- Real planes sometimes have systems to limit total power output, because the power output of the engine (whether torque or internal temperature) can exceed safe operating limits at sea level).
- With X-Plane 9.00 you could set a critical altitude for an airplane - below this altitude, X-Plane would limit the power output of the jet. The idea is (roughly) to simulate these limiters by derating the engine's power output below this "critical altitude".
- This feature was really only meant for reciprocating engines - when Austin discovered in 9.20 that people were using this for turbines (understandable, given that there was no alternative) he simply disabled the feature for turbines. That wasn't so good.
- To resolve the situation a little bit more cleanly, X-Plane 9.30 has a setting per airplane called "FADEC - automatically keep engines from exceeding max allowable power or thrust" that, when checked, gives you version 9.00 style behavior.
Finally with beta 14 we switched things: beta 14 and newer default old planes to have the FADEC checkbox on, so that planes match their old behavior - you can turn the check-box off if you don't want this behavior.
There is one final hitch: if you already went in and edited your airplanes for the earlier betas, you will find that they are now set wrong. You will have to reset the check-box. If you go back to the original, unedited, 920-compatible airplane you will find they "just work".
I mention all of this to make two points:
- File formats for new features are subject to change during beta. In this case, the file format for the new FADEC check-box (introduced in 930) changed at beta 14. The OBJ syntax for dynamic lighting changed during beta too. Don't do "bulk" work (e.g. change a large number of planes in the same way ) on your fleet based on betas - you might have to redo that work again! Wait until the sim goes final. That's when the file formats are locked up.
- Don't work around bugs in the sim. I have seen so many forum posts where there is a trivial bug in the sim (e.g. the sim is just screwed up in a simple way) and authors go in and update scenery to work around the bug. File a bug, then wait! If you work around the bug, we can't fix the bug, and if we don't fix the bug, then the bug just bites other users.
** FADEC isn't a very good name for this feature - the feature generically limits power, without specifying a mechanism. My understanding is that some airplanes have mechanical limters, like a pressure valve on a turbo. Some planes have no limiters at all...ask a pilot "can you cook the engine by pushing the throttle too far" he will say "I'm not going to be the one to find out."