Which firmware (default or fixedwing) should be used for (Delta) Plane?

there are multiple firmware downloads available

  • px4_fmu-v5_default.px4
  • px4_fmu-v5_fixedwing.px4

i’am using a “Pixhawk 4 Mini” for a Fixed Wing (Delta) Plane
so what is the right/best option for that?
or what are the main differences or advantages/disadvantages between them?

Good question.

The difference can be seen in the board cmake files:

So it looks like the fixedwing build is stripped down for less flash usage but does not contain anything more than the default.

This means that you can use either one, however, I don’t think the specific builds such as the fixedwing ones are used or tested yet, so I would recommend to just stick with the default one. It should not have any drawbacks at runtime.