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Outboard blade droop stops
Posted: Wed Apr 07, 2010 9:11 am
by seneca2e
Found one of the outboard blade droop stops with the rivets sheared. This part is retained by the main outboard blade retention bolt anyway but think I'll properly rerivet it. Is it common to find these loose? Don't actually even see a breakdown on the part in the parts manual. I assume just AD structural rivets are what was used.
Re: Outboard blade droop stops
Posted: Wed Apr 07, 2010 7:34 pm
by bryancobb
none of mine even had holes for rivets.
Re: Outboard blade droop stops
Posted: Wed Apr 07, 2010 7:42 pm
by Ron Spiker
Two of mine have the holes for rivets and one does not. None have the rivets in them.
Re: Outboard blade droop stops
Posted: Wed Apr 07, 2010 9:40 pm
by seneca2e
Interesting. I popped the rivet shank remnants out-they were only 3/32" diameter. Since the other two are riveted and these were as well I'm gonna rerivet them. I measured the damper lengths and they appear very close to spec but there were no shims in the fork root as we've been discussing. I'll see how tight they are when I put the outboard blades back on. In the meantime the tail/intermediate gear box reservoir got AS100w plus as did the engine. The tranny got the Mobil 1 synthetic. Gonna remove the sparkplugs and crank it with the starter to get the oil pressure up before I try to start it for the first time since it's been a bit since it was started. Speaking of which have y'all started them with the outboard blades removed? The book says okay just be careful not to overstress the tail rotor drive on startup.
Re: Outboard blade droop stops
Posted: Thu Apr 08, 2010 9:38 am
by bryancobb
About starting with the outer blades off... If your ship has been run a lot recently and you have your priming/starting method FOR YOUR ENGINE nailed down, you can do it without much risk.
If you never have gotten VERY familiar with your engine's personality... DON'T EVEN THINK OF IT! You'll twist your T/R drive system in-to at its' weakest point!!!!
Ask me how I know????
Re: Outboard blade droop stops
Posted: Thu Apr 08, 2010 9:37 pm
by seneca2e
I saw that warning in there as well but thought that risk might be less than the risk of wrinkling the outboard blades on a botched start attempt. I guess either way I go at it I'm going to have to be very careful starting it up. By the way where was the weakest point in the tail rotor drive?
Re: Outboard blade droop stops
Posted: Fri Apr 09, 2010 5:42 am
by bryancobb
On my botched startup, the short shaft between the lower and upper T/R gearboxes was the weak link. The AN-3 drive bolt on the bottom end didn't shear but it did destroy the male bullet fitting that fits on the shaft. The bolt also mangled the shaft itself around the lower hole and the aluminum tube housing.
It didn't start, the engine only surged for 5 or 6 revolutions. I treated it as a sudden stoppage and inspected everything $$$$$. Had to buy a new short shaft and that put me into having to do the recurring AD if the shaft has been replaced with one manufactured after 1990. I THINK it's AD 006-08-07.
Re: Outboard blade droop stops
Posted: Fri Apr 09, 2010 5:44 am
by bryancobb
Just MAKE SURE your rotor brake works and is capable of LOCKING the rotor before attempting to start it, and make sure the go/no-go detent works on the throttle that prevents the starter from working if the throttle is too high.
Re: Outboard blade droop stops
Posted: Fri Apr 09, 2010 9:59 am
by NinerMike
What rpm are the rotors suppose to engage. I was reading some old threads with regards to hot starts and the rotors engaging. Concerns me that that simple act of starting can possibly lead to damage, even when following the checklist! Please bare with me as I'm just trying to learn more.
Re: Outboard blade droop stops
Posted: Fri Apr 09, 2010 11:06 am
by Ron Spiker
They'll start turning when the engine RPM goes above about 1200-1300 or so, and fully engaged at around 16-1700. But, if you have a fast start where the engine takes off with high RPM, you're brake better be tight to keep the blades from taking off too quickly. Good way to spend a lot of money on new blades.