Airborne
A little knowledge is a dangerous thing eh
The guys will be learning to judge where they believe the height of the lowest cable is with reference to the disk. A judgement exercise for both the front and rear crew. Using that they then also descend to a height where they are satisified they are clear of the cable and that no 'arcing' could possible occur to earth via the heli. The judgement excercise and patter will be practiced until those doing the training (and maybe their instructor) are happy it is completed without error. Hence the up and down like a 'purposeful yo yo', and they will spend 20 minutes in the hover if they want until everything is done as per the textbook. Hope that clears things up for you
