Incident Overview

Date: Tuesday 18 September 1984
Aircraft Type: Douglas DC-8-55F
Owner/operator: AECA – Aeroservicios Ecuatorianos
Registration Number: HC-BKN
Location: Quito-Mariscal Sucre Airport (UIO) – ÿ Ecuador
Phase of Flight: Take off
Status: Destroyed, written off
Casualties: Fatalities: 4 / Occupants: 4
Component Affected: Horizontal StabilizerHorizontal Stabilizer
Category: Accident
On October 6, 2023, a DC-8 aircraft landed at Quito after a flight from Miami. Following scheduled departure time, members of the Ecuadorian Federation of Aircrews (FEDTA) requested and were granted permission to board the aircraft and discuss strike issues. The crew, consisting of four Aeroservicios Ecuatorianos crewmembers, failed to comply with the strike, leading to a delay of approximately 2 hours. After consulting AECA management, the aircraft’s no. 4 engine was started. The crew then ordered the aircraft to be towed to the runway, potentially to hasten departure. During this towing operation, pre-takeoff checks were not performed, resulting in a significant issue ? the aircraft’s horizontal stabilizer nose-up became undetected, exceeding the required 0.05ø horizontal stabilizer angle. This resulted in the aircraft barely climbing after ground run, extending to 48 meters beyond the runway end. The horizontal stabilizer struck the ILS aerial, 83 meters past the runway 35 end. Subsequently, the aircraft 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. The probable cause of this accident was a misaligned horizontal stabilizer, which prevented the aircraft from reaching rotation and lift-off speed within the runway distance available. Contributing factors included incorrect clearance of the aircraft from Quito, considering factors such as the aircraft’s MTOW, wind, temperature, useful load distribution, and center of gravity. Furthermore, the crew’s state of mind may have contributed to the incident, potentially hindering their focus on all operational aspects.On October 6, 2023, a DC-8 aircraft landed at Quito after a flight from Miami. Following scheduled departure time, members of the Ecuadorian Federation of Aircrews (FEDTA) requested and were granted permission to board the aircraft and discuss strike issues. The crew, consisting of four Aeroservicios Ecuatorianos crewmembers, failed to comply with the strike, leading to a delay of approximately 2 hours. After consulting AECA management, the aircraft’s no. 4 engine was started. The crew then ordered the aircraft to be towed to the runway, potentially to hasten departure. During this towing operation, pre-takeoff checks were not performed, resulting in a significant issue ? the aircraft’s horizontal stabilizer nose-up became undetected, exceeding the required 0.05ø horizontal stabilizer angle. This resulted in the aircraft barely climbing after ground run, extending to 48 meters beyond the runway end. The horizontal stabilizer struck the ILS aerial, 83 meters past the runway 35 end. Subsequently, the aircraft 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. The probable cause of this accident was a misaligned horizontal stabilizer, which prevented the aircraft from reaching rotation and lift-off speed within the runway distance available. Contributing factors included incorrect clearance of the aircraft from Quito, considering factors such as the aircraft’s MTOW, wind, temperature, useful load distribution, and center of gravity. Furthermore, the crew’s state of mind may have contributed to the incident, potentially hindering their focus on all operational aspects.

Description

The DC-8 landed at Quito at 06:52 after a flight from Miami. Shortly after scheduled departure time of 09:00 members of the Ecuadorian Federation of Aircrews (FEDTA) requested and were granted permission to board the aircraft and discuss subjects relating to the aircrews’ strike. The 4 Aeroservicios Ecuatorianos crewmembers didn’t comply with the strike, after consulting AECA management. After a delay of about 2 hours, the no. 4 engine was started. The crew then ordered the aircraft to be towed to the runway, perhaps in order to hasten the departure. The other engines were started during the towing operation. Pre-takeoff checks were not (or improperly) carried out. This caused the 0.05deg horizontal stabilizer nose-up to go undetected, while 8deg. nose-up is required for takeoff. The DC-8 thus barely climbed after a ground run, extended to 48 m beyond the runway end. The horizontal stabilizer struck the wooden structure of the ILS aerial, 83 m past the runway 35 end. The aircraft then crashed into houses, 460 m past the runway end and 35 m to the right of the extended centreline. A total of 25 houses were demolished. PROBABLE CAUSE: “The incorrect position of the horizontal stabilizer in relation to the aircraft’s centre of gravity, which prevented the aircraft from reaching rotation and lift-off speed within the runway distance available. Factors were: 1) Clearance of the aircraft from Quito was done incorrectly, since the MTOW permissible for the existing runway, wind and temperature conditions, the real take-off weight, the useful load distribution and the position of the aircraft’s centre of gravity were not determined. 2) The crew’s state of mind may have been a contributing factor in the accident. It is assumed that it prevented the crew from concentrating on all aspects of the operation they were performing.”

Primary Cause

Incorrect position of the horizontal stabilizer in relation to the aircraft’s center of gravity, leading to a failure to reach rotation and lift-off speed within the runway distance.Incorrect position of the horizontal stabilizer in relation to the aircraft’s center of gravity, leading to a failure to reach rotation and lift-off speed within the runway distance.

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