Hi there,
You can do it via the SDK, as shown in the video above my post. (Although, of course, this will only work if you have the PC version. There is a Wishlist topic to allow us to remove these aircraft without the SDK.)
(And just a heads up to anyone watching the above video: Unfortunately, that video came out just a month or two before the package reorder tool was released. So, disregard anything you hear about Content.xml in that video.)