ALL-ELECTRIC AIRCRAFTTulsa, Oklahoma-based Advent Aircraft Systems has unveiled its concept for a new self-contained electric power brake system, a follow-up to the company’s eABS anti-skid braking system. The Advent Electric Power Braking System (ePBS) would be aimed at new all-elec-tric aircraft designs, new aircraft with traditional hydraulics but desiring an electric braking system, or as a retrofit for existing aircraft.

Incorporating the Advent eABS as an integral part of the overall design, the

ePBS would be a brake-by-wire system that consists of brake pedal sensors and feel units, a primary brake electronic controller, parking and emergency brake controller, wheel speed transducers and hubcaps, and both primary brake and emergency/parking brake hydraulic units. The electronic controllers would send commands to the brake valves, us-ing state-based logic, based upon the ap-plied brake pedal force.

With a total installed weight target of 30 pounds the ePBS would be compat-ible with all installed or specified wheel brake assemblies for aircraft ranging from 3,500 to 30,000 pounds maximum takeoff weight. The system would require no external hydraulic power and would eliminate master cylinders, hydraulic tubing and all hydraulic fluid from the cockpit and cabin. The ePBS would be compliant with FAA and EASA require-ments and SAE AIR-5372a & AS-8584 guidance.

BELL ROLLS OUT FEATURES-LADEN 407GXI

Bell Helicopter used the month of Feb-ruary to introduce its new 407GXi,

which incorporates new avionics, an upgraded engine, and new executive in-terior design options. Garmin’s G1000H NXi Integrated Flight Deck, complete with high-definition displays and faster processors offers increased brightness and clarity, faster startup and map ren-dering as well as connectivity to tablets and smartphones. Upgrades to the Bell 407GXi include a dual-channel FADEC engine with full automatic relight, and enhanced situational awareness through the G1000H NXi. The Bell 407GXi is outfitted with the new Rolls-Royce M250-C47E/4 dual channel FADEC turbine engine with the ability to cruise at 133 kts/246 km/h. Newly designed executive configuration options bring a modernized look and passenger experi-ence to the five-seat club cabin.

Additional options for the 407GXi in-clude the Garmin FlightStream 510 that allows pilots to upload flight plans from smart devices, Garmin SurfaceWatch that provides runway identification and alerting technology, a 3,100-pound car-go hook, and Health Usage Monitoring (HUMS) for aircraft system diagnostics. The Bell 407 GXi has been certified by Transport Canada and the first delivery is scheduled this spring.

LION AIR RECEIVES THE FIRST MAX 9

Boeing and the Lion Air Group cel-ebrated the very first 737 MAX 9 to be delivered with the airplane going into service during the month of March with Thai Lion Air, where its added capacity will help the airline launch several in-ternational routes. The Lion Air Group is the launch customer for the MAX 9. They were also the first operator to put the MAX 8 into service, and have an-



nounced a commitment for 50 MAX 10s. The Group also has an additional 200 737 MAXs on order and is one of the world’s largest operators of the 737. The 737 MAX 9 is designed for a capac-ity of up to 220 passengers and a maxi-mum range of 3,550 nautical miles. With three additional seat rows compared to the 737 MAX 8, this airplane provides operators added capacity while maxi-mizing profitability within their network

VIH GOOD TO GO AS DIRECTIVE DATE DRAWS CLOSER

Victoria, BC’s MRO service provider VIH Aerospace says it is ready to provide ADS-B installation support to Canadian and US-based helicopter and fixed-wing operators as the directive deadline date of January 1, 2020 draws closer. This is when all aircraft operating in the air-space designated in 14 CFR 91.225 must be equipped with ADS-B-Out avionics systems that meet the performance re-quirements identified in 14 CFR 91.227.

All registered helicopters and fixed-wing aircraft, regardless of their country of origin or operations, need to be in compliance with this FAA directive in order to operate in US airspace. This ap-plies to all private operators, single air-craft operations, fleets and mixed fleets.

Canadian, US and other operators have been instructed that the January 1, 2020 date will not be extended. VIH general manager Arne Arneson believes that because many operators are taking a “wait and see” attitude toward compli-ance, a substantial bottle-neck will occur whereby as January 1, 2020 approaches and operators want to upgrade to ADS-B compliance, capacity of available in-stallers will likely result in many aircraft becoming grounded as they await the required avionics upgrade. n




Feature

In each issue of AirMaintenance Update, our ‘Raising the Bar’ feature provides a syn-opsis of Transport Canada’s investigations into aircraft accidents. Chicago-based DVI Aviation takes a similar approach by providing insurance carriers, courts, manufactur-ers and others with impartial accident case studies. Here are some examples of how DVI’s aircraft maintenance techs and incident experts go about their business.

Tracking Hard Evidence :

AMU-Section2.indd 2 4/5/18 9:29 PM


DVI Aviation has investigated hundreds of aviation re-lated accidents, failures, and calamities. DVI’s Avia-tion Experts always provide independent and unbi-

ased analysis regardless if we are working for the defendants, plaintiffs, insurance carriers, manufacturers, or other such clients. Our investigations are based upon the use of scientific methodologies, physical and factual evidence, and industry best practices. Selected below are some of the types of cases that DVI’s Aviation Experts have been a part of.

Reconstructing Ground Vehicle Incidents

A ground support vehicle accidentally moved, pinching a ramp worker between the vehicle and a regional jet. DVI’s

Aviation Experts were retained to investigate the accident and determine the cause of the unintended vehicle movement. Our investigators are not only trained as accident reconstruc-tionists, but are also licensed aircraft and automotive mechan-ics. The subject vehicle’s throttle control, brake system, and shift control mechanisms were examined, including verifica-tion that all manufactures service recalls were performed.

Full scale testing of the subject vehicle was performed us-ing a data acquisition system and accelerometers, along with video documentation to create demonstrative evidence. DVI provided the client with expert opinions based upon scientific evidence and testing data.

providing analysis



Explaining how cockpit controls are designed

A student pilot, on his first solo cross country flight, inadver-tently pulls the fuel shutoff control knob while reaching for what he believes to be the cabin heater control. Confused as to why the engine shut off, the student decides to make an emergency landing in an open field and sustains serious back injuries. DVI was retained to investigate the accident, on be-half of the flight school that provided the student the training. DVI’s Pilot and Human Factor Experts were uniquely quali-fied to assist in the case, because our real world experience includes providing all levels of flight training, and teaching graduate level courses in Aviation Human Factors. DVI evalu-ated the wreckage deformation, training records, radar plots, and made measurements on several exemplar aircraft. Cock-pit controls are designed based upon Human Factor princi-ples. Control such as the fuel cutoff and heater can be coded for pilot recognition in various ways, to include shape, size, colour, labeling, and type movement. DVI provided opinions describing how controls can be differentiated, and how pilots are trained to deal with emergency situations.

Evaluating aircraft maintenance procedures

An aircraft maintenance facility performed a top overhaul on an aircraft, replacing all six cylinder assemblies. The work was supervised by a certificated aircraft mechanic, but per-formed by an “apprentice” mechanic. Shortly after the work



Above: In-flight bird strikes can bring down even powerful aircraft.



mismatched connecting rods were installed, incorrect cylin-der base nuts were installed, and the prop STC was not ap-proved for the original engine model number. Examination of the failed bolts was found to be consistent with a fatigue fail-ure associated with a loss of pre-load. Fretting found on many other surfaces also suggested that a gradual loss of pre-load could have been occurring due to the excessive vibrations cre-ated by improperly balanced crankshaft and unapproved pro-peller installation.

Analyzing a weld failure on an exhaust manifold

A certified aircraft was destroyed during an on-ground fire following an emergency descent and landing due to an in-flight fire. The left exhaust stack assembly contained an ap-proximately four-inch fracture around the main collector welded joint. The left exhaust stack assembly was manufac-tured by an after market company that reverse engineered an OEM part and obtained an STC. DVI examined the wreckage, and made a comparison between the aftermarket part and the OEM. The design of the OEM exhaust stack assembly was found to differ significantly from the comparable aftermarket, and was inadequate to carry the load of the turbocharger at-tached to the manifold. The weld fatigued and failed due to the unintended bending stresses.

was performed, a cylinder departed the engine while in flight, and the aircraft was forced to make an emergency landing. DVI has on staff certified aircraft mechanics (A&P) that also have FAA Inspection Authorization (IA) privileges. DVI’s Aircraft Maintenance Expert performed a comprehensive wreckage examination, reviewed maintenance records, man-ufacture’s maintenance manuals, and evaluated the proce-dures used by the maintenance shop while performing work. DVI provided expert opinions based upon physical evidence found in the wreckage examination, which correlated to im-proper maintenance procedures, which explained the reasons for the cylinder departing the engine in flight.

Examining a fractured crankcase thru-bolt

An aircraft owner purchased an engine from a salvage yard, and had it field overhauled. During the overhaul the mechanic converted the engine from one model to another, but did not annotate the engine data plate. During annual inspections nuts are consistently found to be loose, including the prop to crankshaft flange attachment. Ultimately, the number two cylinder departs the engine in flight, and the pilot makes a successful off field landing without injury. DVI’s Material Sci-ence Expert was retained to examine the cylinder base studs and thru-bolts that failed. DVI discovered that incorrect and



Explaining an Aircraft Mechanic’s eye injury

A regional airline mechanic was troubleshooting a claim by passen-gers that smoke was coming up from the floor during the flight.

Under the floor there are two air conditioning packages or “packs” for air conditioning and pressurization. Each distribution system has fans and filters in the recirculation duct-ing to clean and condition the air.To troubleshoot the issue, the mechanic removed the floor access panels and activated the air-conditioning units. While observing the operation of the packs, the mechanic’s eyes were ex-posed to a smoke containing super heated particles.

DVI evaluated the maintenance protocols of the maintenance shop and evaluated the failed pack. It was determined the mechanic ignored safety protocols and was not wear-



had a problem but did not state what problem he was expe-riencing. Attempts by the Air Traffic Controller to establish radio contact failed; radar contact was never established. No further radio contact was recorded with the flight nor did the flight arrive at the destination airport.

A day later, an air and ground search team located the wreckage. DVI was retained by the manufacture of one of the aircraft’s primary instruments and was able to accurately reconstruct the accident and determine that the instrument had not failed in flight, and was not the cause of the accident.

In-flight failure of a composite rotor blade

An emergency medical helicopter was dispatched to an acci-dent scene alongside an unpopulated stretch of roadway. The helicopter crew navigated by GPS, and adjacent to the acci-dent scene, the helicopter struck power lines and crashed. The wreckage scatter diagram showed the blades were all thrown in the same direction and within close proximity to each other versus each scattering outwards in a different direction. DVI’s Helicopter Maintenance and Composites experts were re-tained to defend the rotor blade overhaul shop and investigate the cause of the rotor blade separation.

DVI performed testing to replicate and analyze the main-tenance shop’s procedure for replacing the leading edge abra-sion strip, which was allegedly responsible for the composite rotor blade failure. Testing, physical evidence and wreckage scatter indicated that the composite blades struck the power lines, which was indeed the cause of the accident.

ing eye protection, and that the fan motor brushes were found to be 500 hours over the required Time Between Overhaul (TBO). The super heated particles were created by the failing motor brushes, and were being dispersed by the motor fans within the floor cavity.

Determining cockpit visibility

An experienced flight crew was taxiing out to a runway and struck a large and easily noticeable construction vehicle adja-cent to the taxiway. At the time of the accident the aircraft was on the taxiway centerline, and should have been guaranteed taxiway clearances. DVI’s Aviation Human Factors Expert evaluated the cockpit visibility and issues concerning percep-tional blindness. Perceptional blindness explains why an air-crew might only pay attention to a small subset of the stimuli to which they are exposed, and perceptual filtering is the pro-cess of past experience influencing what is or is not processed. In this instance, the aircrew taxied out on the centerline while simultaneously completing their pre-takeoff checklist, just like they have thousands of times before. Because past experi-ences dominated their perception of what should never be on the taxiway, they never registered or reacted to an unforeseen object in their path.

Departure from controlled flight

During the initial climb out after departure on an instrument flight, radio contact was lost after the pilot reported that he



Crash-worthiness of composite airframe structures

A pilot brought his aircraft in for a normal and routine oil change. Unfortunately, the maintenance shop neglected to safety wire the oil drain plug. Shortly after departure, the oil drain plug loosened, resulting in a sudden engine seizure. The pilot elected to make an off field emergency landing in a cornfield. Due to the height of the corn, and the selection of partial flaps, the aircraft stalled slightly above the soft mud, and decelerated quickly. While plowing into the soft mud, the engine structure separated from the structure and entered the cabin structure from underneath the forward cabin structure. DVI evaluated the forces the occupants experienced to deter-mine if those forces were survivable, and reconstructed the speeds and loads associated with the flight and plowing on the ground, the force of the impact with the engine structure, and measured the airframe, seat, and landing gear deformation.

Determining the cause of a jammed flight control surface

During a routine training flight a student pilot and a certified flight instructor were practicing spins and spin recovery. Wit-nesses on the ground saw the aircraft spinning and impact the ground in a nose low attitude.

In the wreckage, the rudder control horn was found to be caught on the rudder stop bolt. The DVI team tried to deter-mine if the rudder became jammed in flight or was a conse-quence of the impact with the ground. They fabricated a test rig using an actual aircraft fuselage, and performed extensive laboratory testing to determine what combination of factors and forces would be necessary for the rudder to snag on the stop bolt.

Recreating an accident flight path for demonstrativeevidence

A pilot purchases an aircraft with a high time engine. On the flight back to his home airport, the pilot has a complete engine failure. The pilot is over terrain that is covered by ap-proximately 50 percent woods intermingled with unplowed farm fields. The pilot attempts to stretch his glide to a landing site, and crashes into a heavily wooded area. DVI’s Aircraft Reconstruction Experts were hired to recreate the flight path, and identify all available landing sites that would have been available to the pilot at the time of the engine failure, given his altitude and airspeed.

The multi-media demonstrative evidence allowed DVI’s clients to explain to the jury what the pilot’s options were at the time of engine failure. The multi-media demonstrative evidence included actual in-flight footage, overlaid on top of satellite imagery, with glide path calculations to each alternate site.

In-flight separation of a wing

A pilot had volunteered to fly a medical transportation flight in his twin-engine aircraft. At, 10,000 feet, the last recollection

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of the pilot was seeing the sunset in the distance, and then see-ing the VSI pegged downwards. One of the passengers recalls feeling three “bumps” and then an extreme pressure on her belt, and then a sudden release.

Radar data and wreckage diagrams showed the aircraft came apart at around 10,000 feet, and miraculously the pi-lot and one of the passengers survived the fall, their impact cushioned by the forest below. DVI was retained by the main-tenance shop that performed the last annual to determine the cause of the in-flight breakup, and was able to identify the correct sequence of the in-flight separation, and during the subject inspection discovered circumferential cracks in the Janitrol heater. The Janitrol heater was never inspected or even disassembled by the NTSB. The cause of the accident was determined to most likely be carbon monoxide poisoning and temporary incapacitation of the pilot.

Measuring the force of a runaway trim motor in-flight

An elderly pilot is flying some friends up the coast of Califor-nia. Radar data indicated that the plane climbed slightly be-fore spiralling into the ocean. DVI was retained by the main-tenance shop that performed maintenance on the aircraft trim and autopilot system, and the team developed a flight test pro-tocol and instrumented an exemplar aircraft with load cells, to measure the actual control forces that a runway trim motor would cause. DVI performed comprehensive flight-testing in all possible configurations and airspeeds, while measuring the force to counteract opposing trim forces. DVI’s testing was in-strumental in bringing about a mediation.

Failure of a landing gear to extend

A twin-engine turbine aircraft was inbound for a landing, and the plot was unable to extend the main landing gear. DVI’s Aircraft Maintenance Expert was sent the actuator for a non-destructive testing, and to facilitate a multi-party inspection.

X-rays were taken to document the subject evidence prior to disassembly. Fractured components were discovered in the actuator, and the fracture surfaces were examined under high power microscopes. DVI was able to research and trace the source of manufacture of the broken component, and found it was an approved part, and that the OEM part had not been available for over 15 years.

Ground tug striking a terminal building

A large aircraft tug pushes a 737 back from the terminal. Af-ter releasing the aircraft the operator attempts to return to his parking spot in front of the terminal, but has a complete brake failure and impacts the building. The impact with the build-ing is severe enough that the tow tug penetrates the wall, and enters the passenger waiting area. DVI’s Ground Vehicle Ex-perts were retained to investigate the accident and determine the cause of the brake failure. They inspected the subject tug, and performed a series of brake tests with data acquisition sensors, and were able to quantify the amount of degraded braking capabilities and identify the cause of the loss of brak-ing power.

In-flight bird strikes

A medium size bird impacts a helicopter flying at a low alti-tude. The impact ultimately causes the helicopter crash. For the client, DVI researched and created a comprehensive ma-trix of windshield designs and control locations for helicop-ters manufactured worldwide. This was a one of a kind matrix, and assisted the client in evaluating the appropriateness of the design configuration of the accident helicopter.

(DVI Aviation is a multi-disciplinary aviation company that combines scientific analysis, material science, laboratory testing, piloting expertise, aircraft maintenance, and human factors to investigate aircraft accidents and promote air safety.) n



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Western AME Association

WE

STE

RN

AME Association of Ontarioc/o Skyservice F.B.O. Inc., PO Box 160, Mississauga, Ontario L5P 1B1tel: 1-905-673-5681 fax: 1-905-673-5681email: [email protected] website: www.ame-ont.com

ON

TAR

IO

AME Credential Changes

Please read the following document from Transport Canada advis-ing of changes to the Aircraft Maintenance Engineer (AME) Licensing program:

Effective February 15, 2018, AME credentials (credit card style licence) will be issued with a ten-year validity and no longer bear a photo of the holder. Therefore: A photo will not be required to be submitted as part of the initial issue, renewal or reissue of an AME licence.

The validity period of the licence will increase from six years to ten years upon issue, renewal or reissue of the licence.

AME licence holders that request a replacement or obtain an addi-tional rating will receive a newly printed credential without the photo of the holder but the validity period will remain as specified on the licence.

Please consult the following AME webpages for more information:http://www.tc.gc.ca/eng/civilaviation/standards/ maintenance-aarpb-ame-menu-530.htm

http://www.tc.gc.ca/eng/civilaviation/standards/ maintenance-aarpb-general-renewal-2543.htm

www.wamea.com

Mentoring

Recently, I had the opportunity to attend a meeting sponsored by one of our local flying clubs. Guest speaker was Vaughn Olmstead, a lo-cally based retired airline pilot who started his aviation career in the mid-1950s. His first job was flying prospectors into the Ontario inte-rior with a de Havilland Fox Moth. Like many “bush pilots” of this era he was also called upon to maintain the aircraft he flew and he soon earned his Aircraft Maintenance Engineer licence. Vaughn’s presenta-tion included several trays of 35mm slides, which showed the many places he visited in the near and far north.

The audience was spellbound! Eventually, the small company that Vaughn was flying for merged with another to become Nordair and in due course Canadian Airlines, which in turn was acquired by Air Canada. Among the many types of aircraft he flew were the DC-3 (on skis), the DC-4 (on ice strips), Cansos, the B-737 (his favourite) and eventually retiring as a B-767 captain. He still flies his PA-12 on skis and floats and maintains other classic aircraft for his friends.

Throughout Vaughn’s presentation he was always pointing out photos and mentioning the many people who worked together to complete the various activities and projects. Although we might think of bush

pilots, AMEs, trappers and prospectors as being loners out in the wil-derness, there is actually a great degree of mentoring and looking out for one-another. From the beginning many people mentored Vaughn and “showed him the ropes” with airmanship, maintenance or even living in the bush; in turn he has passed on his wisdom to others. Many of our local pilots, AMEs and aircraft owners approach him for guid-ance and advice.

We need to consider increasing our level of mentoring to encourage participation in the aircraft maintenance profession. The recent initia-tive by Air Canada Maintenance to run a co-op program with several aviation colleges is to be commended. The Canadian Council for Avia-tion & Aerospace (CCAA) also coordinates the Student Work Inte-grated Learning Program (SWILP) to aid in attracting and retaining well-rounded and qualified maintenance technician students. While the Air Canada program and large aircraft AMOs will bring in M2 license trainees, AMOs maintaining smaller aircraft should consider taking advantage of the program for M1 trainees. Providing employ-ment opportunities and mentoring will ensure a bright future for our aviation minded youth.

— Submitted by Stephen Farnworth For the Board of Directors

AMU-Section3-Cdn1st-a.indd 2 4/3/18 4:09 PM


Atlantic AME Association

ATLAN

TICC

EN

TRA

LPA

CIFIC

Central AME Association

About CAMEA

The Central Aircraft Maintenance Engineer Association is an organi-zation dedicated to maintaining and enhancing the standards, rights and privileges of all AME members in the central region of Canada. Our chapter is one of six similar associations across Canada that col-lectively supports the national body CFAMEA (Canadian Federation of Aircraft Maintenance Engineers Association).

Our organization works with Transport Canada in the formulation of new rules and regulations and provides a collective viewpoint for all AMEs. CAMEA is a not-for-profit organization run by a volunteer group of AMEs. We elect members of our organization to be part of our Board of Directors. Members of CAMEA are comprised of AMEs, AME apprentices, students, non-licensed persons working in the in-dustry and corporate members.

www.camea.ca

Quality Systems Auditor workshop

Quality Systems Auditor workshop on April 16-17, 2018: Upon com-pletion of this workshop, participants will have a sound understanding of the auditing process which is a key part of a Quality Assurance and Safety Management System and its importance in enhancing opera-tional safety and improving operational performance. For more, visit: http://www.avaerocouncil.ca/en/events/quality-systems-auditor-qsa-halifax-ns

ARAMC 2019

At one point there was some thought regarding the possibility of hav-ing the 2019 ARAMC in PEI. It was, however, determined that the 2019 Conference will again be held in Moncton, NB. Jacques Richard

will again chair this conference with the assistance of Gerald Mallon (Display Chairperson at the Halifax event). It is intended to reach out to Association members from PEI to become involved in the presenta-tion in Moncton and be part of the ARAMC 2019 committee.

Membership

Our membership currently shows 109 AMEs, six Technicians, 20 Ap-prentices and 11 Corporate members. These numbers are consistent for AMEs and Technicians in previous years. The growth of apprentice members bodes well for the Association, as they are future AMEs and future members.

www.atlanticame.ca

About us

PAMEA is a non-profit association comprised of aircraft mainte-nance engineers, aircraft maintenance personnel and aviation industry corporate members.

PAMEA is an active member of the Canadian Federation of AME As-sociations (CFAMEA).

www.pamea.ca

[email protected]

Pacific AME Association



If you’d like to contribute your professional association’s newsletter toAirMaintenance Update, contact our editor, John Campbell via email at:

[email protected]

PAMA SoCal Chapter

CE

NTR

AL

OH

IOS

OC

AL

Central Ohio PAMA

Central Ohio Aviation News

CSCC Announces FAA Airman Knowledge Testing Center

Columbus State Community College’s Testing and Talent Assessment Center would like to announce that they are a FAA Airman Knowl-edge Testing Center (FAA LAS#43201) through PSI/Lasergrade offer-ing most of the written testing for FAA Airman Knowledge Tests.

(At this time they are unable to test for the Inspection Authorization).To schedule a test please contact PSI/Lasergrade at www.lasergrade.com or 800-211-2754. CSCC Testing and Talent Center at 614-287-5750 or [email protected]

Local A&P sets up Columbus Model Rocketry School

Pete Bricker, a local Airframe and Powerplant technician, has changed his hobby of model rocketry into a training opportunity for students in Central Ohio. His classes range from beginner rubber-band launched rockets to large Level 1 and Level 2 Certification.

If you or your child have an interest in Model Rocketry as an individual or group event, check out the school’s website. Pete works for one of the regional airlines at Port Columbus and is the husband of

Donna Bricker who was a long term board member and past treasurer of COPAMA.

We need your help!

We can use always use your help in finding the little errors, bugs or outdated data that you may find on our website. If you see something that doesn’t display correctly or sentences or paragraphs that don’t make sense, please drop us a line at [email protected] so we can cor-rect it. Sometimes it’s hard to see the forest for the trees and an extra set of eyes is always appreciated!

Be a content contributor!

Our members work at many airports in the Central Ohio area and may be interested in some event happening at your airport. This in-formation might include visiting vintage aircraft or dignitaries, fly-ins, airshows, etc. If you know of some upcoming event or special interest item at your airport, pass us an email including some base information and we’ll post it here for other members to view.

www.copama.org

Remembering Mike Fleming (March 15, 1964 – January 24, 2018)

The SoCal chapter of PAMA joins the Southern California aviation community in mourning the loss of Mike Fleming following a coura-geous battle with cancer. Mike will be remembered well and missed by his many friends and colleagues at Van Nuys Airport and throughout

the industry. A remembrance was held on February 3rd at Racho Santa Susana Community Center in Simi Valley. Catering was provided and the family asked guests to forgo the traditional solemn black outfits to keep in the spirit of a joyful tribute.

www.socalpama.org





Feature

Evaluating a conversion :All too often, engine conversion projects are a case of “don’t confuse me with the facts.” Here, a piston engine specialist shines cold, hard light on the realities of relative powerplant weights.

Pictured above: Most of the time, replacing a Lycoming or Continental air-cooled aircraft engine with a liquid-cooled piston engine is a bad idea. Opposite page: The table shows representative comparisons of the installation weights of several Lycoming engines against the lightweight, liquid-cooled, normally aspirated 505-HP EPI Gen-1 aircraft engine.

BY JACK KANE



choosing a powerplantAs you read the following, please keep in mind that at

EPI, Inc., a company I founded in 1994, one of our primary specialties is aircraft engine conversions.

Also keep in mind that two of our primary product lines are propeller reduction gearboxes and liquid-cooled V8 aircraft engines.

Yes, we like doing engine conversions. And yes, we like to sell engine and gearbox systems. BUT when you apply the cold, hard engineering realities, it turns out that most of the time, replacing a Lycoming or Continental air-cooled aircraft engine with a liquid-cooled piston engine is a bad idea. That being said, there are a few cases where it is an excellent choice.

If you are convinced that you have decided on a sufficiently reliable powerplant to replace the existing one, here are some thoughts to help decide whether to go further:

1. When you do a true, accurate, apples-to-apples comparison of the total, firewall-forward weight of a complete, flying Ly-coming or Continental powerplant against that of a complete, flyable liquid-cooled powerplant of the same or greater power (real, measured SAE Horsepower, not “BlantonPower”), the liquid-cooled installation will almost always outweigh the Ly-co-Nental by a considerable amount. (There is a table on these pages showing details supporting this statement.)



2. The CG of a V8-Gearbox powerplant will typically be quite a bit further forward than the CG of the air-cooled power-plant.

3. The combination of the greater weight and greater over-hung moment means that the engine mount structure of a V8-gearbox powerplant will typically be heavier than that for the air-cooled engine you are replacing, because it has to sup-port:(a) Greater weight,(b) Whose CG is further from the firewall

4. The combination of greater weight and greater overhung moment applies proportionately larger tensile, compressive and shear forces to the support structure behind the firewall to which the engine mount attaches. MOST airframes (fuse-

lage / nacelle structures) are not strong enough to support these larger forces. In fact, in most conversions we have done or assisted with, significant reinforcement of the airframe was required.

5. The greater weight of the powerplant and the structural ad-ditions to the airframe to support it will increase the empty weight of the aircraft, which will either reduce the payload (if you understand dynamic airframe loading) or significantly reduce the ability of your aircraft to survive in-flight maneu-vering loads if you DON’T understand dynamic airframe loading and arbitrarily decide to “DECREE” an increase of the gross weight.

6. The combination of greater powerplant weight and further-forward powerplant CG location will move the empty CG

Above: Replacing the engine in a Vans RV-7A with a Firebird’s LS1 powerplant struck the author as a really bad idea.



overtaxed Continental GTSIO-520 en-gines with a pair of certified, liquid-cooled Orenda-V8 engines, which had substantially greater takeoff and cruise power.

The Experimental-R&D prototype aircraft was impressive to fly. The take-off, cruise and engine-out performance of the prototype with 1200 HP on tap were stunning, especially if one was ac-customed to the performance of the un-modified aircraft. However, the installed powerplant weight was a major engi-neering flaw, which doomed the project.

The total, firewall-forward weight of the original GTSIO-520 (engine, gearbox, prop, turbo, heat-exchangers, mount, cowling, baffles, ductwork and plumbing ) was about 930 pounds. The comparable firewall-forward weight of the V8 installation (absolutely apples-to-apples comparison) was slightly over 1,260 pounds, which added about 660 pounds to the empty weight of the air-craft.

That increase in the aircraft empty weight had a number of undesirable side effects, including:

of the aircraft further forward. You will have to compensate by moving the wing forward or by moving some other mass-es rearward to re-establish the proper re-lationship between the aircraft CG and the wing center of lift.

7. Unless you move the wing forward (not usually a simple task, nor one with-out other potential pitfalls) the adjust-ments needed to bring the aircraft empty CG back into range, combined with the more-forward CG of the powerplant, will increase the Mass Moment Of In-ertia (MMOI) of the aircraft about the pitch and yaw axes (AND, in the case of a twin, around the roll axis as well).

That change alone can have a dra-matically undesirable effect on the flying qualities of a previously pleasant-flying aircraft. It reduces the stabilizing influ-ences of the rudder and horizontal stabi-lizer on the aircraft. It makes the aircraft less responsive to control inputs, (more “sluggish”). It will reduce the resonant frequencies of the aircraft about the pitch and yaw axes (and roll in the case of a twin). That change in resonant fre-quencies can introduce some nasty dy-namic behavior in flight, such as pitch or yaw instability.The bottom line is: just how competent are you as an aircraft designer? One ex-ample of a really bad conversion idea is the replacement of the IO-540 recom-mended for Van’s RV-10 aircraft with an LS-1-based aluminum V8 engine. This glaring example of “denial-of-reality-engineering” was actually written up in one of the experimental aviation maga-zines as being the greatest thing since sliced bread. This idea exhibits ALL of the problems discussed above.

A very bad example:

The bad ideas get even worse. Here is an example of some of the inquiries we get regarding conversions:

Dear EPI;I am looking for an engine to fit my RV7A, we have an LS1 out of an 2001 Firebird with about 65k miles on it, how much will it cost to have your reduction unit in-stalled and have the LS1 engine rebuild to your specs, I would also need the engine

mount and electrical wiring done with a new computer, also a variable pitch prop governor.

Thanks,xxx xxxxxxxxx

And here is our standard response to such inquiries:

Dear Mr. xxxxxxxxx:Thank you for your inquiry about our products. Regarding your proposed en-gine project, it is a strict company policy that we will neither sell any equipment nor do any work at all on engine conver-sions which obviously violate many of the known laws of physics and engineering.

Sincerely,Jack Kane, EPI, Inc.

A very, very bad example:

Several years ago, we worked on an en-gine conversion project on a popular piston twin, in which the goal was to STC the replacement of the aged and



A. The wing-structures to which the V8 engine mounts at-tached were unable to safely support the substantially higher loads imposed by the V8 engines;

B. The large increase in nacelle overhung moment reduced the resonant frequencies of the wings in torsional and flap-ping modes; oh, and, BTW,

C. The resulting aircraft was a functionally useless “full-fuel, zero-person” aircraft.

The project manager DECREED that this huge weight in-crease was not a problem, because, he claimed, he could eas-

Above: The bottom line when making conversions is, just how competent are you as an aircraft designer.

ily obtain, as part of the STC, a gross-weight increase based on the claimed “similarity” of this model of the aircraft to a turbine-powered model which has a certified gross weight ap-proximately 1,000 pounds greater, and which has substantially lighter (TPE-331) engines.

An unfortunate snag to that decree was the fact that the allegedly “similar” aircraft was very DISSIMILAR in the wing structure (to which the engine mounts attach). And there were other serious snags, including the ones described in (A) and (B) above. This was a prime example of a “don’t confuse me with facts, my mind is already made up” project.

(EPI Inc. is based in Washington State.) n


Feature

From real-time analysis technology to prevention, Pratt & Whitney Canada’s helicopter engine support expert Raymond Arseneau discusses four essentials for your helicopter line mainte-nance toolkit.

The Big Four


2. FAST engine health management

Raymond is a keen advocate of cutting-edge diagnostic and prognostic technology such as the FAST solution (presently offered on the AW139). It captures full-flight helicopter data on all engine parameters in real-time and transmits it wire-lessly after the pilot shuts down the engine for analysis.

FAST is a powerful system if you’re stuck on the top of an oilrig or hospital landing pad and need to get your helicop-ter back in the air fast, says Raymond. “In the past, if a cus-tomer requested customer support, the team would bring the kitchen sink with them. With the new technology, you know what’s happening without seeing the engine, so you just bring the parts you need. It’s much more effective from a cost and service perspective.”

3. Fuel nozzle and seal replacement tooling

Whenever you change a fuel nozzle, you need to check that it’s installed properly and there are no leaks. Make sure to

1. Ground-based software kit

Most helicopters today are equipped with electronic en-gine controls (EEC) or full authority digital engine controls (FADEC). For these rotorcraft, a ground-based software (GBS) kit is invaluable, according to Raymond Arseneau, a Senior Field Support Representative for P&WC’s global ser-vice network.

“By connecting cables into a dedicated helicopter port, downloading raw data from the engine, then reading it on a laptop, you can gain insights about your engine’s condition in real time,” says Raymond, who speaks from four decades of front-line experience assisting helicopter operators around the world on their flying missions.

He said that sometimes, for example, a fault is reported but doesn’t remain annunciated; the GBS readings can help identify a dormant fault. He points to owners of PW210 en-gines, in particular, as operators who can benefit from owning a kit, since they need to perform a data collection unit (DCU) download on their engine every 50 hours.



use fuel nozzle tooling, for the PW210, to apply pressure to the fuel system and verify that the pressure is constant us-ing a measuring device, Raymond said. “You should also have tools in your stan-dard line maintenance kit for basic tasks like replacing carbon or magnetic seals. If you spot a leaking seal, you’ll want to take care of it as soon as possible.”

4. Compressor wash kit

For helicopters that fly in salt-laden en-vironments or in areas of heavy industry with high concentrations of sulfuric acid in the air, regular compressor washes are a must to prevent corrosion. For that, you’ll need a compressor wash kit.

“If you’re flying in a salty environ-ment, a daily desalination wash is the way to go. If you operate near the sea, even if you’re not flying directly over it, you always need to be aware when you are flying in a saline environment,” Raymond advises. “You’d be surprised at how much gets into a helicopter en-gine. Adding engine inlet protection in the form of a particle separator or inlet

Above: A borescope is particularly useful for those being maintained on condition.



Above: Technologies like P&WC’s FAST solution have become a helpful tool to help in making decisions.

barrier filter is the best insurance you can provide for your engines operating in various atmospheric conditions.”

If your engine’s temperature mar-gins start to decrease noticeably—for example, by 10 degrees—one of the first things you should do is check the condi-tion of your compressor. If it’s dirty, use your compressor wash kit to do a perfor-mance recovery wash with a soap-and-water solution. Regular washing will help maintain the engine’s performance levels and keep your costs down by de-laying a premature engine removal, Ray-mond recommends.

Six More Essentials

Here’s a little more practical advice from Pratt & Whitney Canada, whose main-tenance expert recommends these six must-have tools for basic turbofan en-gine line maintenance.

1. Borescope kit and guide tubesA borescope is a valuable tool for any en-gine, but it’s particularly useful for those being maintained on condition.



Above: Work being performed on a PT6 turboprop jet engine.



Once your engines reach a certain usage threshold, you’ll need to start inspecting them to see if they need an overhaul.

Francis de Gruchy, a 20-year P&WC veteran who pro-vides frontline support for all PW300 engine models says that the borescope itself is standard no matter the engine model. However, he pointed out that the guide tubes for inserting the borescope into various engine ports can vary depending on the engine.

“If you have a mixed fleet, you’ll need to make sure you get the right guide tubes for each model. Check your mainte-nance manual for details,” he recommends.

Francis says that in recent years, on-condition mainte-nance is becoming more prevalent among the operators he supports. Technologies like P&WC’s FAST solution have be-come a tremendously helpful tool to help them make deci-sions. By delivering wirelessly captured full-flight analyzed engine data, FAST gives operators the confidence to poten-tially prolong the need for pre-scheduled maintenance.

2. Seal replacement tools

Over time, the seals on a turbofan engine’s accessory gearbox could show signs of leaking—this applies to both neoprene seals found on older turbofan engines or the magnetic and carbon-face seals used on newer models. These leaks are easy to identify by oil stains on the bottom of the cowling, which should be obvious when you do a visual inspection of the en-gine and externals during normal scheduled maintenance. Fixing it is simple enough — just follow the instructions in your engine’s maintenance manual. But if you don’t have the right tools, you’ll have to call a maintenance crew every time you have to replace a seal.

3. Oil pressure adjustment and cold start valve tooling

If there’s a change in your engine’s oil pressure, one of the first things to do is check the pressure adjustment and cold start valve to make sure it’s clean and in good condition.

“You’ll need to disassemble the pistons and springs. You

could pinch your fingers or get hit by a flying part without the right tooling,” Francis warns.

4. Oil and fuel filter replacement tooling

Oil and fuel filter replacement are part of scheduled mainte-nance, and for aircraft with a propensity for fuel contamina-tion, these may also be advisable on an unscheduled basis.

5. Fan blade removal and installation tooling

For engines with a bladed fan, such as PW300 models, wind-milling is a potential issue if the aircraft is left outside without engine covers. Wind turning the fan while the engine is shut down will cause slight friction as the titanium blades shift in their pockets, audible as a distinctive clicking sound. Cold weather conditions can further affect the blades, making cov-ers even more important.

“It’s not a question of how often you fly but how often you don’t fly,” says Francis. “Over a long time, the metal-on-metal friction will induce fretting. This produces microscopic tita-nium dust that will accumulate and may cause some vibration during engine operation.

“The solution is to clean the fan blades one by one and apply lubricant grease to them. That requires special tools for removing and installing the blades, and also for taking off the nose cone on some models.”

6. Helical insert tooling

Helical inserts or helicoils are used to secure steel screws in aluminum or magnesium housing. Sometimes screws get stuck inside these inserts due to corrosion or heat distress.

As a result, if you try to remove the screw during disas-sembly, the insert will be pulled out along with it. When that happens, it’s helpful to have an insert toolkit on hand.

“Every good mechanic should have an insert toolkit. It’s not just for engine maintenance—it can be used anywhere on the aircraft where there’s a screw,” Francis explains. n



Raising the Bar

A bearing assembly breakdown initiates a sequence of mechanical events that ulti-mately grounds a low-flying helicopter.

The aircraft landed hard on the beach, breaking the land-ing gear, and came to rest on its belly. One of the occu-pants was seriously injured, two had minor injuries and two were unharmed in the accident.

History of flight

The day before the accident, the pilot completed a walk-around inspection of the helicopter. He checked all the systems listed in the Rotorcraft Flight Manual (RFM) and detected no anomalies. The next day, at 0638, the he-licopter departed Québec/Jean Lesage International Air-

One Thing

The Bell 206B (registration C-GIFV, serial number 2004), equipped with high skid landing gear and operated by Essor-Hélicoptères Inc., departed

Matane, Quebec, on a visual flight rules flight with the pilot and four passengers on board. The aircraft was fly-ing northeast at low altitude over the south shore of the Saint Lawrence River so that the passengers could evalu-ate and document damage caused by high tides.

At 1131 Eastern Standard Time, approximately 27 minutes after take-off, the helicopter experienced an engine (Rolls-Royce 250-C20B) failure. The pilot did an autorotation with a right turn of more than 180 degrees.

leads to another



port for Rimouski, where it landed at 0820. After 170 litres of fuel were added, 4 passengers boarded the aircraft.At 0940, the aircraft took off on a low-altitude survey flight over the south shore of the Saint Lawrence River, heading northeast. The purpose of the flight was to document the en-vironmental and property damage caused by recent very high tides.

At 1042, C-GIFV landed on the shore of the Saint Law-rence one nautical mile (NM) north of Matane Airport and the pilot shut off the engine. At 1104, the helicopter resumed the survey flight, heading northeast. Approximately 27 min-utes later, when the helicopter was 120 feet above the river and 75 feet from the shore, travelling at 70 knots, there was a bang and the aircraft briefly yawed right. A few seconds later, another bang was heard.

The pilot immediately lowered the collective and turned right to land on the beach into the wind. The low rotor rpm warning horn sounded during the descent. The aircraft land-ed hard on the sand and the landing gear broke. The helicop-ter came to rest on its belly, and the pilot shut off the engine. The passengers evacuated the cabin once the blades stopped turning.

Examination of the wreckage

The aircraft had forward speed when it crash-landed on the beach. The skids sank into the sand, causing rapid decelera-tion and then the rotor mast and gearbox to topple forward.

The movement of the gearbox broke the forward joint of the gearshaft connecting the engine to the main gearbox. This movement also caused the hydraulic pump housing and shaft to break. Examination of the aircraft revealed that all damage observed on the fuselage, rotor assembly, flight controls, and power train resulted from the impact with the ground.

Engine

The occurrence aircraft engine (model Rolls-Royce 250-C20B, serial number CAE 823531) was manufactured by De-troit Diesel Allison. Rolls-Royce is the current holder of the type certificate issued by the Federal Aviation Administra-tion (FAA) for this engine model. The engine is a turboshaft modular-type engine and consists of a compressor, a gearbox, a turbine, and a combustion chamber. It is rated at 420 shp (shaft horsepower).

The engine is equipped with two chip detectors. The pilot did not notice whether the ENG CHIP warning light came on during the flight. Examination of the aircraft revealed that the chip detectors were contaminated. The condition of the aircraft after the occurrence did not prevent the battery from running. A system test showed that both detectors triggered the ENG CHIP warning light. The engine log indicated that the engine had been removed from the aircraft three times in the 35 flight hours before the accident:

1. On 10 September 2010, the engine was removed after it was observed that one of the five studs connecting the compressor

to the gearbox was broken. The gearbox was sent to Essential Turbines Inc.6 (ETI) to have the stud replaced. The engine was rebuilt with a rented gearbox.

2. On 30 September 2010, 30.8 flight hours before the acci-dent, the engine was sent to Essential Turbines Inc. after a crack in the compressor scroll and a leak in the N2 regula-tor were detected. After performing the required work and reinstalling the original gearbox, ETI tested the engine on a test bench. No abnormal vibrations or other anomalies were detected.

3. On 7 December 2010, 27.6 flight hours before the accident, the ENG CHIP warning light came on after returning from a flight to the aircraft’s base. Examination of the chip detec-tor revealed metallic debris, which was retained. The oil filter was clean. Although the engine was covered under warranty by ETI, Essor-Hélicoptères Inc. decided to disassemble it for examination.

When the gearbox was disassembled, a metal fragment was discovered near the No. 2 ½ bearing assembly. After con-sulting with ETI, Essor-Hélicoptères Inc. rebuilt the engine according to the manufacturer’s maintenance manual. The he-licopter did a run-up on the ground for 30 minutes and then made a short flight.

No anomalies were observed, so the aircraft was returned to service. The engine failure occurred 3.2 flight hours after the aircraft departed Québec.



Teardown and examination of the engine

The engine was removed from the occurrence aircraft and torn down in the shop at the TSB Laboratory in Ottawa. The findings from the examination included the following:

1. The engine was lubricated.

2. Three of the 12 fingers on the vibration damper located in the compressor front bearing housing for the No. 1 bear-ing assembly exhibited fatigue failure. Metallurgical analysis suggested that the fingers had fractured separately, one after the other, before the accident. The damper was last examined in 2009 when the compressor was disassembled, and it had logged 329.5 flight hours since being returned to service.

3. Damage observed on the No. 2 bearing assembly is typi-cal of a heat imbalance attributed to the failure of the bearing housing, which also experienced fatigue failure.

4. The oil delivery tube assembly, which lubricated the No. 2 bearing assembly, was working normally during testing.

5. Examination of the metal fragment found near the No. 2½ bearing assembly on 7 December revealed that it did not come from the engine and was of unknown origin.

6. The metal fragment discovered near the No. 2½ bearing as-sembly was too large to penetrate the assembly. Therefore, it did not cause the failure of the No. 2 bearing assembly.

7. Spalling was noted on the surfaces of the balls in the No. 3 and No. 4 bearing assemblies. The No. 3 bearing assembly exhibited micro spalls, and large spalls were visible on the No. 4 bearing assembly. The spalling was smooth, meaning that it had been present before the engine failure.

8. The results of the analysis of the metal debris extracted from the chip detectors on 7 December 2010 showed that its composition was similar to that of the No. 2, No. 3, and No. 4 bearing assemblies.

The modules, compressor and turbine were mounted on either side of the gearbox. Disassembly of the modules exposes the No. 2 and No. 4 bearing assemblies; however, their location

Above: Rolls Royce RR250 C20B.



and the retaining ring made it difficult to detect anomalies in the bearings that may have contributed to a malfunction.

Engine overhaul information

The vibration dampers and the engine bearing assemblies were maintained in accordance with a condition inspection. The No. 2 bearing assembly had logged 2244.4 hours and 3233 cycles since be-ing installed on 13 November 2006. Normally, the service life of a bearing as-sembly is estimated to be between 5,000 and 10, 000 hours.

The No. 2 bearing assembly, located in the diffuser aft of the compressor, is used as a thrust bearing—it absorbs the axial thrust load generated by the compressor impellers. This means that the No. 2 bearing assembly absorbs the highest load of all the engine bearing as-semblies.

Examination of the vibration damp-er fingers revealed rub marks on the fin-gers and on the cup washer in which the damper is mounted. The specification of the metal removed from the fingers and the cup washer is different from the bearing metal specification.

Analysis

The No. 2 bearing assembly in the engine broke down due to the fatigue failure of its cage. Because this bearing served as a thrust bearing, its failure caused the compressor to move forward, which in turn brought the impeller into contact with the shroud.The resulting friction led to significant deceleration and a loss of power. The propulsive movement of the compressor caused it to stall, as demonstrated by the bangs it produced.

The breaking of a gearbox stud, the crack in the compressor scroll and the fatigue failure of three fingers in the vi-bration damper may suggest that the damage was caused by abnormal en-gine vibration. However, after the stud and scroll were repaired, the engine was tested on a test bench, and no anomalies or vibrations outside of the limit were noted.

This suggests that it is unlikely that engine vibration caused the anomalies.

It can also be concluded that the vibra-tion damper was not fractured at the time of the inspection on the test bench. Consequently, the successive fractures of the damper fingers occurred during the last 30 flight hours.

Because three fingers had fractured less than 30 flight hours before the ac-cident, the vibration damper was less ef-fective. It cannot be concluded beyond all doubt that the broken damper caused the No. 2 bearing assembly to fail.

However, the partial failure of a component intended to absorb engine vibration cannot be ruled out; it could have altered the vibration load of the compressor, increasing the load on the No. 2 bearing assembly and causing its cage to sustain a fatigue failure.

Although the gearbox had been dis-assembled three times less than 35 flight hours before the accident, no anomalies were observed. The ball bearings and the vibration damper were not examined because the disassembly of the gearbox was not meant to verify their condition. Therefore, the engine may have been re-built with components that needed to be replaced.

The engine was equipped with a working chip detection system, but the pilot did not notice the warning light be-fore the loss of power, while significant spalling was generated by the slippage of the ball bearings in the No. 2 bearing as-sembly.

However, 3.2 flight hours before the accident, the chip detectors detect-ed metallic debris in smaller quantities from the engine ball bearings, which were starting to break down. Conse-quently, the ENG CHIP warning light may have been illuminated without the pilot noticing.

According to the height/speed chart, the loss of power occurred in an operating range within which a safe emergency landing was possible. At the time of the failure, there were three op-erating conditions posing a greater chal-lenge than usual for the pilot.

Given the height of the aircraft, the pilot had little time to lower the collec-tive, perform a 180 degree turn into the wind, and begin the descent before land-ing on a slope.

The power loss caused a rapid drop

in rotor rpm to the point where the low rotor rpm warning horn sounded dur-ing the descent. It can be concluded that the collective was off the down stop and that the rotor rpm fell below 90 percent.

Findings as to causes and contributing factors

The No. 2 bearing assembly in the engine broke down due to the fatigue failure of its cage. The failure of the bearing as-sembly caused the engine to lose power.The power loss caused a rapid drop in rotor rpm to the point where the LOW ROTOR rpm warning horn sounded during the descent. It can be deduced that the collective was not completely lowered and that rotor rpm dropped be-low 90%. This caused a hard landing.

Findings as to risk

Although the aircraft was operated out-side of the high-risk “to avoid” zone on the height/speed chart, the autorotation resulted in a hard landing. Because of operating factors other than speed and



height, the operation of the helicopter at low altitude posed a risk to safe landing in the event of an engine failure.

Operating an aircraft outside of the weight and balance limits set by the manufacturer can reduce aircraft perfor-mance and cause a power surge, in turn causing major dam-age to the engine, airframe and power train. The aircraft can attain the performance figures in the height/speed chart when it is loaded with its limit weight. Operating the aircraft at a higher weight compromises the success of an autorotation fol-lowing an engine failure.

The wear on the ball bearings and the vibration damper was not observed when the gearbox was examined, because the three engine teardowns performed within the 31 flight hours before the accident did not expose them and were not intend-ed to verify their condition.

(This report concludes the Transportation Safety Board’s investi-gation into this occurrence. Consequently, the Board authorized the release of this report on 30 May 2012. It was officially re-leased on 04 July 2012.) n


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1. Fuel nozzle flow check and pressure check fixturesTypically, ultrasonic fuel nozzle cleaning should be carried out every 200 to 400 hours of flying time, to make sure the noz-zle is performing properly and there are no problems such as blockages. “Whenever you clean your fuel nozzle, you should also check it for leaks and flow irregularities like drooling, spitting, streaking or other patterns that could damage the hot section,” explains Yves Houde, PT6A Customer Manager at Pratt & Whitney Canada.

Checking for irregularities of the fuel nozzle requires the use of both a flow check fixture and a pressure check fixture. These are fit-ted over the nozzle to help identify tips that need to be cleaned or re-placed and verify the presence of any leaks before the aircraft is returned to service.

2. Borescope kitWhenever undertaking fuel nozzle maintenance, make sure to perform a borescope inspection at the same time. To do this, you will need a borescope kit, including a guide tube for accessing hard-to-reach areas of the engine. Using a borescope is much easier than the old-fashioned method, which involves opening up the engine.

A borescope allows for assessment of hot section com-ponents for wear or damage that may not be evident from a regular ground power check or flight data collection. For instance, on a single power turbine engine, inserting a bore-scope through the exhaust duct port and power turbine stage may reveal trailing edge cracks on compressor turbine blades.

“It’s the number one equipment you need to have for line maintenance,” says Yves. “The time when fuel nozzle cleaning is performed is an ideal moment for operators to assess the hot section’s condition with a borescope. We also advise using it to check the first-stage compressor for foreign object damage every year.”

Borescopes kits are made by a number of companies. PT6A owners can check their engine’s manual for the prod-uct’s part number and order it from a designated supplier.

3. Oil filter puller/pusher toolOil filter maintenance is recommended every 100 hours or so. When doing this procedure, use a puller/pusher to open and close the filter’s check valve. While the oil filter can be popped out by hand, it’s not a good idea to do so, since it could damage the oil filter check valve seal, which in turn could lead to static oil leak when the engine is not running.

4. Turbine rinse tube and compressor wash rigPT6A engines may need to be washed periodically to remove

salt and other impurities; how often depends on the operating environment. Whenever it’s time to clean the engine, a com-pressor wash rig and turbine rinse tube are essential.

Unlike other engines, most PT6A engines already have a wash ring installed around the air intake, so all you need to do is connect the compressor wash rig and insert the water. After the compressor wash, use the turbine rinse tube to clean the turbine as well.

You don’t need any special cleaning solution for a desali-nation wash—pure, ionized water will do. “But it’s always a good idea to test the water quality first to make sure it’s suit-able for cleaning,” adds Yves. “If you use the wrong water, washing may end up causing more problems than it solves.”

(This article originally appeared on the P&WC Airtime Blog.)


Certain equipment is essential for keeping a Pratt & Whitney Canada PT6A engine running smooth-ly. Here are four tools and parts that the aircraft owner, operator, or AME needs to have when doing routine maintenance work.

Four must-haves for PT6Aengine line maintenance


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