Incident Overview
On the day of the accident, a DC-8 aircraft arrived at Quito's airport at 06:52 after a flight from Miami. The scheduled departure time was 09:00, but shortly after that, members of the Ecuadorian Federation of Aircrews (FEDTA) requested and were granted permission to board the aircraft to discuss matters related to an aircrews' strike. The four crew members of Aeroservicios Ecuatorianos did not participate in the strike, having consulted with AECA management.
Sequence of Events
After a delay of approximately two hours, the number 4 engine was started. The crew then ordered the aircraft to be towed to the runway, possibly to expedite departure. During the towing operation, the other engines were started. Pre-takeoff checks were either not performed or were performed improperly. Consequently, the horizontal stabilizer was set to 0.5° nose-up instead of the required 8° nose-up for takeoff.
Takeoff and Crash
During the takeoff ground run, the aircraft barely climbed and overran the runway by 48 meters. The horizontal stabilizer struck the wooden structure of the ILS aerial, located 83 meters past the end of Runway 35. The aircraft then crashed into houses 460 meters past the runway end and 35 meters to the right of the extended centerline. A total of 25 houses were demolished. All four crew members and 49 people on the ground were killed, and at least 50 other people on the ground were injured, some seriously.
Probable Cause
The official investigation determined the probable cause to be the incorrect position of the horizontal stabilizer in relation to the aircraft's center of gravity, which prevented the aircraft from reaching rotation and lift-off speed within the available runway distance. Contributing factors included improper clearance of the aircraft from Quito, as the maximum takeoff weight permissible for the existing runway, wind, and temperature conditions, the actual takeoff weight, the useful load distribution, and the center of gravity position were not determined. Additionally, the crew's state of mind may have been a contributing factor, as it may have prevented them from concentrating on all aspects of the operation.