American International Airways Flight 808
- Aircraft: DC 8-61, registration N814CK
- At Leeward Point Airfield, US Naval Air Station, Guantanamo Bay, Cuba
- On Aug.18 , 1993 at 1656 EDT.
NTSB: AAR 94/04
On August 18, 1993, an American International Airways, Inc. Douglas DC-8-61 (N814CK), with three crew members on board struck level terrain 1,400 feet west of the approach end of the runway while landing at Guantanamo Bay, Cuba. The aircraft approached from the south and was making a right turn for runway 10 with an increasing angle of bank to align with the runway. At 200–300 feet AGL the wings started to rock towards wings level and the nose pitched up. The right wing appeared to stall, the aircraft rolled to 90-degree angle of bank and the nose pitched down. Probable cause of the accident attributed primarily to the impaired judgment, decision-making, and flying abilities of the captain and flight crew because of fatigue resulting from extended flight/duty hours.
In analyzing the circumstances and factors of this accident, the NTSB evaluated:
- the conduct of the approach to Runway 10 with regard to the flight characteristics of the DC-8 airplane
- the performance of the flight crew
- the adequacy of guidance provided to the flight crew by the AIA and DOD (Dept. of Defence)
- the special airport training provided by AIA to the flight crew
- the flight crews decision to use Runway 10
- the probable effects of fatigue on flight crew’s performance.
The analysis of this accident also addresses the issue of
- crew flight time policy and regulations as related to flight crew fatigue
- AIA’s management philosophy with regards to flight operations and training
- the FAA’s oversight and surveillance of AIA.
The three flight crews were properly certificated and qualified for their respective positions in accordance with company’s regulations and the FARS. There were no medical problems or life events associated with this accident pertaining to the flight crew involved.
The airplane was certificated, equipped and maintained in accordance with FAA regulations and company procedures. There was no evidence of pre-existing faults in the airplane structure, systems or engines that could have contributed to the accident. The weight and balance calculations for the landing were proper.
Visual meteorological conditions existed at the time of the accident and there were no environmental conditions. Surface wind at the airport reported just prior to the approach, was at 200/07 being favorable for a landing on Runway 28.
The approach to Runway 10
As mentioned above, the approach to Runway 10 is restricted to one from a right hand Base leg, the maximum width of the base leg from the runway extended centerline being ¾ mile. This presents challenges for the type of large airplane such as the DC8. The approach requires good skill in stabilizing the airplane after roll out from a bank angle at least 30 degrees or greater depending on need of alignment with the runway on final over the Touch Down Zone (TDZE) at 120 AGL or less.
There is no margin for error in this maneuver to correct for misalignment after roll out with the runway. The approach is not stabilized at any stage being conducted from a Right Hand traffic pattern with the runway almost invisible to the pilot in the left seat on the base leg. Further the effect of the prevailing wind i.e. the tailwind applicable to Runway 10 would cause the increase of ground speed thereby requiring a further tightening of turn from that calculated, resulting in an abnormal bank angle to compensate for the wind to align with the runway centerline. Calculating from the theoretical safety parameters for the weight, flap configuration, the approach speed would be 147 KTS, (1.3 VSO +5 ) at the inappropriate bank angle of 30 degrees. This is possible from a base leg over the restricted area boundary and the turn commenced prior to the shoreline, about 2000 ft. away.
VSO = Velocity stall in landing configuration
The point where to initiate the turn is determined by the prevailing wind and the bank angle applied to seek alignment with the runway. Any variance in these factors would be prohibitive in achieving a landing. The subsequent roll out on final to wings level at 120 AGL and 1300 feet from the threshold is an unsafe procedure to be enacted in the first place. The downwind leg should have been flown at an altitude of 1500 AGL over the water and not 800 AGL, prior to initiating the turn after visual sighting of the runway. The reported visibility was good although the flight engineer’s report regarding hazy conditions at 1647 seven minutes prior to impact at 12 DME and Radial125 should be considered.
AGL = Above Ground Level
The Captain’s fixation with the strobe light to establish a reference for the airport environment and being too low on the downwind about 800 AGL was the cause of not being able to sight the runway, this pre-occupation also made him oblivious to decaying speed.
Performance of the Flight Crew
The flight crew’s acceptance of the unexpected flight falls short of a professional commitment to safety. None of the crew members had flown to this airport within the last several years. Only the first officer was current on the airport qualification, however dubious the instructional methods applied for the purpose. This helped him in remembering the correct traffic pattern but his comprehension of the various ATC clearances given and their relation to the flight were almost beyond him despite his experience, being a rated captain on the said equipment also.
It is understood that these grave errors in judgment were made by all the crew members owing almost to a sleepless existence within the last 24 hours approximately and the cumulative effect of fatigue again due to the same circumstances, resulting in breaking all rules of the circadian rhythm since starting their duty sequence on the 16th at 2300. This is particularly reflected in the captain’s decision to choose Runway 10 for landing. The reasons for this election are more important.
Just for the heck of in that fatigued state, ignoring and overriding other considerations such as a easy approach to Runway 28, almost a straight in with the wind supporting the landing. It was a fateful decision.
Runway 10/28 is one runway only (but used either side) depending on which side the landing direction is: Runway 10 would be facing east on landing, while Runway 28 would be facing west. An aircraft normally lands into wind; from the direction the wind is coming from.
The other two members being rated pilots didn’t say anything at the time, though the flight engineer’s remark expressed concern regarding bank angles on the final turn.
I am surprised that in the post accident inquiry, the first officer still supported the decision made by the captain to use Runway 10. They should have been more assertive at this stage since this was part of the chain of events process, later the same lack of assertiveness was demonstrated by both of them at least at two more very critical moments of the approach phase. The flight engineer called out thrice in the last two minutes about the speed well below the bug speed for the flaps. In the final moments, the first officer called out a speed of 140KTS, below the Vref. He should have acted then to take controls or merely push the power levers. This act may have woken up the captain from his trance.
Knots = nautical miles per hour
Vref = The speed reference bug set on the airspeed indicator
I am also surprised at the first officer’s later assertion that he was reluctant to take controls near the ground for fear of jeopardizing safety in spite of the obvious. The captain’s overriding concern with the sighting of the strobe light ignoring other visual cues which would certainly have made the airport sighting possible can also be explained away in light of their fatigued state. The captain did sight the edge of Runway 28 as they were flying downwind but again lost contact as they approached the shoreline. His position in the left seat prevented him from regaining contact with the airport, but I wonder why the first officer wasn’t more helpful here. He had visual contact with the runway. On activation of the stick shaker, none of the crew members took a positive action reflexively and merely called out the warning. The captain’s final record to back off, I can’t comprehend.
The safety board believes that the AIA scheduling of crew contributed to their fatigue and substandard performance. Flight and duty time limitations applied through various regulations to suit the company’s economic interest were just a means of ensuring maximum productivity through crew utilization without regard to the human factors involved regarding rest and recreation. Keeping the crew going for 24 hrs through a combination of loopholes is preposterous.
Cockpit Resource Management (CRM)
There was almost no coordination in the critical phases of the flight. Despite repeated concerns expressed by the other two crew members regarding the decaying speed, the captain chose to ignore their concerns and paid for it. The other crew members should have been more assertive and followed through with appropriate action.