Aviation Mechanics Bulletin July-August 1997 · Aviation Mechanics Bulletin Knowledge of Hazardous Chemicals in the Aviation Workplace Can Help Prevent Work-related Illness and Injury

JULY–AUGUST 1997

F L I G H T S A F E T Y F O U N D A T I O N

Aviation Mechanics Bulletin

Knowledge of HazardousChemicals in the Aviation

Workplace Can HelpPrevent Work-related

Illness and Injury

F L I G H T S A F E T Y F O U N D A T I O N

Aviation Mechanics BulletinDedicated to the aviation mechanic whose knowledge,craftsmanship and integrity form the core of air safety.

Robert A. Feeler, editorial coordinator

Knowledge of Hazardous Chemicals in the Aviation WorkplaceCan Help Prevent Work-related Illness and Injury .......................................1

News & Tips ............................................................................................... 12

Maintenance Alerts ..................................................................................... 14

New Products ............................................................................................. 19

July–August 1997 Vol. 45 No. 4

AVIATION MECHANICS BULLETINCopyright © 1997 FLIGHT SAFETY FOUNDATION INC. ISSN 0005-2140

Suggestions and opinions expressed in FSF publications belong to the author(s) and arenot necessarily endorsed by Flight Safety Foundation. Content is not intended to take theplace of information in company policy handbooks and equipment manuals, or to supersedegovernment regulations.

Staff: Roger Rozelle, director of publications; Rick Darby, senior editor; Douglas Greenwood,senior editor; Todd Lofton, editorial consultant; Karen K. Ehrlich, production coordinator;Ann L. Mullikin, assistant production coordinator; and David Grzelecki, librarian, Jerry LedererAviation Safety Library.

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Knowledge of HazardousChemicals in the Aviation

Workplace Can HelpPrevent Work-related

Illness and Injury

Aviation maintenance facilities use anumber of substances containingchemicals that regulatory agencieshave labeled as toxic. These includesolvents, cleaning agents, hydraulicfluids, coolants and fuels.

Inappropriate exposure to or inges-tion of toxic substances may lead toillness or injury, ranging from short-term effects such as headache, short-ness of breath and dizziness, toparalysis, kidney failure, cardiovas-cular disease, blindness, respiratoryailments and even death.

Reactions to a particular chemicalmay vary, depending on the durationof exposure, dosage, personal factors(for example, those who are asthmat-ic, have heart trouble or smoke to-bacco), type of exposure (by

breathing or physical contact), wheth-er exposure was to more than onechemical, and how quickly and effec-tively action is taken to counteract thetoxin’s effects.

Among the most widely encounteredhazardous chemicals in aviationmaintenance facilities are acetone,ammonia, asbestos, carbon monox-ide, chlorofluorocarbon 113 (CFC-113), ethylene glycol, methylenechloride and methyl ethyl ketone(MEK).1 Below is a brief descriptionof each of these chemicals, along withgeneral symptoms from exposureand first-aid action.

As a general rule, prompt profession-al medical attention should be ob-tained any time a person is inappro-priately exposed to a hazardous

FSF Editorial Staff

FLIGHT SAFETY FOUNDATION • AVIATION MECHANICS BULLETIN • JULY–AUGUST 1997 1

chemical. Workers should not wearcontact lenses when working with haz-ardous chemicals; where appropriate,goggles, face masks and respiratorsshould be worn to reduce the proba-bility of exposure or inhalation.

Acetone is a clear, colorless, volatileliquid with a sweet odor. It is used asa solvent in many aviation applica-tions. Individual products may referto acetone as dimethyl ketone, meth-yl ketone, 2-propane or beta-ketopro-pane. Upon exposure, acetone entersthe bloodstream and is circulatedthroughout the body. Limited expo-sure is generally not injurious becausethe liver is capable of turning smallamounts of acetone into harmlessbyproducts. Larger concentrations aremore serious. Breathing moderate tohigh levels of acetone for even a shorttime can cause nose, throat, lung andeye irritation; shortening of the fe-male menstrual cycle; headaches;light-headedness; confusion; in-creased pulse rate; nausea; vomiting;unconsciousness; and coma. Physicalcontact with acetone does not causeskin cancer; no determination hasbeen made if breathing acetone forlong periods will lead to other formsof cancer.2

Medical tests (breath, blood or urinesamples) to confirm exposure to ace-tone are available, but these tests mustbe performed within two days after ex-posure because acetone is naturallyflushed from the body after that time.2

Acetone first aid:

• Eyes: If acetone comes in con-tact with the eyes, they should beirrigated immediately with largeamounts of water, occasionallylifting the lower and upper lidsto further remove the chemical.

• Skin: Skin contaminated withacetone should be washed imme-diately with soap and water. Ifclothing has become contaminat-ed with acetone, the clothingshould be removed and the skinunderneath should be washedwith soap and water.

• Inhalation: A person who has in-haled acetone vapor should bemoved immediately into freshair. If breathing has stopped,mouth-to-mouth resuscitationshould be performed. The affect-ed person should be kept warmand at rest, and medical attentionobtained immediately.

• Ingestion: Immediate medicalattention should be obtained.3

Ammonia is used in the aviation in-dustry as a cleaning agent, particular-ly in fuel cells.1 Its noxious fumes,which can be severe eye irritants,should provide a warning of exposure.When inhaled, ammonia irritates themouth, nose, throat and lungs. Con-tinued exposure by breathing can leadto headaches, loss of the sense of smelland vomiting. The most severe effectof ammonia inhalation is a buildup of

2 FLIGHT SAFETY FOUNDATION • AVIATION MECHANICS BULLETIN • JULY–AUGUST 1997

fluid in the lungs that can lead tosuffocation and death.

A person exposed to high levels ofammonia should be kept under obser-vation by medical personnel for atleast three days, because the buildupof fluid in the lungs might cause a de-layed reaction.

Skin contact with ammonia causesburns, the severity of which dependson the concentration of the ammoniasolution, the moisture content of theskin and the length of time that passesbefore the area is flushed with water.

Ammonia reacts violently with, andshould be stored away from, strongoxidizers, chlorine, bromine, acids,gold, silver, calcium, and hypochlo-rite bleaches.

Ammonia first aid :

• Eyes: If ammonia contacts theeyes, they should be irrigated im-mediately with water for 15 min-utes, holding the eyelids open andaway from the eyeballs. Speed andthoroughness are very important.

• Skin: Skin contaminated with am-monia should immediately beflushed with water. If ammoniapenetrates the clothing, it shouldbe removed and the skin under-neath should be flushed with wa-ter. Ointment should not be appliedto ammonia burns; burned areasshould not be rubbed.

• Inhalation: A person who breatheslarge amounts of ammonia shouldbe moved immediately into freshair. If breathing has stopped,mouth-to-mouth resuscitationshould be performed. Oxygenmay be administered. The affect-ed person should be kept warmand at rest.

• Ingestion: Vomiting should notinduced. A glass of milk or wa-ter should be given to the affect-ed person to drink.3

If symptoms of exposure to ammo-nia persist, immediate medical atten-tion should be sought.

Asbestos, which primarily affects thelungs, may be found in aviation brakelinings, electrical insulation and fric-tion components.1 It is classified as acarcinogen. Few or no symptoms areevident at the time of exposure. As-bestosis, a disease that manifests asscarring of the lungs and shortness ofbreath upon exertion, may not appearfor seven to 30 years after exposure.The risk of lung cancer for tobaccosmokers who have been exposed to as-bestos is 92 times higher than forsmokers who have not been exposed.4

In the United States, and in other coun-tries, there are several requirements forthe handing and storage of asbestos,including: (1) Advanced training mustbe provided for personnel who are tohandle asbestos; (2) a regulated,


marked, enclosed, isolated area mustbe established for asbestos storage andhandling; (3) the asbestos must be keptwet with special surfactant and waterwhile handling; and (4) local exhaustventilation with negative pressure airfiltration and high-efficiency particu-late filters must be used in areas of as-bestos removal.4

Asbestos first aid:

Because there are virtually no symp-toms evident at the time of exposureto asbestos, there are no first aidrecommendations.

Nevertheless, certain preventive andsurveillance measures should be tak-en in the aviation workplace. Careshould be used in handling compo-nents containing asbestos. Where ma-terials containing asbestos arepresent, periodic sampling and analy-sis for airborne asbestos should beconducted to ensure that particulatelevels remain within safe minimums.1

Carbon monoxide (CO) has been de-scribed as one of the most commonindustrial hazards5 and is also a dan-ger to those in aviation maintenance.The U.S. National Institute of Occu-pational Safety and Health (NIOSH)reports that several workers have diedin or near refueling trucks as a resultof CO poisoning.6

When inhaled, CO takes the place ofoxygen in the bloodstream, reducing

the supply of oxygen to the body’scells. CO is colorless, odorless andtasteless, properties that make it par-ticularly difficult to detect.

One of the characteristic signs of COpoisoning is a cherry-red color of theskin and lips. Any of the followingsymptoms can signal moderate COpoisoning: headaches, tightnessacross the chest, nausea, drowsiness,inattention or fatigue. If exposurecontinues, a lack of coordination,weakness or confusion may develop.Breathing high concentrations of COcan lead to unconsciousness, evenbefore other symptoms are evident,and can kill in minutes.5

Because CO remains in the blood forseveral days, a gradual increase in thelevel of CO in the body may occur.The health hazards of CO exposure areincreased for individuals who smoketobacco or have heart damage.5

To reduce workers’ exposure to COwhile operating equipment, NIOSHrecommends the use of diesel-powered equipment. A diesel enginegenerates less CO than a gasolineengine, and the strong odor of dieselexhaust provides a more pronouncedwarning of possible CO presence.

Also important is the proper main-tenance of all vehicles to prevent COfrom entering the cab while the en-gine is running. These measuresinclude:


• Fit tight rubber boots aroundpedals and levers in the vehiclecab;

• Put snug-fitting grommets inholes through the firewall;

• Close rust holes in the cab floorpans or elsewhere;

• Ensure that heater and fresh airintakes are remote from the ex-haust discharge;

• Check regularly for leaks in ex-haust system components;

• Tighten or replace componentsto stop leaks; and,

• Provide vehicle cabs with con-tinuous CO monitors, includingalarms to warn operators beforeconcentrations of CO reach dan-gerous levels.6

Wiring a ventilation fan to operatewhenever the engine is running willusually build positive pressure in aclosed cab, minimizing in-seepage ofCO. But NIOSH cautions that thereare circumstances in which such anarrangement might draw CO into thevehicle.6 Workers in enclosed areasshould be alert to ventilation prob-lems, and, if CO poisoning is suspect-ed, they should vacate the areaimmediately.

Carbon monoxide first aid:

• In mild CO poisoning, half of theCO accumulated in the body will

be eliminated in four hours or fivehours of breathing CO-free air.

• A person who has inhaled largeamounts of CO should be movedinto fresh air at once. If breath-ing has stopped, mouth-to-mouthresuscitation should be per-formed. The affected personshould be kept warm and at rest.In severe cases, the affected per-son should be given 100-percentoxygen to breathe.1,3

Chlorofluorocarbon 113 (CFC-113)is used primarily in aircraft mainte-nance for cleaning of metals and elec-tronic assemblies. Smaller quantitiesare used in aerosol propellants, coat-ings, adhesives, thermal stressing (tolocate faulty components in failedelectronic circuit boards), as a dilut-ing agent and as a lubricant carrier.7

CFCs are commonly referred to by thetrade names Freon 113®, Genetron113®, Halocarbon 113®, or Refriger-ant 113®, or generically as 1,1,2-trichloro-1,2,2 trifluoroethane fluoro-carbons.8

CFCs are noncombustible, colorless,nearly odorless and have only slightirritant effects on the skin.7 CFCshave a relatively low toxicity in lowconcentrations, which can create themisconception that CFCs are safe.

Symptoms of inhalation exposure toCFCs include dizziness, light-headedness and unconsciousness.


Heavy concentrations can cause deathby cardiac arrhythmia (irregularheartbeat) or asphyxiation in as littleas one minute.8

Training of maintenance personnelshould include the hazards of work-ing with CFCs and should provide in-struction on the use of supplied-airrespirators (SARs) or a self-containedbreathing apparatus (SCBA).8 Thereis no known antidote to CFC expo-sure, nor are there any laboratory teststo confirm whether an individual hasbeen exposed.1

Asthmatics are particularly cautionedagainst CFC exposure. Taking epi-nephrine, norepinephrine, dopamine,isoporteranol and medications con-taining catecholamines increases anasthmatic’s risk of CFC poisoning.8

Exposure to CFCs will also aggravateexisting cardiovascular disease (in-volving the heart and blood vessels).

CFCs are being phased out throughoutthe world as commercially practicablealternatives have been developed. Pre-ventative workplace measures shouldinclude the provision of adequateventilation and exhaust systems andthe avoidance of CFC use in closedspaces.1

CFC first aid :

• Eyes: If CFCs come in contactwith the eyes, the eyes shouldbe irrigated immediately with

water for at least 15 minutes, oc-casionally lifting the lower andupper lids.

• Skin: Contaminated skin shouldbe washed with soap and water.

• Inhalation: The health hazardfrom inhalation of CFCs is acute.A person who has breathed alarge amount of CFCs should bemoved into fresh air at once. Ifbreathing has stopped, mouth-to-mouth resuscitation should beperformed. Oxygen should begiven. The affected personshould be kept warm and at rest.Immediate medical attentionshould be obtained.

• Ingestion: Ingestion is not con-sidered a route of entry forCFCs.3

Ethylene glycol is a colorless,slightly viscous liquid with a mildodor. It is used mainly as a coolantand aircraft deicing agent, but is alsofound in paints and hydraulic fluids.Ethylene glycol is not an inhalationhazard unless it is heated and vaporsform; it is not toxic unless it isingested.1

There are three stages of toxic expo-sure to ethylene glycol. Stage I oc-curs up to 12 hours after exposure;the individual may appear inebriat-ed, drowsy, dizzy or unable to coor-dinate voluntary muscle movements.Stage II occurs 12 hours to 24 hours


after exposure and can lead to heartarrhythmia or congestive heart fail-ure. In Stage III, which begins 24hours after exposure, kidney failureis a possible outcome.1

Ethylene glycol first aid:

• Eyes: If ethylene glycol contactsthe eyes, they should immediate-ly be irrigated with largeamounts of water, occasionallylifting the lower and upper lids.

• Skin: Skin contaminated withethylene glycol should immedi-ately be flushed with water. Ifethylene glycol penetrates theclothing, it should be removedand the skin underneath flushedwith water.

• Inhalation: A person who breatheslarge amounts of ethylene glycolvapors should be moved into freshair at once. If breathing hasstopped, mouth-to-mouth resus-citation should be performed. Theaffected person should be keptwarm and at rest.


Fuels. Jet fuel (kerosene) and avia-tion gasoline may not appear to posemajor medical problems. Neverthe-less, the cleaning of closed, unventi-lated fuel tanks can expose anindividual (through inhalation) toconcentrated levels of fumes. Reac-tions include slurred speech, blurred

vision, headache, drowsiness and diz-ziness. In the most severe cases, long-term exposure to jet fuel or aviationgas vapors has caused deaths fromsuffocation.1

Fuels first aid:

• Eyes: If fuel contacts the eyes,they should immediately be irri-gated with large amounts of wa-ter, occasionally lifting the lowerand upper lids.

• Skin: Skin contaminated withfuel should immediately beflushed with water. If liquid fuelpenetrates the clothing, it shouldbe removed and the skin under-neath flushed with water.

• Inhalation: A person whobreathes large amounts of fuelfumes should be moved to freshair at once. If breathing hasstopped, mouth-to-mouth resus-citation should be performed.The affected person should bekept warm and at rest.


Methylene chloride is used as asolvent in paint strippers and de-greasing agents, as a propellant inaerosols and in metal cleaning andfinishing.1 A colorless liquid with amild sweet odor, it is also known asdichloromethane.9 Upon skin con-tact, methylene chloride causes in-tense burning and mild skin redness.


People differ in their ability to smellmethylene chloride, so it is possibleto be unknowingly exposed. Symp-toms of low exposure are slightly im-paired hearing and vision. At higherlevels of exposure, methylene chlo-ride acts like an anesthetic, reduc-ing one’s ability to remain steady orperform tasks that require precisehand movements. Other symptomsof severe exposure include dizziness,nausea, tingling and numbness in thefingers and toes. In most cases, theseeffects stop shortly after exposureends. Methylene chloride is a carcin-ogen, and smokers are at increasedrisk to the effects of exposure tomethylene chloride.9

Methylene chloride first aid:

• Eyes: If methylene chloride con-tacts the eyes, the eyes shouldimmediately be irrigated withwater for at least 15 minutes, oc-casionally lifting the lower andupper lids.

• Skin: Skin exposed to methylenechloride should promptly bewashed with soap and water. Ifthe methylene chloride pene-trates the clothing, it should beremoved and the skin underneathwashed with soap and water.

• Inhalation: A person who hasinhaled large amounts of methyl-ene chloride should be movedinto fresh air at once. If breathinghas stopped, mouth-to-mouth

resuscitation should be per-formed. The affected personshould be kept warm and at rest.


Methylethyl ketone (MEK) is usedin aviation maintenance facilities as asolvent, primarily in paints and glues.1

The EPA has labeled it the “singlemost widely used hazardous air pol-lutant in aerospace applications.”7

Nevertheless, it is not considered par-ticularly toxic unless there is exposureto a very high concentration for anextended period. Also known as 2-bu-tanone, MEK is a colorless, flamma-ble liquid with a sharp, sweet odor thatis similar to that of acetone.10

In the aviation industry, the mostcommon exposure to MEK is bybreathing its fumes, which causemild irritation to the eyes, nose andthroat. Skin contact can lead to dry-ing, scaling and cracking. Mild ex-posure may also manifest inheadache, dizziness, incoordination,nausea and vomiting. High levels ofexposure to MEK, though not com-mon, can cause depression of thecentral nervous system, coma anddeath.1 MEK has not been classifiedas a human carcinogen.10

MEK first aid :

• Eyes: If MEK contacts the eyes,the eyes should immediately beirrigated with water for at least


15 minutes, occasionally liftingthe lower and upper lids.

• Skin: Skin contaminated withMEK should be washed prompt-ly with soap and water. If MEKpenetrates the clothing, the cloth-ing should be removed and theskin underneath washed withsoap and water.

• Inhalation: A person who has in-haled a large amount of MEKshould be moved into fresh airat once. If the person is uncon-scious, cardiopulmonary resusci-tation (CPR) may be necessary.Oxygen may also be given.

• Ingestion: The affected personshould be given two glasses ofwater to drink, with an emetic (anagent that induces vomiting), ifpossible. Liquids should not begiven if the affected person is un-conscious.3

Those who work in maintenance fa-cilities servicing agricultural aircraftshould also be aware of the hazardsof pesticides and insecticides. Gen-eral information on handling andstorage of these chemicals is alsoprovided by special interest groupssuch as the American Crop Protec-tion Association.11

Many other hazardous chemicalsare found in the aviation mainte-nance workplace. These include,but are not limited to, cadmium,

chromium, cyanide, lead, mercury,phenol, phosphoric acid, trichloro-ethylene, tricresylphosphate (TCP),sulfuric acid, tetrachloroethylene,toluene, toluene diisocyanate andxylene.

In the United States, the U.S. Occu-pational Safety and Health Ad-ministration (OSHA) requiresmanufacturers of toxic chemicals toissue a material safety data sheet(MSDS) for each chemical. TheMSDS describes first aid, storage,handling, transportation, fire-fightingand spill and disposal procedures forthat chemical.

OSHA’s Hazard CommunicationStandard (HCS)12 requires that manu-facturers, importers or distributors ofhazardous chemicals or products sup-ply a copy of the appropriate MSDSto their customers. MSDSs are to beprovided automatically, and it is theresponsibility of the producers andimporters of the material — not thepersons who receive their products —to make the hazard determination.Further, the supplier is required to up-date the MSDS with the next shipmentif new and significant informationabout the hazards of a particular chem-ical have come to light.

The HCS directs the employer tomaintain copies of the MSDSs foreach hazardous chemical or product.It also requires that MSDSs be readi-ly accessible to employees in their


work areas. These MSDSs may bemaintained on computer, microficheor other alternatives to paper copiesas long as there are no barriers to im-mediate employee access.

OSHA says that the HCS “coverschemicals in all physical forms —liquids, solids, gases, vapors, fumesand mists — whether they are ‘con-tained’ or not. The hazardous natureof the chemical and the potential forexposure are the factors which deter-mine whether a chemical is covered[by the HCS].”13 If it is not hazardous,or if there is no potential for exposure,the chemical is not covered by HCS.

In the United States, proper employeeaccess to the current MSDS for eachchemical in the workplace is a criticalstep in HCS compliance. The compa-ny should have a written program that:

• Designates a person responsiblefor obtaining and maintaining theMSDSs;

• Describes how employees canobtain access to the MSDSs whenemployees are in their work areas;

• Describes how the MSDSs are tobe maintained (in notebooks orin a computer terminal);

• Outlines procedures to followwhen MSDSs are not received atthe time of the first shipment; and,

• Describes alternatives to MSDSsin the workplace.

The HCS says that employees “whomay be ‘exposed’ to hazardous chem-icals when working must be provid-ed information and training prior totheir initial assignments ... and when-ever the hazard changes.”13 Exposurecan be through any route of entry (in-halation, ingestion, skin contact, eyecontact).

It is the responsibility of OSHA com-pliance officers to determine “if [theemployees] have received training,if they know [whether] they are ex-posed to hazardous chemicals and ifthey know where to obtain substance-specific information on labels andMSDS,” according to OSHA.13

The following checklist will help anorganization determine whether it isin compliance with HCS directives.The organization should have:

• Obtained a copy of the rules fromHCS;

• Read and understood therequirements;

• Assigned responsibility for tasks;

• Prepared an inventory of chemi-cals;

• Ensured that containers arelabeled;

• Obtained the MSDS for eachchemical;

• Made MSDSs available toworkers;


• Conducted training of workers;

• Prepared a written program;

• Established procedures to main-tain a current program; and,

• Established procedures to evalu-ate the program’s effectiveness.♦

References1. Ribak, J.; R.B. Rayman; and P.

Froom (eds.). OccupationalHealth in Aviation Maintenanceand Support Personnel. NewYork, New York, U.S.: AcademicPress, Inc. 1995.

2. Fact Sheet on Acetone. U.S.Agency for Toxic Substances andDisease Registry (ATSDR). 1995.

3. NIOSH Pocket Guide to ChemicalHazards. U.S. National Institutefor Occupational Safety andHealth (NIOSH). 1984.

4. EPA Toxic Substances Data Sheeton Asbestos. U.S. EnvironmentalProtection Agency (EPA). 1987.

5. Fact Sheet 92-11 on CarbonMonoxide Poisoning. U.S.Occupational Safety and HealthAdministration (OSHA). 1992.

6. NIOSH Alert. ControllingCarbon Monoxide Hazard inAircraft Refueling Operations.NIOSH. 1984.

7. Eliminating CFC-113 andMethyl Chloroform in AircraftMaintenance Procedures.

Industry Cooperative for OzoneLayer Protection. EPA. 1993.

8. NIOSH Alert. Preventing Deathfrom Excessive Exposure toChlorofluorocarbon 113 (CFC-113). NIOSH. 1989.

9. Fact Sheet on MethyleneChloride. ATSDR. 1995.

10. Fact Sheet on 2-butanone [alsoknown as Methylethyl ketone, orMEK]. ATSDR. 1995.

11. Boillot, James. Telephoneinterview by Glenn Orthmann,Flight Safety Foundation, onApril 11, 1997.

12. Chemical Hazard Communication.OSHA Publication No. 3084.

13. 29 U.S. Code of FederalRegulations 1910.1200, HazardCommunication. Appendix E,“Guidelines for EmployerCompliance.”

Additional ReadingFrom FSF Publications

Feeler, R. A. “Correct Selection andUse of Respirators Is Vital in Con-taminated-air Environments.” Avia-tion Mechanics Bulletin Volume 42(November–December 1994).

Feeler, R. A. “One Cure for Work-place Safety Complacency: SafetyChecklists.” Aviation Mechanics Bul-letin Volume 43 (September–October1995).


New Advisory CircularsList Certificated Agencies,Designated Airworthiness

Representatives forMaintenance

A new U.S. Federal Aviation Admin-istration (FAA) advisory circular(AC) provides information and guid-ance concerning designee applica-tion, authorized functions andcertificates of authority for Designat-ed Airworthiness Representatives(DARs) for Maintenance.

DARs are individuals, corporations,associations or partnerships whorepresent the FAA in issuing recur-rent and standard airworthiness cer-tificates for U.S.-registered aircraft,non-U.S.-manufactured aircraft im-ported into the U.S. from other coun-tries, restricted-category aircraft andexperimental aircraft.

AC 183-53, Airworthiness DesigneeFunction Codes and ConsolidatedDirectory … defines designee autho-rized functions and function codes,and provides a state-by-state listingof the names and addresses of per-sons currently designated.

The FAA has also announced the avail-ability of AC 140-7I, FAA Certificat-ed Maintenance Agencies Directory,

which contains yearly updated listingsof current FAA repair stations andmanufacturer’s maintenance facilities.

Ultrasound WorkshopCan Lead to Level I

Certification

UE Systems Inc. will present a five-day Ultrasonic Workshop Nov. 11–14 in Elmsford, New York, U.S.Qualified participants will receiveLevel I certification.

The workshop will focus on hand-held, portable, ultrasonic detectorsand inspection devices and their useboth on the ground and in flight.

Some of the topics to be covered in-clude: physical principles of sound;equipment construction, characteris-tics and signal presentations; testingtechniques for leak detection, electri-cal and mechanical inspection; record-ing, documentation and interpretationof test results.

Registration is limited to 25 persons.

For information on cost and enroll-ment, contact Alan Bandes, UE Sys-tems Inc., 14 Hayes Street, Elmsford,New York 10523 U.S. Telephone:(914) 592-1220, extension 614; Fax:(914) 347-2181.

NEWS & TIPS


Aircraft MaintenanceHuman Factors

Seminar/WorkshopScheduled

Human factors error-reduction pro-grams, such as crew resource man-agement, are well established in theairline industry in connection withflight crews. As their benefits havebecome widely recognized, such pro-grams have been increasingly appliedto the technical operations area, in-cluding maintenance.

An Aircraft Maintenance Human Fac-tors Seminar/Workshop, organized byTransportation Systems ConsultingCorp., will be held Oct. 14–17 at theRadisson Hotel, Clearwater Beach,Florida, U.S.

Topics to be presented at the seminarinclude, among others:

• The importance of effectivecommunications;

• The influence of organizationalchanges;

• The safety impacts of mainte-nance errors;

• Managing maintenance error;

• Analysis methods;

• Investigation teams;

• Building a human factors programfor aircraft maintenance; and,

• Key elements of trainingprograms.

There will also be workshops on thefollowing topics, among others:

• Human factors training plan;

• Dealing with human error;

• Maintenance human error casestudies;

• Human performance investiga-tion techniques; and,

• Sharing lessons learned.

For registration or more information,contact: Transportation Systems Con-sulting Corp., 35111 U.S. 19 North,Suite 101, Palm Harbor, FL 34684U.S. Telephone: (813) 785-0583;Fax: (813) 789-1143.

SAE Publishes NewAerospace Standards

The Society of Automotive Engineers(SAE) Inc. has published six newstandards for the aerospace industry.They are:

• AS4873: Gland Design, Elasto-meric O-ring Seals, Static Radi-al and Face 800 psi MaximumService;

• ARP4898: Stands, Shippingand Storage, Aircraft Engines,Reusable;


MAINTENANCE ALERTS

• ARP5007: Development Pro-cess — Aerospace Fly-by-wireActuation System;

• AIR5052: Crack Initiation andGrowth Considerations for Land-ing Gear Steel with Emphasis onAerMet 100;

• ARP5107: Guidelines for Time-limited-dispatch (TLD) Analysis

for Electronic Engine ControlSystems; and,

• AS5255: Exfoliaton Testing ofAluminum.

For further information, contact: So-ciety of Automotive Engineers Inc.,Dept. 2786, 400 CommonwealthDrive, Warrendale, PA 15096-0001U.S. Telephone: (412) 776-4970;Fax: (412) 776-0790.♦

Failure of WindshieldElectrical TerminalBlocks Investigated

An incident involving smoke in aBoeing widebody cockpit in late1992 raised the possibility that thescrew securing the power lead to theterminal block in the windshield mayhave loosened and led to an electri-cal short circuit. Boeing issued anoperator action notice on the subjectin September 1993, suggesting thatall operators of possibly affectedBoeing 767 and Boeing 747 modelscheck the torque on this screw andincrease it if necessary. The in-creased-torque requirement was alsomade part of the appropriate main-tenance manuals.

In a more recent incident, smoke en-tered the cockpit of a B-767-200during cruise at 11,285 meters

(37,000 feet). The crew put on theiroxygen masks, declared an emergen-cy and landed without further inci-dent at Sydney, Nova Scotia, Canada.

In that incident, the technician whoremoved the failed windshield termi-nal block (J5) from the B-767 indi-cated that the screw securing thepower lead was properly torqued. Asa result, maintenance focus has shift-ed away from the screw torque to theterminal block as the likely cause ofthe smoke.

A test facility determined that theterminal block was destroyed inter-nally by heat. The windshield andterminal block were sent to the man-ufacturer for testing to determine theexact cause of the failure. Recentlyreleased findings indicated thatarcing caused the melting of the in-ner glass ply on the terminal block,


but that because of the extensivedamage the origin of the arcing couldnot be isolated. It is suspected thatseverance of copper braid conduc-tors started the arcing.

NTSB RecommendsRequired Inspection of

Beech 1900 Flap-Attachment Bearings

And Aft Roller Bearings

The Beech 1900C twin-turbopropregional commuter aircraft was onfinal approach to Los Angeles Inter-national Airport in visual meteoro-logical conditions (VMC) with acrew of two and 17 passengers. Theaircraft was descending normallywith 20 degrees of flaps selected. At90 meters (300 feet) above groundlevel (AGL), the first officer, whowas the pilot flying, increased theflap setting to 35 degrees. The air-craft suddenly made an uncommand-ed left roll of about 35 degrees. Thepilot was required to apply full rightaileron and strong control-wheelforce to level the wings. The land-ing then continued normally, and noone was injured.

A flight examination showed that,although the inboard flaps and out-board flaps were fully and equallyextended on both sides of the air-plane, the inboard end of the leftoutboard flap had disengaged fromits flap track (Figure 1, page 16).

The inboard aft flap roller-bearingassembly on the left outboard flap,including the bolt and washer (Fig-ure 1, “flap aft roller bearings”), hadpulled through the skin of the flap-track hinge bracket (Figure 1, “flap-attachment brackets”), allowing theinboard end of the flap to disengagefrom the flap track.

A circular wear pattern matching thediameter of the bearing outer-rollerflange was found on the skin of thehinge bracket. As a result, the de-tached inboard trailing edge of theflap was twisted about 7.6 centime-ters (three inches) above its normallyinstalled position in the flap track.The failed flap-track hinge bracketand bearing assembly (Figure 1) arecontained within the interior of theflap structure.

In its investigation, the U.S. Nation-al Transportation Safety Board(NTSB) determined that the flapouter-bearing roller had shifted ax-ially (for reasons unknown), andthat the shift had resulted in erosionand failure of the flap-track hingebracket and bearing assembly. Con-tributing factors to the incident werethe difficulty of inspecting the in-terior of the flap structure withoutdisassembly and the lack of inspec-tion criteria for the flap-track hingebracket and bearing assembly in theRaytheon Aircraft Co. (of whichBeech is a subsidiary) maintenancemanual for the aircraft.


Figure 1

Outboard Flap-attachment MechanismBeech 1900

AftTrack

FlapTrack

BondingCable

FlapForwardRollerBearing

(3) Check for Elongated Holes

(2) Inspect Flap-attachment Brackets for wear

Flap-attachment BracketInspection AreaCheck for Wear That Exceeds 0.03 centimeter(0.01 inch)

(1) Check Flap Aft Roller Bearings

OutboardFlapActuator

Safety SwitchAttachmentBracket

PatchPlates

Patch Plate

Left Outboard(Right Typical)

Outboard FlapActuatorAttachmentBracket

Safety SwitchAttachment Rod

Source: Raytheon Aircraft Co./Rendered by Karen Ehrlich


In April 1996, about a year after theforegoing incident, Raytheon re-vised the Beech Model 1900/1900Cand 1900D maintenance manuals toinclude new criteria for inspectingwing flaps. The wing flaps wereincluded as a new item in the air-plane’s major maintenance sched-ule, shown under “flight controls.”The revised manual required that theflaps be removed every 10,000 (air-craft) cycles or every five years,whichever occurs first, and thatthe flap roller brackets, rollers, bear-ings and attachment hardware bechecked for wear. (An aircraft cyclecomprises engine start-up, increaseto normal flight power, one landinggear retraction and extension, andcomplete shutdown.)

Inspection of these same componentswithout removing the flaps was madea part of the aircraft’s next 200-hourinspection, and Raytheon recom-mended that the components be re-inspected (without removing theflaps) every 1,200 hours thereafter.

A second incident, which occurred inJune 1996, involved a Beech 1900Don a landing approach to Cavern CityAir Terminal, Carlsbad, New Mexi-co, U.S. Extension of the flaps to 35degrees triggered a sharp uncom-manded roll at low altitude. The pi-lot flying righted the airplane, butthere was very little aileron controlduring the remainder of the landingapproach because the control wheel

could be rotated only about 2.5 cen-timeters (one inch) left or right.

An examination of the left wingshowed that the left outboard flap wastilted up on the inboard side and tilt-ed down on the outboard side, andthat the edges of the aileron and flapmetal were ripped.

A third incident involved a Beech1900D approaching Seattle-Tacoma(Washington, U.S.) International Air-port in January 1997 with two crewmembers and five passengers. Whenthe wing flaps were lowered from 17degrees to 35 degrees, the aircraft be-gan an abrupt roll to the right at analtitude of about 150 meters (500feet). The pilot countered the roll withleft control-column input; he saidthat, when he did so, he felt as ifsomething in the controls hadjammed and then had suddenly“popped” free. The airplane landedsafely.

Examination showed that the in-board aft end of the outboard flaphad detached, causing seizure of theinboard flap-track aft roller bearingand tearing of the flap-bracket as-sembly. The seized bearing outerroller had shifted on the roller ele-ment bearing and allowed the outerroller flange to wear against, andeventually pull through, the skin ofthe flap-track hinge bracket. Thethree other flap-track roller bearingswere also examined; they showed


erosion and the presence of dirt anddebris. The outboard edge of theoutboard flap, adjacent to the aile-ron, was gouged.

None of these three Beech 1900airplanes involved in incidents hadhad a detailed inspection of flaphardware as outlined in the April1996 revisions to the Raytheonmaintenance manual.

The roller bearings on the inboardwing flaps are sealed; the roller bear-ings on the outboard wing flaps —the flaps that failed in each of theforegoing incidents — are not sealed.According to the NTSB, sealed bear-ings for installation in the outboardwing flaps will be made available inthe near future.

A review of Raytheon’s databaseshowed 20 reports of worn flap aftroller bearings and damaged flapbrackets in Beech 1900 series aircraft.

On May 19, 1997, Raytheon issuedSafety Communique No. 137 (SC) toalert owners and operators of Beech1900 series aircraft to the flap prob-lem. It said, in part:

“Detachment of the outboard flapfrom [the flap aft roller bearing]could result in a flap asymmetriccondition and the outboard end ofthe flap coming in contact with theaileron and inhibiting the travel ofthe aileron.”

The detachment of this flap aft roll-er bearing from the outboard wingflap resulted from the repositioningof the outer flange element of theroller bearing, which allowed theouter flange element to come intocontact with the attachment andeventually wear through the brack-et. When the bracket failed, the out-board flap detached from the aftroller bearing.

The SC called for expedited inspec-tion of the flaps on all Beech 1900and model C-12J (military version ofthe Beech 1900) airplanes with morethan 2,500 flap cycles (a flap cyclecomprises one downward movementand one upward movement of theflaps), in keeping with the followingschedule:

• Aircraft with more than 10,000flap cycles: inspect within 30days;

• Aircraft with 5,001 flap cycles to10,000 flap cycles: inspect with-in 60 days; and,

• Aircraft with 2,500 flap cycles to5,000 flap cycles: inspect within90 days.

The SC included detailed instruc-tions for the required inspections.They included (1) inspecting the aftroller bearings and their outer-flangeelements for wear and damage,(2) inspecting the surfaces of theflap-attachment brackets that contact


NEW PRODUCTS

Instrument ProvidesClean Air for Pneumatic

Power Tools

The typical compressed air source inan aircraft hangar or shop is subject tocontamination by water, dirt, oil andoil aerosols. The Eliminizer® byReading Technologies Inc., a new airdryer/coalescer, removes contami-nants from compressed air prior to use.

The Eliminizer employs four modesof filtration in one assembly. In thefirst two modes, spinning air drivescontaminants to a collection point.The third mode uses filters: oneof stainless steel mesh, another of

cotton, polyester and stainless steelthat trap contaminants down to onemicron (one millionth of an inch)in size. Finally, the air enters thecoalescer, which removes oil aerosolsdown to 0.01 micron with an efficien-cy near 100 percent.

According to the manufacturer, cleancompressed air extends the life ofequipment using compressed air, re-duces work interruptions caused by aircontaminants and prevents possiblecontamination of paint or other prod-ucts being manufactured or repaired.

The Eliminizer does not use electric-ity, refrigerants, motors, fans, timers

the aft roller bearing for indicationsof wear from the aft roller-bearingouter-flange element and (3) inspect-ing the aft roller-bearing attachmentholes in the flap-attachment brack-ets for elongation (see lower half ofFigure 1, page 16).

The SC said that revisions to mainte-nance manuals were being issued tochange flap-inspection intervals. Therevisions required the removal andinspection of all flap-attachment roll-er brackets, roller bearings and at-taching hardware every 2,500 flapcycles or five years, whichever occursfirst.

In a letter including a recommenda-tion (A-97-37) to the U.S. FederalAviation Administration (FAA), theNTSB said that, to prevent any fur-ther flap malfunction and possiblein-flight loss of control, compliancewith the SC should be mandatory.

The NTSB therefore recommendedthat the FAA issue an airworthinessdirective (AD) requiring an expedit-ed initial inspection of the outboardflap-attachment brackets and aft roll-er bearings as outlined in the SC; andfurther inspection thereafter every2,500 flap cycles or five years, which-ever occurs first.♦


or switches, making it reliable andrelatively inexpensive to acquire andmaintain. It is available in port sizesfrom 0.6 centimeter to five centime-ters (0.25 inch to two inches).

Based on inorganic chemistry, it issaid by the manufacturer to be mild-ly alkaline, nonhazardous, nontoxicand nonflammable, with no volatileorganic compounds or ozone-depleting chemicals.

AquaWorks is product of Church &Dwight Co. Inc., best known for itsArm & Hammer® Baking Soda, andSafety-Kleen Corp. For more infor-mation, contact: Church & DwightCo. Inc., 469 North Harrison Street,Princeton, NJ 08543-5297. Tele-phone: (609) 683-5900.

Hot KnifeCuts and Seals

Fabrics that unravel or fray ifcut by scissors or a razor blade can becut cleanly and sealed with thenew WB-1 Hot Knife from Hot Tools.The tool also reduces exposure torepetitive-motion injury associatedwith use of scissors.

According to the manufacturer, thereplaceable blade reaches 455 degrees

For more information, contact Read-ing Technologies Inc., Airport Indus-tries Building 2, RR9, Box 9391,Reading, PA 19605-9650 U.S.Telephone: (800) 521-9200 (UnitedStates and Canada); (610) 372-9200;Fax: (610) 372-1984.

Cleaning Solution IsWater Based

AquaWorks™ is a new water-basedcleaning solution for industrial use. WB-1 Hot Knife from Hot Tools

The Eliminizer® byReading Technologies


C (850 degrees F) in less thanone minute; as it cuts, it meltswoven expandable plastic sleeving,synthetic ropes and related products,creating a beaded edge that will notunravel.

The knife is 17 centimeters (6.75inches) long and weighs less than28 grams (one ounce). It can be usedhand-held or mounted. For moreinformation, contact: Hot Tools,a division of M.M. Newman Corp.,24 Tioga Way, P. O. Box 615,Marblehead, MA 01945 U.S.Telephone: (617) 639-1000; Fax:(617) 631-8887.

Multichannel UltrasonicInspection Instrument

Uses Standard SoftwareAnd Hardware

The new USPC 2100 from Kraut-kramer Branson is a multichannel,computer-based ultrasonic instru-ment for in-line flaw detection andthickness measurement. Typical ap-plications include the in-line evalu-ation of plate, bar and tubingcomponents.

The manufacturer says that the USPC2100 uses plug-and-play peripheralcomponent interconnect (PCI)boards, a simple Windows 95™ graph-ical interface and easy menu config-urations to set up and run theinspection.

The new instrument has eight chan-nels of parallel firing, cross-channelfiring, a 16-cycle sequencer, real-time gating, user-configurable appli-cation screens and comprehensiveoutputs. It supports all generationsof recorders, alarms and programma-ble logic controllers, and is compat-ible with off-the-shelf hardware andsoftware such as special keyboards,remote monitors and word process-ing software.

USPC 2100 fromKrautkramer Branson

The USPC 2100’s individual chan-nels can be configured for either flawdetection or thickness measurement.It is said to allow for fast replacementinto existing lines, integration intonew systems and expansion as test-ing requirements change.


For more information, contact:Krautkramer Branson, 50 IndustrialPark Road, Lewistown, PA 17044U.S. Telephone: (717) 242-0327;Fax: (717) 242-2606.

Hand ProtectionSprays On, Protects

Against Irritants

Aircraft technicians are exposed tomany skin-irritating or -damaging sol-vents and chemicals in the normalcourse of their work. Wearing protec-tive gloves is necessary in the case ofexposure to harsh or toxic chemicals,but a new product that resembles“spray-on gloves” can reduce minorirritation and skin-drying effects ofexposure to petroleum products, paintsolvents, glues, grease, dirt, coolants,chlorine, and detergents.

According to the manufacturer, theliquid in Gloves in a Bottle penetrates

the outer skin layer, and one applica-tion lasts four hours or more. Glovesin a Bottle is said to protect againststains and odors, to protect hands thatare often immersed in water and toprevent moisture loss. When usedwith gloves, the product is said toprotect against skin reaction to latexand latex powder irritants in neopreneand other repeat-use gloves.

The product is described as safe,nontoxic, nonallergenic and fra-grance-free, leaving no sticky orgreasy feeling. A 227-gram (eight-ounce) bottle delivers about 150applications.

For more information, contact: Glovesin a Bottle, P.O. Box 1430, Glendale,CA 91209 U.S. Telephone: (800) 600-1881 (United States and Canada);(818) 247-2170; Fax: (818) 247-2253.

“MiniButton” Can BeUsed as Electronic

Logbook

The MiniButton™ by MacSema Inc.serves as a small stand-alone data-base, offering access to many pagesof information that can be reviewedand updated.

When associated with a particularpiece of equipment, the MiniButtonbecomes an electronic logbook thatcan be used to record the equipment’shistory, maintenance performance,Gloves in a Bottle


Bend, OR 97701-4346 U.S. Tele-phone: (541) 389-1122; Fax: 541-389-1888.

Wireless ComputerTerminal Goes Where

Technician Goes

A new hand-held, portable computerterminal brings the power of a net-worked personal computer (PC) tolocally mobile aircraft workers, al-lowing them access to computing ca-pabilities without being restricted toa fixed location.

According to the manufacturer,Motorola Inc., the SitePadTM runsstandard Windows® applications,including Microsoft Word® andExcel®, on a Windows NT server.

The SitePad can be operated byscreen touch or mouse. Its perfor-mance, except for motion video, issaid to be equivalent to most desktopPCs. Only screen updates (no files)are transmitted wirelessly, ensuringinformation security. Security canbe further enhanced by the use ofpasswords.

The manufacturer says that no newsoftware is needed to use the SitePad,and that its low-power, spread-spectrum radio technology does notrequire U.S. Federal Communica-tions Commission (FCC) licensing.

The MiniButton™ by MacSema Inc.

parts lists, changes in configurationor calibration, time-limited compo-nents, or any other information thatcan be entered into the nonvolatilememory.

Electronic data are added, deletedor read with a hand-held, portableterminal, and each transaction is dateand time stamped. Data can be lockedagainst changing or removal. A vari-ation using permanent data storage issaid to be useful in helping to guardagainst counterfeit parts.

The MiniButton uses electricallyerasable, programmable, read-onlymemory technology and does not re-quire batteries. It is 10.7 millimeters(0.4 inch) diameter and three milli-meters (0.1 inch) high, weighs 0.8gram (0.027 ounce) and is availablein two sizes with read/write contactmemory up to 8K bytes. The manu-facturer says that a 32K version willbe available in 1998.

For further information, contact Mac-Sema, 358 NE Marshall Avenue,


For more information, contact Motor-ola Worldwide Data Solutions Divi-sion, 1301 E. Algonquin Street,Schaumburg, IL 60196 U.S. Tele-phone: (800) 247-2346 (United Statesand Canada); (847) 576-6931.

Tamper-evident LabelsLeave an Impression

Supermark Labels from Seton Iden-tification Products are backed with anetching compound that leaves a sten-cil behind if they are tampered with,so the owner of the asset is still iden-tified. Supermark Labels can be cus-tom printed in four colors, areavailable with bar coding and sequen-tial numbering and can accommodateup to two lines of stenciling.

According to the manufacturer, themarking compounds will work onglass, aluminum or plastic, leaving afrosty mark on glass and a shiny markon aluminum.

For more information, contact: Set-on Identification Products, Dept.ZSR, P.O. Box 819, Branford, CT06405-0819 U.S. Telephone: (800)243-6624 (United States and Cana-da); Fax: (800) 345-7819.

Cabinet OffersProtection for On-site

Computers

A specially designed new nonmetalcabinet from Stanley Storage Systemsprotects computers that reside in workareas, including hangar floors.

The computer screen can be viewedthrough a window at the top of thecabinet. The central processing unit(CPU) is kept in a hideaway stowagecompartment, below which are a fold-away keyboard drawer, an optionalmousepad work-surface extension anda rollout printer shelf. A ventilating fanbrings filtered air into the housing.

The cabinet is 76 centimeters (30inches) wide, 71 centimeters (28inches) deep, and 165 centimeters (65inches) high and has six wheels formobility. It is designed, its manufac-turer says, to provide an effective safehaven for computers in the harsh fac-tory environment.

For more information, contact Stan-ley Storage Systems, 11 GrammesRoad, Allentown, PA 18105 U.S.Telephone: (610) 797-6600; Fax:(610) 776-3895.♦


BLANKINSIDEBACK

COVER

A Joint Meeting of

Visit our World Wide Web site at http://www.flightsafety.org

Flight Safety FoundationInternational Federation

of Airworthiness27th International Conference

International Air Transport Association

iass50th annual

International Air Safety Seminar

W A S H I N G T O N , D . C .N o v e m b e r 3 – 6 , 1 9 9 7

For information contact: Steve Jones, director of membership, Flight Safety Foundation601 Madison Street, Suite 300, Alexandria, VA 22314 • Telephone: (703) 739-6700 Fax: (703) 739-6708

AVIATIONSAFETY:

CONFRONTINGTHE FUTURE

Documents

Aviation Mechanics Bulletin July-August 1997 · Aviation Mechanics Bulletin Knowledge of Hazardous Chemicals in the Aviation Workplace Can Help Prevent Work-related Illness and Injury