Fuel planning

Model: Trip = Σ time × burn over the legs; alternate and reserve = time × cruise burn; total = taxi + climb + trip + alternate + reserve. Reserve minimums: airplane VFR 30 min by day and 45 min at night (14 CFR 91.151(a)), rotorcraft VFR 20 min (91.151(b)), IFR 45 min, or 30 min for helicopters, after the alternate (91.167(a)(3))

Show your work

1. Trip fuel

   trip = Σ time × burn

   14.3 + 6.8 = 21 US gal

2. Reserve

   reserve = reserve time × cruise burn

   45 min ÷ 60 × 9 gal/h = 6.8 US gal

3. Fuel required

   $$\mathrm{taxi}+\mathrm{climb}+\mathrm{trip}+\mathrm{alternate}+\mathrm{reserve}$$

   1.4 + 0 + 21 + 0 + 6.8 = 29.2 US gal

The same steps an agent gets from the MCP server with explain: true.

Accuracy: Arithmetic on your times and burns. The reserves are the regulatory minimums as of the review date shown; operators and good judgment often carry more. Summary, not legal advice.

Worked example: Two legs at night with a VFR reserve. Source: add-aviation-suite VFR night scenario: a 45-minute reserve at the entered cruise burn, cited to 14 CFR 91.151(a)(2).

Review: Not yet independently reviewed by a flight instructor (CFI).

Last verified: 2026-09-19, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.

Status: version 1.1.0, core 0.1.0. See this tool in the verification report.

Changes

• 2026-09-22, result change: The reserve basis now links 14 CFR 91.151 and 91.167 where eCFR files them, in subpart B; the first release pointed at subpart C, which does not hold them. The fuel figures are unchanged. Tool version 1.1.0. Changelog

Checked against: 12 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.

Sources

• 14 CFR Part 91, General Operating and Flight Rules, Federal Aviation Administration, eCFR, current. § 91.151 (fuel requirements for flight in VFR conditions) and § 91.167 (fuel requirements for flight in IFR conditions). Rules as of 2026-09-22.
• Pilot's Handbook of Aeronautical Knowledge, FAA-H-8083-25C, Federal Aviation Administration, FAA-H-8083-25C. Aircraft Performance and Navigation chapters (pressure and density altitude, wind triangle).

Terms

CFR: Code of Federal Regulations

The codified US federal regulations. Aviation rules are in Title 14, written as 14 CFR. Source: 14 CFR Part 1 definitions

IFR: instrument flight rules

The rules for flying by reference to instruments under air traffic control, required in clouds and low visibility. IFR flights must carry fuel to an alternate airport and a reserve. Source: Aeronautical Information Manual

POH: Pilot's Operating Handbook

The manufacturer's handbook for an aircraft: limitations, procedures, performance charts, and weight-and-balance data. Its numbers govern over any calculator. Source: Pilot's Handbook of Aeronautical Knowledge

Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.