German investigators have established that the safety pin intended to prevent the nose landing gear from retracting had not been installed on the Lufthansa Boeing 787-9 that collapsed onto its nose during maintenance at Frankfurt Airport in early June. The pin was later found inside its storage box in the aircraft’s avionics compartment.

The incident occurred on June 4, 2026, while the aircraft, registered D-ABPQ, was parked at stand A15 and being prepared to operate flight LH450 to Los Angeles. Passengers had not yet boarded, but flight and cabin crew members, technicians and other personnel involved in the flight’s preparation were inside the aircraft.

According to an interim report by Germany’s Federal Bureau of Aircraft Accident Investigation, the BFU, technicians were troubleshooting a fault related to the main landing gear door control system. The maintenance procedure required the landing gear lever to be moved to the retracted position, while all landing gear assemblies were supposed to be mechanically secured with dedicated safety pins.

The pins had been correctly installed on both main landing gear assemblies, but not on the nose gear. When the landing gear lever was moved to the up position, the nose landing gear began to retract, causing the forward section of the aircraft to drop onto the apron.

After the aircraft was lifted, investigators found no safety pin either in the designated opening or near the nose landing gear. It was subsequently discovered inside its storage box in the avionics compartment and was later used to secure the landing gear before the damaged aircraft was moved to a hangar.

The BFU has not yet explained why the pin was not installed and has not assigned responsibility to any individual technician or maintenance organisation. The interim report presents the facts established so far, while the final cause and the possible role of organisational, procedural or human factors remain under investigation.

At the time of the accident, 28 people were inside the aircraft, while another six were directly involved in work outside it. According to the investigation, 21 people suffered minor injuries and two were seriously injured. Lufthansa initially said that two cabin crew members and employees of external service providers required hospital treatment.

Security camera footage showed the nose wheels moving forward as the landing gear folded, after which the front section of the fuselage struck the ground. A ground worker standing close to the aircraft managed to move away only moments before the nose dropped.

The accident resembles an incident at London Heathrow Airport in June 2021, when a British Airways Boeing 787-8, registered G-ZBJB, also collapsed onto its nose during maintenance.

In that case, the maintenance procedure also required the landing gear lever to be moved to the up position. However, the UK investigation found that the safety pin had been inserted into an adjacent opening rather than the one that actually locked the nose landing gear in the down position. Because of the proximity of the two openings, the technician could receive tactile and audible indications suggesting that the pin had been correctly installed.

The Frankfurt case differs in one important respect: the safety pin was not inserted into the wrong opening, but had not been installed at all. The BFU has not yet determined whether the two accidents point to broader similarities involving maintenance procedures, checklists or human factors.

The damaged D-ABPQ was one of the newest aircraft in Lufthansa’s fleet. Boeing delivered it in January 2026, and it entered commercial service the following month. The flight to Los Angeles was cancelled after the accident, while no date has yet been announced for the aircraft’s possible return to service.