X-Plane 10.40 fixes a few bugs where:

  • The bug fix applies once you save your aircraft with Plane-Maker version 10.40 or newer; older planes will maintain compatibility with the old and buggy behavior.
  • You may need to edit your aircraft when running under the new non-buggy code (by re-saving your aircraft).

In other words, these are bugs that were fixed, where aircraft may have been relying on the buggy behavior.  We strongly recommend you re-save your aircraft and re-check these items.

High Altitude Fuel Consumption for Jets

This applies only to jet aircraft: X-Plane 10.36 and older incorrectly interpolated between the 50% and 100% N1 fuel flow SFC numbers. If your 100% and 50% N1 SFC numbers are not the same, the new, correct interpolation will change your fuel consumption at high altitudes.

  • If your 50% SFC is higher than your 100% SFC, you will see lower fuel consumption.
  • If your 50% SFC is lower than your 100% SFC (this is not usual) then you will see higher fuel consumption.

Billboard Light Sizes

Before X-Plane 10.40, the size of lighting billboards for named and param lights was fixed in pixels. This meant that as a user increased screen size, the lights looked smaller, relative to the scene, and everything looked dark.

X-Plane 10.40 changes this behavior to keep lights consistent relative to the screen.  When you save your aircraft for X-Plane 10.40, this will apply to your aircraft too.

You may have to make your lights smaller – the larger the screen where you authored your lights, the larger the increase in size you will see relative to X-Plane 10.36.

Once you have re-tuned your light sizes, their appearance in X-Plane 10.40 will be consistent for all users.

Check Engine Oil Pressure

X-Plane 10.36 and earlier incorrectly failed to feather the prop on low oil pressure for twin props. Once your aircraft is saved in 10.40 this logic will work; if you set the oil pressure to be too low in your aircraft, you may find the prop spontaneously feathering itself. Fix this by changing the red line oil pressure in Plane-Maker.



  • Aircraft Development

Article type:

  • Tips & Tricks