Improved Aircraft Performance formulas


Fix and/or improve the current set of performance formulas:

  • Better formulas for fuel consumption and thereby maximum payload, taking into account things like fuel reserves
  • Simple approximation of altitude-based take-off performance
  • Simple approximation of altitude-based landing performance

These would come with a better performance tool and a feature flag to disable the dependence on altitude in existing game worlds.

There will also be a fallback mechanism to continue using the old formulas while we don’t have properly vetted data for all aircraft types.


The current formulas are just plain wrong. In fact, our volunteers on the aircraft data team had to “fake” aircraft attributes to get anywhere close to “real” performance characteristics. The primary goal of the new formulas is to alleviate this issue: When putting in real parameters, the result should make sense.

The new fuel formulas will also allow for payload-dependent fuel consumption. So when an aircraft flies a mission with less payload than what was originally planned, the fuel consumption will actually be slightly lower.

The new field length formulas will bring quite a bit more realism to aircraft choices, as suddenly the origin and destination airports one intends to fly from/to greatly influence the decision.

That said, the performance calculations cannot and won’t ever be perfect. They’ll always stay an approximation and simplification of the real thing.


We have in fact already started work on this (see for example Dev Log Week 2024-06: Diversions or Dev Log Week 2024-07: Sick Leave). But so far this work only revolved around fuel consumption. Since this feature makes little sense without proper input data and we want to minimize the amount of research effort required, it would definitely make sense to find a new model for take-off/landing performance as well before starting full-on data research work.