Well, try and climb on an iced crane on a windy day! Fit or not, there is a risk of injury when doing maintenance or a D.I. if one slips and falls.
Canadian/Erickson have implemented attach points on the aircraft for use of fall restraint for flight crews. Use is mandatory for us.
There have been several cases of injuries due to falls off the aircraft over the years. Sucks to be out of work for an indefinete period of time when you have a family to support.
A note.....the ones injured, where young, agile and extremely fit.