Hardest Aircraft to Track and Balance?

[toolguy]

A few of us were comparing notes around the coffee machine about which aircraft is the hardest aircraft to track and balance. The 500 and 530 came up, as did the A109. I can smooth out a S76 in about 3 to 4 moves on a good day, and a 206 in about 2. Now that optical tracking gear and computers are more common, what aircraft are still tough to tame? :}

[Backward Blade]

I've had experiences with with 206, A-Star,214 and for the most part things move, generally speaking, along quite well. The R-44 on the other hand is a whole different beast entirely. I swear that sometimes you have to use the force, voodoo, pick a religion! Found myself doing circles to get within .2 for days. And what doesn't work one time, all of a sudden seems to rectify itself. I swear that sometimes if I sit more on one butt cheek than the other it could very well make a difference!!LOL

[TukTuk BoomBoom]

412s arent the easiest to smooth out sometimes.
I think part of the problem is they have so many adjustments available but with RADs or the 8500 you can tell within about 4 moves if its going to be a long day.
I made myself pretty unpopular in my last job by rejecting 5 blades trying to get the aircraft smooth, they were junk.
I like the response i got from a Bell tech rep about the 2per in the 206, he said its basically black magic reducing those vibes and they have come out of the factory with a 2p as high as 1.8 ips!

[AB139engineer]

I agree, tracking & balancing the 412 can be a long day, BO 105 tail rotor can be a challenge also.:ugh:

[S92mech]

A 412 with allot of time on it is the worst I've balanced. It all depends on how much money you want to spend on bearings, mounts, dampers and blades. 407's are very easy. The S92 isn't very hard to make the 1P's very low, usually two moves.

[spinwing]

Mmmm ...

The secret of the balancing the Bo105/Bk117 T/R is to have that expensive little tool that allows you to set the trunion/yoke/bearing preload relationship correct ... without it you in for a tough time ! with it ...easy!!!

[fling-wing_1]

Sweet Cthulhu!! it must be the 500!!! I just today dispatched my nemisis back to it's lair on the lake. I swear changing the head was like giving the damn beast a lobotomy. It's alive I tell you, ALIVE!!! Nothing I did would satisfy the thing. I contemplated human sacrifice for a time. Perhaps it's blood lust was sated when I nicked myself on a cotter pin and dripped a few drops of my own life giving element on the monster. It at long last appeased us with a .16 at 130 kts. As the owner said to me yesterday, up till now you WERE the track and balance god. Now I simply bow before the Machiavellian bastard and give thanks that it has gone away for now, knowing that it will return to vex me another day.

DISCLAIMER: Written after a few well deserved glasses of cheap vino but all facts represented herein attested to be true to the best of my knowledge given my present state of mind.

[Scissorlink]

500 with PMA blades :ugh:

[Alloa Akbar]

You could throw many different types, M/R, T/R, Engine Fans blah blah, the bottom line is, if the boys who configure the kit smartcharts / scriptfiles etc have got their act together, then the kit should do it without a hitch. However, throw in an aircraft chart which was calculated using only one representative aircraft for configuration trials (As most companies do these days) add to the mix an operative who hasn't been formally trained in the finer points of RTB, and has instead been told which buttons to push by someone on the other shift who is the "Company guru" and all of a sudden you are in the guano. Thats even before you think about mechanical wear / offsets etc etc etc.

There is usually a good reason for aircraft being a pain, some, like the AS350 / 355 / A109 Tail rotors are extremely sensitive and require patience and small moves. Others such as the Bell 412 are actually very straightforward, however some kits (I'm thinking RADS specifically) will have you changing tabs or chord weights on the ground.. wtf??? Keep to the simple basics of RTB theory and the 412 is a pussy cat... Unless of course you have blades fitted which have been in for repair.. then let the games begin..:ugh: