Flight Eleven on Day Three
It is day three of a five-day pipeline inspection contract. The time is 17:35 and sunset is 17:50. You are the RPIC, 34 years old, 9.5 hours into duty, and you have flown 11 sorties today; you last ate at 11:30. The aircraft is on its second battery, showing 30 percent. The observer is scrolling on his phone ten metres away. Your thumbs are trembling slightly, and you have just noticed that you have been holding your breath through the turns. The flight before this one returned a compass error warning that cleared after a reboot. The client's engineer is asking for 'one quick pass' over the span that crosses the national highway, which he says will take four minutes. The corridor waypoints run within 60 m of live 69 kV transmission lines. The wind has dropped to near calm and there is a low sun directly down the corridor.
1. Identify the threats, the errors already made, and the error traps in the request, using a structured framework.
Read the worked answer
Use a simple threat-and-error model: threats are what the environment and the operation present; errors are what the crew has already done; error traps are the design features of the request that will induce a mistake.
Threats
- Fatigue: 11 sorties, 9.5 hours on duty, no food for six hours, end of day. Fatigue degrades exactly the skills this sortie needs - timing, scan, inhibition of a bad decision.
- Light: a low sun straight down the corridor destroys depth perception and contrast and will hide thin wires.
- Obstacles: 69 kV lines within 60 m of the waypoints, and a highway under the pass.
- Equipment: an unresolved compass anomaly from the previous flight.
- Time: 15 minutes to sunset, which constrains any go-around or re-fly to effectively zero.
Errors already made
- The observer is disengaged. The see-and-avoid barrier that justifies VLOS is currently not running.
- The aircraft is being considered for flight at 30 percent battery with a transit, a task and a return still to be flown.
- The compass warning was cleared by reboot and not investigated.
Error traps in the request
- 'One quick pass' - the client's four-minute estimate is not your flight time; it excludes transit, turnaround, wind and go-around.
- The task is framed as small, at the end of the day, which is precisely when the plan-continue bias is strongest.
- The span crosses a highway, adding a third party who has not consented to any risk.
2. Make the decision and justify it in a way that would satisfy an incident investigator reading the log six months later.
Read the worked answer
Decision: stop for the day. Do not fly the highway span.
Justification, in the order an investigator would want it
- Crew state. Eleven sorties and 9.5 hours on duty with a missed meal is a documented fatigue exposure. Tremor and breath-holding are physical signs of elevated arousal, not normal operating state. Under fatigue, the pilot is least able to detect his own degradation, which is why the objective indicators matter more than how you feel.
- Loss of a safety barrier. The observer is not observing. Flying a highway span with wires, at low sun, with no see-and-avoid is a different risk from the one the site assessment approved.
- Energy state. 30 percent with a transit out, a task, and a return is not a four-minute problem; it is a reserve calculation that has not been done and cannot be done conservatively in the time available.
- Unresolved technical anomaly. A compass warning that clears on reboot has not been cleared; it has been reset. Magnetic interference near 69 kV lines is plausible, and a compass fault at low altitude near steel and lines is a control problem.
- Third-party exposure. A highway beneath the aircraft changes the consequence of any failure from 'lost airframe' to 'possible vehicle accident'.
- No recovery time. Fifteen minutes to sunset means no time to re-fly a failed pass and less margin for any diversion.
What would change the decision: a rested crew at the start of a duty period, a full battery, a functioning observer, an investigated compass system, sun not down the corridor, and a written plan for the highway crossing. None of those can be manufactured tonight.
3. How do you execute the stop and hand over to day four so that the next crew is not set up to repeat the day?
Read the worked answer
Execute the stop
- Call it out loud and use a positive stop: 'Knock it off, we are done for today.' A clear verbal stop is more effective than an unspoken decision, particularly with a client standing next to you.
- Tell the client's engineer directly and without apology: the sortie is not going to happen tonight, here is why, here is when it will happen. Give him a real alternative rather than an open-ended 'later'.
- Secure the aircraft and the battery, and note the battery state and the compass anomaly in the aircraft documentation before anyone goes home.
Debrief within the crew, tonight
A short structured debrief: what were the threats, what did we do, what would we do differently. Include the observer - his disengagement is a conversation, not a reprimand, and it should cover why the phone matters.
Report
Raise the fatigue pattern through the SMS. Eleven sorties in a day is a rostering decision, not a pilot failing, and the report should name it that way. Report the compass anomaly as a technical defect so it is tracked rather than rebooted again.
Handover brief for day four
Aircraft status and defects, battery inventory, tasks completed and outstanding, airspace and NOTAM changes, weather trend, sun and light windows, who is RPIC, and the crew rest plan. Whoever takes the first sortie tomorrow should hear about the compass anomaly from you, not from the logbook.