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Engine Failure at Takeoff (OGHFA SE)
From SKYbrary Wiki
|Content source:||Flight Safety Foundation|
|Human Factors Aspects||Airmanship|
|Flight Phase||Take Off|
|Operator's Guide to Human Factors in Aviation|
|Engine Failure at Takeoff|
The Incident as a Situational example
Weather conditions are excellent. You, the first officer, complete flight preparations alone, as your captain arrives late. The chief flight attendant is also on the flight deck, which causes some distraction while conducting the takeoff checklist and the announcement of the selected takeoff speeds — V1, 144 kt; VR, 146 kt; V2, 150 kt. The actual takeoff weight is close to the maximum due to the airport altitude and the high temperature.
A very casual taxi to the runway takes place, not in keeping with the sterile cockpit concept. There is no briefing to prepare for takeoff contingencies, as prescribed by company procedures.
How well-prepared would you be at this stage?
The crew is not psychologically prepared to face any possible problems. Takeoff immediately follows taxiing onto the runway. You are the pilot flying. Acceleration is normal, with the standard speed announcements made up to rotation (VR).
About 5 seconds after rotation, at the exact moment for landing gear retraction, a loud noise is heard from the left engine, and the aircraft veers left.
What is your immediate reaction?
You apply a correction. The captain takes over the controls, and you tell the tower, “We have a slight problem.” You offer to retract the gear several times without receiving any reply from the captain.
Would you retract the gear?
The airplane loses altitude rapidly, with a vertical speed between 1,400 and 1,800 fpm, airspeed 160 kt and an 18-degree pitch-up attitude. The high pitch-up attitude is maintained by the captain, and stall speed is reached in a short time. Fourteen seconds after the engine noise, the ground-proximity warning system (GPWS) “DON’T SINK” alarm calls your attention to the fact that the airplane is dropping toward the ground.
The control column is shaking, indicating a stall. The airplane strikes the ground tail first in a right roll, bursts into flame immediately and skids through the airport fence and across a nearby road.
Data, Discussion and Human Factors
The above scenario shows:
- A lack of preparation and coordination between the two pilots.
- An absence of mutual control and coordination.
- Nonadherence to standard operating procedures (SOPs).
This accident resulted from the failure of the left engine after rotation. This event alone, although critical at that moment in the flight, was not in itself sufficient to cause the airplane to crash.
According to the airline’s SOPs, the initial climb after a single engine failure should be conducted with the gear retracted; while maintaining the V2 safety speed until the safety altitude is reached; and in a climb performed with a maximum rate of climb of 500 fpm and a maximum pitch attitude of 12 degrees.
The profile flown was 1,400 to 1,800 fpm at 18 degrees.
When the engine failure occurred after rotation, the captain immediately took over in a brusque manner. Since he was pilot not flying (PNF) and as such had not previously been directly involved in control inputs, he flew with too high a pitch-up attitude that was incompatible with the lack of power due to the engine failure and led directly to the stall.
By taking control so suddenly, the captain had no strategy to react to the failure appropriately in order to recover from the situation. The lack of a briefing before takeoff did not prepare the crew to operate effectively in such a situation.
In addition, the failure of the left engine at the same time the first officer called for gear retraction hampered efforts to maintain speed. The first officer again called for gear retraction. Since the captain took over, task sharing was switched between the two pilots; the first officer was no longer pilot flying. It was now up to the captain to request gear retraction, but he failed to do so. The gear remained extended until impact. Total absence of mutual control and crew coordination prevailed here.
With the gear extended, one engine out and a high pitch attitude, the aerodynamic characteristics deteriorated rapidly. The yaw created by the failed engine also contributed to the increase in drag following the engine failure.
From these events, the following contributory factors can be identified:
- Insufficient flight preparation prior to takeoff that made it impossible for the crew to be alert and ready to face a critical situation.
- The coincidental timing between the engine failure and the call to retract the gear.
- A takeoff weight close to maximum at a high-altitude airport altitude with high temperature.
- The very short reaction time available to recover from the situation.
Prevention Strategies and Lines of Defense
The following strategies might have helped the crew to recover control after the engine failure:
Adherence to company SOPs: The situation and the associated factors were not formalized; no announcements of the failure were made. After the failure, standard callouts such as airspeed, vertical speed and attitude were not made. The airline’s procedures called for gear retraction, maintaining a maximum pitch angle and V2 speed. Sticking to the SOPs fosters greater self confidence and a structured frame of mind, which help avoid failing to take such vital actions as retracting the landing gear, controlling pitch attitude and vertical speed.
Crew coordination and mutual control: The brusque takeover by the captain destabilized the first officer, putting her out of the loop and upsetting the crew’s task sharing. Trajectory management and flight strategy were critically affected. Proper phraseology must be used to avoid uncertainties, not only when requesting an action, but also when getting acknowledgement from the other crewmember that he or she has understood the request and has acted appropriately. In this example, that would have prevented the landing gear from remaining extended, even after several questions from the first officer.
Quality of briefing and sterile cockpit concept: Adequate flight preparation, including briefings, helps the crew to:
- Focus on the tasks ahead.
- Prepare for task sharing in case of an abnormal situation.
- Reduce reaction time.
- Favor the proper corrective actions in order to recover from the event.
The sterile cockpit concept is implemented to concentrate on the important data the crew must share to get the same overall picture. Along with adherence to SOPs, this helps the crew to be in the proper state of mind prior to a critical flight phase such as takeoff.
An accident like this one can be avoided by understanding the following key points:
- Flight preparation ensures correct mindset.
- The sterile cockpit concept supports crew concentration.
- Adherence to SOPs and checklists allow crews to react quickly and appropriately.
- Clear communication and cross-checking is essential to safety.
- Conducting effective briefings reduces reaction time and clarifies task sharing.
Associated OGHFA Material
- Flight Preparation and Conducting Effective Briefings
- Decision-Making Training
- Stress and Stress Management