In response to these findings, the NSIB has urged the NCAA to conduct a thorough inspection of all Allied Air aircraft, focusing on potential weaknesses in their flap and landing gear systems.
BY ANTHONY OMOH
Preliminary Findings on the Allied Air Accident
The Nigerian Safety Investigation Bureau (NSIB) has released a preliminary report on the accident involving an Allied Air Boeing 737-400 Freighter, registered as 5N-JRT, which suffered a landing gear collapse upon touchdown at Nnamdi Azikiwe International Airport, Abuja, on December 11, 2024. Following an initial assessment, the NSIB has issued a critical safety recommendation urging the Nigeria Civil Aviation Authority (NCAA) to conduct a thorough inspection of all Allied Air aircraft. This directive aims to identify potential mechanical and structural vulnerabilities, particularly concerning the flap and landing gear systems, which have now come under scrutiny.
Details of the Incident
Findings from the investigation indicate that the aircraft, arriving from Douala, Cameroon, was operating a cargo revenue flight but had no cargo on board at the time of the incident. The flight crew was qualified, held valid licenses, and had met regulatory certification standards, while the aircraft itself had an up-to-date Certificate of Airworthiness. The occurrence took place during the first sector of a planned six-sector flight that included stops in Lagos, Abuja, Sokoto, and Yola.
According to the preliminary report, the flight crew attempted to deploy flaps to 30 degrees during the final approach to Runway 22, but they remained stuck at 15 degrees. Upon touchdown, a loud bang was heard from the right side of the aircraft, and the right main landing gear assembly detached. The aircraft veered off the runway before coming to a halt on the grass verge, with the No. 2 engine nacelle scraping along the runway surface. The control tower at Abuja Airport promptly alerted the Aerodrome Rescue and Fire Fighting Services (ARFFS), which responded swiftly to the emergency.
Mechanical Observations and Data Analysis
Further examination of the aircraft revealed that the No. 3 and No. 4 main wheel tires had burst. However, post-occurrence inspections did not indicate any evidence of a hard landing. Data retrieved from the Flight Data Recorder (FDR) showed that out of 101 landings performed by the aircraft between November 1 and December 11, 2024, 85 were conducted with flaps at 15 degrees. This raised concerns about possible mechanical issues affecting the aircraft’s flap deployment mechanism, prompting investigators to examine the system further.
Safety Recommendation and Further Investigation
In response to these findings, the NSIB has urged the NCAA to conduct a thorough inspection of all Allied Air aircraft, focusing on potential weaknesses in their flap and landing gear systems. The Bureau has also outlined further investigative steps, including a detailed examination of the right main landing gear assembly to determine the cause of its detachment.
Investigators will also conduct a comprehensive assessment of the flap drive system components, including transmission assemblies, universal joints, ball nuts, flap tracks, and jack screw actuators. Additional inspections will be carried out on the aircraft’s main wheel tires to identify any structural deficiencies that could pose future safety risks.
Flight and Crew Information
The accident occurred during a scheduled flight designated AJK 206, which departed Lagos at 09:11 h for Abuja under Instrument Flight Rules (IFR). On board were six individuals, including two flight crew members, two engineers, and two representatives from the Central Bank of Nigeria (CBN). The aircraft landed at 10:04 h under visual meteorological conditions, and all occupants remained unharmed. The flight crew promptly shut down the engines and safely evacuated through the forward main door, ensuring a controlled response to the emergency.
Regulatory and Industry Response
In light of the NSIB’s recommendations, industry stakeholders, including the NCAA and Allied Air, are expected to take corrective measures to prevent a recurrence of similar incidents. Aviation safety experts have underscored the importance of proactive maintenance and real-time system monitoring to enhance aircraft operational safety. Additionally, flight crews have been advised to report any irregularities in aircraft performance to ensure timely interventions before potential failures occur.
Ongoing Investigation and Industry Implications
The investigation remains ongoing, with further updates anticipated as additional findings emerge. The aviation industry continues to monitor developments closely, recognizing the importance of rigorous safety compliance in maintaining operational reliability and public confidence in air travel. The NCAA’s response to this recommendation will be crucial in determining the next steps for ensuring the continued safety of Allied Air’s operations. Report available here.
