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Your four-engine airplane is scheduled for a midday departure for a long-haul flight from a major airport. Your crew receives a forecast of severe turbulence during climb-out as well as a notice that severe turbulence has been reported by the crews of other large airplanes. You brief your crew on the possible turbulence and tell them to be prepared for a rough ride.
After takeoff, at about 2,000 ft, the airplane experiences an uncommanded left roll of approximately 50 degrees. While the target airspeed is 183 kt, the airspeed fluctuates by about 75 kt, from a high of 245 kt to a low of 170 kt. Just after that, you experience significant yaw, the no. 2 throttle lever slams to its aft stop, the no. 2 reverser indication shows thrust reverser deployment, and the no. 2 engine electrical bus fails.
In fact, unknown to you, the no. 2 engine has actually separated from the airplane. Witnesses on the ground report later that the airplane experienced several severe pitch and roll oscillations before the engine separated. Detailed investigation after the event indicates that there is no reason for you to have suspected that the airplane would be damaged during climb-out as the level of turbulence encountered is within the design limits of the airplane, and previous departures encountered the same conditions without any problems.
Shortly after the engine separates from the airplane, your crew carries out the emergency checklist memory items for an engine failure.
You decide to make an in-flight turn-back (IFTB) and instruct the first officer (FO) to declare an emergency. Air traffic control (ATC) accepts the emergency and offers any of the airport’s runways for the return. You instruct the flight engineer (FE) to lock down the leading edge devices using the manual extension method and to begin dumping fuel.
Immediately after deciding to declare an emergency and executing an IFTB, you begin delegating important duties. You choose to concentrate entirely on flight path control and to delegate communications to the FO. The FE is assigned systems management, including the engine shutdown procedure, fuel dumping and handling the subsequent failures of a generator and hydraulic system. The FE is later assisted by two positioning FEs aboard as passengers in making calculations on the fuel dumping procedure and landing weights.
You are initially unable to maintain altitude.
You use emergency/maximum power on the no. 1 engine, full rudder authority and almost full right aileron to maintain control. The stick shaker and bank angle warnings activate intermittently throughout the remainder of the flight. Once you re-establish a reasonable degree of control, you initiate a wide-radius turn to the left to return and land on the departure runway. While on the downwind portion of the landing pattern, bank angles alternate between wings level and momentary excursions that exceed 40 degrees.
The FO maintains ATC communications while surrounded by high background noise from multiple alarms and alerts. Poor sound quality on the intercom also limits the potential use of ground resources such as the airline’s technical department. Even though two fighter airplanes rendezvous with your airplane to assess the extent of the damage, any possible assistance is thwarted by poor communications. You are not able to confirm the nature and extent of the damage the aircraft has sustained until after you land.
Because of the handling and communications difficulties, you decide to make an overweight landing instead of continuing to dump fuel. You instruct the FE to stop dumping fuel as the airplane turns onto final approach. The extension of the landing gear is delayed until the airplane is on short final. The airplane intercepts the glideslope between 500 and 600 ft. At 300 ft, you call for flaps 25. The aircraft lands and taxies safely to the gate even though the landing weight is 17 percent higher than the maximum certified value.
After landing, you note that the brakes on the left side are very hot. You inform ground personnel to take precautions to protect themselves from the potential danger of an explosion of the wheels and brakes due to the overheating. The damage to the airplane is substantial — likely beyond what would be economically viable to repair. Nevertheless, the event results in no loss of life or injury.
From the review of this accident, it is clear that the crew:
The crew was cool, calm and collected in its response to stress and time pressures despite the many physical and emotional stress factors that could have affected performance, including:
Despite these stress factors and pressures, the captain was able to maintain control of his emotions and transfer his positive attitude and confidence to the other crewmembers. The negative effects of the acute stress only appeared after landing, when the captain suffered a severe stomach ache for several hours.
The crew’s situational awareness was incomplete as a consequence of limited information availability. They therefore focused on producing an accurate response to their situation rather than becoming fixated with determining the causes of their predicament. It is ironic that the crew’s lack of complete situational awareness of the seriousness of the aircraft failure may actually have protected them from developing excessive anxiety.
The captain quickly realized that the aircraft was in significant danger and devoted his efforts to re-establishing and maintaining aircraft control. He delegated additional critical tasks clearly to the other crewmembers so that everyone had a full understanding of the duties they were to perform. Likewise, the FO focused on helping the captain by handling communications and assisting in the engine failure procedure rather than overanalyzing the causes of the situation.
The crew never lost sight of the operations golden rules. In spite of many competing needs, they never permitted distraction to compromise the primary functions of aviate-navigate-communicate-manage that are fundamental to safe flight.
The crew remained disciplined throughout the event. They remained calm, followed standard operating procedures (SOPs), did not cut corners and showed appropriate concern for others by warning ground personnel of the excessive brake and wheel temperatures.
Good CRM was applied throughout, including:
Good judgment and decision making were exhibited throughout the flight, along with proper and timely setting of priorities. Examples of good judgment and decisions included:
This event is an excellent example of how the application of various human factors techniques can combine with technical knowledge and good flying skills to produce effective airmanship and successful problem resolution.
The main lessons that can be derived from this event include:
The successful resolution of an in-flight problem such as an engine separation is dependent on the application of good human factors principles. Airmanship, discipline, communication, CRM (teamwork, leadership), judgment, effective decision making and adherence to the operations golden rules (aviate, navigate, communicate, manage) are vitally important when dealing with unexpected events.
The following briefing notes provide expanded information on key human factors principles:
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