The Nigerian Safety Investigation Bureau (NSIB) has disclosed the cause of the incident involving a Boeing 737-400 aircraft operated by Max Air Limited with registration number 5N-MBD.
The Director General of the NSIB, Akin Olateru, disclosed this while speaking with journalists on Thursday in Abuja.
According to Olateru, the incident which occurred on May 7th, 2023 was due to poor maintenance and power failure.
He said the Yola ATC Voice Recording System did not record any communication between the pilot and the duty controller on the day of the occurrence.
He however tasked Nigeria Civil Aviation Authority (NCAA) to ensure that the Federal Airport Authority of Nigeria (FAAN) and Nigerian Airspace Management Agency (NAMA) ensure uninterrupted power supply to avoid the vulnerability of operations.
He said days before the aircraft was operated, the wheel of the aircraft was worked on.
He said, “Days before the use of the aircraft, the wheels were worked on and when you work on the wheel, there are ways you are supposed to tighten the knots, there is what we call locking wire of the knots and there are other things to secure the wheel in place.
“Two days after, the wheel came out, which shows that something must be wrong with the maintenance of the aircraft. Whoever did the wheel definitely did not follow the manufacturer’s recommendation on how to change the wheel.
“So, for a wheel to have fallen off, even Boeing was also interested in this because it is their aircraft and they find the news very embarrassing. So, they are working with us so that they can have firsthand information.
Giving further details of the incident, Olateru said: “At 12:10 h 5N-MBD departed Nnamdi Azikiwe International Airport (DNAA) for Yola (DNYO) as NGL1648 and arrived at Yola at 13:25 h.
“The aircraft was on ground Yola for about 30 minutes before the turn around for Abuja adding that after takeoff, the landing gear was left extended for three minutes to allow cooling due to high temperature on ground Yola.
“At 14:08 h, Nigerian Air Force personnel from the Air Force Hanger close to runway 35, reported to Yola Control Tower that an object appearing like a tyre fell off from the departing NGL1649.
“Yola DATCO promptly informed the Pilot of NGL1649 as well as Kano Area Control (ACC) and Abuja Tower. The flight purser (L1) and another cabin crew (L2) informed the Pilot that a passenger in seat row 24 informed them about seeing a wheel fall off from the aeroplane.”
Olateru added that the pilot mentioned that instruments and landing gear indications were normal.
“At 14:51 h Yola ATC informed Abuja Tower and NGL1649 that nothing was found after the runway inspection.
He disclosed that the landing was normal but after the aeroplane started decelerating, he noticed the port side wing was dropping lower than normal, he applied full aileron control to keep the wing from dropping until the lift decayed.
“Thrust reverser and minimal braking were used to stop the aircraft on the runway. At 14:57 h, Abuja ATC informed NGL1649 “Be advised, it appears you have smoke around your aircraft.
“We called the fire watch room, the Aerodrome Rescue and Fire Fighting Services (ARFF) and emergency services were alerted. The aircraft came to a stop between Link A5 and A6 about 2900 m from the threshold of runway 22.
“The port wheel assembly was located by personnel of the Federal Airports Authority of Nigeria (FAAN) about 1000 m from the threshold of Runway 35 Yola airport on 08th May 2023.
“The roller bearings on the wheel assembly of No. 1 main wheel had discolouration and were burnt out. The CVR recording was found to be overwritten.
Olateru continued, “Max Air Limited stated that they were unaware of the NCAA All Operators Letter (AOL). (NCAA/FSG/AOL/19/03) in respect of continuous overwriting of Cockpit Voice Recorder (CVR) Information. There was a wrong tech log entry for the service.”