Any tips for shooting from a Cessna plane?

I will be shooting from a Cessna top winged plane window next week. No budget for giro, any tips for low budget stabilization for Cannon 7D. My plan is to use a inflated rubber ball to cushion the jitter from the plane and shoot downwind. Heard of bungees doing the trick.

Would appreciate any experience and pointers on the matter. I have to do a shot of a woman that will be on a field on the ground so probably will need 0 70mm lens or more to get in close but that meen more vibration in the shot.

Many thanks.

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