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R44 ground handling

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R44 ground handling

Old 7th Jun 2020, 22:32
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R44 ground handling

I was at a local airport the other day, visiting an avionics shop and I watched a mechanic at an adjacent hangar, moving an R44 into the hangar.

In order to put the rotor blades fore and aft, he rotated the tail rotor by hand. Is that a permitted practice?
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Old 7th Jun 2020, 23:19
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It’s normal practice.
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Old 7th Jun 2020, 23:48
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Yes, normal. I like to do it by the hub, though. No point in putting stress on the actual tail rotor blades.
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Old 8th Jun 2020, 00:24
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Originally Posted by India Four Two View Post
I was at a local airport the other day, visiting an avionics shop and I watched a mechanic at an adjacent hangar, moving an R44 into the hangar.

In order to put the rotor blades fore and aft, he rotated the tail rotor by hand. Is that a permitted practice?
Seems like we all do it, but I've always wondered this as well?

,...primarily due to "safety tip 14" where it states that, "Stopping or rotating the tail rotor by hand can damage the tail rotor drive"

It seems like such an obscure place to put that? If it were a true "caution don't do this" I would image they'd put it somewhere more "out in the open", but I always forget to ask when I'm at RHC,...and I was just there in February!,...ha!
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Old 8th Jun 2020, 01:35
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In what document and page is this safety tip?
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Old 8th Jun 2020, 03:04
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Originally Posted by aa777888 View Post
In what document and page is this safety tip?
Section 10 of my R44 POH "Safety Tips And Notices" page 10-3. Its the last line of a paragraph which begins on, not raising the collective during shutdown to slow the rotor.

,...but its also in my R22 book as well.
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Old 8th Jun 2020, 12:32
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If you are referring to Safety Tip 14 in the current R44 II POH, that's not relevant. Apples and oranges. Gently repositioning blades that are already stopped using the tail rotor is acceptable. Trying to use the tail rotor as a rotor brake is not.

"14. Do not use collective pitch to slow the rotor during shut-down. Collective pitch produces lift on the blades which can disengage the droop stop friction and allow the blades to strike the tailcone. Also, do not slow or stop the rotors by grabbing the tail rotor. Stopping the tail rotor by hand can damaged the tail rotor drive."
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Old 8th Jun 2020, 12:35
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if the helicopter I was on was so fragile in the drivetrain, that rotating the TR by hand was a risk to damage it, then i would rethink flying it.

now taking into consideration that there are many hamfisted individuals out there...i can see why the cautions are there.
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Old 8th Jun 2020, 13:24
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Spinning the Blades

“Stopping or rotating the tail rotor by hand can damage the tail rotor drive”.
Is possibly referring to the practice of spinning the blades in cold weather prior to engine start, I would carry an 18in folding step allowing me to remove the front blade tie-down, spin the blade to take off the rear tie-down then continue spinning 4 more revolutions to listen to the gearbox and drive.
This was standard procedure on a Gazelle which didn’t require an 18in Step.
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Old 8th Jun 2020, 14:40
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Originally Posted by aa777888 View Post
If you are referring to Safety Tip 14 in the current R44 II POH, that's not relevant. Apples and oranges. Gently repositioning blades that are already stopped using the tail rotor is acceptable. Trying to use the tail rotor as a rotor brake is not.

"14. Do not use collective pitch to slow the rotor during shut-down. Collective pitch produces lift on the blades which can disengage the droop stop friction and allow the blades to strike the tailcone. Also, do not slow or stop the rotors by grabbing the tail rotor. Stopping the tail rotor by hand can damaged the tail rotor drive."
Hmm, upon further comparison between my old POH and the one I downloaded in '16. it seems the words, "or turning" have been omitted.

They change this thing so much, its hard to keep up.
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Old 8th Jun 2020, 17:08
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Regularly turn the blades by rotating the TR during pre-flight. Never standing outside it when the blades are moving after shut down.
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Old 8th Jun 2020, 18:10
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Originally Posted by Hilico View Post
Regularly turn the blades by rotating the TR during pre-flight. Never standing outside it when the blades are moving after shut down.
Well that's just it. Not grabbing the tail rotor to stop it after shutdown always seemed like what we used to call, "common sense".

Not turning the tail rotor by hand (like say during preflight) is what always had me wondering,...why? Maybe it was just a typo in the old books?
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Old 8th Jun 2020, 20:59
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Not sure there's any other way to check the tail rotor flex coupling than by turning the tail rotor blades and looking through the sight glass.

aa777888, interesting point. I wonder what the stresses are on the blades in flight? Longitudinally, I'd guess they're enormous, laterally, they'll be huge. But lead/lag, wonder where they fit in?
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Old 8th Jun 2020, 23:07
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I think it is just that the piddly gears in the T/R box are designed for stresses in only one way. Sudden stoppage or a rapid change in direction by hand could cause some problems. Be gentle.
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Old 9th Jun 2020, 05:11
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Originally Posted by India Four Two View Post
I was at a local airport the other day, visiting an avionics shop and I watched a mechanic at an adjacent hangar, moving an R44 into the hangar.

In order to put the rotor blades fore and aft, he rotated the tail rotor by hand. Is that a permitted practice?
if it gets one of those things in the hangar it’s got to be ok
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Old 9th Jun 2020, 11:28
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to put things in context: machine force against human force

The tail rotor system is likely absorbing 10% of your total power at times, let say up to 20Kw, with wide variations of torque on pedal input.

A bicycle rider can produce 100W to 300W
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Old 9th Jun 2020, 17:10
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Originally Posted by Robbo Jock View Post
Not sure there's any other way to check the tail rotor flex coupling than by turning the tail rotor blades and looking through the sight glass.

aa777888, interesting point. I wonder what the stresses are on the blades in flight? Longitudinally, I'd guess they're enormous, laterally, they'll be huge. But lead/lag, wonder where they fit in?
Yes, exactly: it's not easy to do a thorough pre-flight without rotating the entire drive-train in order to inspect it properly. You can do it, but there is a lot of squinting and peering and flashlights and stuff. It's a lot easier and probably more thorough to rotate the entire mess. It's a lot easier to inspect and touch everything that way. I will push on the upper belt sheave to get things moving around in the transmission area. I will grab the *hub* of the tail rotor and rotate it to get a better look at all of the main and tail rotor components. That way I don't have to drag a ladder around to both sides, and it's the only way to really look at both sides of the main rotor assembly without a ladder since you can only climb up the helicopter on one side. And I'm sufficiently OCD that I only rotate the drive-train in the direction it normally goes
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Old 11th Jun 2020, 17:39
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aa: if you really want to awaken your OCD, think about the loads on the tail rotor gearbox when you rotate the tail rotor in the "right" direction. They are actually opposite the normal.
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Old 11th Jun 2020, 19:13
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Actually they're exactly the same as the load from autorotation.
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Old 11th Jun 2020, 19:14
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Ha ha, true! I guess I better rotate it the other way from now on!
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