Overland AT72 at Ilorin on Nov 29th 2014, runway excursion

Last Update: January 2, 2023 / 18:10:20 GMT/Zulu time

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Incident Facts

Date of incident
Nov 29, 2014

Classification
Accident

Flight number
OJ-1186

Destination
Ilorin, Nigeria

Aircraft Registration
5N-BPG

Aircraft Type
ATR ATR-72-200

ICAO Type Designator
AT72

An Overland Airways Avions de Transport Regional ATR-72-202, registration 5N-BPG performing flight OJ-1186 from Abuja to Ilorin (Nigeria) with 59 passengers and 4 crew, landed on Ilorin's runway 05 at about 16:45L (15:45Z) but veered right off the runway and came to a stop on soft ground with all gear, the nose gear collapsed. There were no injuries. The passengers disembarked onto the runway via the rear left door and were taken to the terminal.

The airline reported that the aircraft landed normally and safely at 16:45L as scheduled and slowed to taxi speed but went off the runway while attempting to turn off the active runway. The aircraft was evacuated, there were no injuries. In the meantime the passengers have collected their luggage and have gone home.

Nigeria's Civil Aviation Authority have opened an investigation.

On Nov 29th 2021 the NCAA released an interim report stating that the draft of the final report is nearing completion. The AIB/CAA sumarized the sequence of events:

On 29th November, 2014 at 15:43 h, an ATR 72 aircraft with nationality and registration marks 5N-BPG operated by Overland Airways Limited with call sign OAL1186 departed Nnamdi Azikiwe International Airport, Abuja (DNAA) on a scheduled passenger flight for Ilorin Airport, (DNIL) on an Instrument Flight Rules (IFR) flight plan. Onboard were 63 persons including two flight crew, two cabin crew and 59 passengers. The Pilot was the Pilot Flying (PF) and the Co-Pilot was the Pilot Monitoring (PM).

At 15:50 h, at about 7,000 ft during climb, the flight crew stated that, the LO LVL (low Level) light of the Blue hydraulic system came ON; the HYD LO LVL checklist of the ATR 72 QRH (Quick Reference Handbook) on page 2.19 was executed and the flight continued.

At 16:01 h, OAL1186 established contact with Ilorin Tower (TWR) and the TWR cleared OAL1186 for VOR approach Runway (RWY) 05.

At 16:30 h, while on final approach, the flight crew observed that the LO LVL light of the Green hydraulic system came ON. The HYD LO LVL and BOTH HYD SYS LOSS checklists of the ATR 72 QRH pages 2.19 and 2.20 were executed.

At 16:37 h, TWR informed ARFFS of OAL1186 position, hydraulic system problem and the runway in use.

At 16:39 h, OAL1186 reported 8 NM final RWY 05 and TWR asked OAL1186 to report field in sight.

At 16:43:02 h, OAL1186 flared and touched down well aligned with RWY 05.

According to the flight crew, the Reverse Thrust did not operate during the landing roll, then emergency braking was applied and asymmetric braking was felt.

At 16:43:23 h, OAL1186 veered off the runway at low speed into the grass verge and its nose gear collapsed. At 16:43:28 h, OAL1186 came to a stop at a distance of 4,400 ft from RWY 05 threshold, 40 ft from the edge of RWY 05 with its tail 12 ft from runway shoulder. The engines were shut down by pulling the respective ENG FIRE handles as the condition levers were jammed. The crew and passengers were evacuated uninjured.

The incident occurred at 16:44 h, in daylight and Visual Meteorological Conditions (VMC).

On Jan 2nd 2023 the NAIB released their final report (actually marked as a draft final report on its cover page, however described as final report on the Website) concluding the probable cause of the serious incident was:

Loss of directional control on ground due to the aircraft being dispatched with one brake inoperative and Loss of both hydraulic systems in flight.

Contributory factor

Inappropriate application of the Standard Operating Procedures (SOP) following the display of HYD LO LVL indication of the Blue hydraulic system shortly after takeoff.

The NAIB analysed:

OLA1186 departed Nnamdi Azikiwe International Airport, Abuja (DNAA) on a scheduled passenger flight for Ilorin International Airport, Ilorin (DNIL) on an Instrument Flight Rule (IFR) flight plan. Seven minutes into the flight, at 7,000 ft climbing, the flight crew noticed that the LO LVL (low Level) light of the Blue Hydraulic System came ON. Although the flight crew reported that the HYD LO LVL checklist items of the ATR 72 QRH were accomplished, the FDR data analysis indicates that the ACW electric motor driven pump of the Blue hydraulic system was not switched OFF, as the LO PRESS indication displayed severally along the flight. The action of switching OFF the ACW electric motor driven pump would inhibit the LO PRESS alert. Therefore, the HYD LO LVL checklist items of the ATR 72 QRH was not accomplished correctly. Thus, there was inappropriate application of the Standard Operating Procedures (SOP).

The aircraft reported 30 NM and requested further descent and straight-in VOR approach RWY 23. However, OLA1186 was asked to standby due traffic on Finals RWY 05 about 16 NM and then instructed to reduce speed, make an orbit about 20 NM to the field.

The flight crew did not inform the ATC of the hydraulic system malfunction and did not request a priority landing during initial contact with ATC. The flight crew should have considered other systems that are dependent on the hydraulic system which might have degraded as a result of the malfunction. Thus, early notification of the situation by the flight crew would have prompted ATC to provide assistance which might include: separation of the aircraft from other traffic, prioritization of the aircraft for landing and providing any other pertinent information that might be required by the flight crew.

On final approach, the flight crew stated that the LO LVL light of the Green hydraulic system also came ON and thus, they requested to enter holding pattern overhead DNIL to allow them figure out the hydraulic problems and also to accomplish the HYD LO LVL and BOTH HYD SYS LOSS checklist items of the ATR 72 QRH.

Total or complete loss of hydraulic system will also have an impact on approach and landing speeds, cross-wind limits and landing distance required. Landing distances will also be increased should the failure result in degradation of braking capability and loss of ground spoilers.

Metars (the station as well as local weatherstation reported NIL all day except following):
DNIL 291900Z 04003KT 9999 FEW011 29/18 Q1012
DNIL 291800Z 07002KT 9999 FEW011 31/17 Q1011
Incident Facts

Date of incident
Nov 29, 2014

Classification
Accident

Flight number
OJ-1186

Destination
Ilorin, Nigeria

Aircraft Registration
5N-BPG

Aircraft Type
ATR ATR-72-200

ICAO Type Designator
AT72

This article is published under license from Avherald.com. © of text by Avherald.com.
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