As regards to equipment the one thing you need to consider before the camera
is the transport. Will it be Helicopter, Plane, Hot Air Balloon, Cable Car.

I've done some of this. I'm a pro photographer and amateur pilot.

First, form a relationship with the people who are going to do the flying.
Talk to them about your needs and follow their advice on what they can and
can't do. What can be done depends a great deal on the aircraft you're
going to be using. Many helicopters have sliding doors that can be left
open, but make sure you are harnessed! I've shot pictures from the open
side door of a US Marine Corps CH-46 helo but was wearing a gunner's belt
at the time.

Helos are expensive, though, so you might want to go for a fixed wing plane.
A high-wing (such as a Cessna) is easier (though watch out for wing
struts), though it is possible with low-wing, especially if you have a good
pilot who can hold a tight, slow turn. On some aircraft, you can remove a
door or a window. I've shot from a Cessna 172 where the window stay was
removed. The window hinges from the top, so I could carefully open up the
window until it was horizontal just beneath the wing, where it was held in
place by the airflow. But this is where a good relationship comes in: I had
to ensure the aircraft was flying slow enough before opening it, so good
communication between you and the pilot is essential.

I've also taken successful pics from an aircraft with a sliding canopy (a
Rallye), because it's possible to have the canopy open by about 10-15cm in
flight, giving a wide enough gap to shoot through. I've even shot through
the clear-vision port of a Katana, though that meant sitting in the left
(pilot's) seat, so I needed a pilot used to flying from the right seat
(instructors are accustomed to this).

In terms of gear, a short telephoto is the most useful focal length, I find
- something in the 85mm-100mm range (for 35mm). A zoom with vibration
damping is ideal. Switch off autofocus and manually focus at infinity.
Don't be tempted to zoom to long focal lengths - you'll find the vibration
a real problem.

Watch out for horizons. When the aircraft is banking, it's easy to get wonky
pictures. Shooting early morning is best - you get good definition of
ground details from the lower sun. Late afternoon can be good too, but in
some places may suffer a little from the haze that builds up during the
day.

Brief your pilot carefully about what you're trying to achieve. Ask him to
reduce power while you're taking pictures, it'll reduce the vibrations, but
be aware that, especially when banking (ie, turning), there's a limit to
how slow he can go before the aircraft stalls (a *bad* thing at low
altitude).

How low you go depends on what you're trying to photograph and any legal
restrictions (eg, there are minimum heights for flying over towns &
villages, people, buildings, nature reserves etc, and there may be
restricted, prohibited or other kinds of airspace that limit your options).
In general, however, I've got my best results from 500-1000ft. (In most
countries, 500ft is the lowest you're allowed if there are people, animals
or buildings).

Take plenty of film/memory cards, but don't overload yourself with other
gear. Cockpits are cramped places - you're best off with a single body and
lens.

Hope that helps.

@+
Steve

I've heard of using a rather expensive gyroscope device to stabilize the
camera from the airplane's bouncing & vibration. Same basic idea as a VR
or IS lense.

If you haven't yet, check out google earth, it's almost like being
there. Anyways you could scout out locations easily that way.

I shoot digital with a Canon 10D & 20D using a Canon 2.8L IS 70-200
lens. I try to keep my shutter speed pretty high (around 1/250
to1/500). Biggest problem I find is the haze.  Photoshop can do a lot
to correct the haze, but is not a fix-all solution.

Weather is a huge factor as well in addition to relative distance from
your target.  In Florida we have a good amount of haze this time of
year which requires you to get relatively low/close to what you are
trying to shoot.

I hope this helps.