Thanks and that is a great idea but I want to remove the complete aircraft to gain space on my hd.
That is NOT the way to gain space on the hard drive. How about deleting the paints of addon aircraft you don't use? Or removing addon scenery in areas where you are not currently flying?
I would suggest that the space savings of removing defaults are in the region of bugger-all when the addons are the ones that generally consume the space. As you can never know what addons are aliasing gauges, sounds or other aspects of the defaults I would recommend you NEVER, EVER remove them. It's quite possible that there are elements of the jets you don't like popping up in addon piston or turbo-prop aircraft - switc panels, gauges, throttle parts, pop-up windows. The sim EXPECTS to see those defaults and so you should not remove them.
Find other ways of saving or creating space: The addon scenery folder does NOT need to be located in the FSX folder, or even on the SAME hard drive - either letter or physical; the aircraft folder needs contain only those aircraft you are using or might need to select for that sim session. Consider creating an `off FSX` folder on a spare drive and simply cut'n'paste the aircraft you are not currently flying to that folder - as you leave everything else installed it's only a copy back to get them active and in the GUI again
I use the `one in, one out` rule on my aircraft folder, as I also can't stand waiting for two minutes for the aircraft selection menu to show. Whenever I add a new aircraft, I move an old one to my `hangar` folder, whcih is on my backup external USB drive. Anything I've not flown for a month or two or is required for AI gets moved, too.
You don't say how many aircraft and paints you have in the simobjects/airplanes folder but consider this: You can only fly one at a time...