I didn't rent a camera or a lens, but it was $960 to rent this guy and an experienced Cessna for a two hour flight (that price included a seat for my wife, which made the expense easier to justify.)
We flew over the Kluane Icefields, the largest non polar ice cap in the world, covering an area about as large as Switzerland. The photo below is just one arm of the Kaskawulsh Glacier. Our plane didn't have an inset window that could be opened for poking a camera out of, but considering the time of day (airborne at 8:15AM) and the camera was pointing back towards the sun through Plexiglas, I was happy with how it turned out.
Our destination was Mt. Logan, the highest mountain in Canada at 19,551 feet above sea level, the picture below was taken at about 17,000 feet . I brought my camera bag with me, but 18mm on an APS-C camera was as wide of a focal length as I could use with the lens pressed to the window without including airplane parts on all sides of the frame.
At the telephoto end, it was pointless to go longer than 135mm, without reference points, the rock faces and icefield lakes all look the same.