Engine Fire After V1 on a Twin-Jet Departure
A twin-engine business jet, mass 19,800 kg, departs runway 16 from a Japanese airport. MTOW is 20,000 kg, MLW 18,000 kg, MZFW 16,500 kg. V1 is 118 kt, VR 124 kt, V2 132 kt. At V1+5 kt and about 80 ft AGL, the right engine fire warning illuminates. N1 rolls back, EGT rises, and the aircraft yaws right. The runway is 2,600 m, dry. The departure has a close-in obstacle requiring a 4.5% climb gradient; the AFM one-engine-inoperative gradient at the current mass and temperature is 3.2%. Fuel on board is 3,200 kg; planned trip burn is 1,200 kg. The fire warning remains after the first agent bottle; a second bottle is available. The acceleration altitude is 1,500 ft. The weather is CAVOK with calm wind. A long runway with emergency services is available behind the aircraft. The crew must decide whether to continue, return, or hold to burn fuel.
1. State the immediate actions after the fire warning at 80 ft and explain whether the crew may continue the departure.
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At V1+5 kt and 80 ft, the aircraft is committed to flight; a rejected takeoff is no longer appropriate. The immediate actions are: maintain directional control with left rudder against the right yaw, keep wings level, pitch to V2 (132 kt), and establish a positive climb. Confirm the affected engine, bring its thrust lever to idle, operate the fire handle, and discharge the first agent. Do not continue the departure.
The one-engine-inoperative climb gradient is 3.2%, while the obstacle requires 4.5%. Continuing would not assure obstacle clearance. In addition, the fire warning persists after the first bottle, so this is a time-critical fire, not a simple engine failure. The correct decision is to return to the departure airport and land as soon as possible, using the second bottle if the warning remains. ATC should be told clearly: 'Mayday, engine fire, returning, request immediate landing and emergency services.' Aviate, navigate, communicate - in that order.
2. Calculate the likely landing mass and discuss the overweight landing.
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Takeoff mass 19,800 kg minus planned trip burn 1,200 kg gives about 18,600 kg at landing. MLW is 18,000 kg, so the aircraft would land about 600 kg overweight.
That is not a reason to hold and burn fuel. With an engine fire warning that has not extinguished, the risk of delaying exceeds the risk of an overweight landing. The aircraft should land at the nearest suitable runway, preferably the long runway behind it with emergency services. Use the AFM overweight-landing checklist: expect a higher approach speed, longer landing distance, higher brake energy, and a subsequent structural inspection. If fuel jettison is not available or not quickly usable, do not delay for it. The crew should brief a longer landing roll, consider the wet/dry runway condition, and plan to stop straight ahead if necessary. After landing, shut down the affected engine, evacuate if fire persists, and have fire services check the engine.
3. Prioritize the checklist and ATC communication. What should be done after landing?
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The order is: fly the aircraft, complete the memory items, then run the checklist. The memory items are directional control, V2 pitch, identify/confirm, thrust lever idle, fire handle, and agent discharge. Only after the aircraft is under control should the crew start the non-memory checklist and talk to ATC.
ATC communication should be short and specific: declare an emergency, state the nature (engine fire), position, intention to return, request a runway and emergency equipment. Do not let radio work interfere with flying or the fire drill.
After landing, stop on the runway if fire is still indicated, shut down both engines, and order evacuation as required. If the fire warning has cleared, taxi clear only if fire services advise it. The aircraft must not be dispatched again until maintenance has inspected the engine fire loop, bottles, and structure. The crew should also consider whether the second bottle was used and preserve all indications for the report.