Used my Surefire headlamp to assist in a pre flight inspection of a helicopter, Bell Jet Ranger, owned by an old friend of mine. (He has a private jet too). He had just got the chopper back from a basic routine maintenance job that cost over $40,000. Headlamp was great because there are more things to check on helicopters.
But, you still need to do the pre flight checks, many more than the little planes I fly. I don't fly very much these days, however, the headlamp made the checks so much simpler than a regular flashlight on somethings, many things.
You still need a flashlight, even in the day, but the headlamp is something I would loved in the 80's for this. When my friends and I would fly up and down California all night long for something to do.