Aircraft · Edition II · September MMXXVI · 6 min
xxiv. Cabin · a reference figure, not a promise
"NBAA IFR range" describes a performance figure calculated under standardized assumptions that include reference IFR reserves. It isn't a universal operating distance, and it isn't authorization to promise a nonstop. The figure has to be read alongside payload, wind, temperature, altitude, alternates, and the operator's own fuel policy.
The FAA uses performance examples built on NBAA IFR reserves and conditions like ISA, zero wind, a defined payload, cruise speed, and stage length. Change any one of those assumptions and the result changes.
What it means on a quote
The figure can be useful for comparing aircraft under matched conditions. It shouldn't be used as the final answer to a request from, say, Lima to Europe, or any other route, without an actual mission calculation. The real route can involve airway routing, ATC restrictions, alternates, contingency fuel, and a reserve policy higher than the regulatory minimum.
For IFR flights under Part 91, §91.167 requires fuel to reach the first airport of intended landing, fly to the alternate when required, and continue for 45 minutes at normal cruising speed. Part 135's §135.223 sets a comparable structure for aircraft, with its own rules on alternates and reserves.
That doesn't mean every operator loads exactly the same fuel. The regulatory minimum interacts with weather, performance, operator experience, restrictions, and pilot judgment. The FAA has noted that the fuel-consumption data used for planning has to be accurate and verifiable.
How to word it correctly
A spec sheet can say "NBAA IFR range: [manufacturer figure]" as long as it names the source and the assumptions. A quote should say "final range and nonstop capability subject to operator flight planning." That difference is what keeps a technical comparison from turning into a commercial promise.
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