Fifth flight in heat and glare
You are flying a 900 g drone at 100 m AGL on a clear July afternoon at 34°C. It is your fifth flight in four hours after a short night. You are tracking a moving tractor for a farm survey. The tablet screen is dimmed by sun glare, and you realise you have been watching the screen more than the sky. Your spotter has gone to move a car. Battery is 38%, wind 12 kt, and the return path crosses a busy footpath. You have a headache and slight dizziness.
1. Identify the human-performance hazards and explain how they interact.
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- Fatigue: short night plus five flights in four hours reduces attention, slows decisions and increases the chance of fixation on the screen.
- Heat and possible dehydration: 34°C, headache and dizziness are warning signs. Heat strain impairs concentration and judgement.
- Glare: the dim screen encourages closer screen staring, which pulls attention away from the sky.
- Task saturation: tracking a moving tractor is demanding, and the spotter is absent, so the see-and-avoid workload falls entirely on you.
- These hazards compound each other: fatigue and heat reduce vigilance, glare increases screen fixation, and the missing spotter removes the backup that would catch a loss of visual line of sight.
- The result is a realistic risk of losing the drone visually, misjudging the return path, or making a poor low-battery decision.
2. Should you continue for 10 minutes to finish the survey or land? Justify your decision.
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- Land. The symptoms and the missing spotter already indicate that your capacity to monitor the aircraft and the surrounding airspace is degraded.
- You have been watching the screen more than the sky, so visual line of sight is not being maintained reliably.
- A 38% battery is not an emergency, but with wind and a return path over a busy footpath you should preserve margin rather than extend the task.
- Do not use automatic return-to-home over the footpath. Choose a safe open landing area away from people and land there.
- After landing, stop flying for the day, cool down, drink water and reassess. Headache and dizziness in heat are not symptoms to 'push through'.
3. What pre-flight and in-flight mitigations would have reduced the risk?
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- Plan fewer flights or longer breaks, and avoid scheduling demanding survey work after a short night.
- Hydrate before and during the session; use shade and cooler times of day.
- Keep the spotter in position for the whole flight, or do not accept the task without one.
- Use a sun hood or better screen position, and deliberately alternate between screen and sky scanning.
- Set a conservative battery reserve and identify emergency landing areas before take-off.
- Set the return-to-home path and altitude away from the footpath, and brief a clear abort rule for heat, fatigue or loss of visual contact.