The Accident Investigation Bureau AIB has attributed the helicopter crash in Kabba, Kogi state to a brownout during it’s landing in a dry, dusty environment.
At a news conference in Lagos during the release of the preliminary report into the incident, the Commissioner AIB, Mr.Akin Olateru said due to the dusty condition, the crew lost visual contact with the ground.
The helicopter, an AgustaWestland AW139 operated by Caverton Helicopters Limited crashed on the 2nd of this month while trying to land at the Kabba stadium carrying Vice President Yemi Osinbajo and 11 others including two crew members.
According to the Commissioner Accident Investigation Bureau, AIB, Mr. Akin Olateru ” after the crew identified a landing spot, brownout occurred which brought the aircraft down”.
He explained the brownout to mean a condition generated during landing in a Sandy, dusty environment.
The AIB Commissioner said the crew then lost control of the helicopter as visual contact with the ground became impossible.
“The crew lost visual contact with the ground and elected to use the Instantaneous Vertical Speed Indicator (IVSI) and Radio Altimeter (RAD ALT) to control the descent.
The Co-Pilot began RAD ALT callouts “35, 30, 25, 20 and 15”. After the RAD ALT 15 Callout, neither the Co-Pilot nor the Captain could remember making or hearing further callouts”.
Mr. Olateru emphasized that the crash had nothing to do with the weather, stressing that as at the time of the incident, the weather was good.
He however noted that Caverton Helicopters Limited did not conduct a site survey of the landing prior to the flight.
The AIB, therefore, issued two immediate safety recommendations both to the Nigeria Civil Aviation Authority, NCAA and Caverton Helicopters which includes that an advisory circular should be issued to all helicopters flying in Nigeria of the possibility of a brownout.
“NCAA should issue an Advisory Circular to all helicopter operators flying in Nigeria to be alert of the possibility and the effect of brownout. Appropriate procedures should be put in place to mitigate its effect(s). Caverton Helicopters Limited should ensure that flight operations are carried out in accordance with the company’s approved operations manual, vis-a-vis site survey and proper safety risk analysis are done before dispatching any helicopter to unapproved landing pads”.
The final investigation report into the crash is expected to be released in a few months time by the AIB.