R44 Hydraulic

[HeliEng]

Would like to hear from anyone with any views or opinions on the aforementioned helicopter!

Let us know!

[Lu Zuckerman]

To: HeliEng

I believe you already know of my opinions regarding Robinson helicopters but I would like to make this comment about the R44 Raven. The installation of servos in the flight control system was in my opinion to counter the feedback forces emanating from the rotorhead mainly due to centrifugal twisting forces and cyclic pitch change of the blades as they rotate. This in itself is good. However, if the upper flight controls were not modified to withstand these trapped loads the reliability of the upper controls will be adversely effected.


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The Cat

[HeliEng]

I believe that not only that upper flight controls but the frames too will be affected. Is this not also possible?

[Lu Zuckerman]

To: HeliEng

You are so right. Anything that supports the servos and anything above the servos including control rods, pitch links and pitch horns will be effected.

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The Cat

[HeliEng]

I know some problems were encountered after relatively few flying hours (20-25).

Is this the start of things to come?
Considering that Robinson have claimed to have carried out extensive testing on the aircraft as a whole with the Hydraulics fitted, the first indications are not so good!

Another thing I have noticed, is that there is no warning light to indicate whether Hydraulic power has been selected or not. Anyone have any opinions on this?


[This message has been edited by HeliEng (edited 01 January 2001).]

[Lu Zuckerman]

To: HeliEng

Don't hold back on what you know. I predicted structural/control problems when they first concieved the Raven. At that time I was crucified by staunch Robinson supporters just like those you find on these threads.

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The Cat

[sprocket]

HeliEng, would a warning light be of any real use to the pilot?
Does it (the R44) have dual hydraulic systems?


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sprocket: .. No standards? Nooo problems!

[This message has been edited by sprocket (edited 02 January 2001).]

[HeloTeacher]

I agree, like the Jetranger, a light is't necessary. The a/c is controllable w/o hydraulics and lack of boost will be readily apparent.

[Lu Zuckerman]

To: HeliEng

I don’t know if you have read the Robinson Certification thread but some of the responses were quite troubling. One of the main thrusts of my thread was that there were restrictions placed on both the R22 and the R44 preventing the pilots from flying out of trim and doing sideslips. The reason for the restriction was to cut down on the flapping loads and flapping excursions to minimize the possibility of mast bumping. I caught a lot of flack on that point as many of the responses indicated that many pilots totally ignored the restrictions.

If this mentality is carried through onto the R44 Raven then they could be introducing higher than anticipated feedback forces when they violate the restrictions thus causing problems with the attaching structure and the upper control system. With the hydraulic servos blocking the feedback the pilots are unaware of these feedback loads although they might feel it in the form of fuselage vibration. Just a thought.


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The Cat

[HeliEng]

O.K, sorry for delay, been a little busy, with distinct lack of time for 'ME'. Anyway.


I haven't actually read the Robinson Certification thread. Where can I get a copy of that?

1. Mr Robinson seems very concerned about inexperienced pilots giving his aircraft a bad name.
I am sure when most people see a Robinson accident, they DON'T immediatly think that the pilot messed up.
'Generally' the reaction is Oh, another Robinson.
Frank seems to be aware of this, and will not sell a new aircraft to anyone with less than 200 hrs (I THINK this is so, please correct me if this is not true, but there is some minimum flying time for purchasing a new Robinson)
I would have expected him to have put a light on the console to inform the pilot that the Hydraulic controls were not switched on.
I understand that the aircraft is controllable without them, but if the pilot is under the impression that they are on, surely this could lead to problems when lifting off? Would the pilot not handle the aircraft differently if he/she assumed the hydraulics were on?

2. I think I am just going to wait and see on the structure side. I think that more problems will develop, and it will just be a case of time.

Lets wait and see Lu!!!

P.S:- Another question, anyone got any idea why the FAA have approved 4 of the Robinson warning lights to be amber and not red? (Three of which are T/R chip, M/R Chip and Low Fuel.)


[This message has been edited by HeliEng (edited 13 January 2001).]

[Lu Zuckerman]

To: HeliEng

Log onto the Rotorheads Forum. The original certification thread and several others are inactive at this time. Look into the archive section under the last twenty or thirty days.

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The Cat

[HeliEng]

To:- Lu

O.K, have just spent a lengthy amount of time seraching the previous 30 days of discussions. Any idea at all what it was called or approx date?

Do you have any opinions on my previous points?

THOSE WHO HAVE THE WILL TO WIN CANNOT BE BEATEN!

[This message has been edited by HeliEng (edited 13 January 2001).]

[piloteddy]

HeliEng:

Click on the link and it'll take you to the Certification Of Robbo's thread:

http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000426.html

Hope it helps.
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PilotEddy.

[HeliEng]

Cheers, thanks very much!

[Lu Zuckerman]

To: Helieng
I pulled this from a UK helo forum.

Posted by Phil (195.7.227.146) on January 14, 2001 at 04:49:42:

9 hours total, 3 hours since delivery and hydraulics failure.
I try to believe the sales pitch about reliability and am mindful of isolated mechanical failures, however there seems to be an awful lot of them reported.
Please let me know if yours has failed? Has it happened since the first time?
For those uninitiated, try flying (with an instructor who you trust with your life) with hydraulics turned off – you’ll only do it once.
A days flying lost and a nagging thought that it might happen again. Frank and me need to talk.



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The Cat

[HeliEng]

Sorry for delay once more, things all a bit hectic as always!

No failures here! What was the cause of the Hydraulic failure of which you refer, and Where can I find out more about it.

I have flown a Raven with the hydraulics off, and you are absolutly right, it is JUST ABOUT managable, but is a lot worse than the pre-hydraulic Astro!

Like I say, I think time is the only teller here!!!

SOME DAYS YOU ARE THE PIGEON AND SOME DAYS YOU ARE THE STATUE!!