(a) When an aircraft engine is running; <br /> (b) When an aircraft is being warmed by <br /> application of exterior heat; <br /> (c) Inside a hangar or an enclosed area; <br /> (d) While an aircraft radio transmitter or <br /> receiver is being operated, or other electrical appli- <br /> ances are switched on or off; <br /> (e) When there are people aboard the aircraft <br /> unless the aircraft door is open, there is an attendant <br /> at the door, and a passenger loading stand is at the <br /> cabin door; or <br /> (f) From drums, small containers, or similar <br /> items. <br /> 5.4.2 Particular Restrictions. <br /> 5.4.2.1. Fuel storage and servicing equipment, including <br /> fuel servicing vehicles, fueling pumps, meters, hoses, nozzles, <br /> fire extinguishers and grounding devices shall be UL approved <br /> where applicable, shall comply with state laws and regulations, <br /> and shall be kept in first class non-leaking condition at all <br /> times. <br /> 5.4.2.2. A fuel servicing vehicle, including tank trucks <br /> and tank semi-trailers, when servicing an aircraft, must be posi- <br /> positioned: <br /> (a) So as to not interefere with the discharge <br /> of persons from the aircraft during an emergency; and <br /> (b) So that it can be readily driven forward <br /> to an open area during an emergency. <br /> 5.4.2.3. Fuel servicing vehicles will proceed slowly <br /> with caution on the apron. <br /> 5.4.2.4. A fueling operations attendant shall be fully <br /> trained and competent to operate the emergency pump controls. <br /> 5.4.2.5. Prior to fueling an aircraft the fuel dispensing <br /> equipment shall be grounded to a point or points of zero electri- <br /> cal potential in the order indicated below, and when complete, in <br /> the reverse order to prevent the possibility of static ignition <br /> of volatile liquids: <br /> (a) Refueling unit tb ground, <br /> (b) Refueling unit to aircraft. <br /> <br /> Rules - 13 <br /> <br />