According to a manufacturer's performance chart, a fixed-wing sUAS's maximum allowable gross weight decreases as density altitude increases. At a density altitude of 5,000 feet, the chart lists a maximum gross weight of 46 pounds. The pilot's aircraft, with payload, weighs 48 pounds. What must the pilot do to comply with safe operating limits?
- AReduce weight or wait for lower density altitude conditions to stay within the charted maximum gross weight
- BAdd more battery capacity to offset the weight difference
- COperate as planned since 48 pounds is within the 55-pound structural limit
- DIncrease airspeed to compensate for the extra weight
Show answer & explanationAnswer & explanation
Correct answer: A. Reduce weight or wait for lower density altitude conditions to stay within the charted maximum gross weight
The performance chart's maximum gross weight at a given density altitude reflects the weight beyond which safe climb, stall margin, and control performance cannot be guaranteed. Since 48 pounds exceeds the 46-pound chart limit at that density altitude, the pilot must reduce weight or operate when density altitude is lower to bring the chart limit back above the actual weight.
Why the other options are wrong
- B. Adding battery capacity increases weight further, worsening the problem rather than solving it.
- C. Structural limits and performance chart limits are separate; the performance limit governs safe operations at that density altitude.
- D. Increasing airspeed does not resolve exceeding a charted weight limit tied to density altitude.
Performance Chart Weight Limits
Manufacturer performance charts specify maximum gross weight as a function of density altitude; exceeding this charted limit compromises climb, stall margin, and control even if under structural weight limits.
- Max gross weight decreases as density altitude increases
- Charted limits are separate from structural limits
- Pilot must reduce weight or wait for better conditions if exceeded
Memory trick: The chart is the real speed limit sign, not just the structural guardrail.