I normally have no problem in an aircraft, although I don't like cliff edge paths or looking out from the top of high buildings. However, as it was very hot for a short time a couple of weeks ago, I took both doors off my R22 and flew it around like that. While at low level say 500 feet or so this was OK, but I found that if I climbed to 1000 feet plus it felt really scary especially in steep turns!