Originally Posted by wobble2plank
The chalk was then replaced by a 1 inch square numbered flag on each blade tip with a strobe light connected to a microswitch on the head which gave a 4R/5R (dependant upon the number of blades obviously) flash that enabled the Grubber to see 'static' numbers with track and lead lag and write down the adjustments to each blade based on how high the flags were relevant to each other or how far forward or back. The blade adjustments still used the colour code from the chalk days though! E.g. 'Blue blade 1 flat down'. Was great fun at night, just like being with John Travolta in the disco!
For some reason the original reflectors didn't have numbers, but instead had /, \, -, | and (IIRC) O. We carried a strobe onboard the Sea Kings during 4 hour Jumpex/CASEX and took readings when the mood suited, giving the results to the grubbers when we returned for them to puzzle over and come up with a solution
Bit of pain at night, it certainly didn't do much for the night vision but tended to be a lot easier to see the reflectors and estimate the track than during sunny daylight. Just imagine trying to estimate by how many inches one reflector was higher or lower than the others some 20-30 feet away, then suitably jotting it all down for "analysis" during debrief
The flag tracking (Whirlwind/Wessex) was an exercise best participated in from the cockpit or (better still) the ACRB. Just watching the black hand gang rotating the flag into the disc gave me the heebies
