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23 May 2015 - The Nigerian AIB have published their final report into the runway excursion involving Boeing 737-500, 5N-BLE at Yakubu Gowon Airport, Jos, Plateau State, Nigeria On 21st August, 2010.

Synopsis

On 21st of August, 2010, about 1738 hrs, Aero Contractors flight 210, a Boeing 737-500, 5N-BLE, skidded off the threshold of runway 28 while landing on approach into Yakubu Gowon Airport, Jos, Plateau State. The flight was operating under the provisions of NCAA regulations as a scheduled domestic passenger flight from LOS to Yakubu Gowon Airport, Jos. The flight departed LOS about 1627 hrs, with two pilots, three flight attendants, and 87 passengers on board. The airplane commenced an approach and touched down with the Right Main Wheel 135 metres from the threshold, skidded off the runway 28 to the left into the grass area, damaged three runway light assemblies and uprooted the armored cables at the airport. All 92 persons on board sustained little or no injury, and the aircraft was substantially damaged. The airplane was operated on an instrument meteorological condition (IMC) flight plan. The incident happened at about 1738 hours..

The investigation identified the following causal and contributory factors:

Causal Factor The decision of the crew to continue the approach in an unstabilized condition, coupled with the Captain in-appropriate attempt to take over control of the aircraft.

Contributory Factors

  1. Fatigue, which impaired the Captain’s performance and reflected the effects of a long, demanding duty day associated with check airman functions.
  2. Poor Crew Resource Management.
  3. The prevailing weather condition.

Two safety recommendations were made.

1. Aero Contractor should review its Safety Management System making all safety critical staff aware of their responsibility to alert the system whenever signs of stress, fatigue or disordered behaviours are noticed in any operating flight crew members.

2. Aero Contractor should re-emphasize adherence to safety and company operating procedures by flight crew members and for captains to take over control of the aircraft promptly whenever critical operational deviations are noticed during flight in adverse weather conditions.

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1.0 FACTUAL INFORMATION

1.1 History of Flight: Flight AJ 345, 5N-BLE, B737-500 departed Lagos for Yakubu Gowon airport, Jos at 1627 hrs, with 87 passengers and 5 crew on board. The weather report of Jos Airport for 1500 UTC was made available to the captain of the aircraft on ground Lagos. At 1703 hrs, Flight AJ 345 contacted Jos Airport and was updated with the hourly weather report. Heavy rain was reported in Jos at this moment, crew was advised and aircraft was about 35 minutes to the station. The aircraft was given an inbound clearance for Runway 28, which was acknowledged by the crew. The aircraft was released to Jos by Kano Area Control Centre at 1722 hrs, with descent and approach clearance given for runway 28 by Jos ATC. Prior to this, FAAN Electrical Unit was informed by Jos ATC to switch on the Approach and Runway lights for Runway 28. At 1729 hrs, the Tower cleared the aircraft to 7000 ft and for VOR/DME Approach on Runway 28. The Captain requested for the runway lights to be turned ON by 1732 hrs and was told by the Tower that FAAN Electrical Unit was having problem putting on the lights. The weather situation was bad even though the rain had stopped. There was low cloud base and wet runway. The runway 10 equipped with Instrument Landing System (ILS) was unserviceable. At 7 nautical miles (NM) final, the Tower re-advised the crew that the runway lights were not ON due to technical problem encountered by FAAN Electrical Unit.

The captain reported ‘Field in Sight’ at 1737 hrs while Tower requested him to confirm “Runway in Sight” which he replied in the affirmative. Based on this confirmation, the aircraft was cleared to land on Runway 28. According to ATC, within few seconds later, the aircraft was sighted about 1 nautical mile, struggling to align to the centre line of the runway. The aircraft touched down with the Right Main wheel 135 meters from the threshold, skidded off the runway to the left into the grass area, damaged three runway lights and uprooted the armored cables. The Starboard engine made contact with the runway, damaged the lower cowling and ingested foreign objects that resulted to fan blades damage and punctures at the air intake section of the engine. The aircraft recovered from the grass area back to the centre line of the runway and came to rest at 2000 metres from the threshold of runway 28. The Nose gear shock strut collapsed and the two nose wheels were damaged and deflated. The captain requested for step to disembark the passengers as he could not taxi the aircraft off the runway. Passengers were later evacuated in an orderly manner without injuries or further incident. The incident occurred at runway 28 of Yakubu Gowon Airport at about 1738 hours in daylight.

1.7 Meteorological Information The actual meteorological condition as obtained from Nigerian Meteorological Agency (NIMET) was as follows: Time : 1500 UTC Wind : 300/18kts Visibility : 10km Weather : Thunderstorm Cloud : BKN 180m Few CB 420m SE Temp. : 230C/200C QNH : 1018 hPa Time : 1600 UTC Wind : 260/18kts Visibility : 2500m Weather : Thunderstorm Cloud : BKN 150m Few CB 450m Temp. : 190C QNH : 1018 hPa

1.8 Aids to Navigation NOTAM was issued showing that E/ILS Glide Slope with Frequency 330.2 MHz now serviceable and Non-Directional Beacon (NDB) with Frequency 270 KHz was not serviceable at the time of the incident and shut down for maintenance. Approach light of runway 10 and edge lights were reported to FAAN as unserviceable.

1.9 Communication There was good communication between the aircraft and the control tower throughout the duration of the flight.

1.10 Aerodrome Information The aerodrome is situated to the South, 34km from the city. It has elevation of 4232ft (1,290m). It is a controlled airfield for both IFR and VFR operations with runway orientation of 10/28. The runway is 148ft (45m) wide and 9843ft (3000m) long. The airport has an off-set VOR/DME approach on Runway 28. See below Fig.1.10a-b the Jeppesen chart on VOR/DME of runway 10/28.

1.12 Wreckage and Impact Information The aircraft touched down with the Right Main wheel 135 metres from the threshold, skidded off the runway to the left into the grass area, damaged three runway lights and uprooted the armored cables. The Starboard engine made contact with the runway, damaged the lower cowling and ingested foreign objects that resulted to fan blades damage and punctures at the air intake section of the engine. Both fuel tanks were intact and not ruptured. The aircraft recovered from the grass area back to the centre line of the runway and came to rest 2000 metres from the threshold of runway 28. The Nose gear shock strut collapsed and the two nose wheel were damaged and deflated. See fig 1.12a-g below;

1.14 Fire There was no evidence of fire in-flight or post impact fire.

1.15 Survival Aspect The incident was survivable although the aircraft skidded off the runway, and the damage to the aircraft was substantial but a liveable volume existed. The crew and the passengers survived the incident without any fatality. The mishaps occurred within the vicinity of the airport.

2.0 ANALYSIS

2.1 Conduct of Flight

The crew operated a scheduled public transport (passenger) flight AJ 345, from M.M.A. Lagos to Yakubu Gowon airport, Jos at 1627 hrs, with 87 passengers on board. They were aware of the NOTAM stating that E/ILS Glide Slope with Frequency 330.2 MHz serviceable and E/Locator Beacon Frequency 270 KHz was unserviceable and shut down for maintenance. While approaching Jos airport, the Captain requested for the runway lights to be turned ON by 1732 hrs and was told by the Tower that FAAN Electrical Unit had problem to put on the lights. According to ATC transcript, on approach, the captain reported ‘Field in Sight’ at 1737 hrs while Tower requested him to confirm “Runway in Sight” which he replied “affirmative”. Based on this confirmation, the aircraft was cleared to land on Runway 28. Few seconds later, ATC sighted the aircraft about 1 nautical mile away struggling to align to the centre line of the runway. The aircraft drifted off the extended centerline of runway 28. The aircraft touched down with the Right Main wheel 135 metres from the threshold, skidded off the runway to the left into the grass area, damaged three runway light assemblies and up-rooted the armored cables. The Starboard engine made contact with the runway, damaged the lower cowling and ingested foreign objects that resulted in fan blades damage and punctures at the air intake section of the engine.

The aircraft recovered from the grass area back to the centre line of the runway and came to rest 2000 metres from the threshold of runway 28. The Nose gear shock strut collapsed and the nose wheel was damaged and the tyres deflated. The captain was busy calling Lagos, and the emergency evacuation was not accomplished as required by the Emergency Operation Check List and Company’s Ops Manual see section 1.17.1.4 above. He later requested for step to disembark the passengers as he could not taxi the aircraft off the runway. Passengers were disembarked without injuries or further incident. The investigation revealed that due to the nature of the incident there was a risk of fire outbreak. The crew did not follow the approved emergency and company procedures to mitigate this possibility. According to the records available, the aircraft was serviceable at the time of the incident. The last Certificate of Airworthiness (C of A) was issued 3rd January 2009 and valid to 9th of February, 2011.

2.2 Extra Ordinary Events Preceding the Incident

According to evidence available to the Bureau, on the incident day, the captain (the fleet captain) was rostered on a route training flight (LOS–QOW–ABV-LOS), which he operated early in the day. Another captain was rostered to operate LOS-JOSLOS later in the day. The rostered captain was to position Lagos from Abuja. Unfortunately, the captain that operated into Abuja on diversion enroute Kaduna, had an issue with NCAA Air Safety Inspector and his licence was seized. He could not operate the flight any further. The First Officer after reporting for duty on the incident day was informed of the delay (LOS–JOS–LOS) due to the fact that the flight operated by Chanchangi Airline aircraft had an incident the night before in Kaduna, and this resulted in the early morning Aero Contractors’ flight from Lagos diverted to Abuja. This made the rostered captain for the LOS-JOS-LOS sector to operate the Kaduna flight from Abuja and subsequently LOS–KANO-LOS exhausting his duty time for the day. Meanwhile, the fleet captain ended his route training flight arriving back to Lagos, met a scheduled flight (LOS-JOS-LOS) waiting to be operated. The captain was hoping to go home, as he had finished his flight for the day when the issue of the stand-by pilot who reported sick came up. The fleet captain (The captain) opted to operate the Jos flight with the rostered First Officer for the flight.

2.3.1 The Captain (Fleet Captain)

The captain was qualified to fly the aircraft. He had total flying time of 13800 hours and 2172 hours on type. He was not rostered for the flight while the captain scheduled for the service had exhausted his duty time for the day. The standby pilot reported sick and he (the fleet captain) had to reposition for the flight. He was the pilot monitoring (PM) on the incident flight. He did a route training flight for that day and performed the duties of a check airman. He had good communication with the tower as the PM. The captain was doing the radio work while the first officer was the pilot flying.

2.3.2 The First Officer

He had total flying time of 2869 hours and as well rated on the aircraft. The first officer was qualified to fly the aircraft and was the pilot flying at the time of the incident. He had 1670 hrs on type.

2.3.3 Human Factor

Elements According to evidence from the crew, the captain resumed duty at about 6:30 hrs and did line training for three sectors. However, trainings are usually demanding and exhausting to flight crew. The Captain was tired and this was confirmed during the cause of discussions with the First Officer before the incident flight. The long wait by the crew for about one and half hour for refuelling of the aircraft added to anxiety and further tiredness. The First Officer resumed duty at 11:30 hrs and waited till 17:30 hrs for an aircraft to operate the incident flight. According to evidence obtained from the First Officer, he discussed the possibility of cancellation of the flight due to sunrise–to-sunset operation of Jos airport followed by the weather forecast made available to the crew; and to this the Operations Department disagreed. There was element of organizational pressure to operate the flight, which the Captain accepted as the fleet captain B737 and a management staff of the airline. The Captain had the option to cancel the flight if he so wished based on the company’s standard operating procedures on duty time. He was not rostered for the flight; but accepted to do the flight as all efforts to access another captain failed. The unstabilised approach led to the Captain attempting to make necessary corrections with inappropriate procedure. The correct procedure would have been the Captain announcing that “I have control” which should be responded by the pilot flying “You have control”. The aircraft lost proper control which resulted in the runway excursion. However, good airmanship requires the captain to take control of the aircraft early enough with a standard callout, when he noticed deviation from the runway centerline axis or make the standard call-out for “Go-around” as the PM.

2.3.4 Crew Resource Management (CRM)

The investigation also revealed poor crew resource management precipitated by lack of adequate communication and poor standard call-out. The CVR revealed that during touchdown neither the captain nor the first officer was in control of the aircraft. “I wanted to go-around; I thought you were the one flying”, crew comment captured in the CVR.

2.4 Meteorological Information The meteorological condition as obtained from Nigerian Meteorological Agency (NIMET) was as follows: Time : 1500 UTC Wind : 300/18kts Visibility : 10km Weather : Thunderstorm Cloud : BKN 180m Few CB 420m SE Temp. : 230C/200C QNH : 1018 hPa Time : 1600 UTC Wind : 260/18kts Visibility : 2500m Weather : Thunderstorm Cloud : BKN 150m Few CB 450m Temp. : 190C QNH : 1018 hPa The weather report of Jos Airport for 1500 UTC was made available to the captain on ground Lagos. Heavy rain was reported when the crew had contact with Jos ATC about 35 minutes to the station. The weather situation was bad even though the rain had stopped. There was low cloud base and wet runway and high wind at 18kts coupled with the thunderstorm in the vicinity. This weather situation should have informed the captain to take control of the flight from the onset as part of initial planning. However, at short final the captain requested for wind and was given 300/05kts.

2.5 FAAN Electrical Department According to records available to AIB in this investigation, the approach lights and the edge lights of runway 10 were severally reported unserviceable to FAAN Electrical Department. The Duty ATC officer reported the case of approach light to Electrical department of FAAN as evident in the ATC record from June through July to August 2010; but nothing was done to rectify the issue. The aircraft landed without runway approach and edge lights ON on the day of the incident. Approach lights allow the pilot to visually identify the runway environment and align the aircraft with the runway. It is installed on the approach end of an airport runway and consists of a series of light bars, strobe lights, or a combination of the two that extends outward from the runway end. Runway Edge Lights are used to outline the edges of the runways during periods of darkness or restricted visibility conditions. Runway lightings are used at airports for day and night landings. However, NCAR 8.8.4.15 stipulates what a pilot on approach should use as a visual reference. At Decision Height (DH), if the above references are not available, the pilot must call for a missed approach/go-around.

2.6 Flight Data Recorder/Cockpit Voice Recorder The FDR and CVR were sent to the United Kingdom Air Accident Investigation Branch (AAIB) for download and analysis.

2.7 Approach Briefing and Go-around procedures According to Aero Contractor operations manual part A section 8.4.1, approach briefing and go-around procedures are clearly stated to guide the crew in critical segments of flight operations. Industry best practices recommend the use of checklists and application of the relevant approach plate in approach briefing and go-around procedures. The evidence available to AIB from CVR downloads indicated that the crew did not adequately make reference to checklists in the approach phase of the flight. The investigation revealed that the crew did not brief or execute a missed approach when it became obvious that the aircraft was unstabilised to continue with the approach.

2.8 Descent and Approach The weather situation was bad even though the rain had stopped. There was low cloud base and wet runway. The runway 10 equipped with Instrument Landing System (ILS) and the Non-Directional Beacon (NDB) were unserviceable and shut down for maintenance (See Appendix A&B). See section 1.17.1.3.1. Therefore, the Tower could not advise the captain to consider Runway 10 on VMC approach landing. At 7 nautical miles final, the Tower re-advised the crew that the runway lights were not ON due to technical problem encountered by FAAN Electrical Unit. The captain reported ‘Field in Sight’ at 1637 UTC while Tower requested him to confirm “Runway in Sight” which he replied affirmatively. Based on this confirmation, the aircraft was cleared to land on Runway 28. Few seconds later, the aircraft was sighted about 1 nautical mile away struggling to align to the centre line of the runway. The aircraft touched down with the Right Main wheel 135 meters from the threshold, skidded off the runway to the left into the grass area, damaged three runway light assemblies and uprooted the armored cable.

2.9 Stabilized Approach According to Aero standard operational procedure (SOP), which requires that for a precision approach the pilot must be established in the landing configuration, on profile with the required speed and trim by 1000ft. If the aircraft is not established as above, a missed approach or a go-around must be initiated. However, the height may be reduced to 500ft during a visual approach. The crew did not adhere to the above requirements, instead continued the approach, which resulted into runway excursion and substantial damage to the aircraft.

2.10 Nigerian Airspace Management Agency (NAMA) According to the record available, it was evident that two days after the accident on 23rd of August 2010 the E/ILS glide slope became operational. NOTAM was issued accordingly (See Appendix A &B).

2.11 Evacuation The CVR download, revealed that the captain did not initiate Emergency evacuation procedure as was prescribed in Aero Operations manual; instead the captain was engaged in notifying Lagos about the loss of tyres saying “Lagos Lagos, we lost two tyres … ”. No command of emergency evacuation was carried out. The pilot could not respond to the Cabin Crew Manager (CCM) who came into the cockpit to request for evacuation. From the company’s standard operational procedure, the pilot is to initiate or announce the evacuation of the passengers.

 

3.0 CONCLUSIONS

3.1 Findings

3.1.1 The Instrument Landing System (ILS) on runway 10 which was reported unserviceable and NOTAM was issued in the last three months was made serviceable 24 hours after the incident. 3.1.2 The faulty runway lighting system on runway 28 was rectified shortly after the incident occurred. 3.1.3 Runway surface friction assessment has never been carried out, and no record of the current friction level to enable ATC advise pilots in wet runway condition. 3.1.4 The first officer was the pilot flying at the time of the incident. 3.1.5 The runway was wet after the heavy rainfall reported earlier at the station. 3.1.6 The cloud base was low at the time of the incident. 3.1.7 The pilot was advised and also aware of the weather and runway lightings situations prior to commencement of VOR/DME approach on Runway 28. 3.1.8 The airport has an off-set VOR/DME approach on the Runway centre line. 3.1.9 The Non Directional Beacon (NDB) was unserviceable and NOTAM. 3.1.10 The aircraft was serviceable and had no deferred defects. 3.1.11 The aircraft had a runway excursion. 3.1.12 The crew did not carry out emergency evacuation. 3.1.13 No evidence to confirm that approach briefing was carried out. 3.1.14The crew did not execute a go-around procedure following an unstabilised approach. 3.1.15The captain was not the rostered pilot initially for the flight. 3.1.16 The captain as a fleet captain B737 had earlier carried out a route training flight before the incident flight. 3.1.17 The captain was tired based on the duty schedule of the day which involves three training sectors as check airman.

3.2 Causal Factor

The decision of the crew to continue the approach in an unstabilized condition, coupled with the Captain inappropriate attempt to take over control of the aircraft.

3.3 Contributory Factors

1. Fatigue, which impaired the Captain’s performance and reflected the effects of a long, demanding duty day associated with check airman functions. 2. Poor Crew Resource Management. 3. The prevailing weather condition.

4.0 RECOMMENDATIONS

4.1 Safety Recommendations Aero Contractor should review its Safety Management System making all safety critical staff aware of their responsibility to alert the system whenever signs of stress, fatigue or disordered behaviours are noticed in any operating flight crew members.

4.2 Safety Recommendations Aero Contractor should re-emphasize adherence to safety and company operating procedures by flight crew members and for captains to take over control of the aircraft promptly whenever critical operational deviations are noticed during flight in adverse weather conditions.

 

The full report is available here

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