Air India Express flight IX-611,a Boeing 737-800, VT-AYD 11th Oct 2018 suffered an accident soon after getting airborne. During takeoff roll, the Captain’s seat recline lock failed and the seat reclined. This resulted in an inadvertent action on the throttles pulling them back inadvertently. The thrust reduced from 98% N1 to 77% N1 and the crew did not realize this thrust reduction.
The Captain recovered from the reclined seat and took back the controls after having briefly handed them over to the Co-Pilot. Due to the reduced thrust, the aircraft took a longer roll on the runway but reached the rotation speed with approx 1500-2000ft runway remaining. They attempted to liftoff but the aircraft did not react except for lifting the nose up. The tail of the aircraft hit the ground as the aircraft left the paved surface of the runway.
The aircraft now managed to get airborne but soon the landing gear, wheels probably hit a portion of the boundary wall, breaking a portion of it. The investigating authorities released the report after 33 months but it does not address the root causes of the accident nor does it analyze the human factors.
The AAIB Final report is available here..
Safety matters has written a brief report on the subject. After reading the report I have come to the conclusion that the investigation report is inconsistent in facts and provides selective data, thereby rendering it biased and inaccurate. The accident at Trichy would have been catastrophic had the aircraft suffered an engine failure(50% thrust) during takeoff. The aircraft would not have been airborne since she struggled with 80% thrust in this occurrence.
Certain critical facts have been ignored and there are plenty of errors. Therefore I am writing to you calling for a re-investigation of the said accident.The decision of the crew is not the primary objective of the investigation nor is it the cause. A separate investigation may investigate the crew and organization actions.
Through this communication I would like to highlight a few basic points which will change the course of investigation and lead to a different conclusion.
The reasons are listed below and a detailed analysis pdf report is attached herewith.