reporter: if you re one of those people who doesn t like heights you would not want to climb this ladder. there is always somebody that thinks we re a little crazy. may have to be a little bit to do it, so. reporter: they may be a little crazy but they re looking out for you. they have been hired by virginia dominion power. they arrive at work by md-500 helicopter. best way i put it we take all the work of getting to the job site. reporter: they work for half very field aviation in gettysburg. most of them are lineman and they re accustomed to danger. we re not adrenaline junkies. we re not out there to get a fix. it is our cup oftae. reporter: what they re replacing is insulatetores. one of these. these wear out in about 15 years. so far the ones here are okay. but when they stop working, hundreds of thousands of people could lose power. right now, what he is doing he is already grounded a line out and he is already rigged up his hoist. and they re taking the old