John D.,

We flew the S-62 from Sikorsky's facility at ...Stratford? prior to joining the Manhattan at Newport News.

Here is a link.
Planes and Choppers Photos - Sikorsky S-62

It had received a good refurbish after spending around 48 hours floating in the Atlantic off the coast of West Africa, downed it seems by contaminated fuel loaded at Dakar International Airport.

Yep, in later years we used electronic track and balance gear on 212's in Abu Dhabi.

Exmek

I remember witnessing the 'accurate' track of the blades using the chalk and flag method on a Wasp back in the 80's at Portland.

What amuses me is that the blades continued to be marked with the same colours as the chalk even when the method died out.

The inaccuracies were mainly down to the most junior 'bod' being the poor sap with the pole. In his ensuing panic the pole was rarely held steady! It was difficult to achieve on board as the rubber strip would often be flung into the sea! Added to the above problems the boat (I was never a ship driver!) movement added its own problems. As the old beasties were so damn clunky and could put up with far more abuse than the 'sensitive' choppers of today the 'belt and braces' approach worked rather well.

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!

Finally they were all replaced with some sort of electronic blade and track gizmo that even took the tail and the battery balance into account!

Various straight and level flights at differing speeds gave the reading. Nowhere near as much fun but it did seem to work.

Sorry, no pictures, just reminiscing! :ok:

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 :hmm: 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 :eek:

deano
 

Looking for Helicopter pictures of M/R and T/R track and balance using the flag and pole method.

John Fay's book (I suppose it was the fifties version of Bailey) has a picture of a Sikorsky / Westland R-4 being tracked that way IIRC. I think it was actually in the hover.

Here's an old one of a JetRanger track from 1968 via an engineer chum :ok:

We used to track Bell47s using a paint brush dipped in grease and adjusting on that

Yes, I remember that as a young apprentice (and being shouted at too!) :sad:

We used to wrap bubble wrap around the top 2 1/2 feet of a 12 foot pole until we got it about four inches thick then completely wrap that with duct tape. Pick a point in the pilots view (10 or 2 O'clock) and bring a blade to that point and set the pole vertically on the ground with the wrapped duct tape just touching the blade tip. Then we marked the spot on the ground, put a red and green grease pencil (can you even buy those these days?) mark on the respective blade and laid the pole down while they started and warmed up. Once they had it up to full RPM we would raise the pole ever so slowly until we got a touch with the blade tip then lower it back to see if we got good marks. Sometimes we could rotate the pole 90* and get a second touch. Then shut it down and make a correction and do it all again. There were lots of conditions to play with such as doing a low RPM check then a high RPM check with tabs zeroed to see if you wanted to tweak a tab or make a PC link adjustment.
The Strobex was a Godsend when it showed up.

had a similar experience after replacing a blade in Evanston, WY over 30 years ago. Used a strip of packing foam, duct tape, and the mech bought a box of crayons from some sort of "dollar" store. You do what you gotta do.

We used to do it frequently on Whirlwinds & Wessex. Since the blade tracking could be affected by wind gusting, on one occasion, at Leconfield, in 1971, we did it INSIDE No 5 hangar, with hangar doors fully open, and a Mk6 Alvis 6-wheel fire tender in attendance.

It was done by riggers, (airframe tradesmen), and often in conjunction with post-scheduled maintenance runs. I recall one such was in mid-winter, on a snow-covered tie-down pan. It went on for some time, the riggers freezing from the rotor-induced blizzard. I was an engine fitter at the time, so opened the engine access door, while it was running, and basked, to the riggers' chagrin, in the warm airflow around the efflux, all the time smiling like a cheshire cat! - NOBODY loves a smart-ar$e!

Can remember many moons ago, late 50's early 60's (still in short trousers!) watching someone at Southend with a bucket of whitewash and a long handled brush tracking a helicopter (try as I might cannot remember what).
He simple loaded the brush with whitewash, stood underneath the whirling blades and poked the brush up till it touched a blade.
Then they stopped the engine, tweaked the (white) blade, wiped the blade clean and repeated the process.