The Accident Investigation Bureau has released the preliminary report of the helicopter accident involving the Vice President, Prof. Yemi Osinbajo.
The Commissioner, AIB, Mr. Akin Olateru, on Wednesday said the investigation was still ongoing but that among other causal factors, the crew lost visual contact with the ground at landing due to a “brownout.”
According to him, brownout is caused by landing in a dry, sandy environment.
“Caverton Helicopters Limited did not conduct site survey of the landing field prior to the flight and did not carry out safety and risk assessment,” he said.
A helicopter conveying the Vice President to a campaign rally in Kogi State had crash landed in Kabba on February 2.
Nobody died or sustained injury in the crash.
The News Agency of Nigeria reports that AIB released its preliminary report on the February 2 Caverton Helicopter crash involving Vice President Yemi Osinbajo in Kabba, Kogi.
Olateru, presenting the reports exactly 11 days after Osinbajo and 11 others survived the crash, said: “The findings revealed that the helicopter had a valid Certificate of Air Worthiness.
“But the operators, Caverton Helicopters Ltd., failed to carry out risk assessment test of the Kabba Stadium prior to the flight.
“Caverton Helicopters Ltd did not conduct site survey of the landing field prior to this flight.
“Caverton Helicopters Ltd did not carry out safety and risk assessment of the landing area prior to dispatch of the flight.
“The helicopter hovered to land in a brownout condition.”
The AIB commissioner also attributed the crash landing of the Agustawestland W139 Chopper, with registration number 5N-CML, to brownout, a condition generated by trying to land in a dusty and sandy environment.
Olateru said that the purpose of the preliminary investigation was to provide details of the initial facts, discussions and findings surrounding the occurrence.
He said that the investigation was conducted using information gathered from the witness statements, flight recorders, Health and Usage Monitoring System, HUMS; and Data, Flight Data Monitoring.
The commissioner said that it also included preliminary inspection of the accident site and the wreckage. He said drug and alcohol test for the crew could not be carried out, but they were properly licensed and adequately rested to operate the flight.
According to him, the Captain was the Pilot Flying, and the co-pilot was the Pilot Monitoring; while the take-off, climb out, cruise and approach phases were normal.
Olateru said another helicopter operated by Nigeria Police Force (Bell 412; SN-PEJ) landed ahead of NGR002.
He added that the crew briefed on landing in brownout and used the company’s Brownout Landing Procedures.
“During the landing, at about 50 R to touchdown, a heavy brownout enveloped the helicopter and the crew lost visual contact with the ground.
“The Co-Pilot called out radio altimeter 35, 30, 25, 20, 15 and no more.
“At about 14:34 hour (2.34pm), the helicopter touched down hard on the right main landing gear and rolled over to the right.
“The crew carried out Emergency Landing Procedures which included immediate engines shutdown, fuel shut OFF, battery switch OFF, and generators switch OFF,” Olateru said.
He said that all occupants of the helicopter were evacuated uninjured, but the helicopter was substantially damaged.
Olateru said the bureau had, as part of the safety recommendations, directed the Nigerian Civil Aviation Authority to issue an Advisory Circular to all helicopter operators flying in Nigeria to be alert to the possibility and effects of brownout.
He said this was to ensure that appropriate procedures were put in place to mitigate its effect(s).
The commissioner said the AIB also advised Caverton Helicopters Ltd. to ensure that flight operations were carried out in accordance with the company’s approved operations manual.
He said this include site survey and proper safety risk analysis are done before dispatching any helicopter to unapproved landing pads.