The Fourth Sector: Night Freight, Fatigue and a Request to Do More
You are the sole pilot of a Cessna 208B Caravan on a Part 135 night freight run, Auckland–Palmerston North–Christchurch. You reported at 1700 NZDT and are now 45 minutes from Christchurch, 8 h 20 min into a duty that the company limits to 11 h. Freight loading delays have put you 90 minutes behind schedule. You slept 4.5 hours in the previous 24, this is your second consecutive night shift, and you have eaten only a muesli bar since midday. For the last 20 minutes your eyelids have been heavy, your mouth is dry, and you twice 'came to' with the aircraft about 200 ft below the selected altitude. You have re-read the same Christchurch METAR three times without taking it in. Christchurch is forecast fine; company operations has radioed asking you to add a Christchurch–Invercargill sector after landing to cover a sick pilot.
1. Assess your fitness to continue and decide whether to land at Christchurch and stop, or accept the additional sector. Show the reasoning behind the decision.
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The decision turns on the evidence of degraded performance, not on how tired you feel. Four points drive it. First, the sleep history: 4.5 hours in 24, on a second consecutive night shift, means a significant sleep debt and a body clock fighting the roster. Second, the errors already observed are not trivial: a 200 ft altitude excursion is a breakdown of active monitoring, and re-reading the same METAR three times is a working-memory failure. Both are objective signs of fatigue, not attitude problems. Third, the duty is already 8 h 20 min with an added sector likely to push past the 11 h limit once turnaround and the return leg are counted. Fourth, fatigue-related risk rises steeply in the early hours and on the approach and landing phase, which is exactly where the remaining risk sits.
The correct decision is to land at Christchurch, terminate duty, and decline the additional sector. Continuing to Invercargill would require the very faculties that are demonstrably degraded. The fact that Christchurch is forecast fine does not offset crew fatigue. If the aircraft must be repositioned, that is an operator resourcing problem to be solved with a rested crew, not a single-pilot decision made at 0120.
2. Identify the fatigue-related errors already evident and explain which defences, both scheduling and in-flight, should have prevented or caught them.
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The altitude excursion reflects a lapse in monitoring: the pilot's attention drifted from the instrument scan and the autopilot was left to fly an unchallenged altitude. The repeated METAR reading reflects a short-term memory/encoding failure; the information was not being consolidated, so the same sentence was re-read without being retained. The dry mouth and heavy eyelids point to inadequate hydration and food, which amplify fatigue effects.
Scheduling defences: the operator's fatigue risk management should flag a second consecutive night shift on 4.5 hours of sleep as high risk, and should not be adding sectors to a crew already behind. Better rostering, protected sleep opportunity, and a dispatcher who is authorised to say no are the primary controls.
In-flight defences: use the autopilot deliberately and set the altitude alerter; make verbal callouts at each level-off; plan food and water before departure rather than relying on a snack bar; use caffeine strategically before the circadian low, not on final approach; and brief an early diversion trigger. In a single-pilot aircraft there is no controlled rest option, which raises the importance of the pre-flight decision. The system should have caught this before engine start, not over Canterbury.
3. Draft what you would say to company operations and describe the post-flight actions you would take.
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The call should be short, factual and unambiguous: 'Operations, this is [callsign]. I am fatigued. I had an altitude deviation on the last sector and I am not fit to continue. I will land at Christchurch, shut down and hand over the aircraft. I am not taking the Invercargill sector; you will need a rested crew.' State the safety outcome, not an apology, and do not leave the door open to negotiation.
Post-flight: complete a company safety report describing the fatigue state, sleep history, duty time and the altitude deviation so the operator can act on the roster rather than on the individual. Notify the chief pilot or duty manager, and file an occurrence report if the operator's SMS or Part 12 obligations require it. Do not drive home if you are dangerously tired; arrange transport. Arrange unbroken sleep before the next duty. Follow up in writing so the pattern is recorded. If the operator's response is to pressure the crew, that is itself a safety issue to escalate.