The only consideration I can see when preparing a cadaver specifically for air transport would be to make applowances for the lowered air pressure by ensuring than any gas pockets in the body have a route of escape to prevent unpleasant swelling or even explosion. Alternatively (and more likely), the cadaver could be transported in an airtight coffin.
The kind people at the Bradely Funeral Home tell us that:"The embalming process is much the same as embalming for a funeral without air travel involved. A thorough embalming should take place no matter what."
And they point to an article about the general process: http://www.dodgeco.com/articles/embalming.html
More specific detail may follow.