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

Robinson R44

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

Robinson R44

Thread Tools
 
Search this Thread
 
Old 23rd May 2010, 20:52
  #1241 (permalink)  
 
Join Date: Sep 2002
Location: UKdom
Posts: 4
Likes: 0
Received 1 Like on 1 Post
A Raven II will easily do 110kts especially if you push through the bow wave and hold it there steady i.e. level off within 5 minutes on take-off rating and allow A/C accelerate, then gently reduce power to max cont - you'll find she'll cruise a tad faster (extra 5-10kts) but the trick is to hold her steady otherwise you'll lose the advantage as the bow wave builds back up. I was was introduced to the technique by a fixed wing bod.

On my own (I'm only a lightweight) I can get 115-120kts cruise out of a good clean Raven II.

As for APS - 1520lb is about right for Raven IIs with night kit, 1460lb for Raven I and Astros.
misterbonkers is offline  
Old 9th Jun 2010, 11:49
  #1242 (permalink)  
 
Join Date: Jul 2009
Location: Perth/Inverness
Age: 67
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
'Bump' in flight

We have had a bump/bang reported on an R44 during flight, no associated feedback or vibration felt through airframe or controls, no evidence of birdstrike, extensive engineering checks revealed no abnormalities with the aircraft, the freewheel checks iaw R44 SL-33 check out fine on rundown, also during auto's & recovery.

The aircraft is used in a training environment, so the freewheel is 'exercised' more frequently than during normal use.

We can reproduce a similar sound by flexing the side panels.

Any thoughts?

Bondu121 is offline  
Old 9th Jun 2010, 12:14
  #1243 (permalink)  

Better red than ...
 
Join Date: Aug 2004
Location: Appleby-in-Westmorland Cumbria England
Posts: 1,412
Likes: 0
Received 0 Likes on 0 Posts
I've heard the two rear removable panels bang occasionally (cooling down on a hot day) but not sure you would hear it in flight?? Also maybe the fuel tank if the cap was tight and loosened up a bit allowing pressure out?

Bumps and Bangz and quite different things - which was it?
helicopter-redeye is offline  
Old 9th Jun 2010, 12:23
  #1244 (permalink)  
 
Join Date: Jul 2009
Location: Perth/Inverness
Age: 67
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Bump/bang

A noise without any associated vibration or feedback through airframe or controls.
Bondu121 is offline  
Old 9th Jun 2010, 21:54
  #1245 (permalink)  
 
Join Date: Oct 2007
Location: Close to the hangar, UK.
Posts: 162
Likes: 0
Received 0 Likes on 0 Posts
My 44 occasionally makes a noise during the transition as one of the panels "pops" due to pressure differentials. Only ever does it the once and never in the transition back to the hover.
firebird_uk is offline  
Old 9th Jun 2010, 22:16
  #1246 (permalink)  
 
Join Date: Jun 2004
Location: UK Scotland
Age: 62
Posts: 192
Received 0 Likes on 0 Posts
My friend once had the pilots door on his R44 pop in flight, and although it seemed closed at the latch beside the handle, he discovered the latch at the top of the door was outside the door frame when he landed. He hadn't realised the door latched at the top also. Closed normally on the ground and never happened again, just a thought.
R
RINKER is offline  
Old 10th Jun 2010, 08:23
  #1247 (permalink)  
 
Join Date: Jun 2008
Location: England & Scotland
Age: 63
Posts: 1,413
Likes: 0
Received 0 Likes on 0 Posts
Bondu121


And you have already read / considered posts 1229 onward (see last page)?

A "bump" like a bird strike (no bird) with no loss of power or vibration was exactly what this felt like in the early stages. Did not show up in the run-down freewheel checks and only when the sprag clutch was removed and tested was it found.

John
John R81 is offline  
Old 10th Jun 2010, 09:32
  #1248 (permalink)  
 
Join Date: Apr 2001
Location: Deep inth Norhtern Hills
Posts: 264
Likes: 0
Received 0 Likes on 0 Posts
Devil 44

You mentioned that your machine is used for training, if in the previous lesson the guy has been doing some run on landings, this usually leads to the side panels getting a bit distorted, seen by the bowing of the panels between the screws.

Could have been the panels springing back in to shape once in the air.

PB
PENNINE BOY is offline  
Old 4th Aug 2010, 17:11
  #1249 (permalink)  
 
Join Date: Aug 2010
Location: US
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
A Raven II will easily do 110kts especially if you push through the bow wave and hold it there steady i.e. level off within 5 minutes on take-off rating and allow A/C accelerate, then gently reduce power to max cont - you'll find she'll cruise a tad faster (extra 5-10kts) but the trick is to hold her steady otherwise you'll lose the advantage as the bow wave builds back up. I was was introduced to the technique by a fixed wing bod.
Misterbonkers,
Refer to page 2-1 in your POH. If you are using the five minute take-off rating to accelerate over 100 KIAS, you are exceeding a limitation.
"Do not exceed 100 KIAS when operating at power above MCP."

Also refer to SN-37, at the bottom of the page.
"The most damaging conditions occur when flying or maneuvering at high airspeeds combined with high power settings."
r44guy is offline  
Old 4th Aug 2010, 20:40
  #1250 (permalink)  
Passion Flying Hobby Science Sponsor Work
 
Join Date: Apr 2004
Location: Belgium
Age: 68
Posts: 461
Likes: 0
Received 0 Likes on 0 Posts
Power setting

R44guy

fully agree on limitations. Imho such power settings are also not really usefull.


Misterbonkers

A well tuned R44-II should achieve those speeds well below max continuous. I don't know about bow-waves etc other than with boats that sail on a boundary surface between two media, but I would call it fine tuning.


My personal experience and my computer models show that 2 POB gives a higher max speed than 1 POB. A possible explanation is that if it is too light, drag may be bigger because of a more forward tilt of rotor disk, thus higher induction. Any body with similar experiences/thoughts on that paradox ?

d3
delta3 is offline  
Old 5th Aug 2010, 10:21
  #1251 (permalink)  
 
Join Date: Jul 2009
Location: Perth/Inverness
Age: 67
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Sprag clutch

The sprag clutch was in several parts when investigated, very worrying that all the recommended checks do not show up a failing clutch.

When removed from the aircraft the sprag felt a little rough, when dismantled it was obviously not far off complete failure.

A new design clutch is now in use - C188-3 Rev H.

Be wary of writing off bangs in flight as panel flexing.

MOR raised & RHC notified.
Bondu121 is offline  
Old 5th Aug 2010, 17:47
  #1252 (permalink)  
 
Join Date: Jun 2008
Location: England & Scotland
Age: 63
Posts: 1,413
Likes: 0
Received 0 Likes on 0 Posts
How many sprag clutch failures are needed before CAA (etc) get interested?
John R81 is offline  
Old 9th Aug 2010, 00:28
  #1253 (permalink)  
 
Join Date: Jun 2009
Location: AUSTRALIA
Age: 55
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
After 25 years and 14 Robinson aircraft I would like to make a couple of observations, limited to the R44
Most cost effective helicopter available, as long as you sell before the 2200hr
Only helicopter I know that if you U/S one blade you have to do both
In the highest speed to lowest fuel burn ratio they are tops
Safe within limitations
The only aircraft I know of with in built recurring corrosion problems
Robinson should at least offer them without paint so the buyer can get a decent job done, including undercoat.
A pleasant aircraft to fly, maintain and store, no fuss operation with great dependability.
DEER CULLER is offline  
Old 6th Nov 2010, 10:16
  #1254 (permalink)  
 
Join Date: Dec 2006
Location: England
Posts: 121
Likes: 0
Received 0 Likes on 0 Posts
Robinson Paint

Do Robinson supply touch up kits for their machines. Just had mine back from its annual and would like to touch up all the screw heads etc to make it look presentable again.

Thanks
valve guide is offline  
Old 6th Nov 2010, 11:39
  #1255 (permalink)  
 
Join Date: Mar 2003
Location: here and there
Posts: 105
Likes: 0
Received 0 Likes on 0 Posts
Dont think so VG, if you ask your maint. outfit they may have the right colour Robbo paint (and activator) that they can let you have a small jar of. Depending on how big they are they may not though because its expensive (not so much the paint, getting it here).

Failing that with new machines there is/should be a bag of spare screws that could be used if no paint is available. It should be in the RHC under seat bag with all the other goodies they give you.
Practice Auto 3,2,1 is offline  
Old 6th Nov 2010, 12:24
  #1256 (permalink)  
 
Join Date: Feb 2005
Location: Australia
Posts: 1,957
Likes: 0
Received 0 Likes on 0 Posts
It should be in the RHC under seat bag with all the other goodies they give you.
tha's right, right along with that good ol' US of A quarter they give you that you do the tap test with

good luck ha ha.
tet
topendtorque is offline  
Old 6th Nov 2010, 15:36
  #1257 (permalink)  
 
Join Date: Jun 2005
Location: Earth.
Posts: 465
Received 0 Likes on 0 Posts
If you have painted fuel caps take one off and head down to a paint shop and they can make up a small can for you. We used to do that and it worked really well on small areas like screw heads.

TiP
TiPwEiGhT is offline  
Old 8th Nov 2010, 06:08
  #1258 (permalink)  
 
Join Date: Jun 2010
Location: EU
Posts: 79
Likes: 0
Received 0 Likes on 0 Posts
Any advice on how to prepare an R44 for a 3 months 'wintersleep'? It's kept in an isolated hangar, but temperatures of -20 C are possible.
Thanks in advance,
FTF
FullTravelFree is offline  
Old 8th Nov 2010, 08:20
  #1259 (permalink)  
 
Join Date: Mar 2006
Location: Land of damp and drizzle
Posts: 608
Likes: 0
Received 0 Likes on 0 Posts
Probably a good idea to take the battery out and put it somewhere warm. Can you run a dehumidifier in the hangar?
Pandalet is offline  
Old 8th Nov 2010, 08:40
  #1260 (permalink)  
 
Join Date: Nov 2008
Location: UK
Posts: 91
Likes: 0
Received 0 Likes on 0 Posts
The IO540 manual from Lycoming has some specific advice (from memory), including removing the plugs to squirt in some kind of corrosion inhibitor.

Robinson customer service would, I'm sure, provide some advice too.

I would personally prefer going to the trouble of turning it over at least once a month and ground/hover running to keep all the seals well lubricated. Then the hassle of protecting the cylinders is unnecessary.

Lafite
61 Lafite is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.