The final report of the December 10, 2005 Sosoliso air crash in Port Harcourt was yesterday released by the Accident Investigations and Prevention Bureau (AIPB) which blamed adverse weather conditions and crew�s delayed decision to carry out a missed approach as contributory and probable causes of the mishap.
Coming about 10 months after the tragedy which claimed the lives of 108 passengers and crew, the report did not show any marked departure from the preliminary one which had earlier attributed the accident to a sudden change in wind speed and direction when the aircraft was on approach.
The report said no wind information was given to the pilot just as he did not demand for same, adding that although the airfield lightings, including runway edge lights and Precision Approach Path Indicator (PAPI), among others, were operational; they were switched off at the time of the crash.
Briefing newsmen on the report in Lagos yesterday, Director, AIPB, Engr. Angus Ozoka however cleared the fog on the airworthiness status of the aircraft and the competence of the crew, noting that the aircraft had a valid certificate of airworthiness without known defects that could have contributed to the accident while the crew had valid licence and were qualified to fly the aircraft on the day of the tragedy although the first officer had limited experience.
Ozoka who stated that the AIPB collaborated effectively with the United States� National Transportation Safety Board (NTSB) in the investigation of the accident, noted that recording of the ill-fated plane�s Cockpit Voice Recorder (CVR), otherwise known as the black box which was read in the facility of NTSB was poor as there were problems of echo effect, unintelligible data and faulty erase function.
But he however stated that these defects were effectively taken care of by filtering at the NTSB read-out facility.
On the probable and contributory causes of the crash, the report blamed the crew�s decision to continue the approach beyond the �Decision Altitude� without having the runway and/or airport in sight as a probable cause of the air disaster.
On the contributory factors, the report said the aircraft encountered adverse weather conditions with the ingredients of wind shear activity on approach, which is a sudden change in wind speed and direction.
�The reducing visibility in thunderstorm and rain as at the time the aircraft came in to land was also a contributory factor to the accident. And the fact that the airfield lightings were not on may also have impaired the pilot from sighting the runway.
�Another contributory factor was the fact that the aircraft had an impact with the exposed drainage concrete culvert which led to its disintegration and subsequent fire outbreak�, the report affirmed.
Giving a blow by blow account of the ill-fated flight, the report said the aircraft, which departed Abuja en route Port Harcourt, got in contact with the approach controller at 1241 hours UTC (about 1.41 pm local time), maintaining flight level 240 (altitude of 24, 000 feet above sea level).
The report added that the approach controller then gave the aircraft an in-bound clearance of no delay expected on ILS (Instrument Landing System) approach runway 21, adding that basic meteorological equipment for measuring visibility and cloud conditions were lacking at the airport.
The report however said the data generated by the Nigerian Meteorological Agency (NIMET) officials was in agreement with the data obtained from the satellite Imagery from the United States of America.
It noted that the flight continued its descent until about 2pm when the crew asked the approach controller whether it was raining over the station (Port Harcourt) but got a negative response, adding that at 2.05pm, the aircraft contacted the control tower and the controller cleared it for landing on Runway 21 while advising the crew to exercise caution as the runway surface was slightly wet.
�The aircraft on final approach encountered adverse weather with change in wind speed and direction changing from 220o/09kts (headwind) in nil weather to 360o/05kts (tailwind) while the visibility was reducing in thunderstorm and wind.
The report added that there was no standard instrument call-out by the crew as evidenced by the Cockpit Voice Recorder, adding that the aircraft continued it descent and went below the �Decision Altitude�, the attempt of which was said to be unsuccessful.
The aircraft�s tail section was said to have made contact with the grass strip between Runway 21 and taxiway, 70 metres to the left of the runway edge and 540 metres from the runway threshold.
�At about 6om from the first impact, the aircraft rear fuselage impacted heavily with an exposed concrete drainage culvert where the number two engine of the aircraft and the rear staircase were detached and lodged. The exposed concrete drainage is badly located and poses a real danger to aircraft landing on runway 21.
�The aircraft disintegrated and caught fire along its path spanning over 790m. The cockpit section with the forward fuselage was found at further 330m from the rest of the wreckage trail on the taxiway giving a total wreckage distance of 1120m�, the report said, adding that the response time of the fire services was reasonable (about 1 minute) but were hampered by widespread fire covering 1.2 kilometres as well as very strong winds and paucity of resources to combat the tragedy.
While stating that the rescue team recovered 103 bodies and seven survivors, the report said five of the seven survivors later died in the hospital while two are still receiving treatment.
The accident investigators recommended that where the training captains of domestic airline operators conduct simulator training for their pilots at overseas institutions, the final check should be carried out and certified by instructors designated or appointed by the host country�s civil aviation authority for transparency.
Asked if this recommendation was informed by suspicion on any foul play, Ozoka responded in the negative.
The report also recommended that pilots flying into Port Harcourt and other coastal areas of the country should be mindful of weather hazards such as wind shear activity, adding that recognition and recovery from adverse weather/wind shear should be mandatory part of pilots� initial and recurrent simulator trainings.
Although the Bellview crash occurred two months earlier than that of Sosoliso, the report of the former is yet to be released.
Ozoka attributed the delay in the investigations to the inability to recover the Cockpit voice Recorder (CVR) and Flight Data Recorder (FDR) and the absence of survivors as well as eyewitnesses, adding however that investigations were continuing.
Ozoka, who said investigations into air crashes all over the world might take several years, noted that the Bellview accident might fall into that category, assuring however that in collaboration with United States agencies, no effort would be spared to unravel the causes of the accident.