View Full Version : Question for Nick regarding Centrifugal force.
Lu Zuckerman
7th Dec 2003, 09:07
To: NickLappos
The design philosophy of Sikorsky since the S-55 all the way to the CH-53 the rotorheads had centrifugally operated anti cone stops and droop stops. Looking at a picture of the UH-60 rotorhead I do not see these devices. What do they have on the UH-60 to perform these functions?
:E :E
NickLappos
7th Dec 2003, 11:17
Lu,
The droop stops on the H-60 family are there, just hard to see.
see photo SH60B_0001T rotorhead (the square tabs below the hub arms are the droop stops) on this page:
http://www.sikorsky.com/details/0,3036,CLI1_DIV69_ETI1005,00.html
The stops are spring loaded and flip out at about 60% Nr.
Lu Zuckerman
7th Dec 2003, 11:35
To: NickLappos
Thanks Nick. I found this on the internet and if you look carefully you can see the springs.
http://www.b-domke.de/AviationImages/Rotorhead/1642.html
:E :E
http://www.b-domke.de/AviationImages/Rotorhead/Images/1642.jpg
Jcooper
7th Dec 2003, 13:20
Coming from a robbie pilot that looks like way too much sh!t to have on a rotorhead :)
NickLappos
7th Dec 2003, 21:26
Jcooper,
That head is actually fairly simple, but the blade fold mechanism and de-ice harnesses add complexity. The rotor folds itself with a few button presses, even in high winds.
JCooper, if you think that's bad you should see our Sea King head - it combines all the experimental plumbing Sikorsky played with before they got to the simple blade fold system pictured in Lu's reply
Jcooper
8th Dec 2003, 06:07
The preflight on that thing prolly takes as long as it does for the entire robbie :) Looks neat though, I should have checked it out more closely when we had a Pavehawk come into Des Moines. I noticed the little pop out ladder system on the pylon to get to the tail rotor though, very inventive.
rotorusa
9th Dec 2003, 03:21
Nick,
Isn't such a complex rotorhead a major source of rotor noise? Would a couple of flexible sleeves over all those hoses make any difference? Your S92 paid a visit to our base a while ago but I didn't get a chance to examine the rotorhead upclose. Apart from the fact that it doesn't have the folding system, I imagine it to be more streamlined than the UH-60 head.