Negligence, human error cause four air mishaps-Report

• AIB expands scope to probe rail, road crashes

The Accident Investigation Bureau (AIB) said the June 5, 2015 Aero Contractor serious incident involving a B737-500 with registration number 5N-BLE which occurred at flight level 330 feet was as a result of negligence and pilot’s error occasioned by the inadvertent failure to discover that the pressure regulating and shutoff valve was in the locked closed position after the engine change.

 The crew also failed to recognise that the number two bleed pressure was zero after engine start and subsequent failure to monitor the pressurisation system during climb.

The Federal Government had concluded plans to upgrade the Accident Investigation Bureau (AIB) by expanding its functions, which would be similar to that of America’s National Transportation Safety Board (NTSB).

The AIB Commissioner, Mr. Akin Olateru, an aircraft engineer disclosed this while presenting final reports on the crash and three other serious incidents to the public.

The three other reports released today included reports on the accident involving Gitto Construction Nigeria Limited’s Bell 407 Helicopter with registration 5N-BIC which occurred at Uyo Airport on October 21, 2009; Nigeria College of Aviation Technology (NCAT) Socata TMB 850 aircraft with registration 5N-BZA which occurred Kaduna on May 21, 2013 and one involving an aircraft belonging to International Aviation College (AIC) which occurred on August 18, 2014.

The AIB was not officially notified but got to know of the serious incident the following day, June 6, 2015 through the media. Relevant authorities and stake holders were appropriately notified thereafter.

His words, “The Air Traffic Control (ATC) cleared the aircraft for take-off and to climb and maintain Flight Level (FL) 350. Normal cabin rate of climb (300ft/min) was observed during the initial climb. During climb at approximately 23 minutes, the cabin altitude warning horn sounded and the cabin altitude warning light came on”.

 “The Captain took control of the aircraft, passenger announcement was made and emergency descent initiated to an altitude of 10,000ft. The flight diverted to Abuja with a distance of about 120nm to go. The aircraft made a safe landing in Abuja at 1932hrs and all passengers and crew disembarked normally and without injuries. The incident occurred at night”, he added.

The AIB however recommended that the Nigeria Civil Aviation Authority (NCAA) should ensure that the activities of flight operations and maintenance departments of Aero Contractors Company of Nigeria Limited are carried out in compliance with the Nigeria Civil Aviation Regulations (NCARs).

Following the recommendation and due to the frequent engine changes, NCAA is considering issuing an All Operators’ Letter (AOL), requiring operators of aircraft to mandatorily inform it of any engine changes prior to accomplishment. This it said would enable the authority to monitor the processes.

He attributed the causal and contributory factors of Nigerian College of Aviation Technology (NCAT) Socata TBM 850 aircraft accident with registration 5N-BZA which occurred Near Kaduna Airport, Kaduna, Nigeria on the May 21, 2013 to the decision of the crew to depart Abuja airport with the knowledge of weather forecast, and failure to follow the guidance provided by the weather radar advisory to avoid the impending adverse weather.

 He also stated that late recognition of the icing/hailstorm encountered by the pilot during the flight, failure of the pilot to adequately follow aircraft certification standards (procedures/limitations) for turbulent air, storms and icing conditions penetration contributed to the accident.

The safety issues in this report focused on TBM-850 procedures for the use of ice protection systems, radar system, turbulence and icing penetration, airspeed limitations and information, stall warning/protection system capabilities, operation of the autopilot in icing conditions, aircraft icing certification requirements, and icing-related research as per NCAT’s Approved Operations Manual (AOM) and Airplane Flight Manual (AFM), duty and rest period compliance.

 On the what led to accident involving Gitto Construction Ltd’s Bell 407 Helicopter which occurred on October 21, 2009, Olateru disclosed that improper maintenance of the oil system which led to oil starvation resulting in the failure of the No. 6, 7, and 8 bearings in the power turbine section of the engine led to power loss, including improper identification by the pilot of the transmission chip light illumination during flight instead of the engine chip caused the accident.

 “The decision of the pilot to continue with the flight from Uyo to Port Harcourt International Airport without identifying the cause of the transmission chip detector indication. The non-replacement of the stage 1 & 2 turbine wheels due to limited life remaining are also contributory factor”.

He explain that early this year, when he assumed office,  they pledged to clear the backlog of outstanding accident investigation reports they inherited, which were about 27 as at the time they took over.

 He said his management embarked on a relentless pursuit of releasing accident reports in order to achieve the main purpose of accident investigation.

 Accident Investigation plays a vital role in enthroning and sustaining a robust air safety regime. This cannot, however be achieved when outcomes of accident investigations are not timely released.

Wole Shadare