exhaust etc.) 3) Frictional hot spots 4) Electromagnetic energy (radio transmissions or radars) 5) Static electricity 6) Lightning
 C. Purging and Fuel Tank Entry - Airplane Precautions
 S 912-221
 (1)  
Do the maintenance on the fuel tanks in areas which allow the free movement of air, fire fighting equipment and other emergency equipment.

 S 912-222

 (2)  
A rope barrier must be placed around the airplane, to identify the Clas I, Division 1 hazardous locations. See Figure 201 for the distance requirements. The rope barrier must include signs or placards which state "DANGER - OPEN FUEL TANKS.

 S 912-223

 (3)  
The airplane must be correctly grounded to an approved ground before you defuel the airplane or open any fuel tanks.

 S 912-224
 WARNING: DO NOT USE AIRPLANE ELECTRICAL POWER WHEN FUEL TANK ACCESS
_______ DOORS ARE OPEN. A FIRE OR EXPLOSION CAN OCCUR IF FUEL VAPOR IS IGNITED BY SPARK(S) FROM ELECTRICAL EQUIPMENT. A FIRE OR EXPLOSION CAN CAUSE SERIOUS INJURY OR DEATH TO PERSONS AND CAN CAUSE DAMAGE TO EQUIPMENT.
 (4)  
Before the fuel tank access doors are opened, all of the electrical power to and from the airplane must be removed. Placards which state that power should not be restored on the airplane until the fuel tank(s) are closed should be attached to applicable locations.

 S 912-225

 (5)  
The main, and APU batteries must be disconnected. Placards which state not to connect the batteries unit the fuel tanks are closed should be attached to all disconnected battery locations.

 S 912-226

 (6)  
All safety, support and maintenance equipment must be in place before you open the fuel tank access doors. Movement of equipment can cause sparks which can cause fuel vapors to ignite.

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 S 912-227
 (7)  
No painting operations are allowed on airplanes with open fuel tanks.

 D.
Purging and Fuel Tank Entry - Electrical Equipment Precautions

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