Remove Before Flight — The Gear Pins That Stayed In

This is a pattern card: landing-gear ground-lock and downlock pins left installed — or fitted in the wrong hole — before flight or during maintenance. The anchor: a Qantas Boeing 787-9, VH-ZNH, was towed to the terminal at Sydney on the morning of 21 June 2021. The tow supervisor and a wing walker — neither of whom had towed a 787 before — removed three of the five downlock pins and stowed them in the electrical equipment centre, a 787 stowage location other Qantas types don't have; the available ladder was too short to see into the rack, so the pins went in by feel. Two pins, one in each main landing gear, stayed in. The engineer signed the technical log for removal and stowage after a second by-feel check of the same rack; the relief pilot's external inspection did not pick up the streamers. On gear-up selection in the initial climb the nose gear retracted and both main gears stayed locked down. The crew put the gear back down and returned to Sydney. The same device in the wrong hole is just as effective: a British Airways 787-8's nose gear collapsed on stand at Heathrow in June 2021 when the downlock pin was inserted into the adjacent apex-pin bore — that event carries its own card.

"Landing gear ground lock pins not removed before departure" is on the UK CAA's published list of the leading recurring maintenance discrepancies (UK CAA CAP 718, Chapter 2 §1.5). The ATSB's safety message names the mechanism that keeps it recurring: streamers weather and fade, and the likelihood of detecting a remove-before-flight streamer drops sharply when nobody expects it to be there (ATSB AO-2021-026, Safety message). The defence is positive count and positive sight — of the pins in their stowage, not of an absence of flags on a walkaround.

1. Know the pin count and pin stowage for the type before touching it — the 787 carries five gear pins, and stows them in the electrical equipment centre, not the flight deck.
2. Pin removal after towing is a counted task: pins removed, pins in hand, pins in their stowage receptacles — seen, not felt. Get access equipment that lets you see the rack.
3. Sign the technical log for removal and stowage only on a positive count of stowed pins — a by-feel check of a rack you cannot see into is not a count.
4. On the external inspection, check each gear leg at the pin hole itself. Do not scan for streamers: they fade, foul and hide, and expectation bias hides them further.
5. At handover between tow crew, engineering and flight crew, state the pin status explicitly — quantity removed, quantity stowed, by whom.

Public rate figures do not exist, but the UK CAA lists ground-lock pins not removed before departure among the most frequently recurring maintenance discrepancies (UK CAA CAP 718, Chapter 2 §1.5), and the ATSB published its Qantas investigation expressly "to allow for greater industry awareness" of the recurring remove-before-flight failure (ATSB AO-2021-026, The investigation).

The anchor event cost an air-turnback and nothing else: both main gears stayed locked down, there was no damage and no injury, and the aircraft landed back at Sydney without event (ATSB AO-2021-026). The pattern's other face is costlier — the same pin family wrongly fitted at Heathrow in 2021 dropped a 787's nose onto the stand during pre-flight maintenance. Between those two outcomes sits every rejected takeoff and gear-down turnback the pin family has caused.