Good housekeeping in hangars, shops, and on the flight line is essential to safety and efficient maintenance. The highest standards of orderly work arrangements and cleanliness should be observed during the maintenance of aircraft. Where continuous work shifts are established, the outgoing shift should remove and properly store personal tools, rollaway boxes, all workstands, maintenance stands, hoses, electrical cords, hoists, crates, and boxes that are superfluous to the work to be accomplished.

Safety Lanes

Pedestrian walkways or fire lanes should be painted around the perimeter inside the hangars. This should be done as a safety measure to prevent accidents and to keep pedestrian traffic out of work areas.

Power Cords

1. Power cords should be heavy industrial type which are able to resist abrasion and impact.

2. Power cords should not be run over by any equipment.

3. Lights should be explosion proof.

4. Connections should be locking type to prevent accidental disconnection.

5. All lights or equipment should be switched "off", to prevent arcing before connecting or disconnecting.

6. Power cords should be straightened, coiled, and properly stored when not in use.

Disregard of the above suggestions may result in explosions and fires with damage into millions of dollars and loss of life.

Compressed Air System

Compressed air is like electricity - an excellent tool as long as it is under control.

1. Air hoses should be inspected frequently for breaks and worn spots. Unsafe hose should be replaced immediately.

2. All connections should be kept in a "no leak condition".

3. In line oilers, if installed, should be maintained in operating condition.

4. The system should have water sumps installed and they should be drained at regular intervals.

5. Air used for paint spraying should be filtered to remove oil and water.

6. Never use compressed air to clean hands or clothing. Pressure can force debris into the flesh leading to infection.

7. Never use compressed air for "horse play".

8. Air hoses should be straightened, coiled, and properly stored when not in use.

Spilled Oil and Grease

Oil, grease, and other substances spilled on hangar or shop floors should be immediately cleaned or covered with an absorbent material to prevent fire or personal injury. Drip pans should be placed beneath engines and engine parts wherever dripping exists. Waste oil and dirty cleaning fluid should be stored in containers for future salvage. Under no circumstances should oil or cleaning fluid be emptied into floor drains. Fumes from this type "disposal" may be ignited and cause severe property damage.

Aircraft Tire Mounting

To prevent possible personal injury, tire dollies and other appropriate lifting and mounting devices should be used in mounting or removing heavy aircraft tires. When inflating tires on wheels equipped with locking rings, tire cage guards should always be used. Where possible, all tires should be inflated in tire cage guards. Because of possible personal injury, extreme caution is required to avoid overinflation of high pressure tires. Pressure regulators should be used on high pressure air bottles to eliminate the possibility of overinflation of tires.

Tire cages need not be used when adjusting pressure in tires installed on aircraft.


Welding should not be performed except in designated areas. Any part to be welded should be removed from the aircraft, if possible. Repair would then be accomplished in the welding shop under controlled environment. A welding shop should be equipped with proper tables, ventilation, tool storage, and fire prevention and extinguishing equipment. Welding on an aircraft should be performed outside if possible. If welding in the hangar is necessary, these precautions should be observed:

1. No open fuel tanks or work on fuel systems should be in progress.

2. No painting in progress.

3. No aircraft within 35 feet.

4. Immaculate housekeeping should prevail around the welding area.

5. Only qualified welders should be permitted to do the work.

6. The area should be roped off and placarded.

7. Fire extinguishing equipment of a minimum rating of 20B should be in the immediate area with 80B rated equipment as a backup.

8. There should be trained fire watches in attendance at the above equipment.

9. Aircraft should be in towable condition, with a tug attached, aircraft brakes off, and a qualified operator on the tug with mechanics available to assist in the towing operation. Hangar doors should be opened.