How to break your neck?
REMEMBER, IF HANGING UPSIDE DOWN IN THE AIRCRAFT, you can be badly injured if undoing the straps without great caution and care.
Meanwhile, driving your car round the countryside, stop now and then and have a look at field surfaces. Usually one used for grazing sheep or cattle will be OK. Ploughed surface almost certain to tip you ass over teakettle. One that has been harrowed ready for seeding should be better. Crop is OK, usually, if it is very tall, plan to land on the top of the crop....eventually everything will turn green as you sink in!