FAA Sport Pilot Airplane (SPA)RegulationsEasy
A pilot had two alcoholic drinks the previous evening and plans to act as pilot in command of a light-sport airplane 9 hours later. At departure time, the pilot's blood alcohol concentration is 0.02% and there are no lingering effects. According to 14 CFR 91.17, is the pilot legal to fly?
- AYes, because only alcohol consumed within the preceding 4 hours matters
- BNo, a pilot must wait a full 24 hours after any alcohol consumption
- CNo, the BAC must be exactly 0.00% before flight
- DYes, because more than 8 hours have passed and the BAC is below 0.04%
Show answer & explanationAnswer & explanation
Correct answer: D. Yes, because more than 8 hours have passed and the BAC is below 0.04%
14 CFR 91.17 prohibits acting as a crewmember within 8 hours of consuming alcohol, while under the influence, or with a BAC of 0.04% or greater. Since 9 hours have elapsed, the pilot is not under the influence, and BAC is 0.02%, the pilot meets all three conditions and is legal to fly.
Why the other options are wrong
- A. 91.17 uses an 8-hour window, not 4 hours.
- B. 24 hours is not the regulatory standard; 8 hours is.
- C. BAC must be below 0.04%, not necessarily zero.
91.17 Alcohol Rule
No person may act as a crewmember within 8 hours of alcohol consumption, while under the influence, or with a BAC of 0.04% or greater.
- 8-hour 'bottle to throttle' minimum
- 0.04% BAC limit
- Cannot fly while under the influence even if outside these limits
Memory trick: 'Eight hours, oh-four percent, or you can't fly.'