Borescopes Help Solve Inspection and Maintenance Problems in Aviation

Photograph not available.

Borescopes allow quick but thorough evaluation of wear and tear deep inside engines (Photo courtesy Lenox Instrument Co., Inc.). Borescopes Help Solve Inspection and Maintenance Problems in Aviation

If you can look at something, you taining dangerous materials. When can better understand it; if you can- inspection itself becomes difficult, not see it, then understanding is we must guard against failure to more difficult, and reckoning en- properly perform inspections. Oth- ters the picture. In our world of erwise the results could be disas- inspection and maintenance, there trous. Enter the “inside look” of are many instances of a technician the borescope. not being able to see clearly the object to be inspected. Often it is The primary types of borescope are hidden out of sight, within a closed the rigid and flexible variants. The system, down a piping run, inside rigid borescope is much like a tele- a chamber, or inside a vessel con- scope: a long tubular instrument

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 1 with optical lenses. However, al- housing of sealed flexible stain- though a telescope narrows the field less steel conduit, allow the of vision for the observation at a borescope to bend around corners distance, a borescope spreads the while sending back to the viewer field of vision for close-up work. a sharp, clear image. The borescope also has relay lenses along its length to preserve pre- With this tool, a technician can cise resolution. The magnifica- inspect for such problems as: im- tion is usually three to four times perfect welds in piping, heat ex- (3X-4X). changers, or pressure vessels; cracks or foreign object damage (FOD) Rigid borescopes are made in one in aircraft engine components; blade or more modular sections for ease wear in gas turbines, and the pres- of storage and handling. Self- ence of contaminants and surface illumination is provided either by flaws in casting and tubing. Other internal lamps at the view head or borescope targets are: cracking or through the use of fiber optics that stress in structural members, metal lead the light to the subject. The corrosion in systems carrying chemi- view head itself can provide right cals or fluids and instances where angle, bottoming, circumference, there is a need to inspect a compo- forward oblique, or retrospective nent in all corners and behind work- (recall) views through the use of ing parts. mirrors and prisms. Rigid borescopes are available in lengths Aircraft operators use the borescope from three to 100 feet, and in di- to check rubber hoses and aircraft ameters from 0.118 to 2.75 inches. fueling lines for flaws. Overhaul and repair facilities use the borescope Flexible borescopes are useful in to make thorough inspection to applications that provide no straight better estimate repair jobs. Deci- passageway to the point of obser- sions to scrap or repair can be made vation. These operate entirely with on the spot and much time saved as an internal fiber optic light source. a result. This capability can be a A flexible borescope holds two boon to both the owner and the re- optical bundles — each consist- pair facility — and all because a ing of as many as 40,000 individ- direct look inside was possible. ual strands of glass fibers. One Recently, an aircraft manufacturer bundle carries light to the inspec- set up the use of a borescope vari- tion area and the other carries the ant, called a chamberscope, to ex- image back to the eyepiece. These amine incoming engines for corro- optical bundles, protected by a sion within combustion chambers—

2 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 a problem that otherwise would not One aircraft mechanic told of us- turn up until final testing and in- ing his borescope for two hours to spection, where it would be very locate a problem and only one-half expensive to rectify. hour to fix it. The same job, without a borescope, previously had taken There are major points to consider five hours to determine the trouble in selecting a borescope. The dif- and three hours to fix it. ference between the right borescope and the almost-right borescope is Although the borescope serves a basic the difference between easy inspec- and simple purpose, the technol- tions and troublesome ones. Con- ogy of its operation and its appli- sider your uses and particular re- cation is fairly complex. You have quirements before settling on one so many choices in borescope com- type. The rigids, the flexible and ponents, and every inspection job the periscope types all are useful at has its own special characteristics. an aviation repair and overhaul fa- You should share every bit of in- cility. The professional aircraft information you can with your spector may need all versions, too. borescope manufacturer’s applica- Critical factors to consider in se- tion engineer, so he can suggest the lecting a borescope are illumina- components to do the job best.o tion, environment, reflectivity, power, black light, camera or recorder needs, and whether flexible or rigid fits the need. NEWS & TIPS

From the aviation technician’s viewpoint, you can usually get more ap- Aviation Maintenance plications out of the rigid borescopes Technician Of 1989 than the flexible type. For example, if you want to inspect the inside of Honored in U.S. a gas cylinder, you might believe that a flexible scope would let you Dwight Dean Law of McHenry, examine every inch, and you would Maryland, U.S., was named the be correct — but it would be a very 1989 Aviation Maintenance Tech- slow process. In this case, a rigid nician of the Year by the U.S. aviation scope with a quartz lamp, a mov- industry and the U.S. Federal Avia- able mirror, and with variable mag- tion Administration (FAA). nification (zoom capability) would The annual national award recog- accomplish the job in much less nizes the vital role played by pro- time. fessional aviation technicians in

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 3 Photograph not available.

Dwight Dean Law is awarded the Aviation Meaintenance Technician of the Year Award by FAA Administrator James B. Busey. aviation safety and the promotion tenance and an FAA-authorized in- of aviation technology. spection mechanic for Lakeside Aviation, Inc., of McHenry, Mary- FAA Administrator James B. Busey land. His intense concern for avia- presented the FAA award to Law tion safety led to his development in ceremonies honoring the main- of an aircraft battery that discon- tenance technician of the year and nects upon impact, thus prevent- the flight instructor of the year. ing post-accident aircraft fires that During the presentations held at that could be caused by the battery’s FAA headquarters in Washington, internal charge. Law is now working D.C. November 2, 1989, Busey with Aerosafe, Inc., and Ohio State praised their high level of “pro- University at Columbus, Ohio, to fessionalism, creativity, skill, cha- further develop the patented safety risma, excellence and contributions battery. to safety” and said, “It’s dedication and performance such as dem- Law has been employed by an air- onstrated by these two that keep craft repair facility in Petersburg, the spirit of general aviation grow- West Virginia, and previously ing,” Law is the director of main- served as a mechanic on U.S. Army

4 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 helicopters during the Vietnam requires conscious effort when War. working on aircraft outside. One mechanic was observed to take off The award program is sponsored his gloves to touch aircraft skin to by the AOPA Air Safety Founda- check for a loose rivet; he quickly tion, General Aviation Manufac- pulled his finger away as if it had turing Association, Helicopter As- been burned, which is exactly what sociation International, National it appeared to be to first aid room Business Aircraft Association, Na- personnel. It took an incident like tional Air Transportation Associa- this to convince him to keep his tion and the FAA. Editorial coor- gloves on in the future and to use dinator, Robert Phillips, of the a tool, such as a screwdriver, to Flight Safety Foundation Aviation use as a probe instead of his bare Mechanics Bulletin has served on skin when working with frozen the judging panel since the incep- metal. tion of the program in 1966. Carrying the Flame Is Only for Love Frostbite Warning And the Olympics Worth Repeating The story goes that an electrician Exposed skin is always susceptible was checking emergency power to frostbite when the temperature lead-acid batteries that were on a drops below freezing — and tissue trickle charge in a poorly lighted can be frozen even though cov- area. Not having a flashlight, he ered. Here are a few tips to pre- used a cigarette lighter to provide vent cold damage to the human part illumination to check the battery of the aviation maintenance safety water level. As the mechanic bent equation. forward toward the opened batteries, the fumes exploded, throwing ¥ Wear enough clothing for pro- battery acid into his face. The re- tection, Protect the face in high sult was serious burns and perma- winds. Wear loose-fitting and well- nent disability. Warnings about ventilated clothing in layers for best using an open flame to check things protection. in flammable atmospheres have been given to us so often for so ¥ Do not touch bare metal with long that some of us may have be- bare skin in extremely cold tem- come deadened to them. However, peratures. This is one “don’t” that there’s always that two percent that

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 5 does not get the word, and new- services at PAMA ’90. comers who can profit from safety messages, no matter how unneces- More details are available from sary they may sound to old timers. PAMA at Suite 401, 500 Northwest Plaza, St. Ann, MO 73074, U.S. Trade Shows Telephone 314-739-2580.

Coming Up On March 1 and 2, the Minnesota Aviation Maintenance Conference The 19th Annual Trade Show and will be held at the Thunderbird Symposium will be hosted by the Hotel in Bloomington, Minnesota, Professional Aviation Maintenance U.S. Sponsored by the Minnesota Association (PAMA) February 27 Department of Transportation through March 1. In a special seminar Aeronautics Office, in cooperation devoted to safety, the subject of with the U.S. Federal Aviation hazardous chemicals as it affects Administration (FAA), the confer- the aviation industry will be exam- ence is open to aviation mechan- ined and discussed. Site of the 1990 ics, aircraft refueling technicians, meeting will be the George R. Brown students and pilots interested in Convention Center in Houston, Texas, keeping up-to-date on maintenance U.S. technology.

PAMA has scheduled a wide Program features will include variety of technical seminars for education and safety presentations, I.A. (Inspector Authorization) cer- industry exhibits and recognition tificate renewal and to maintain the of the outstanding Minnesota avia- high level of professionalism in the tion maintenance technician of the aviation maintenance industry. Top- year. More information on the con- ics on many aspects of aviation ference is available from Donald maintenance and safety will be pre- Goserud, Office of Aeronautics, sented from the viewpoint of both Minnesota DOT, Transportation the technician and management. One Building, Room 417, St. Paul, MN panel will address industry con- 55155, U.S. Telephone 612-296- cerns over revisions to U.S. Fed- 7285. eral Aviation Regulation (FAR) Part 65, “Certification: Airmen Other The fourth annual International Than Flight Crewmembers.” The Aviation Maintenance and association expects approximately Ground Support Equipment 200 aviation maintenance suppli- Tradeshow and Conference ers to exhibit their products and (AMTECH 90) will be held at the

6 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 Dallas Convention Center, Dallas, swore that he would never remove Texas, U.S. March 26-28. Spon- the wedding band from his left sored by Aviation Equipment Main- hand ring finger. One wonders how tenance magazine, the activities he would be able to wear a ring will include seminars and forums on a finger that has been ampu- as well as product exhibits by ap- tated because the original ring got proximately 200 companies, with caught in moving machinery. For a first-time outdoor exhibit of large some other reason, the same per- equipment and vehicles. son also continued to wear a sig- net ring on his right hand while A special seminar program will operating machinery.o identify the differences between ground support equipment (GSE) needs and what is available today, MAINTENANCE ALERTS the purpose of which is to promote better understanding between the The following information on acci- end-user and the manufacturer. A dents and incidents is intended to technical forum will be devoted to provide an awareness of problem addressing the needs of GSE and areas through which such occur- maintenance equipment, with pres- rences may be prevented in the fu- entations by industry representa- ture. Maintenance Alerts are based tives. Other sessions will include upon preliminary information from presentations during which various government agencies, aviation and companies will describe new main- other sources. The information may tenance procedures and practices not be complete. they have developed for the improvement of maintenance quality and safety. Fatigue Fractures Flap Fitting

With This Ring The Boeing 747 was on a sched- I Put Thee at Risk uled flight from Los Angeles, U.S., to London, U.K. The aircraft, with Jewelry may be attractive, but it 313 occupants, took off at 0122 hours can be a hazard in the workplace. and had an uneventful flight until We continue to see accident and approaching its destination. incident reports of people whose finger rings get caught in machin- The aircraft was turning on to the ery. One mechanic, whose loyalty ILS centerline at Heathrow Air- exceeded his safety consciousness, port with the captain flying a manual

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 7 approach. Shortly after the flaps With the failure of the fitting, the were lowered from 10 to 20 de- section of flap was free to move grees, a bang was heard from the upwards beyond its normal limits right side of the aircraft; there was and the outboard section of the bull also a light vibration throughout nose scraped against the engine the aircraft. Simultaneously, three pylon. stewardesses working on the right side of the aircraft reported hear- Detailed metallurgical examination ing a bang that they initially thought of the failed piece showed a small was a bird strike. area of fatigue cracking around an area of undercut on one of the side- There were no abnormal indica- plates; fatigue fracture in this tita- tions on the flight deck and the nium material is characterized by captain had no difficulty control- an extremely small critical crack ling the aircraft. The landing was length. The side plate failed in rapid normal and the aircraft disembarked overload. The missing sections of the passengers at the terminal with- the fitting and the Krueger flap were out incident. not recovered.

The first indication of what had occurred was a report from the Drag Stay Didn’t ground crew that the number 16 Krueger (leading edge) flap adja- The Piper PA-23-250 Aztec had cent to the number 3 engine was made an uneventful flight and was damaged. The flap had travelled landing at Cambridge Airport, U.K. above its normal position and was There were three passengers and pointed upward. It had scraped the pilot. The touchdown was nor- against the engine pylon on the way mal. up, which had caused a portion of the front flap section, the “bull nose,” However, before the pilot applied to break off. This had struck the brakes, the aircraft began to veer fuselage. to the right and the right wing began to settle to the runway. The Later examination showed that the pilot kept the aircraft straight and extra movement of the flap had shut down the engines. After the been caused by the failure of the aircraft came to rest, the occupants gimbal fitting that links the were unable to leave through the ballscrew transmission system passenger door, so they had to evacu- (mounted in the wing) with the ate through the emergency exit. support arms of the Krueger flap. There was no fire and there were

8 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 no injuries. After the aircraft was caused two fatigue cracks that be- jacked up, the passenger door began at the point of corrosion pits. came free. The two bolts that attach the drag Later examination of the right landing brace to the airframe and landing gear revealed that the drag stay had gear also showed varying signs of failed, which allowed the gear leg pitting corrosion. The antirotation to pivot to the rear and become flat for the leg attachment bolt had wedged under the wing. The cen- been damaged by the head of the ter pivot bolt of the drag stay was bolt, but not enough to allow rota- found to have failed near its mid- tion. point. Detailed examination of this bolt showed that it had failed in reverse bending fatigue and that it Engine Failure was generally in poor condition. Most of the shank showed signs of pit- The WW II vintage Spitfire took ting corrosion and there was sur- off from its home airport in the face damage, consistent with the United Kingdom and was seen car- effects of the bolt rotating under rying out a series of climbing and load, in the upper drag link and the turning maneuvers. Witnesses re- two lower drag links it connected. ported not seeing or hearing any- The bolt holes in the links were thing to indicate that it was per- oval. Inspectors also found that forming abnormally. the machined antirotation flat on the inboard lower drag link had been After the aircraft departed the air- damaged by the bolt head to the port area, several ground witnesses point that rotation was possible. A heard the engine misfiring and saw bronze bushing in the center (up- a trail of vapor streaming from it. per) drag link also exhibited some A Mayday call was heard indicat- ovality. ing that the pilot would attempt a landing at a nearby airport, fol- Investigators concluded that after lowed within seconds by another the bolt flat had been damaged by call that changed the intended point its rotation, wear had occurred be- of landing to a field near the air- cause of continued rotation on the port. unlubricated outer links which also had no bushings. The bolt then The aircraft was seen with its was no longer under shear stresses propeller stopped as it barely cleared alone, but could also experience high tension cables and maneu- bending stresses. These, in turn, vered to the field. The aircraft struck

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 9 the ground in a nose-down atti- takeoff, the controller gave the tude and caught fire immediately. crew the latest winds from 101 The pilot was killed and the entire degrees at 10 knots. The captain center section of the aircraft was then requested a different runway destroyed by fire. since the the aircraft’s takeoff weight was too high for that tail The force of the impact had been wind. absorbed mainly by the engine, which was embedded in the ground. The tower granted permission to The propeller blades had failed in use another runway and the air- a rearward direction indicating that craft was backtaxied along the en- they had not been under power at tire length of the runway. Before the time of impact. The tail sec- the aircraft reached the end of the tion, starboard wing, outer left wing runway, there was a muffled bang and engine had survived the fuel which the crew and the tower con- fire. troller assumed was a compressor stall. However, the controller then The upper and lower surfaces of reported that the aircraft had blown the starboard tailplane were stained a tire. He told the crew to hold with oil, and fragments from the position and initiated an airport alert. shattered cockpit canopy that had The aircraft was then taxied to the been thrown clear also were cov- end of the runway and turned off. ered in oil. Although the engine A second bang was heard and the was buried, an oil deposit was seen crew announced a second blown in the exhaust stub from cylinder tire. Shortly afterwards the con- 1A, and the fractured end of a controller informed the crew that the necting rod was found lodged out- landing gear was on fire and up- side the crankcase. When the en- graded the airport alert for emer- gine was uncovered, the crankcase gency services to respond. was found to have holes on both sides. The passengers were evacuated with only one passenger injured when Corrosion Again he fell from the aft slide and sus- tained head injuries that required Rears its Ugly Head hospitalization. The fire in the left undercarriage area was quickly ex- The McDonnell Douglas DC-8-62 tinguished. was lined up for takeoff on runway 23 at Stansted Airport, U.K. When Later examination revealed that the tower cleared the aircraft for the number 8 wheel assembly had

10 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 failed around the mid tubewell move even though he had not re- because of fatigue emanating from leased the brakes. There was an- multiple corrosion pits, releasing other aircraft parked a short dis- the outer rim and the tire. The tance ahead and the pilot had to use adjacent number 7 tire then failed the nosewheel steering to avoid a from overload. The aircraft had collision. The toe brakes proved rolled on the remaining rims ineffective and the pilot shut down until the aircraft began to turn off the engines. By then the aircraft the runway. At that time the rims had turned through 120 degrees to failed, causing the wheels to skid the left and was heading towards and erode the hubs through to the two other aircraft parked to the left. brake units. The number 8 wheel assembly had been manufactured This time the pilot could not avoid in 1959 and was cleared to a maxi- a collision and the left propeller of mum takeoff gross weight of the Twin Otter struck a Britten 315,000 pounds, 20,500 pounds Norman Trislander and caused mi- less than the aircraft’s takeoff nor damage to the Trislander’s left weight. The number 7 assembly wing. The right propeller struck a was cleared to a gross takeoff Cessna 177 and removed the out- weight of 35,500 pounds less than board section of the Cessna’s right the actual weight. wing. The Twin Otter stopped and the pilot evacuated without injury. There was no fire. Brake Failure It was later found that the left brake Wreaks Ramp Havoc caliper had failed through the casting and had separated from the disc. The de Havilland DHC-6 Twin Ot- A piston from the caliper was found ter was being prepared for a cargo in a pool of hydraulic fluid close to flight scheduled to depart at 2130 the Twin Otter’s original parking hours from Southend Airport, U.K. place. The pilot, using a flashlight to pre- flight, found the brakes and tires Later inspection revealed that the satisfactory. The engines were started failure had started at a fatigue crack using external power. with multiple origins on one side of the caliper slot. Some cracks When he looked up to signal to the were also found on the other side. ground controller to disconnect the In both cases the crack origins had ground power cable, the pilot real- initiated from corrosion on the hori- ized that the aircraft had begun to zontal surface, an area normally

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 11 corrosion-protected during manu- ties that contribute to back injury facture. Although there was evi- and related illnesses and presents dence that some corrosion protec- ways to modify behavior that can tion had been applied, it was ap- lead to back problems both on and parent to investigators that it had off the job. not remained effective during the estimated 8,000-hour/8,000-landing The program provides techniques life of the caliper.o from the company’s Safety Train- ing Observation Program (STOP). Users learn to apply the program’s five-step process (Decide, Stop, NEW PRODUCTS Observe, Think, and Act) as a way to identify and modify behavior that contribute to back injury and ill- Information on the following prod- ness. The program modules focus ucts, services and literature is pub- on three areas that are important to lished in the interest of improv- back health: biomechanics (the theory ing aviation safety through a well- and movement of the spine), ergo- informed, better-equipped aviation nomics and fitness. mechanic. Module 1 examines biomechanics Program Introduced and how to avoid injury to the ver- To Prevent Back tebrae and discs due to repetitive activities such as reaching, lifting, Injuries on the Job stretching, bending and twisting. Module II focuses on ergonomics Du Pont Safety and Environmental and how to structure environments Services has introduced a three- so they reduce strain on the spinal module safety training program areas. Module III describes the role aimed at increasing back-safety of fitness in improving and main- awareness to improve safety and taining the health of the spine, and health. The aviation industry has provides suggestions for daily ex- contributed its share of serious back ercise routines. The program com- injuries to the total since many air- ponents include an administrator’s craft components are heavy and and leader’s guide with step-by-step working within tight quarters is instructions for implementing the commonplace. program; three video tapes and ac- companying participant meeting Du Pont’s back injury prevention guides; and a back injury preven- program identifies everyday activi- tion booklet for reference by em-

12 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 ployees and their families.

These program modules could be used by employees during lunch hours or training breaks, and they could Photo not assist in reducing injuries both off and on the job. available.

For further information contact Back Safety, Du Pont Safety and Environmental Services, Mont- gomery Building, P.O. Box 80800, The two-inch-wide OT-30 is spe- Wilmington DE 19880-0800, U.S. cifically designed so that it will not Telephone 800-532-SAFE. delaminate when wet. However, for areas where a wider tape would make installation easier, OT-30 can be custom cut up to 50 inches in Carpet Tape width. Resists Fire For additional information contact Orcon Corp., 1570 Atlantic Street, Orcon Corp. has introduced a light- Union City, CA 94587 U.S. Tele- weight pressure-sensitive aircraft car- phone 415-489-4699. For Europe, pet tape. Double-sided with differen- contact American Aviation, 180 tial tack, the tape will adhere to aircraft Varick Street, New York, NY floor panels and is removable from the 10014-4699 U.S. Telephone 212- panels for up to one year after installa- 620-4500. tion without leaving a residue. The OT- 30 aircraft carpet tape meets flamma- bility requirements of FAR 25.853 and Monitor ‘Cleans’ has a self-extinguishing time of less than one second and a burn length of Aviation Fuel 2.2 inches (5.6 cm). Facet Quantek fuel monitors are According to the manufacturer, the tape installed on delivery facilities to weighs 75 percent less than the most eliminate the need for other water currently specified aircraft carpet tapes, defense devices and to provide maxi- and therefore can offer two-and-a-half mum water removal, solids hold- times more tape per roll than other ing capacity and shutdown protec- brands. tion to assure clean and water-

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 13 free fuel. The heart of the monitor curs, indicating that the cartridge is the filter cartridge. should be changed. The cartridge’s maximum operating temperature is The monitor continually checks the 240 degrees F (115 degrees C). For entire fuel flow, not just samples, more information, contact Facet for contamination by water or sol- Quantek, Inc., a subsidiary of ids. In the process, it absorbs free Facet, P.O. Box 50096, Tulsa, OK and emulsified water, removes ul- 74150, U.S. Telephone 800- tra-fine solids and shuts down the 888-9129. system flow when hit with a local- ized slug of water. Thus, the de- vice performs the three most essen- Bulletins Describe tial jobs required in the delivery of Use and Care of fuel, even when surfactants and fuel additives are present. The monitor Aviation Tires is designed to operate at a maximum 150 psi working pressure on The Rubber Manufacturers Asso- jet fuel and aviation fuel at flow ciation (RMA) has released several rates up to 36 gpm. tire information service bulletins cov- ering a variety of care and service The single cartridge housing is said aspects of aircraft tires. They to be easy to maintain and requires include: Aircraft Tire Recom- only a two-inch base clearance for mended Operating Inflation Pres- cartridge change. Both the interior sure Maintenance Criteria; Use of and exterior surfaces of the carbon- Aircraft Tires and Wheels in Other steel body are epoxy coated to pro- Than Aircraft Service; Aircraft Tire tect against corrosion. The stain- and Tube Storage Recommenda- less steel V-band closure is designed tions; Aircraft Tire Bursts; and for ease of handling and holds the Radial Aircraft Tire/Wheels Com- die-cast aluminum head and O-ring patibility. seal to the body. The bulletin on inflation pressure lists The cartridge incorporates layered criteria to maximize tire serviceabil- and pleated multi-media sections ity for in-service aircraft. Bulletin in- with inner support shells and an formation includes tire inflation tips, outer wrap. A special water ab- service pressure recommendations, sorbant media retains water, which frequency of pressure checks, causes the pleats to expand. As reinflation procedures, removal from the maximum water-holding capacity service recommendations, notes on is reached, a reduction in flow oc- removal of tire and axle mate from

14 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 service and removal of blown fuse emphasizes the extreme danger re- plug recommendations. sulting from the force of tire bursts, includes the reasons for these occur- The Use of Aircraft Tires and rences and reminds the reader that ex- Wheels in the Other Than Aircraft tra caution must be observed during Service bulletin warns that the bead deflation and inflation procedures. seat diameters of aircraft wheels are different from those of ground ve- The bulletin concerning radial air- hicles. If an attempt is made to craft tire/wheel compatibility empha- mount a tire on a wheel other than sizes that the stresses which radial one for which it is designed, the tires impose on wheels are different tire could break with explosive from the stresses imposed by bias force and cause serious injury or tires. death. All of these bulletins stress safety as- The tire storage bulletin includes pects that maintenance personnel details on avoidance of adverse should address when working with air- conditions, so prevalent in many craft tires and tubes. The five aircraft storage facilities, and recommenda- tire information service bulletins are tions concerning tire and tube age free of charge and be requested by limits. Included are suggestions writing: Rubber Manufacturers Asso- about placing stored tires into ser- ciation, Publications Desk, 1400 K vice, rotating tire stock and shipping Street, N.W., Suite 900, Washington, tips. DC 20005, U.S. Please included a stamped, self-addressed business-size The bulletin on aircraft tire bursts envelope.

Photo not available.

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 15 Call for Nominations for The Joe Chase Award

A call for nominations is being FAX (314) 739-2039. made for the Joe Chase Award, administered by the Professional Eligibility Requirements Aviation Maintenance Association (PAMA) and presented in conjunc- One or more of the following is tion with Flight Safety Founda- needed for the candidate to qual- tion events. This year’s award ify for the award: will be presented during the Foundation’s Corporate Aviation 1. Candidate should show dedi- Safety Seminar in Montreal, Can- cation to learn and continuously ada, April 18-20, 1990. educate himself or herself and communicate what is learned Joe Chase, known in aviation circles to others in the aviation field. as the champion of the forgotten 2. Candidate must show dedica- man — the aviation technician — tion to the improvement of com- originated publication of the FSF munications between employer Aviation Mechanics Bulletin. He and employee in the aviation used the Bulletin and other means industry. to raise the status of the aviation 3. Candidate must show dedica- maintenance technician. Chase tion to the communications recognized that technicians play methods which advance the a vital role in aviation safety and knowledge of the aircraft tech- strove to communicate this belief nician. throughout the industry. 4. Candidate must show dedication to the improvement of the Foundation readers are encouraged role of the aviation technician. to participate in the Joe Chase Award program and to submit This dedication to the improve- nominations by February 1, 1990 ment of communications and in- to PAMA Headquarters, 500 NW creased learning must be con- Plaza, Suite 401, St. Ann, MO ducted beyond the normal work 63074. Phone (314) 739-2580; requirements.

16 FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 Nomination for Joe Chase Award

Nominee Information Name ______

Address ______City ______State ____ Zip ______Telephone (Home) ______

(Office) ______

Employer ______Employer’s Address ______City ______

State ____ Zip ______Telephone ______

Nominee’s position ______FAA License # ______

FAA Certificate # ______

PAMA National # (if applicable)______Nomination submitted by ______

Address ______City ______

State ____ Zip ______Telephone (Home) ______(Office) ______

Signature ______Date ______

• Please use a separate sheet of paper to list nominee’s achievements.

FLIGHT SAFETY FOUNDATION ¥ AVIATION MECHANICS BULLETIN ¥ JANUARY/FEBRUARY 1990 17