During fueling operations, which equipment must be shut down?

• A. Flight data recorder
• B. Landing gear indicators
• C. Autopilot system
• D. Radar and radio transmitting equipment

Answer: (D)

During fueling, the primary safety concern is the presence of flammable fuel vapors and the need to eliminate any ignition sources. Radar and radio transmitting equipment can produce electrical energy and RF emissions that have the potential to ignite vapors or create arcing hazards in the fueling environment. Shutting these transmitters down removes a possible ignition source and helps maintain a safer fueling operation.

The other items listed do not present ignition sources in the fueling context, so there’s no safety benefit to turning them off specifically for fueling. The flight data recorder, landing gear indicators, and autopilot system are not sources of ignition during fueling, and their operation isn’t a direct safety risk in this scenario.