I am not sure why you would want to do this but if possable it would have to be part of the scenery for that area. I do not know of any other way you could do this. Only problem is that I do not know if you could draw a crashed plane with a scenery design program
GMAX is the only way it might work. You might be able to make it an XML addon but not sure what the needed code would be if there is one. I check it out tonight

[quote author=papa-metro  link=1090439178/0#0 date=1090432326]Hey, anyone know how to add a few crashed planes to Alaska/British Columbia scenery?[/quote]

You could try using MdltoBgl.exe to create scenery bgls for selected (FS98) aircraft. This program lets you either make macros for incorporation into sceneries OR stand-alone bgls for individual aircraft which you can place at specific lat/long locations.

Now if instead of placing them at ground level you place them just under (eg -0.5 metre) and select wheels up (ie not down!) and select eg suitable sloping locations where you can make a wing disappear by hiding it in the ground, you could do a pretty fair job ;)