AFOSHSTD91-100.pdf

BY ORDER OF THE

SECRETARY OF THE AIR FORCE

AIR FORCE OCCUPATIONAL SAFETY

AND HEALTH STANDARD 91-100

1 MAY 1998

Safety

AIRCRAFT FLIGHT LINE - GROUND

OPERATIONS AND ACTIVITIES

ACCESSIBILITY: Publications and forms are available on the e-Publishing website at www.e-publishing.af.mil for downloading or ordering.

RELEASABILITY: There are no releasability restrictions on this publication.

OPR: HQ AFSC/SEGS Certified by: HQ AFSC/SEG (Colonel Robert W. Scott)

Supersedes AFOSH Standard 127-100, 30 November 1992

Pages: 83

The criteria in this standard are the Air Force’s minimum safety, fire prevention, and occupational health requirements. Major commands (MAJCOM), direct reporting units (DRU), and field operating agencies (FOA) supplement this standard when additional or more stringent safety, fire prevention, and health cri-teria are required. Refer to Air Force Instruction (AFI) 91-301, Air Force Occupational and Environmen-tal Safety, Fire Protection, and Health (AFOSH) Program, for instructions on processing supplements or variances. Report conflicts in guidance between this standard, federal standards, or other Air Force direc-tives through MAJCOM, DRU, or FOA ground safety offices to Headquarters Air Force Safety Center, Ground Safety Division, Safety Engineering and Standards Branch (HQ AFSC/SEGS), 9700 Avenue G, SE, Suite 222, Kirtland AFB NM 87117-5670.

This standard applies to all US Air Force organizations, including all US Air Force Reserve personnel and when Air National Guard personnel are on federal service. It includes general safety information applica-ble to aircraft ground handling, servicing, and inspections. The standard addresses safety, fire prevention, and health protection requirements associated with ground handling, servicing, inspection, and mainte-nance of aircraft, engine runup, and vehicle and support equipment (SE) operations on the flight line.

Sources of additional or more specific guidance are shown in parenthesis throughout the standard. It does not apply to combat quick turns. Technical Order (TO) l-1-3, Inspection and Repair of Aircraft Integral Tanks and Fuel Cells, will be used for aircraft fuel cell tank repair system to include related areas and facilities. Not included are safety, fire prevention, and health requirements addressed in specific equip-ment TOs. This standard implements regulatory provisions of several Occupational Safety and Health Administration (OSHA) Standards and also Air Force criteria not addressed in the OSHA standards.

SUMMARY OF CHANGES

This document is substantially revised and must be completely reviewed.

Administrative changes have been made to update this standard to electronic format. References have been updated as required. Spark arrester (paragraph 1.2.3.1.) and cardiopulmonary resuscitation require-http://www.e-publishing.af.mil

2 AFOSHSTD91-100 1 MAY 1998

ments (paragraphs 1.2.5.1.and 1.2.5.5.) are updated. Reference to job safety analysis (JSA) as a manage-ment tool and a suggestion to secure metal-framed eyeglasses are added (paragraphs 1.2.7.2., 1.2.7.1.2., 8.2.9., and 8.3.2.11.). Aircraft grounding requirements are modified to bring them into line with TO requirements (paragraph 4.2.1.). Adverse weather condition requirements are added (paragraph 1.2.15.).

Towing supervisor may allow tow vehicle operators to look over their shoulder when towing a vehicle (paragraph 2.2.3.2.). Tail walker proficiency testing and qualification requirements are waived if towing procedures are their only task (paragraph 2.2.3.5.). Criteria for taxiing operations (paragraph2.3.), passen-gers in vehicles (paragraph 6.4.6.), means of egress from hangars, and clear space requirements around hangars (paragraph 7.2.4.) are changed. Fall protection requirements are updated to incorporate AF-wide variances previously in effect (paragraph 8.2.5.). AGE towing requirements are better defined (paragraph 8.3.4.2.). Restrictions on the use of cordless screwdrivers and drills are added (paragraph 8.3.9.). Para-chute Shops are added (paragraph8.4.). A glossary of references, abbreviations, acronyms, and terms is included at Attachment 1 and checklists at Attachment 2 through Attachment 13are updated. Changes are annotated by a bar (|). NOTE: AFOSH 127-series standards are being converted to 91-series standards and the 161-series to 48-series standards. However, not all standards have been converted as of the effec-tive date of this standard. To help you locate these documents, references to AFOSH standards are stated in the updated series and standard number, with the outgoing series and standard number stated as “for-merly designated as” in the references section of Attachment 1.

Chapter 1— INTRODUCTION 5

1.1. Hazards and Human Factors:

1.2. General Requirements:

Chapter 2— TOWING AND TAXIING AIRCRAFT 22

2.1. Hazards and Human Factors

2.2. Towing Operations

2.3. Taxiing Operations

Chapter 3— AIRCRAFT JACKING OPERATIONS 28

3.1. Hazards and Human Factors

3.2. General Requirements:

3.3. Specific Requirements:

Chapter 4— AIRCRAFT CLEANING AND DECONTAMINATION 30

4.1. Hazards and Human Factors

4.2. General Requirements

4.3. Aircraft Cleaning Operations:

4.4. Fire Control:

4.5. Decontamination of Aircraft Contaminated With Radioactive and Toxic Materials: 31

AFOSHSTD91-100 1 MAY 1998 3

Chapter 5— AIRCRAFT TIRE MOUNTING AND SERVICING OPERATIONS 33

5.1. Hazards and Human Factors

5.2. Aircraft Tire Mounting

5.3. Aircraft Wheel Removal

5.4. Employee Training

5.5. Tire Servicing Equipment

Chapter 6— FLIGHT LINE VEHICLE OPERATIONS 36

6.1. Hazards and Human Factors

6.2. General Requirements

6.3. Responsibilities

6.4. Operating Standards

Chapter 7— AIRCRAFT HANGAR OPERATIONS 44

7.1. Hazards and Human Factors

7.2. Requirements:

Chapter 8— AIRCRAFT SHOP AND FLIGHT LINE MAINTENANCE OPERATIONS 47

8.1. Hazards and Human Factors

8.2. General Requirements:

8.3. Specific Requirements:

8.4. Parachute Shops

Attachment 1— GLOSSARY OF REFERENCES AND SUPPORTING INFORMATION 59

Attachment 2— FORKLIFT OPERATIONS CHECKLIST 68

Attachment 3— HI-LIFT TRUCK CHECKLIST 70

Attachment 4— ROLLER PRY BAR CHECKLIST 71

Attachment 5— K-LOADER CHECKLIST 72

Attachment 6— CHECKLIST FOR CHAPTER 1--INTRODUCTION 73

Attachment 7— CHECKLIST FOR CHAPTER 2--TOWING AND TAXIING

AIRCRAFT 75

Attachment 8— CHECKLIST FOR CHAPTER 3--AIRCRAFT JACKING

OPERATIONS 76

4 AFOSHSTD91-100 1 MAY 1998

Attachment 9— CHECKLIST FOR CHAPTER 4--AIRCRAFT CLEANING

AND DECONTAMINATION 77

Attachment 10— CHECKLIST FOR CHAPTER 5--AIRCRAFT TIRE MOUNTING

AND SERVICING OPERATIONS 78

Attachment 11— CHECKLIST FOR CHAPTER 6--FLIGHT LINE VEHICLE

OPERATIONS 79

Attachment 12— CHECKLIST FOR CHAPTER 7--AIRCRAFT HANGAR

OPERATIONS 81

Attachment 13— CHECKLIST FOR CHAPTER 8--AIRCRAFT SHOP

AND FLIGHT LINE MAINTENANCE OPERATIONS 82

AFOSHSTD91-100 1 MAY 1998 5

Chapter 1

INTRODUCTION

1.1. Hazards and Human Factors:

1.1.1. Hazards. During ground operations, various hazards are encountered due to the nature of the work and the equipment and tools involved. Other factors involve the variety of weather conditions, the different conditions during day and night operations, mission priorities, and the various aircraft systems. Before examining safety precautions, it is appropriate to outline the major sources of mainte-nance hazards. Aircraft and flight line areas present potential fire and explosion hazards. Gasoline, explosives, jet fuel, cleaning solvents, oxygen, ejection seats, and powered support equipment are typ-ical of these hazards. Falls present another source of injury to personnel. The potential for falls increases while performing maintenance at elevated levels and during winter or high winds (AFOSH Standard 91-22, Walking Surfaces, Guarding Floor and Wall Openings and Holes, Fixed Industrial Stairs and Portable and Fixed Ladders). Engine operation may expose personnel to dangers such as burns, high noise levels, jet blast from the exhaust, and suction from intakes. Electrical shock ranging from the minor shock of static electricity to electrocution from ground power units is another potential hazard. Fuels, cleaning compounds, and fire extinguishing agents can be toxic and harmful when inhaled or contact is made with the skin. Improper lifting procedures while handling tires, brakes, and other aircraft parts can cause back and muscle strains. Handtools and power tools are potential sources of injury if used improperly. Air compressors are potentially hazardous if operated without regard for established safety standards.

1.1.1.1. Personnel who work around aircraft must be alert for hazards from protruding controls, surfaces, antennas, static wicks, pitot tubes, open access hatches, and other projections.

Fixed-bayonet static discharges on jets and turboprop aircraft are examples of sharp appendages that can cause injury if contacted.

1.1.1.2. Bumping hazards are created by dropped leading and trailing edges, speed brakes, pylons, pods, and other devices that extend below the main wing surface and fuselage.

1.1.1.3. Many tripping hazards are present around the aircraft and on the ramp. Examples are aux-iliary power cables, grounding cables, tie-down ropes or chains, fuel hoses, ladders, and air condi-tioning ducts.

1.1.1.4. The cause of many falls can be attributed to slipping hazards from oil, deicing fluid, hydraulic fluid, grease spills, and weather conditions. Fuel spills can cause, not only a very slip-pery surface on the ramp, but also a fire hazard.

1.1.1.5. The potential for serious burns exists while working around aircraft. Areas to be alert for are exhaust areas, pitot tubes, hot brakes, and lights. Also, the exhaust from Aerospace Ground Equipment (AGE), such as auxiliary power and air conditioning units, can burn. Immediately after engine shutdown, the exhaust nozzles and reactor areas are extremely hot and personnel can receive moderate to severe burns. Other sources of burns from aircraft are from support electrical equipment.

6 AFOSHSTD91-100 1 MAY 1998

1.1.1.6. Jet engine electrical systems can give a severe electric shock. Aircraft electrical systems can be a potential ignition source, which could result in a serious fire if an arc occurs when flam-mable fuel vapors are present.

1.1.1.7. A potential for serious injuries and fatalities exists during tire inflation and wheel chang-ing on aircraft.

1.1.1.8. Personnel working on or near operating jet aircraft are potentially exposed to the most intense and sustained noise exposures experienced in the Air Force. Possible adverse effects of noise exposure include hearing loss, interference with speech communications, and disruption of job performance. In addition to hearing loss, there are suggestions that noise can cause other phys-ical and psychological disturbances. However, noise exposure limits designed to protect against noise-induced hearing loss should also control these other potential adverse health effects. The most serious aspect of noise exposure is that it can produce permanent hearing loss without recog-nizable symptoms of ill health or pain. The Air Force hearing conservation program prescribed by AFOSH Standard 48-20, Hearing Conservation Program, and OSHA 29 Code of Federal Regula-tions (CFR) 1910.95, Occupational Noise Exposure, establishes procedures for monitoring per-sonnel who are potentially exposed to hazardous noise, in order to detect early signs of hearing loss.

1.1.1.9. Personnel are subject to potential injury from environmental temperature extremes. Inju-ries resulting from cold weather exposures in northern climates can be serious. Heat exhaustion, sunburns, and strokes are potential concerns in hot and humid climates, especially when combined with physical activities. Fatigue, disorientation, and other physical and mental effects may con-tribute to mishaps if proper personal protective equipment (PPE), adequate rest periods, and other considerations are not addressed in locally developed guidelines for operational and maintenance tasks.

1.1.2. Human Factors. Human factors may also affect work. Human factors fall into two major cate-gories: mental, such as attitude, emotion, job or domestic pressure, distractions, job knowledge, or hurrying; or physical, such as fatigue, physical strength, and reactions to prescription medications or drugs. These factors can affect workers who, by their commission (what they do) or by their omission (what they fail to do), can contribute to or cause a mishap. Some examples are:

1.1.2.1. Ignoring directions from supervisors.

1.1.2.2. Improper operation of equipment while angry or distracted.

1.1.2.3. Distractions from job while thinking of personal problems.

1.1.2.4. Not following proper procedures or taking shortcuts because of a feeling of being hurried.

1.1.2.5. Drowsiness or hyperactivity on the job caused by prescription medications, alcohol, or illegal drugs.

1.1.2.6. Use of equipment although not qualified.

1.2. General Requirements:

1.2.1. Guidance:

1.2.1.1. Most hazardous situations can be avoided by simply following procedures, asking for help when needed, and using PPE. Potential safety, fire, and health hazards can be effectively con-

AFOSHSTD91-100 1 MAY 1998 7

trolled by proper training before job accomplishment, appropriate work procedures, and supervi-sory controls.

1.2.1.2. Guidance contained in AFI 91-202, The US Air Force Mishap Prevention Program, and AFI 91-301 can be used by supervisors and managers in identifying, assessing, and abating haz-ards within their areas of responsibility. A working knowledge of these two instructions, TOs, and other AFOSH standards applicable to aircraft maintenance activities are expected to make super-visors and managers aware of the hazards associated with their areas of responsibility.

1.2.2. Fire Prevention. Fire and explosion are potential hazards associated with aircraft maintenance and servicing operations. Servicing and maintenance operations will be performed in facilities con-forming to the requirements of Air Force design criteria or equivalent Air Force-approved engineering guidance. Contractor aircraft maintenance facilities will conform to the requirements of this standard and the National Fire Codes. Also see paragraph 1.2.18. for additional guidance on contractor opera-tions.

1.2.3. Flight Line Potentially Hazardous Areas and Operations:

1.2.3.1. Flammable Fuel Vapor Areas. The supervisor will ensure all personnel are aware of potentially flammable fuel vapor areas and the restriction against bringing sources of ignition into these areas. Fuel vapors are heavier than air and will settle to ground level and enter below-ground areas. Some examples of hazardous fuel vapor areas are fuel pits below ground level, and areas within 10 feet of aircraft fuel vent systems and fuel spills. Spark arresters are no longer required on general or special purpose vehicles that operate on the flight line and in and around aircraft.

However, these Air Force vehicles are not designed, certified, or authorized to operate in flamma-ble fuel vapor areas. Personnel whose duties include requirements to work in flammable fuel vapor areas will receive specialized training with emphasis on the hazards associated with these operations. See Air Force Manual (AFMAN) 91-201, Explosive Safety Standards, paragraph

2.71.6. for requirements of spark arresters on general or special purpose vehicles within the vicin-ity of structures containing exposed explosives.

1.2.3.2. Electrical Receptacles. Electrical receptacles, located on the flight line, are only required to be protected from environmental weather conditions. Aircraft fueling and defueling operations should not be conducted in areas where outside electrical receptacles are installed. If because of space constraints this separation is not possible, the receptacles in the immediate area of the fuel-ing or defueling operations will be deactivated, using lockout and tagout procedures according to AFOSH Standard 91-45, Hazardous Energy Control and Mishap Prevention Signs and Tags.

1.2.3.3. Aircraft Maintenance Operations. Aircraft maintenance operations conducted within han-gars, aircraft shelters, or docks (closed or semi-enclosed), on the flight line or outside maintenance areas such as wash racks will be accomplished according to Air Force guidance or other Air Force-recognized national consensus standards. MAJCOMs, operating in overseas or remote areas, may supplement this standard to provide additional guidance to meet international or host country safety requirements or unique environmental working conditions.

1.2.3.3.1. Electrical Devices and Power Equipment. All fixed and installed electrical devices and fixed power equipment in hangars, shelters, or docks will comply with the Air Force design criteria or equivalent Air Force-approved engineering guidance. Portable electrical equipment, used in Class I, Division 1 and Class I, Division 2 locations, will be explo-sion-proof or intrinsically safe. Any equipment not meeting this requirement may be tempo-

8 AFOSHSTD91-100 1 MAY 1998

rarily approved by the installation fire chief. This approval will be provided prior to the use of the equipment and documented in writing which will state the area, nature, duration, and the reason for the exception. If the working environment has been tested and determined to con-tain flammable fuel vapors, all maintenance activities will be discontinued until the hazardous condition has been eliminated and a safe working environment restored. Equipment, that is located in an area which has a high potential for flammable fuel vapor release and that may become energized automatically when unattended, will be considered for explosion-proof or intrinsically-safe design.

1.2.3.3.2. Smoking. Smoking is prohibited in aircraft maintenance facilities, the flight line areas, and weapons storage and maintenance areas except where designated by the installation fire chief in coordination with the functional manager and (or) supervisor.

1.2.3.3.3. Aircraft Fuels Management and Servicing. Maintenance of fuel systems and fuel servicing operations will be done according to TO 00-25-172, Ground Servicing of Aircraft and Static Grounding/Bonding, AFOSH Standard 91-38, Hydrocarbon Fuels General, and other applicable TOs. Aircraft fuel cell and integral tank inspections and repairs will be accomplished according to TO 1-1-3.

1.2.3.3.4. Cleaning Parts. At no time will maintenance personnel clean aircraft parts, hangar floors, equipment, or clothing with gasoline or unauthorized solvents. Cleaning will be done with approved high flashpoint or nonflammable solvents or cleaning compounds whenever possible. If an operation requires the use of low flashpoint solvents, the operation will be con-sidered as potentially hazardous and will be done in a facility or area compatible with the char-acteristics of the substances. Flammable liquids, when stored in buildings, will be in approved containers (marked to identify contents) and stored in areas specifically approved by the fire chief (AFOSH Standard 91-43, Flammable and Combustible Liquids). Wiping cloths, oily waste, and other combustible materials will be placed in suitable, self-closing metal containers which will be available in the immediate work area. These containers will be emptied and con-tents disposed of according to established local procedures. Proper ventilation will be main-tained and proper protective clothing will be used when working with solvents. See AFOSH Standard 48-21, Hazard Communication, for program requirements for handling and using hazardous materials.

1.2.3.3.5. Welding on Aircraft. Welding on aircraft should be done outside of hangars if pos-sible. An AF Form 592, USAF Welding, Cutting, and Brazing Permit, shall be issued prior to all aircraft welding operations. Welding will only be done on aircraft system components specified in the technical data applicable to each aircraft (AFOSH Standard 91-5, Welding, Cutting, and Brazing). Welding operations in hangars will meet the requirements of National Fire Protection Association (NFPA) 410, Aircraft Maintenance, chapter 6. Information on the qualifications of aircraft welders is contained in AFI 21-105, Aerospace Equipment Structural Maintenance. The requirement for industrial ventilation during welding on aircraft will be according to AFOSH Standard 161-2, Industrial Ventilation.

1.2.3.3.6. Fire Extinguishers. A suitable fire extinguisher will be placed within easy reach of the operator and close to ground power equipment. For additional information on fire extin-guishers, refer to AFOSH Standard 91-56, Fire Protection and Prevention.

AFOSHSTD91-100 1 MAY 1998 9

1.2.3.3.7. Nondestructive Inspection (NDI). NDI operations involving ionizing radiation (nor-mally X-ray operations) will be conducted as specified in TO 33B-1-1, Nondestructive Inspec-tion Methods, and AFOSH Standard 91-110, Nondestructive Inspection and Oil Analysis Program. Normally, flight line X-ray procedures and locations must be approved by the bioen-vironmental engineer (BEE), in coordination with fire protection and ground safety officials.

1.2.4. Confined Spaces. Supervisors will ensure the requirements established in AFOSH Standard 91-25, Confined Spaces, are complied with when entering confined spaces. The definition of a con-fined space is in the reference section of Attachment 1.

1.2.5. Cardiopulmonary Resuscitation (CPR):

1.2.5.1. CPR is required training for all personnel (assigned to aircraft maintenance areas) who install, maintain, relocate, inspect or repair electrical systems and (or) equipment, or perform duties as safety observers. This training will include bleeding control (bloodborne pathogens train-ing and disposal instructions), shock management, and emergency care of persons having open wounds and burns.

1.2.5.2. CPR training is required by TOs (e.g., TO 1-1-3) for certain maintenance processes.

1.2.5.3. Local authorities may identify other job tasks that may require CPR training due to poten-tial hazards associated with the job.

1.2.5.4. Unit CPR instructors are usually trained by host installation medical personnel. If the host installation cannot provide the support, unit personnel may be certified through the American Red Cross or the American Heart Association.

1.2.5.5. All personnel requiring CPR training, as identified in the paragraphs above, will receive refresher training at least every 2 years.

1.2.6. Wearing Apparel. Hats or caps will not be worn in an engine intake danger zone, as defined by the specific aircraft TO, while engines are operating. When working around hot exhaust or tail pipes, maintenance personnel should wear heat-resistant gloves and long-sleeve shirts to prevent burns.

Bump caps may be worn when working in and around aircraft, for protection from minor bumps and lacerations. Bump caps will not be worn during engine starts and runups unless the engine inlet ducts are equipped with inlet duct runup screens. Hair fasteners (constructed of metal, plastic, or leather materials) and wigs will not be worn by on-duty personnel engaged in aircraft maintenance. A rubber band or hair net that holds the hair wrapped in a bun at the back of the head may be worn, providing the hair net has no metal parts. Metallic shoe cleats and taps pose spark generation and foreign object damage (FOD) hazards and will not be worn on the flight line. Except when assisting passengers on arriving or departing aircraft during inclement weather, umbrellas will not be permitted on the opera-tional flight line. When aircraft or equipment TOs do not provide specific guidance for PPE, criteria established in AFOSH Standard 91-31, Personal Protective Equipment, will be used. When in doubt, installation ground safety and bioenvironmental engineering (BE) personnel will be consulted.

NOTE: Helmets for the protection of workers from impact and flying objects must meet American National Standards Institute (ANSI) Standard Z89.1-1986, Standard for Personnel Protection - Pro-tective Headwear for Industrial Workers - Requirements. (Refer to AFOSH Standard 91-31 and 29 CFR 1910.135, Head Protection.)

1.2.7. Finger Rings and Other Jewelry:

1.2.7.1. Finger Rings:

10 AFOSHSTD91-100 1 MAY 1998

1.2.7.1.1. Finger Rings will not be worn by personnel engaged in the following activities or operations:

1.2.7.1.1.1. Climbing, ascending, or descending where the individual might fall with their ring catching on an object, resulting in an injury. Some examples include personnel work-ing on elevated surfaces (ladders, scaffolds, platforms, roofs, high reach vehicles, etc.) or personnel ascending or descending from large vehicles (petroleum, oil, and lubricants [POL] trucks, wreckers, sweepers, dump trucks, stake bed trucks, etc.).

1.2.7.1.1.2. Performing maintenance on aircraft or ground support equipment, including civil engineering-type maintenance.

1.2.7.1.1.3. Certain materials handling operations. Examples include supply workers, parts handlers, equipment operators, personnel attaching and detaching equipment to tow vehicles, etc.

1.2.7.1.1.4. Any type of work where individuals are exposed to moving machinery, rotat-ing or revolving parts, or activities that could result in their hands being caught by a mov-ing part causing any injury (for example, machine or equipment operators or inspectors).

1.2.7.1.1.5. Any type of work or inspection where an individual is exposed to an energized electrical circuit.

1.2.7.1.2. Individual supervisors will identify those tasks where wearing a ring is prohibited.

In some instances the supervisor may elect to determine that individuals will not wear rings while engaged in work activities in general, instead of identifying individual tasks, or conduct a job safety analysis (JSA) according to AFI 91-301, Attachment 2.

1.2.7.1.3. Supervisors will include this information as part of their employee briefing required by AFI 91-301.

1.2.7.1.4. Supervisors will ensure prohibitions on the wearing of rings are enforced. (This pro-hibition applies only to personnel actually performing the work and is not intended for administrative and support personnel assigned to or visiting these areas.) WARNING: The practice of placing tape over rings is insufficient protection and does not satisfy the require-ment for removing the ring.

1.2.7.2. Other Jewelry. The potential for catching, snagging, pulling, and tearing exists in and around most industrial operations. Because of this, controls should be exercised over the wearing of watches, bracelets, necklaces, or other items of jewelry. Metal-framed eyeglasses should be secured by a band or cord to prevent them from falling into energized electrical circuits. The supervisor should evaluate all jewelry before an individual begins work in an industrial area.

1.2.8. Reflective Materials. Light-reflective and luminescent materials are particularly effective for reducing mishaps caused by poor visibility or darkness. Reflective coatings are available in the pri-mary safety code colors so standard signs and markings can be made with these materials. Material will reflect light when wet.

1.2.8.1. Wearing by Personnel. Personnel exposed to vehicle or aircraft traffic on the flight line during hours of darkness or periods of reduced visibility will be provided reflective accessories or will use organizational clothing with sewn-on reflective tape (red or orange reflective colors pro-vide better contrast in a snow or white environment). Security police flight line operations are

AFOSHSTD91-100 1 MAY 1998 11

exempt from this requirement at the option of the local security police commanders in coordina-tion with the installation ground safety manager. Reflective tape will not be sewn on the subdued fatigue uniform (AFOSH Standard 91-31 and AFIs 91-207, The US Air Force Traffic Safety Pro-gram, and 36-2903, Dress and Personal Appearance of Air Force Personnel).

1.2.8.2. Vehicle and Equipment Marking. Reflective materials for marking vehicles and ground servicing and ground powered equipment will be used to the maximum extent authorized by appropriate TOs such as 36-1-3, Painting, Marking, and Lighting Requirements for USAF Vehi-cles, and 35-1-3, Corrosion Prevention, Painting, and Marking USAF Equipment. Additionally, hazardous obstacles existing on or adjacent to the flight line will be marked with reflective mate-rial.

1.2.8.3. Bicycles. All bicycles (Air Force and privately owned), when authorized to operate on the flight line during the hours of darkness, will be equipped with a suitable headlight (turned on) and reflective markings front and rear. Also see paragraph 6.4.3.3.

1.2.9. Flight Line Maintenance Stands. See paragraph 8.3.4.10.

1.2.10. Lifting Devices. Improper handling and lifting of heavy parts presents a potential for injury and extensive damage to aircraft components. Engines and other heavy parts will be handled with the assistance of hoists, approved hoisting slings, and other similar equipment. Maintenance personnel will be familiar with the directives and the general safety standards established for the equipment being used. Safe loading capacities will be stenciled on all hoists and will be strictly observed by oper-ating personnel. At no time will personnel work under loads suspended by hoists. Inspections of hoist-ing equipment will be done according to AFOSH Standard 91-46, Materials Handling and Storage Equipment, TOs, ANSI standards, and (or) the manufacturer’s manual. The hoist will be locked and

(or) tagged out of service if found to be defective. The hoist will remain out of service until repairs are completed (AFOSH Standard 91-66, General Industrial Operations). Weight testing of all lifting devices will be according to AFOSH Standard 91-46 and (or) applicable TOs.

1.2.11. Compressed Air. Compressed air is used in many flight line operations. When handled with care and according to accepted safety standards, compressed air can be used safely.

1.2.11.1. Eye protection will be used at all times when cleaning with compressed air. A diffuser nozzle shall be provided and pressure will not exceed 30 pounds per square inch, (psi) for clean-ing. Compressed air will not be used to clean clothing on the body.

1.2.11.2. Only qualified and authorized personnel will be allowed to operate air compressors and

(or) repair or adjust pressure-regulating equipment.

1.2.11.3. Before servicing any aircraft unit, such as tires, air bottles, or landing gear struts, mechanics will:

1.2.11.3.1. Inspect all chucks and valve stems for serviceability to ensure safe servicing;

1.2.11.3.2. Take care not to over-inflate these components; and

1.2.11.3.3. Install pressure regulators to prevent over-pressurization of components being ser-viced.

1.2.11.3.4. Have proper eye protection available and wear the equipment according to TO requirements or when a potential for injury exists.

12 AFOSHSTD91-100 1 MAY 1998

1.2.11.4. A drain pipe and valve shall be installed at the lowest point of the air receiver to provide for the removal of accumulated oil and water. The drain valve on the air receiver shall be opened and the receiver completely drained daily, if not automatic, to prevent the accumulation of exces-sive amounts of liquid in the receiver. Workers will:

1.2.11.4.1. Avoid bending or kinking air hose lines.

1.2.11.4.2. Place air hose lines where they do not create a tripping hazard and are protected against damage caused by equipment or vehicles rolling over them.

1.2.11.4.3. Inspect air lines and fittings before each use for defects.

1.2.11.4.4. Ensure non-interchangeable chucks and connections are used on high- and low-pressure equipment to preclude servicing low-pressure systems with high-pressure equip-ment.

1.2.11.5. Compressed air used for breathing air will meet requirements of AFOSH Standard 48-1, Respiratory Protection Program.

1.2.12. Oxygen and Nitrogen (Liquid and Gaseous):

1.2.12.1. General Information. The wide use of oxygen in Air Force operations presents many serious safety problems. There is the possibility of injury to workers, but there is the more serious possibility of fire and explosion. While oxygen itself is not flammable, it will support combustion.

If oxygen is permitted to contact petroleum products, a fire or explosion may result. Another source of danger occurs if oxygen systems are subjected to pressures that cause excessive stress on lines and tanks which may result in rupture and explosion. Nitrogen depletes oxygen in unventi-lated, confined areas. Liquid oxygen (LOX) and liquid nitrogen (LIN) are extremely cold and can cause serious burns, and can freeze skin upon contact (AFOSH Standard 91-67, Liquid Nitrogen and Oxygen Safety).

1.2.12.2. Personnel Training and Safety. Only fully trained and qualified personnel shall operate oxygen and nitrogen equipment or service aircraft systems. Servicing personnel shall understand the system being serviced, the operation of their equipment, precautions, and instructions for han-dling liquid or gaseous oxygen and nitrogen. A trainee may service only if directly supervised by a qualified supervisor or operator. Personnel engaged in oxygen handling and servicing operations will strictly observe pertinent safety standards and TOs.

1.2.12.3. Mobile Servicing Unit or Bottles. The mobile servicing unit or bottles used to service aircraft or components shall be carefully positioned and shall not be left unattended after hook-up and during filling.

1.2.12.4. Personal Protective Equipment. When transferring LOX or LIN, personnel shall wear:

1.2.12.4.1. Head covering (AFOSH Standards 91-31 and 91-67);

1.2.12.4.2. Face shield (National Stock Number [NSN] 4240-00-542-2048);

1.2.12.4.3. Gloves, heat protective, leather welder’s gauntlet cuff, Federal Specification KKG486, Type 11 (NSN 8415-00268-7860), medium with insert-cloth, work, cotton knit (NSN 8415-00-964-4760), medium; or leather (NSN 8415-00-268-7871) with insert, wool

(NSN 8415-00-682-6673);

1.2.12.4.4. Apron (NSN 8415-00-715-0450);

AFOSHSTD91-100 1 MAY 1998 13

1.2.12.4.5. Cuffless trousers and long-sleeve shirt or jacket or coveralls, cotton, white (NSN 8405-00-037-9274); and shoes with rubber soles and heels which fit closely around the top.

NOTES:

1. Stock numbers are informational only and may change.

2. All items shall be clean and free of grease, oil, and fuel (TO 00-25-172 and AFOSH Standards 91-31 and 91-67).

3. The above NSN data are for gloves sized medium. Other sizes may be ordered as required but all sizes will meet the criteria of the federal specification and military specification identified above.

1.2.13. Powered Aerospace Ground Equipment (AGE). Operators will be thoroughly familiar with the handbook of operating instructions for the equipment involved and know emergency shut-down and other precautionary measures, including the use of fire extinguishers. They will review mainte-nance records and inspect the equipment for leaks, damage, or malfunction before operation. (See paragraph 8.3.4. for additional guidance on AGE.) WARNING: Danger Area. Personnel will not stand in line with the painted stripe on AGE that designates the plane of rotation of the turbine wheel.

1.2.14. Parking Aircraft. Strict adherence to standards will ensure the safety of parked aircraft. Per-sonnel engaged in parking operations will comply with all pertinent guidance. (Refer to AFMAN 91-201, and TO 11A1-33, Handling and Maintenance of Explosive Loaded Aircraft, for parking of explosives loaded aircraft.)

1.2.14.1. Parking Spaces. Specific parking locations will be designated for each aircraft as out-lined in Air Force Handbook 32-1084, Facility Requirements. Generally, the distances to be left between parked aircraft will be enough to allow immediate access of emergency vehicles in case of fire and also to permit free movement of equipment and materials.

1.2.14.2. Temporary Parking. If it is necessary to temporarily park aircraft with any portion extending into an active taxiway, a ground observer (qualified in the task) will be strategically placed to warn oncoming traffic of the hazard. During hours of darkness, the ground observer will be equipped with a high-visibility reflective vest and a warning light (red preferred) and in the daytime, a suitable flag. The observer will remain with the aircraft until it is moved to a safe loca-tion.

1.2.14.3. Wheel Chocking. Wheel chocks, fabricated according to US Air Force specifications, will be placed fore and aft of the main landing gear or as specified in applicable aircraft TOs.

1.2.14.4. Clean Parking Areas. During periods when maintenance equipment, workstands, loose aircraft parts, and materials are not actually required for work in progress or planned, they will be removed from the aircraft parking area to designated storage locations. Equipment remaining out-side buildings will be adequately secured with tie-downs and (or) chocks or an integral brake sys-tem to prevent movement by winds or engine blasts. When not being transported, mobile work platforms and stands will be secured to prevent collision with aircraft, vehicles, or other equip-ment. Designated flight line support equipment storage areas will be approved by the appropriate group commander in coordination with ground safety officials.

14 AFOSHSTD91-100 1 MAY 1998

1.2.14.5. Guide Lines. Adequate guide lines will be painted on ramp and taxiway parking areas, and where necessary in hangars, to aid in the safe movement of aircraft and vehicle traffic. Parking guide lines should have spots painted where the nose or forward wheel of the aircraft will be posi-tioned. This is mandatory when helicopters are parked inside the hangar, to prevent the blades from making contact with the hangar walls. Where a portion of a large hangar is used for helicop-ter maintenance parking, guide lines and rotor blade lines will be painted on the floor. When numerous types of aircraft use the same facility and multiple paint lines would be confusing, lines are not required, providing local procedures include the marking and identification of fixed objects, the use of wing and tail walkers during hangaring, and the marking of rotors or wingtips with streamers. Spots will be painted where each wheel of aircraft will be positioned in nose docks or other maintenance facilities to prevent aircraft from striking portions of the building during docking and undocking. Guide lines will be painted on outside wash rack pavement to aid in posi-tioning aircraft.

1.2.14.6. Mooring or Tie-Down of Aircraft. This will be accomplished according to applicable aircraft TOs. When ropes are used, they will be tied to designated mooring fittings on aircraft.

Normally, square knots or bowline knots will be used to prevent slippage and to provide secure fastenings. Just enough slack should be allowed to prevent excessive stress on the wings, fittings, and rope due to tire or strut expansion or deflation and to prevent contraction of the tie-down ropes due to moisture or wetness. The mooring points on the ground should be as close as possible to being directly under the respective mooring points on the aircraft.

1.2.14.7. Aircraft Emergency Removal. Emergency procedures to remove endangered aircraft in the event of fire on the flight line or in hangars will be developed. These defined responsibilities and procedures will eliminate confusion and expedite the evacuation of aircraft should it become necessary. (Also, see paragraph 7.2.9.)

1.2.15. Adverse Weather Conditions. The base weather station (BWS) is responsible for making the initial notification to pre-determined support agencies of adverse weather conditions. Adverse weather conditions include: strong surface winds, heavy rain, freezing precipitation and thunder-storms (i.e., frequent dangerous lightning, damaging winds, and hail).

1.2.15.1. General Lightning Safety for All AF Activities and Operations:

1.2.15.1.1. When lightning is detected or observed within the immediate vicinity of any activ-ity or operation, do not go out of doors or remain out unless it is absolutely necessary.

1.2.15.1.1.1. Seek shelter as follows:

1.2.15.1.1.1.1. Dwellings or other buildings that are protected against lightning;

1.2.15.1.1.1.2. Protected underground shelters;

1.2.15.1.1.1.3. Large metal-framed buildings;

1.2.15.1.1.1.4. Enclosed automobiles, buses, aircraft, and other vehicles with metal tops and bodies;

1.2.15.1.1.1.5. Streets that may be shielded by nearby buildings.

1.2.15.1.1.2. Certain locations are extremely hazardous during thunderstorms and should be avoided:

AFOSHSTD91-100 1 MAY 1998 15

1.2.15.1.1.2.1. Hilltops and ridges;

1.2.15.1.1.2.2. Areas on top of buildings;

1.2.15.1.1.2.3. Under isolated trees;

1.2.15.1.1.2.4. Near electrical appliances, telephones, plumbing fixtures, and metal or electrically conductive objects; and

1.2.15.1.1.2.5. Aircraft dry bays, tanks, and wheel wells.

1.2.15.1.2. Each Air Force installation will develop a local procedure to ensure key personnel and agencies involved in high weather risk activities and operations are notified according to the installation support plan. Normally, these agencies are those having aircraft, POL facilities, open air work and recreational activities, and underground utilities work. Key personnel, in turn, will advise all on-duty supervisors to take proper precautions and timely actions.

1.2.15.1.3. Each installation will employ a lightning safety program with a two-tiered notifi-cation system to minimize personnel exposure to lightning hazards.

1.2.15.1.3.1. A Lightning Watch is in effect 30 minutes prior to thunderstorms being within a 5 nautical mile (nm) radius of any pre-determined location or activity as forecast by the BWS. NOTE: Lightning is a direct product of a thunderstorm. During a Lightning Watch, accomplish the following:

1.2.15.1.3.1.1. Operations or activities may continue; however all personnel must be prepared to implement Lightning Warning procedures without delay.

1.2.15.1.3.1.2. Be alert for any lightning activity, to include audible thunder, and advise supervisory personnel of any observations.

1.2.15.1.3.2. A Lighting Warning is in effect whenever any lightning is occurring within a 5 nm radius of the pre-determined locations and activities. Personnel in affected locations or engaged in affected activities will take the following actions:

1.2.15.1.3.2.1. Cease all outside activities and seek shelter.

1.2.15.1.3.2.2. Recommended locations that provide safe shelter and locations to avoid are listed in paragraph 1.2.15.1.1.

1.2.15.1.4. If lightning does not occur within a 5 nm radius at the valid (forecast) time of the Lightning Watch, BWS will reassess the Lightning Watch and amend as needed. Lightning Warnings will be canceled when the thunderstorms have passed beyond the 5 nm radius of the location or activity. A Lightning Watch will not be canceled if there is potential for more thun-derstorms within 30 minutes.

1.2.15.1.5. All aircraft fuel servicing and maintenance activities (including LOX servicing) will cease whenever a Lightning Warning is in effect. EXCEPTIONS: Vehicle movements (including refuelers) and pipeline transfers (including bulk storage to hydrant tanks). (Refer to AFI 23-201, Fuels Management.)

1.2.15.2. Safeguarding Aircraft During High Winds. Serious structural damage to aircraft can be caused by high velocity surface winds. When possible, aircraft will be evacuated to safe weather areas when tornadoes, hurricanes, or unusually high winds are predicted. Locally established high

16 AFOSHSTD91-100 1 MAY 1998

wind safety precautions or plans will be developed and observed along with the guidance pre-sented below:

1.2.15.2.1. Taxiing Aircraft. Taxiing aircraft during unusually high winds will be avoided.

They may be taxied at the discretion of the wing commander when the action will lessen the possibility of aircraft damage.

1.2.15.2.2. Outside Parking. If possible, light aircraft will be parked inside hangars. Those parked outside will be faced into the wind and tied down. Wing spoilers will be used to reduce airfoil lift. Transient aircraft will be tied down as directed by the aircraft commander.

1.2.15.2.3. Extremely High Winds. When wind velocity exceeds 30 knots (sustained or gusts), light aircraft in temporary docks or extending outside the hangars will be towed clear and parked in compliance with applicable aircraft TOs. When wind velocity exceeds 50 knots (sus-tained or gusts), medium or heavy aircraft in temporary docks or extending outside the hangars will be towed clear and then parked in compliance with applicable aircraft TOs.

1.2.15.2.4. Work Materials. All maintenance equipment, workstands, loose aircraft parts, and materials not in use will be removed from the parking area and stored in a safe area. Equip-ment remaining outside will be secured against wind movement.

1.2.15.2.5. Personnel. When winds reach hazardous velocities, activities other than those required to safeguard the aircraft will be avoided. Guidance for actions involving electrical storms is found in paragraph 1.2.15.1.

1.2.16. Aircraft Engine Operation. Engine starts and runups present hazards to both personnel and other aircraft. The fire hazard is particularly acute because fuel vapors may be ignited by exhaust flames. Rotating propellers are dangerous to personnel and can cause extensive equipment damage.

Except for turboprop aircraft, personnel will not hand-pull the propeller of an engine that has been recently operated. The ignition switch of reciprocating or electric start engine aircraft will be in the OFF position when engines are not operating, and the master battery switch will be turned off when no longer required. For C-130 aircraft, personnel will not be in the vicinity of (or go through) the static propeller arc if bleed air is applied to the aircraft. Personnel will not stand in line with the stripe that designates the plane of the turbine wheel and propeller operation, which is painted on the fuselage or engine nacelles of aircraft. WARNING: Danger Area. Personnel will not be in the vicinity of or go through the static propeller arc of reciprocating and turboprop aircraft or helicopters unless absolutely necessary in the performance of duties. Radio contact with the control tower will be maintained at all times during engine operations or taxiing. If engine runs are necessary while the control tower is not operating, radio contact will be maintained with job control. Maintenance Operations Center (MOC) will be prepared to request assistance from the fire department or medical services as needed.

1.2.16.1. Aircraft Chocks. Before starting engines, the aircraft will be properly chocked and parked according to applicable TOs and handbooks. Suitable wheel chocks, manufactured to Air Force specifications, will be used at all times. Functional managers will ensure only those chocks approved for the specific aircraft are used. When aircraft engines are in operation, chocks will be removed with the utmost caution after the proper signal has been given. Personnel will approach the aircraft from the safest direction with regard to the location of propellers and jet intakes and exhausts.

1.2.16.2. Personnel on Exterior Portions of Aircraft. Personnel will NOT be allowed on any exter-nal portion of an aircraft during engine start or when the aircraft is being taxied. Qualified person-

AFOSHSTD91-100 1 MAY 1998 17

nel may stand on the external portion of an aircraft ONLY during instruction on ground operation procedures and necessary adjustments. Qualified personnel may service hydraulic fluid and engine oil or make minor adjustments on multi-engine aircraft with engines operating on the opposite wing as long as the engines on the wing being worked are shut down and the engines on the opposite wing remain in idle. Interphone or radio contact will be maintained with the cockpit operator, if possible. If effective interphone or radio contact can not be maintained, personnel on the wing will be under the direct observation of another crewmember, team member, or fire guard, who has direct communication with the cockpit operator. Aircraft wing lights and formation lights will be turned on to warn all personnel the aircraft engines are in operation (AFI 11-218, Aircraft Operation and Movement on the Ground).

1.2.16.3. Fire Guard. A qualified (trained) fire guard will be positioned, if required by the aircraft TO, prior to starting the engines. This individual will stand by in readiness until all engines are operating and the danger of fire no longer is present. If no fire guard is specifically identified in the aircraft TO data, the following will apply:

1.2.16.3.1. On aircraft having internal fire fighting capability, a ground observer will be in position on interphone to monitor and report any problems (e.g., fire, fuel leakage, aircraft movement) and will remain in position until released by the individual operating the engine.

1.2.16.3.2. On aircraft not equipped with interphone capability, a ground fire guard will be stationed to observe the starting engine process. After the engine starts, the fire guard will remain in clear view of cockpit personnel and observe the aircraft and area during engine oper-ation. WARNING: Extreme caution will be exercised to ensure all personnel remain clear of propeller arc and (or) jet intakes and exhaust during ground operation.

1.2.16.4. Qualified Engine Operation Personnel. Only those personnel trained and certified according to instructions in AFI 11-218 will be authorized to start and run up aircraft engines. The individual in charge of engine runup operations will be responsible for inspecting the surrounding area to ensure it is clear of equipment, personnel, and materials that might cause or be subject to FOD. Equipment or materials, that may be subjected to engine blasts or blown into other equip-ment, will be repositioned or secured (AFI 21-101, Maintenance Management of Aircraft).

1.2.16.5. Observers for Jet Engine Starts. A ground crewmember, stationed in front of and to one side of the jet engine being started, will be in contact by interphone at all times with…