Qantas B789 at Sydney on Jun 21st 2021, gear problem on departure

Last Update: November 16, 2021 / 11:30:33 GMT/Zulu time

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Photo of Qantas VH-ZNH, Boeing 787-9 Dreamliner — Qantas VH-ZNH, Boeing 787-9 Dreamliner (Photo credit: ahisgett / Flickr / License: CC by)

Incident Facts

Date of incident
Jun 21, 2021

Classification
Incident

Airline
Qantas

Flight number
QF-645

Departure
Sydney, Australia

Destination
Perth, Australia

Aircraft Registration
VH-ZNH

Aircraft Type
Boeing 787-9 Dreamliner

ICAO Type Designator
B789

A Qantas Boeing 787-9, registration VH-ZNH performing flight QF-645 from Sydney,NS to Perth,WA (Australia) with 119 people on board, was climbing out of Sydney's runway 16R when the crew stopped the climb at 9000 feet reporting a gear issue. After working the checklists the crew decided to return to Sydney advising they expected a normal landing, no services were needed. When the controller queried whether they had their gear already down with 3 greens, the crew replied in the negative, when the controller subsequently queried whether the gear was fully retracted, the crew also replied in the negative. The aircraft positioned for the approach, landed safely on runway 16R about 30 minutes after departure and taxied to the apron.

The flight was cancelled, the passengers were rebooked onto the next flight.

The ATSB reported during the climb the main gear did not retract and the crew received a gear disagree message. The post flight inspection revealed "that the forward gear pins on the left and right main landing gear were not removed prior to the flight." The ATSB rated the occurrence an incident and opened a short investigation that will include a review and examination of maintenance records beyond collecting other relevant evidence.

On Nov 16th 2021 the ATSB released their final report concluding the probable causes of the incident were:

Two of the five landing gear pins were not removed as per the operator’s procedures, nor identified by engineering, flight crew or dispatch during pre-departure checks. This resulted in the aircraft departing without the functionality to retract the main landing gear.

The ATSB analysed:

In this occurrence, multiple factors led to an aircraft departing configured such that the flight crew were unable to retract the main landing gear. Specifically:

- The tow crew used the visible streamers to identify what they incorrectly believed were the only three gear pins installed the aircraft.

- While the LAME was aware the 787 had five gear pins, they did not confirm all of them had been removed and stored before signing the tech log. Instead, the AME physically checked for the presence of pins without knowing the number to expect.

- The ladder used to access the gear pin stowage location was not of sufficient height to allow visual confirmation of pin stowage. Sighting of ‘empty’ pin stowage receptacles would have provided a clear indication that not all pins had been removed from the landing gear.

- The flight and dispatch crews conducted their external inspection with no expectation of finding streamers indicating gear pins were still installed. This was likely due to the tech log being endorsed and a belief that the gear pins had been removed by engineering personnel.

- There was probably reduced visibility of the streamers, due to their degraded condition and the likelihood they were stuck on the gear, from a combination of grime and the recent wet and windy conditions.

Research has demonstrated that people are more likely to detect targets (such as gear pin streamers) when they are expected and less likely to detect targets that are not expected (Wickens and McCarley 2008). In addition, bias can occur when prior knowledge, combined with an expected outcome, influences decision making.

The tow crew were expecting to see the gear pin streamers, as they had just completed moving the aircraft. The tow crew then identified, and removed, three main landing gear pins, which was consistent with the aircraft types they had experience on. In contrast, as the gear pins were typically removed prior to the flight and dispatch crew external inspections, they were not expecting to see any gear pin streamers.