Posted by Sade Williams
The Accident Investigation Bureau (AIB) on Wednesday, released the preliminary report of the accident involving Agustawestland aw139 helicopter (5N-CML) operated by Caverton helicopters limited which conveyed 12 souls, including Vice President Yemi Osinbajo to Kabba Stadium, Kogi State.
The report which was read by the Commissioner, Engr. Akin Olateru, although, stated that investigation was ongoing, but explained that the flight departed Murtala Mohammed International Airport Lagos, for Nnamdi Azikiwe International Airport Abuja, to conduct a chartered VIP flight from Abuja to Okene via Kabba and then return to Abuja.
It has however issued two immediate safety recommendations, one each to the Nigerian Civil Aviation Authority and Caverton helicopters.
It has asked the NCAA to issue an Advisory Circular to all helicopter operators flying in Nigeria to be alert of the possibility and the effect of ‘brownout’ while appropriate procedures should be put in place to mitigate its effects.
It has also asked Caverton Helicopters Limited to ensure that flight operations are carried out in accordance with the company’s approved operations manual, vis-à-vis site survey and proper safety risk analysis are done before dispatching any helicopter to unapproved landing pads.
It explained that at about 13:46 h, the helicopter departed Abuja runway 22 for Kabba, Kogi State on a VIP chartered flight Nigeria 002 (NGR002), on a Visual Flight Rule (VFR) Flight Plan with 12 persons onboard, including the Vice President of the Federal Republic of Nigeria, his entourage and three crew members (Captain, Co-Pilot and an Engineer). The fuel onboard was 1,268 kg. A squawk code of 1301 was given by the Air Traffic Control (ATC) for radar monitoring.
The report stated among other things that after the crew identified the stadium in Kabba, flight crew members agreed on the selected landing spot within the stadium.
“The NGR002 got into hover to land and at 50 ft above ground level, a brownout set in. 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. At about 14:34 h, the helicopter experienced a hard landing on the right main landing gear and rolled over to the right.
“The Captain immediately shut the engines while the Co-Pilot shut off the fuel. The flight crew could remember executing the emergency landing procedures, which included switching off the battery and the generators. According to the weather report obtained by Nigerian Airspace Management Agency (NAMA), the prevailing weather at the stadium was good (CAVOK)”, the report stated.
The report revealed that the Kabba football stadium, where it landed is an unpaved field. It has the elevation of 1500 ft (457 m) above mean sea level and located at about the coordinate 07°50’32”N 06°04’42”E.
AIB initial findings include in the report show that: the helicopter had a valid certificate of airworthiness; Caverton Helicopters Limited did not conduct site survey of the landing field prior to this flight; Caverton Helicopters Limited 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 while drug and alcohol test for the crew could not be carried out.
It added that the flight crew were properly licensed and adequately rested to operate the flight; the Captain was the Pilot Flying (PF), and the Co-pilot was the Pilot Monitoring (PM); the take-off, climb out, cruise and approach phases were normal; during cruise at 5,000 ft and at about 10 minutes to touchdown, the crew noticed the flight recorder light on the Crew Alerting System (CAS) come ON. Quick Reference Handbook items were accomplished while another helicopter operated by Nigeria Police Force (Bell 412; 5N-PEJ) landed ahead of NGR002.
Others are that the crew briefed on landing in brownout and used the Company’s Brownout Landing Procedures; during the landing, at about 50 ft 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 h, 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.
N.B::A brownout is an in-flight visibility restriction due to dust or sand in the air. In a brownout, the pilot cannot see nearby objects which provide the outside visual references necessary to control the aircraft near the ground.