Question 12
Domain 2: FAA Part 107 WeatherA remote pilot is planning a mission at a location with the following conditions: elevation 4,000 feet MSL, temperature 100°F, altimeter setting 29.50 inches Hg. What should the pilot expect regarding aircraft performance?
Correct answer: B
Explanation
Density altitude increases when pressure altitude and temperature are high, and aircraft performance decreases as density altitude rises. Here, 4,000 feet MSL with a low altimeter setting of 29.50 inches Hg and a temperature of 100°F produces a very high density altitude, so the aircraft will need more takeoff distance and climb performance will be reduced.
Why each option is right or wrong
A. Performance will be better than at sea level standard conditions
B. Performance will be significantly degraded due to very high density altitude
Under 14 CFR § 107.49, the remote pilot must assess environmental conditions that affect safe operation, and density altitude is the controlling performance factor here. At 29.50 inches Hg, pressure altitude is about 500 feet higher than field elevation (4,000 + [29.92−29.50]×1,000 ≈ 4,420 feet), and with an outside air temperature of 100°F (about 38°C), the density altitude rises to well above 8,000 feet. At that density altitude, the aircraft will require substantially longer takeoff distance and will have markedly reduced climb and overall performance.
C. Performance will be approximately the same as sea level
D. The aircraft will be unable to take off regardless of weight