Checklist Interruption During a Turnaround
During a 45-minute turnaround at a busy airport, the captain is running the before-start checklist from memory while the first officer is outside doing a walkaround. A ramp agent interrupts to ask about a missing baggage tag. After resolving it, the captain resumes the checklist at the item 'fuel pumps - ON' rather than where he left off at 'beacon - ON'. He also skips the 'flight controls - full free and correct' check because the first officer is not yet in the seat. On pushback, the beacon is still off; a ground vehicle passes behind the aircraft. Later, during taxi, the captain notices the fuel pumps were selected on before the fuel quantity was confirmed. No damage results, but the event is reported. The airline uses a LOSA programme and has just introduced a new checklist card.
1. Classify the errors in this event and identify the performance-shaping factors.
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The resumption at the wrong item is primarily a lapse-a prospective-memory failure after an interruption. The captain intended to resume at 'beacon' but forgot the exact place. Skipping the flight-controls check is a slip/lapse in routine procedure and may also be a violation if done deliberately to save time; the scenario says it was because the first officer was not in the seat. The beacon omission is another slip. These are not knowledge-based mistakes: the captain knows the checklist. They are action and attention failures.
Performance-shaping factors include the interruption, time pressure of a 45-minute turnaround, the first officer being outside the flight deck, the new checklist card, ramp noise and divided attention. Running a checklist from memory removed the challenge-response barrier. The ground vehicle passing behind the aircraft shows how a small omission can become a serious hazard. The errors form a chain: interruption → wrong resumption → omitted item → missing cross-check → unsafe pushback.
2. Explain how checklist discipline and crew coordination could have broken the error chain.
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A checklist is a barrier, not a memory aid. When interrupted, the captain should announce the interruption, mark the card or say the last completed item aloud, deal with the interruption, then resume at the marked item-or restart the checklist from the top. Resuming at the wrong item is exactly the failure the written card is meant to prevent.
The first officer's absence removed the challenge-response cross-check. On returning to the flight deck, the first officer should have asked where the checklist was resumed and verified the critical items: beacon, fuel pumps, flight controls. The captain should not have run the before-start checklist from memory while the other pilot was outside; a two-pilot checklist requires both pilots. The beacon is also a visual signal to ground crew, so its absence degraded coordination with the ramp. A short threat briefing before the turnaround-covering the interruption risk and the new card-would have raised awareness. The first officer should feel able to say 'we skipped flight controls' without fear.
3. Recommend systemic defences for the airline.
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The airline should introduce an interruption-management SOP: when a checklist is interrupted, the crew announces it, marks the card physically, and resumes at the marked item. Critical checklists should require both pilots and should not be run from memory. The new checklist card should be designed with clear resume points, larger type and obvious critical-item markings. If it is new, crews need familiarisation and a reporting channel for design problems.
Training should cover prospective memory, the 'do-verify' technique, and the difference between slips, lapses and violations. LOSA data should be used to identify turnaround interruptions and ground-crew intrusions. The operator should give ramp agents a clear rule not to interrupt the flight deck during checklist execution, and the flight deck should use a 'do not disturb' signal. Finally, the airline should reinforce a just culture: the captain's report should lead to system learning, not blame, while still addressing the procedural deviation.