What are the FAA fuel reserve requirements for VFR flight?

Under 14 CFR 91.151, VFR flights during the day require enough fuel to fly to the destination plus 30 minutes at normal cruise. For VFR night flights, you need fuel to destination plus 45 minutes reserve. These are legal minimums - professional pilots typically carry more.

What are the IFR fuel reserve requirements?

Under 14 CFR 91.167, IFR flights require fuel to: fly to the first airport of intended landing, then to the alternate airport (if required), then fly for 45 minutes at normal cruise. The alternate requirement adds significant fuel needs that must be calculated carefully.

How much extra fuel should I carry beyond legal minimums?

Professional pilots typically add 10-20% above calculated requirements. Consider adding extra for: forecast headwinds (which may be stronger than predicted), possible holds or vectors, weather deviations, and the psychological comfort of having options. Remember: fuel in the tanks is always cheaper than an emergency.

How do headwinds and tailwinds affect fuel planning?

Headwinds increase flight time and fuel burn proportionally. A 20-knot headwind on a 2-hour flight could add 15-20 minutes of flying time. Always calculate using forecast winds, then add margin for wind forecast errors. Tailwinds help but don't reduce your reserve requirements.

What causes fuel exhaustion accidents?

NTSB data shows fuel exhaustion accidents commonly result from: improper preflight planning, failure to monitor fuel consumption in flight, inaccurate fuel gauges combined with no manual check, get-there-itis leading to continued flight with low fuel, and unexpected headwinds or weather deviations not accounted for.

How does altitude affect fuel consumption?

Higher altitudes generally improve fuel efficiency because the engine runs leaner and true airspeed increases. However, the climb to altitude consumes extra fuel. For short flights, the fuel burned climbing may exceed savings. Generally, flights over 100nm benefit from higher altitudes; shorter flights may be more efficient staying lower.

Aviation Fuel Planning Guide - VFR & IFR Requirements

Legal Fuel Requirements

VFR Day (14 CFR 91.151)

Fuel to destination + 30 minutes at normal cruise speed

VFR Night (14 CFR 91.151)

Fuel to destination + 45 minutes at normal cruise speed

IFR (14 CFR 91.167)

Fuel to: First airport of intended landing → Alternate (if required) → + 45 minutes at normal cruise

These are legal minimums, not recommended practices

Professional pilots carry significantly more fuel as a safety margin.

Professional Fuel Planning

Add 10-20% Safety Margin

Beyond legal requirements, add margin for forecast errors and unexpected situations.

Account for Real Winds

Calculate with forecast winds, then assume they could be 10-20% worse than predicted.

Plan for Diversions

Identify fuel stops along your route. Know where you can land if conditions change.

Monitor In-Flight

Compare actual fuel burn to planned. Divert early if consumption exceeds expectations.

Preventing Fuel Exhaustion

Fuel exhaustion remains a leading cause of preventable accidents. Common contributing factors:

Inadequate preflight planning

Not calculating actual requirements

Get-there-itis

Continuing when fuel stop is prudent

Trusting fuel gauges

Gauges only required accurate at empty

Unexpected headwinds

Not recalculating when winds differ

The Golden Rule

Land with at least 1 hour of fuel remaining. The extra fuel costs far less than the alternative.

Aviation Fuel Planning Guide