Did a similar exercise at night using a Smoke Stack, NVG's, and FLIR.....hover at several assigned heights above the stack (using FLIR to peer down the inside of the Stack for position and RadAlt for height) and hold position for a minute or two until told to move up to the next height.
We were not told the reason for the Test Program.....as we did not have a need to know....as it was at a sensitive location.
I can only imagine how hard maintaining position using a laser must have been....as we had far more tolerance but far less accurate a measuring system.
Odd thing....we never experienced VRS.....unless only in the incipient stage. Light aircraft with ample surplus power margin and I always used a heading into the prevailing wind as that made the exercise very much less a chore.
Edit: Upon some reflection I recalled there were onsets of some loss of control....felt as sloppiness in being able to control Pitch and Yaw....always combined with a loss of height...but never an elevator ride kind of loss of height.....perhaps we were just powering out of it as we accelerated forward into cleaner airflow through the rotor system.
It was pretty much an Instruments only process with the added cross check of the FLIR Screen.
I am guessing our target was about a Three Foot Diameter hole at the top of the Stack.
The Boffins sure seem to have an uncanny ability to conjure up challenging tasks for us lesser beings to perform.
At times it allows you to empathize with a Lab Rat.
Last edited by SASless; 10th Apr 2022 at 17:52.