The Nigerian Safety Investigation Bureau (NSIB) has released a preliminary report on the crash landing of an Allied Air Boeing 737-400 Freighter at Nnamdi Azikiwe International Airport in Abuja. The incident, which occurred on December 11, 2024, has raised significant concerns about aircraft safety and maintenance protocols. The NSIB’s findings provide a detailed account of the events leading up to the crash, the extent of the damage, and the immediate safety measures recommended to prevent similar incidents in the future.

The Incident: A Cargo Mission Gone Wrong

The Allied Air Boeing 737-400 Freighter was on a mission to collect cargo for the Central Bank of Nigeria when the incident occurred. The aircraft had taken off from Murtala Muhammed International Airport in Lagos at 09:11 and began its descent into Abuja at 09:44. The flight was operated by a two-person crew, with the First Officer serving as the Pilot Flying (PF) and the Captain as the Pilot Monitoring (PM).

During the final approach, the crew encountered a critical malfunction with the aircraft’s flaps. According to the NSIB report, “attempts to deploy Flaps 30 were unsuccessful, leaving the flaps stuck at Flaps 15.” This mechanical failure significantly impacted the aircraft’s ability to land safely.

The Crash Landing: A Harrowing Sequence of Events

The aircraft touched down at a speed of 157 knots, which is notably higher than the recommended landing speed for such conditions. Upon touchdown, a loud bang was heard from the right side of the aircraft. The right main landing gear assembly detached, causing the No. 2 engine nacelle to drag along the runway for approximately 1,172 meters. The aircraft eventually veered off the runway and came to rest on the grass verge, facing 170 degrees from the runway heading.

The NSIB report detailed the extent of the damage:

• The right main landing gear was sheared off from its attachment point.
• The No. 3 and No. 4 main wheel tires burst.
• Significant damage was observed on the No. 2 engine nacelle and the lower right-wing section.

Despite the severity of the crash, all occupants escaped unharmed. The NSIB confirmed that “the structural integrity of the cabin and cockpit remained intact,” and all occupants exited safely through the forward main door without injuries.

Flight Crew and Aircraft Status

The NSIB’s investigation revealed that both the Captain and First Officer held valid licenses and medical certificates, and the aircraft had a valid Certificate of Airworthiness. The aircraft had performed 101 landings since November 1, 2024, with 85 of those landings using Flaps 15.

Weather conditions at the time of the incident were deemed favorable, with no adverse meteorological factors reported. All navigational and communication equipment, except for the Airfield Lighting Panel System, were serviceable.

Initial Safety Findings

The NSIB’s preliminary findings indicated that there was no evidence of a hard landing, and no snags were recorded in the aircraft’s technical logbook prior to the incident. However, the malfunction of the flap system during the final approach was identified as a critical factor in the crash.

Immediate Safety Recommendations

In response to its findings, the NSIB issued an immediate safety recommendation:
Safety Recommendation 2025-001: The Nigeria Civil Aviation Authority (NCAA) should inspect all Allied Air aircraft for potential mechanical and structural vulnerabilities, specifically focusing on the flap and landing gear systems.

This recommendation underscores the need for rigorous maintenance checks and proactive measures to ensure the safety of aircraft operating in Nigerian airspace.

Ongoing Investigations

The NSIB has outlined several areas for further investigation, including:

• A detailed inspection and examination of the Right Main Landing Gear Assembly.
• Testing and inspection of the flap drive system components, including the transmission assemblies, universal joints, ball nuts, and flap track.

These investigations aim to identify the root cause of the flap malfunction and determine whether similar issues exist in other aircraft within the Allied Air fleet.

Broader Implications for Aviation Safety

The Allied Air crash landing highlights the importance of stringent maintenance protocols and the need for continuous monitoring of aircraft systems. Mechanical failures, particularly those involving critical components like flaps and landing gear, can have catastrophic consequences if not addressed promptly.

The NSIB’s findings and recommendations are expected to prompt a broader review of safety standards within Nigeria’s aviation sector. Stakeholders, including airlines, regulatory bodies, and maintenance organizations, will need to collaborate to implement the necessary changes and prevent future incidents.

Conclusion: A Wake-Up Call for the Aviation Industry

The crash landing of the Allied Air Boeing 737-400 Freighter serves as a stark reminder of the challenges facing the aviation industry. While the incident did not result in any injuries, it underscores the need for vigilance and proactive measures to ensure the safety of passengers, crew, and cargo.

As the NSIB continues its investigation, the findings will likely lead to significant changes in how aircraft maintenance and safety inspections are conducted in Nigeria. The aviation industry must learn from this incident and take decisive action to prevent similar occurrences in the future.