Aviation disclaimer
Every calculator on this site is an educational and planning aid. None of them is approved data. Nothing here authorises, clears or approves any flight.
What you must use instead
For any real flight, the authoritative sources are:
- Current official weather. Actual reports and forecasts from the meteorological service responsible for the area, obtained close to the time of flight. This site has no live weather and no weather data of any kind.
- Your aircraft flight manual. The approved performance data, limitations and procedures for your specific aircraft at its actual weight and configuration. No general purpose calculator can substitute for it.
- The rules that apply to your flight. The regulations of the state you are flying in, the requirements of your operation, and any conditions attached to your licence. Fuel reserve requirements in particular differ between countries and between operations, which is why this site never assumes one.
- Current aeronautical information. Charts, plates, NOTAMs and the aeronautical information publication for the area.
What these calculators cannot tell you
A correct answer from one of these tools is still only an answer to a narrow arithmetic question. It cannot tell you whether a flight is safe, whether your aircraft can achieve a figure on the day, or whether a decision is legal.
There is deliberately no takeoff or landing performance, no weight and balance approval, no aircraft limitation checking, and no go or no go indicator on this site. Those require aircraft specific approved data and validation beyond what a general purpose calculator can responsibly provide.
Assumptions you have to check
Several calculators rest on assumptions that are frequently untrue in practice. Each page states its own, but the recurring ones are worth repeating here.
- Still air. The glide range calculation assumes no wind at all. A real engine failure into a headwind gives considerably less distance.
- Standard atmosphere. Pressure and density calculations use an agreed model of the atmosphere, not the actual one above you on the day.
- Dry air. Density altitude ignores humidity, which makes the real figure slightly worse than calculated on a humid day.
- Steady conditions. Wind, groundspeed and fuel flow are treated as constant across a whole leg or a whole climb. None of them is.
- Your own figures. Fuel flow, glide ratio, fuel density and reserve all come from you. If any of them is wrong or guessed, the result is wrong no matter how precisely it is calculated.
A disclaimer does not make a wrong answer safe
This page does not exist to transfer risk onto you for a mistake in the calculations. Care is taken to get them right and the methodology page describes how each one is checked. If you find an error, please report it to contact@aviationcalculators.com and it will be fixed.
What this page does say is that a correct number, applied to the wrong situation or without current official information behind it, is still dangerous.
Responsibility
The pilot in command is responsible for the flight. Using this site does not change that in any way, and no liability is accepted for decisions made using it. See the terms of use.