A fixed-wing small unmanned aircraft cruises at 70 knots airspeed with a direct 20-knot tailwind, giving a groundspeed of 90 knots. Is this within the part 107 operating limitations?
- AYes, because the speed limit applies to airspeed, which is only 70 knots
- BNo, because the groundspeed exceeds 87 knots
- CYes, because the groundspeed limit is 100 knots
Show answer and explanation
Correct answer: B. No, because the groundspeed exceeds 87 knots
§107.51(a) limits the groundspeed of a small unmanned aircraft to 87 knots (100 miles per hour). A 20-knot tailwind raises the groundspeed to 90 knots, which exceeds the limit even though the airspeed is 70 knots.
- A. Incorrect. §107.51(a) limits groundspeed, not airspeed.
- B. Correct. §107.51(a) says groundspeed may not exceed 87 knots (100 miles per hour); 90 knots is too fast.
- C. Incorrect. The limit is 87 knots, which equals 100 miles per hour, not 100 knots.
Source
14 CFR Part 107 (eCFR), §107.51(a) (a) The groundspeed of the small unmanned aircraft may not exceed 87 knots (100 miles per hour).