FAR 91.151 — VFR Fuel Requirements
FAR 91.151 sets minimum fuel reserves for VFR flight: 30 minutes day, 45 minutes night for airplanes, 20 minutes for rotorcraft. Study guide for pilots.
FAR 91.151 sets the minimum fuel you must have on board before starting a VFR flight. The rule requires enough fuel — considering wind and forecast weather — to fly to your first point of intended landing at normal cruising speed, plus a reserve.
The required reserves are:
- Airplane, day VFR: at least 30 minutes of additional flight time
- Airplane, night VFR: at least 45 minutes of additional flight time
- Rotorcraft, VFR: at least 20 minutes of additional flight time
Why it matters: fuel exhaustion remains a leading cause of preventable accidents. This rule forces you to plan with a realistic margin, accounting for headwinds, possible diversions, and traffic delays. Note the reserve is calculated at normal cruising speed, not at a low-power setting. The rule sets a legal minimum — most operators and instructors recommend planning for 1 hour of reserve as a safer personal standard.
Five FAA-written-style questions. Instant explanations, every answer cites its source — no account needed.
You are flying VFR in Class E airspace at 8,500 feet MSL during the day. What are your minimum visibility and cloud clearance requirements?
Q1What are the fuel requirements for a VFR flight in an airplane during the day and at night?
Q2Do the VFR fuel reserve requirements apply to helicopters?
Q3How is the VFR fuel reserve calculated — at best endurance or cruise speed?
VFR fuel reserve planning examples
The rule is time-based, but pilots buy fuel in gallons. Use the table as a quick checkride bridge from the legal minimum fuel reserve to the fuel quantity you would brief for a day VFR, night VFR, or rotorcraft scenario. These are planning examples; your POH, actual fuel flow, taxi fuel, climb fuel, winds, forecast weather, and personal minimums still control the real dispatch number.
What 14 CFR § 91.151 actually requires
| Citation | When it applies | Minimum reserve | What the rule says |
|---|---|---|---|
| § 91.151(a)(1) | Airplane — day VFR | 30 minutes | Fuel to the first point of intended landing, then 30 min at normal cruising speed. |
| § 91.151(a)(2) | Airplane — night VFR | 45 minutes | Same destination fuel, but a 45-minute reserve for any flight begun at night. |
| § 91.151(b) | Rotorcraft — VFR | 20 minutes | One reserve for rotorcraft, day or night, at normal cruising speed. |
| § 91.167(a)(3) | IFR — for comparison | 45 min · 30 min heli | Destination + alternate (when required) + 45 min, or 30 min for helicopters. |
| Cruise burn | Day VFR airplane | Night VFR airplane | Rotorcraft VFR |
|---|---|---|---|
| 6 GPH | 3.0 gal | 4.5 gal | 2.0 gal |
| 8 GPH | 4.0 gal | 6.0 gal | 2.7 gal |
| 10 GPH | 5.0 gal | 7.5 gal | 3.3 gal |
| 12 GPH | 6.0 gal | 9.0 gal | 4.0 gal |
The reserve is added after reaching the first point of intended landing at normal cruising speed. It is not a shortcut around trip fuel, taxi/runup fuel, or the extra fuel needed when forecast winds make the leg longer than planned.
At 8 GPH, the legal reserve alone is 4.0 gallons for day VFR and 6.0 gallons for night VFR. A conservative student-pilot briefing usually rounds up and adds a personal reserve above the regulation.
VFR fuel requirement FAQ
What is the minimum fuel reserve for a day VFR flight?
Under 14 CFR § 91.151(a)(1), an airplane flown under VFR by day must carry enough fuel to reach the first point of intended landing and then fly for at least 30 minutes more at normal cruising speed, considering wind and forecast weather.
What is the night VFR fuel reserve requirement?
Section 91.151(a)(2) raises the airplane VFR reserve to at least 45 minutes at normal cruising speed beyond the first point of intended landing for any flight begun at night.
What is the VFR fuel reserve for a rotorcraft?
Section 91.151(b) sets a single VFR reserve for rotorcraft — at least 20 minutes at normal cruising speed after reaching the first point of intended landing, day or night.
How is the § 91.151 VFR reserve different from the IFR fuel rule?
Section 91.151 covers VFR only (30 minutes by day, 45 at night). IFR fuel is governed by 14 CFR § 91.167: enough fuel to fly to the destination, then to the alternate when one is required, and then 45 minutes more at normal cruising speed (30 minutes for helicopters).
Is the § 91.151 fuel reserve measured at cruise speed?
Yes. The reserve is computed "assuming normal cruising speed" and is added after the first point of intended landing. It is a planning minimum on top of taxi, runup, climb, and trip fuel — not a substitute for them.