Preliminary readout and analysis by the Accident Investigation Bureau on the Associated Airlines plane that crashed in Lagos on Thursday last week have revealed that the aircraft’s flaps and right engine were not technically fit before take-off.
The bureau said the crew, prior to departure, expressed some concerns about the plane.
Despite the concerns, the crew still flew the aircraft, which was conveying the corpse of the former governor of Ondo State, Dr. Olusegun Agagu. The plane eventually crashed and killed over 15 persons.
The Commissioner/Chief Executive Officer, AIB, Capt. Muhtar Usman, who spoke at the headquarters of the bureau in Abuja on Friday, said, “The Flight Data Recorder contains several engine related parameters which the AIB is studying. At this point, we can state that the right engine appears to be producing considerable less thrust than the left engine.
“A warning configuration setting suggests that the flaps were not in the correct position for take-off and there is some evidence that the crew may have chosen not to use the flaps for take-off.”
Usman said that the AIB had been able to determine from its preliminary assessment of the Flight 361 recorders, the likely causes of the crash.
According to him, the likely causes include, mechanical and electronic engine control issues related to the right engine and right engine propeller system as well as the take-off configuration issues with respect to flap settings.
He listed other likely causes as “aural warnings related to auto-feather and the flap settings, required for take-off and when and how the number two engine fire handle was pulled”.
The commissioner listed other likely causes to include crew decision making and training with respect to proceeding with the flight, in spite of concerns regarding the aircraft’s suitability for the flight.
“The investigation is also focusing on the standard operating procedure with respect to continuing the take-off roll, in spite of continuous automated voice warnings of both take-off flaps and auto feather when there was ample time to abort the take-off.
Usman also said that the bureau was in the process of developing a comprehensive computer reconstruction of the aircraft to assist its investigation team to understand the sequence of events that led to the crash.
According to him, this will enable the bureau to come up with a comprehensive report of what led to the crash.
He, however, said that the bureau had not been able to come up with any safety recommendations yet.
Usman noted that the AIB would not wait until the final report to make recommendations, if any issue that needed immediate attention arose.
He said that the AIB planned to release the transcript of the Cockpit Voice Recorder (CVR), which contained the internal conversation of the two pilots, radio calls and the overall aural environment in the cockpit area microphone.
According to him, the CVR is of good quality and the bureau is in the process of generating a complete transcript of all relevant information.
“However, the actual recording is under international protocol, sensitive and therefore, privileged information and will not be released at any time‚Äô‚Äô he said.
The AIB is a parastatal agency in the Federal Ministry of Aviation and was established in 1989. It is responsible for the investigation of civil aircraft accidents and serious incidents within Nigeria.
Its fundamental objective is to improve aviation safety by determining the circumstances and causes of air accidents and serious incidents.
The AIB is also saddled with the responsibility of making safety recommendations intended to prevent recurrence of similar accidents in future.