Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

Robinson R44

Rotorheads A haven for helicopter professionals to discuss the things that affect them

Robinson R44

Old 19th Aug 2008, 08:21
  #1061 (permalink)  
TrT
 
Join Date: Feb 2006
Location: South Africa
Posts: 34
Starter Engage in Flight

I have not had a chance to go through all the threads... Has anyone heard of the bendix(starter) kicking out in flight R44, causing a loss of RPM(warning light). This would give a false indication of complete engine failure, your reaction auto.
From what i know even if you bump the starter button on the cyclic or collective it will not engage?
Anyone know off any similiar happenings?
TrT is offline  
Old 19th Aug 2008, 13:56
  #1062 (permalink)  
 
Join Date: Feb 2005
Location: Australia
Posts: 1,958
kicking out in flight R44
Did you mean to say kicking IN in flight?

Don't know if it can happen in R44's, as the starter circuit usually would not be interfered with unless it was a wiring problem, but it certainly can in "47's. If you get to talk to an old '47 engineer you you will hear about what sort of 'violent' indications that you will get if you dared touch the red button during flight.

For that reasonn we had as SOP's to pull the starter circuit breaker after start for all newbies.
topendtorque is offline  
Old 19th Aug 2008, 15:46
  #1063 (permalink)  
 
Join Date: May 2006
Location: uk
Age: 55
Posts: 179
Believe the 22+44 have a starter inhibitor, but not sure under what circumstances it operates, I'll have to take a peek at the manuals, (obviously you'd want to be able to attempt a midair restart so it must be tied to rpm in some way?)
Twiddle is offline  
Old 19th Aug 2008, 16:10
  #1064 (permalink)  
 
Join Date: Jan 2007
Location: UK
Posts: 31
In the R44 the low rpm warning unit has a starter inhibitor built into it. So I presume that means that starter is inoperable when the rpm is above the alarm point.
Chopper Doc Junior is offline  
Old 19th Aug 2008, 16:42
  #1065 (permalink)  
 
Join Date: Nov 2006
Location: After all, what’s more important than proving to someone on the internet that they’re wrong? - Manson
Posts: 1,514
I may be considered "old" and have worked on the 47 a little. The "violent reaction" is the fact that apart from the starter trying to engage (messy) you will have energised the "shower of sparks" and the retard points in normally the LH magneto. For the retarded i.e later ignition to be effective the normal points are shorted to ground. Engine will go a little funny all right. I guess they don't call them "retard" points for nothing!

Robinson setup is pretty much similar.

Have a read http://www.aeroelectric.com/articles...erOfSparks.pdf
The key switch controlled diagram is the one to look at.
Probably the single biggest reason for starter failure is the poor condition of the starting circuits in the mags etc. BTDT. If it doesn't start at any time within a couple of compressions it CAN be fixed!

The practice of cranking with the MAG switch in the OFF switch and then switching to BOTH (while still cranking) would probably instigate physical violence from most engineers witnessing the event. If you really want to crank to check for "flat" cylinders, which is an OK practice, do it with the MAG's OFF, STOP CRANKING, SWITCH MAGS ON, then start the engine. Yes I am YELLING.
RVDT is offline  
Old 19th Aug 2008, 19:23
  #1066 (permalink)  
 
Join Date: Nov 2006
Location: Pensacola, Florida
Posts: 667
RVDT sez:
The practice of cranking with the MAG switch in the OFF switch and then switching to BOTH (while still cranking) would probably instigate physical violence from most engineers witnessing the event.
Yet that's exactly how we used to crank 47's. (And yes, I am that old too.)

Why is this objectionable to engineers/mechanics? In retrospect, I can't really think of a good reason to do it that way, other than to get some fuel into the cylinders prior to adding the spark.
FH1100 Pilot is online now  
Old 19th Aug 2008, 23:56
  #1067 (permalink)  
 
Join Date: Nov 2006
Location: After all, what’s more important than proving to someone on the internet that they’re wrong? - Manson
Posts: 1,514
FH,
I know a lot of people used to do it - but take a look at the wiring diagram link and in the internals of the mag switch. The transition between OFF and L to R then BOTH internally within the switch can do all sorts of unintended things like allowing the retard to be out of the circuit. Ping goes the starter jaw!

Do it the way I recommend, net result is no different apart from no busted jaw.
RVDT is offline  
Old 11th Sep 2008, 14:04
  #1068 (permalink)  
 
Join Date: Feb 2006
Location: The Alps
Posts: 2,131
I am currently doing my PPL(H) on R44 Raven II and love it. Love the handling of it.
chopper2004 is offline  
Old 14th Sep 2008, 20:56
  #1069 (permalink)  
 
Join Date: Jul 2008
Location: where I'm told
Posts: 38
I am currently doing my PPL(H) on R44 Raven II and love it. Love the handling of it
Good value always comes cheap(ish).... Enjoy
ivakontrol is offline  
Old 17th Sep 2008, 19:32
  #1070 (permalink)  
 
Join Date: Nov 2007
Location: Russia
Posts: 5
Exclamation R44 from cold wild country

Hi all !!!

I've got an idea to buy the used R44(Clipper I) with around 1010h 2003, but there is one problem – for the first 550h there aren't any notes in its logbooks, because it was flown illegally in some cold country. Next 450h it flew under local Robinson dealer and from this point all service bulletins and agenda works were done.

The price and conditions of this R44 are quite good, but I think that within first 400h the counter didn’t work at all and real air frame is different.

So, the question is how can I find out the real TT – may be some parts have special parameters???…
Ars_rr is offline  
Old 23rd Sep 2008, 01:36
  #1071 (permalink)  
RCG
 
Join Date: Feb 2001
Location: New Zealand
Posts: 8
R44 Chugging

Has anyone out there experienced this in a R44 before;
A forward & aft movement of the main rotor mast which causes a rocking sensation in flight.

The severity of this rocking is largely dependent on the aircraft C of G loading and the abruptness of flight manoeuvres.

Rocking can get severe enough that pilot and passengers seriously believe that their life is about to end.

Worst case scenario is a complete loss of aircraft control. Recoverable situations may result in the bottom of the mast cowling contacting the front and rear aircraft panels sustaining damage to the roof panels and mast cowling.

The cause is unknown, however some theories are based around the change in chord length on the main rotor blades compared to the R44 Raven model, additionally the standard transmission mounts have been found to be made of a soft compound which may aggravate the problem. Low rotor head friction may also exacerbate this issue. Harder compound transmission mounts are available which, when fitted, along with a re-torque of the mast head improves the situation, however there is currently no complete solution to this phenomenon which the Robinson factory are aware of.

Please don’t remove this post Mr Moderator.
RCG is offline  
Old 23rd Sep 2008, 01:43
  #1072 (permalink)  
 
Join Date: Aug 2004
Location: No where
Posts: 54
You have spoken to Frank about this? What was there response? I certainly would be concerned about entering a low G situation if the rocking is fore and aft...
ketchup is offline  
Old 23rd Sep 2008, 10:51
  #1073 (permalink)  
RCG
 
Join Date: Feb 2001
Location: New Zealand
Posts: 8
Eh? Did I say low g somewhere?

Anyway before someone beats me to it NO this phenomenon is not induced by a ham fisted 65 year old trying to learn to fly.

Instances of chugging have generally occurred on aircraft operating with high forward C of G conditions (large pax/low fuel), with the phenomenon usually encountered during a descending turn, however it can also be in evidence in other flight modes, such as straight & level at high speed. Aggressive manoeuvres may also initiate the onset of chugging.

I hear you saying “what is this guy on about” but believe me this is real folks.

No I have not given Frank a collect call yet. I have been told they are aware of this phlemanemenom though.
RCG is offline  
Old 23rd Sep 2008, 13:12
  #1074 (permalink)  
 
Join Date: Feb 2005
Location: Australia
Posts: 1,958
Eh? Did I say low g somewhere?
Err, no you didn't, Ketchup did, you obviously did not use enough observation in reading his short post.

do your observational skills extend to the accurate reporting of in flight phenomina?

But, as far as your knowledge of the personalities of a certain "industry" person this little gem below surely takes the cake.

No I have not given Frank a collect call yet.
and yes there has been talk as you say,
they are aware of this phlemanemenom though.
Ppruners have discussed it also, it may even be hidden in this thread.

I am sure that it would do you a lot of good to have a look around for it.

Its been discussed at least once in the last twelve months or so.
cheers tet
topendtorque is offline  
Old 23rd Sep 2008, 18:19
  #1075 (permalink)  
 
Join Date: Nov 2005
Location: UK
Posts: 281
RCG,

I know the exact situatuation you describe! It didn't happen to me personally, but there were several such incidents reported here about 18 months ago, to pilots I know. One incident did result in the mast cowling contacting the cabin roof panels. The engineer involved (senior UK) allegedly refused to believe there was any problem with the helicopter and blamed the pilot.

Robinson should be aware of the issue, and the transmission mounts fault was mentioned also, but I believe the main cause was traced to the torque setting of the coning (flapping) hinge bolts being mismatched, or incorrectly set. You should be very careful not to overload the helicopter or exceed the forward CG limits as this will make it much worse. If you want to speak to a very experienced UK pilot who could explain more, PM me and I will tell you how to contact him.

Good luck,

BC
Bladecrack is offline  
Old 23rd Sep 2008, 21:49
  #1076 (permalink)  
Rotorheads Moderator
 
Join Date: Sep 2007
Location: PPRuNe
Posts: 3,110
RCG,

Try Post #857, and adjacent posts.
Senior Pilot is offline  
Old 23rd Sep 2008, 23:09
  #1077 (permalink)  
RCG
 
Join Date: Feb 2001
Location: New Zealand
Posts: 8
Ah yes there it is...

Thanks Senior Pilot yes there it is, interesting to see that the same eye opening experience has happened to another poor unsuspecting pilot.

This did not happen to me and I was told about it third hand. I guess I was surprised to hear that it was not common knowledge amongst R44 pilots considering the usual response is to put the puppy down before it fly’s to pieces. Education about standard recovery procedures should be given to all pilots hopefully avoiding a low timer wrecking their helicopter and passengers while getting it on the ground (in a panic).

I did try to search for the phenomenon but no one has called it chugging before. It would have been nice to have a thread devoted to ‘chugging’ instead of having it lost into the depths of the 1080 post novel that this thread has become.

Can I be un-merged?

Last edited by RCG; 23rd Sep 2008 at 23:27.
RCG is offline  
Old 24th Sep 2008, 04:11
  #1078 (permalink)  
 
Join Date: Apr 2008
Location: Louisiana, USA
Age: 50
Posts: 62
Electrical problems

R44 Raven II with less than 200 Hours is an electrical nightmare. Intermittent illumination of the fuel filter light in flight and on the ground during cool down. Cleaned the gascolator screen and the fuel servo inlet screen(no contamination), problem still exists. Talked with Robinson and they said they had problems with earlier revision vacuum switches in the gascolator, but we have the latest and greatest switch. Got a new one and that problem seems to be fixed. Cyl head temp readings occasionally fluctuating from dead zero to pegged out and any where in between. Checked wiring harness from stem to stern, found no problem. Seems to have fixed itself for now. Rotor tach readings tend to fritz out from time to time in flight and doing pre flight run ups. Checked points in mag and associated wiring. Found a shielded wire nicked at a connector that may have been grounding out. Fixed wiring and problem went away...and comes back and goes away. This aircraft is a lemon. And Robinson wiring diagrams suck. Too much info on one page. How bout splitting up systems so I don't go blind trying to fix a problem.
helofixer is offline  
Old 24th Sep 2008, 18:58
  #1079 (permalink)  
 
Join Date: Jul 2008
Location: where I'm told
Posts: 38
R44 Sprag Clutch

Robinson R44 Sprag Clutch Failures

We are beginning to see far too many of these at the moment. Anyone else experiencing failures/slipping/banging? Or has anyone else inspected one early and found excessive wear or damage?
Found on the Tech Log Forum

Last edited by Senior Pilot; 24th Sep 2008 at 21:55. Reason: add Tech Log link
ivakontrol is offline  
Old 27th Sep 2008, 00:52
  #1080 (permalink)  
 
Join Date: Nov 2007
Location: Away out There
Posts: 54
Raven 2 starter activation

I understand there have been a couple of incidences of power loss in R44 Raven 2's in flight lately.

It sounds to me like the starter is engaging in flight switching to the retard points and dropping one mag like its supposed to and everyone is bound for the ground.

I imagine there is a compicated loom for the starter with 2 alternative start buttons at the ends of moving levers (collective cylic) and there must be a soleniod that switches off the running points and engages the start points.

I wonder if the problem is as simple as a shorting wire or a faulty soleniod.
Does anyone have any other ideas as what might be happening.

Does the Raven 2 have the starter lockout feature when the clutch is engaged the R22's are supposed to have. (I have never heard of anyone testing this) More wiring for potential trouble but I like the idea.

If you have any theories on this it would be great to hear them.

Waragee
waragee is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.