The towing supervisor shall terminate the operation if ______ drops below safe operating limits.

• A. Hydraulic pressure
• B. Brake pressure
• C. Tire pressure
• D. Fuel pressure

Answer: (B)

The essential factor here is the braking capability during a tow. Brake pressure reflects the actual hydraulic force available to apply the aircraft’s wheel brakes. If that pressure drops below the safe operating limit, the braking response becomes unreliable, making it difficult or impossible to stop or control the aircraft safely. Terminating the operation at that point prevents a loss of control or an accident.

Other pressures aren’t direct indicators of braking performance in this scenario: general hydraulic pressure covers other systems, tire pressure affects traction but not immediate braking capability, and fuel pressure relates to engine operation rather than braking.