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-   -   Robinson R44 (https://www.pprune.org/rotorheads/189931-robinson-r44.html)

sprocket 8th Jun 2002 22:08

With the hydraulics defaulting to on when electrical power is off could make for an even more interesting flight, should you have a servo fail at the same time as an electrical failure.
[This is just an observation as I realise the odds of that happening are very low.]

Normally, a hydraulic warning light on a Raven would have the same effect as having an engine out warning light. It will tell the pilot what he already knows.
In helo's that use dual hydraulic systems, the warning light for each system does serve a purpose.

A lot of aircraft systems have an electrical auxillary pump installed which act as a backup in case of main pump failure or for activating systems when the aircraft is not operating.
Can anybody enlighten me as to why helicopters dont use aux hyd. pumps? :confused:

The Nr Fairy 9th Jun 2002 06:48

My understanding - and this comes from the one trip I did in an R44, with an instructor - is that the CB is pulled to isolate the switch, should it fail, and therefore restore hydraulics. The inference for me is that switch failure is more likely than complete hyd. failure.

Any comments ?

Rotor Nut 9th Jun 2002 10:53

The Raven is silky smooth with hyrdraulics - I love it...

I do the hydraulics off bit on the annual check - hate it! Hovering is like stirring treacle and lots of sideways pressure at 75knots.

Totally agree, warning light not needed - you would know!

Helinut 9th Jun 2002 15:48

The hydraulic system is functionally similar to the B206 system for example, which also does not have a light or a gauge (similar to many light single engine helicopters that use hydraulic power-assistance controls, as distinct from hydraulic power control). The hydraulic system is powered from a pump mechanically driven from the MGB transmission and is controlled electrically, because it is not practical to route the hydraulic system direct to the cockpit. The electrical control system is "fail safe" in that if anything shuts off the wigglies to the valve that dumps the hydraulic pressure, it fails so that hydraulic pressure remains ON.

When a helicopter has only one hydraulic system, failure of that single system is foreseeable and it must be possible to cope with such a failure in flight. That's why the aircraft can be flown without hydraulics and we practice hydraulic failures in types that have such single systems. If not, you would need at least 2 entirely redundant systems.

The light or gauge would not really help you much - you notice almost immediately if you lose hydraulics in flight!

buttline 15th Jun 2002 10:34

Just done my B206 TR and taught as follows:

- Check the hyd switch is on

- If it is, check the CB - pull it out to try the fail safe

- If hydraulics do not come back on, you must reset the hyd
switch to off in case the hydraulics come back on when you're not expecting it and applying a lot of effort on the controls

- Do a hydraulics off landing

ShyTorque 15th Jun 2002 18:28

On an aircraft with switchable hydraulics I would recommend the following actions, some of them already covered by other contributors:

1. Move the switch!

If it's OFF you want it ON; if it's ON you need it OFF. Simple. If nothing happens (hydraulic assistance not restored) confirm which way it is now selected.

2. Check the pressure if a gauge is fitted. Check the CB.

3. Before resetting the CB ensure the switch is OFF. You do NOT want to restore hydraulic assistance by the CB with the controls not covered.

4. Switch the hydraulics back ON if appropriate. Expect the controls to jump and expect to overcontrol for a few seconds. Think about what stage of flight you are in before re-selecting the hydraulics ON.

5. A running landing should be planned for.

Final caution. Hydraulic fluid is flammable, especially when in aerosol form so think about the possible further consequences. (Minor consideration: It also melts tarmac so concrete is a better surface to avoid later embarrassment)!

SFIM 16th Jun 2002 13:48

R44 Raven 2
 
hi there,

someone was telling me the other day about a Raven 2 that is coming out with fuel injected engine and a higher AUW,
does anyone know if this is true and if so what the spec is or is it just horse***t.

standing by

nikki 17th Jun 2002 01:26

SFIM,

I have heard that before too. I would bet it's in the works to happen. It's the next logical step.

:)

ppheli 17th Jun 2002 05:12

SFIM
I've also heard this and that it will be an option (ie the existing model will continue). Look for a price differential of $25-30K and 100lb more in mtow.

Hone22 17th Jun 2002 06:55

What ever happened to the R66 (turbine jobbie)??????


Or was that just a vicious rumour?:D :D :D


I read it on this web site ..........so it musta been true:p

CRAN 17th Jun 2002 10:26

Raven 2 True!
 
The was a joint HeliAIR/Sloane Robinson conference at Helitech 2001 at which Frank Robinson was scheduled to speak & answer questions. However due to 9/11 he could not attend because of difficulties at the factory due to the flight restrictions opposed on US airspace at the time.

In his place one of his senior engineers provided a telephone conference to the audience. I believe his name was Pat Cox. During this one of the features that he commented on was that Robinson was currently flight testing an R44 with a fuel injected engine. So its true. That of course assumes that no other technical difficulties arised in the testing program!

I quizzed him about a turbocharged version instead (more power) but although a turbocharged engine has been tried, it cannot be used because it gets too hot. It is only cooled by the same squirrel cage fan.

There were some articles in the aviation press about a Lycomming 580 model, if you look at the Lycomming web page you'll see this engine is available so this might also be being considered - though i've heard no follow up on this.

As to the R66 I heard rumours about this machine back in 99 when I was in LA but it is unlikely to materialise in my opinion. The 22 and 44 slot directly into gaps in the market and provide very cost effect solutions due to the cost savings made by FR in his airframe design. In small piston engined helicopters this is a significant proportion of the cost due to the relatively small cost of piston engines for aircraft. If you try and apply the same technique to a turbine helicopter the saving wouldn't be as significant. There are no 'cheap' light turboshaft engines available for helicopters, and for light turbine helicopters the cost of the engine is very significant in terms of the overall cost of the aircraft therefore the cost saving approach Robinson has adopted for the 22 and 44 will be ineffective for a R66. Hence he will end up with an aircraft that costs roughly the same as the competition and doesn't do anything 'specific' better than the competition - Jetranger, EC120 etc etc. Since he wouldn't be able to make them any cheaper, he would get his volume and hence couldn't make his margin - it's not really worth his while pursuing the program. :( He would also have to consider aesthetics a little more carefully too with a bigger turbine machine if he were to dent the competition! :eek:

Hope this helps ;)
CRAN

moosp 17th Jun 2002 12:43

On the May 2002 Robinson Flight Safety course, Frank as usual gave the first 45 minutes briefing. Ref the improved power version of the '44, he seemed pretty confident that it would fly.

The requirement came out of some hot and high operators of the R44 that were asking for more power. Their engineers looked at many ways of providing same and seem to have firmed up on a positive maybe of valve changes and fuel injection which adds 30-35 bhp. Unfortunately it will be around 55 lbs heavier to give an AUW of 2500lbs, but the power excess is worthwhile. Fuel burn looks about the same.

When pressed on costs, Frank was cautious and simply suggested that it would cost more. He said that the standard R44 will still be produced for those of us that do not need the extra performance.

My two cents...

Rotorbike 17th Jun 2002 17:23

Raven II
 
This new model will be produced alongside the existing Raven, and features:

Fuel injected Lycoming IO-540 engine
Increased power
Max take-off weight increased from 2400 lb to 2500 lb
28 volt system
Larger main rotor blades

This option will be priced at no more than $30,000 over the standard Raven list price.

Copied from the UK importer of Robinson products website.

t'aint natural 17th Jun 2002 21:04

Frank Robinson once told me (1995) that his whole approach was predicated on the fact that pistons were much more cost-effective that turbines and that he would never produce a turbine helicopter. So fat so true.
CRAN: 7/11? Frank got stuck in a convenience store?

Gaseous 18th Jun 2002 00:27

Enstrom manage to get a turbocharged O360 to cool OK and produce 225 BHP - The same as the 5 minute rating for the R44 540.

It can be done.

And the Enstrom is fuel injected -no carb heat, max UAW 2600 lb
The Enstrom design is 27 years old - and reliable - and cheap(ish)
Price comparisons not valid as only 3 pax.

Its about time Robinson stopped fobbing us off with carburettor equipped lycomings and dragged themselves into 1970s technology.

I would still rather have an R44 - even an Astro, though!

Lu Zuckerman 2nd Jul 2002 18:01

UK & Oz R-44 operators. Are you aware of this?
 
SUPPLEMENTARY INFORMATION: On March 26, 1999, the FAA issued Priority Letter AD 99-07-18, applicable to RHC Model R44 helicopters, which requires, before further flight, inserting a Special Pilot Caution into the Normal Procedures section of the RFM. That action was prompted by several reports of sprag clutch assemblies, including one from wreckage of an accident that occurred within the past year, with cracked or fractured sprag ends. The sprag clutch failures, determined to be due to a change in the manufacturing process, could result in loss of main rotor RPM during autorotations. The intent of that priority letter AD is to alert pilots of the potential for the sprag clutch failing to overrun during autorotation, loss of main rotor RPM, and subsequent loss of control of the helicopter.

The FAA has reviewed Robinson Helicopter Company R44 Service Bulletin SB-32, dated March 22, 1999, which describes procedures for checking whether sprag clutches with certain serial numbers are installed and replacing certain serial numbered sprag clutches, and inserting a Special Pilot Caution in the Normal Procedures section of the RFM.

Since the unsafe condition described is likely to exist or develop on other RHC Model R44 helicopters of the same type design, the FAA issued Priority Letter AD 99-07-18 to alert pilots of the potential for the sprag clutch failing to overrun during autorotation due to the failure of the sprags within the sprag clutch assembly and loss of main rotor RPM. The AD requires, before further flight, inserting a Special Pilot Caution into the Normal Procedures section of the RFM which primarily addresses autorotation maneuvers and a before every flight sprag clutch (split tach needles) check for proper function of the sprag clutch. Inserting the Special Pilot Caution is an interim action. The FAA will issue an AD to supersede this AD and require replacing the clutch assembly when parts become available from the manufacturer. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the helicopter. Therefore, inserting a Special Pilot Caution into the Normal Procedures section of the RFM is required before further flight, and this AD must be issued immediately.

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on March 26, 1999, to all known U.S. owners and operators of RHC Model R44 helicopters. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.

The FAA estimates that 200 helicopters of U.S. registry will be affected by this AD, that it will take approximately 0.5 work hour per helicopter to insert the caution into the RFM, and that the average labor rate is $60 per work hour. Based on these figures,

Rotor Nut 2nd Jul 2002 18:28

Lu, this is old news as Robinson authorised service agents were some of the first to hear about this and all our Robinson helos had the modified sprags fitted yonks ago....


:rolleyes:

Grainger 2nd Jul 2002 20:33

Yeah, we had a copy of this bulletin up on our notice board shortly after it was issued and we've all seen it.

Sprag clutch needle split check is part of the standard preflight anyway.

It was a long time ago - why raise it now ? :confused:

Lu Zuckerman 2nd Jul 2002 20:43

To: Rotor Nut

My reason for posting the above was as a result of some communications I have had with the CAA AIB relative to their communications with the FAA in respect to the R-22 and R-44 POHs.

It seems that the FAA had taken a different approach to elements of the two POHs as opposed to what the CAA Safety Regulation Group had indicated what they were going to do regarding the same material. The Safety Data Unit advised me that they were going to issue a GASIL making the material mandatory as opposed to the FAA making it a recommendation. That was in November of 2000 and to my knowledge that action is yet to be taken. The Safety office was supposed to notify me by letter when that action was taken. Nothing to date. So when I saw the above AD I thought I would post it just in case it was not disseminated within Oz and the UK. There was no malice intended.

:o

Rotor Nut 2nd Jul 2002 22:44

There's not much point putting the information in the handbook because all Robbos in the UK will have been modified. It was a maintenance issue anyway. I don't see the need for a page in the handbook - its history, been and gone...

You say there's been no action - sorry, I think there has - the really relevant action (to fix the problem) has been done. Give the CAA and Robinson some credit - the information was clearly disseminated and acted upon.

And as Grainger said, we check the sprag clutch every startup - a SOP.

Lu, you may have safety at heart but by being so pedantic you just become irritating, out of date, and spoil any valid point you might have had to make.....

In contrast, when Dick Sanford imparts something Robbo related, I get elephant style ears and take in every word he has to say and it gets fixed in the memory bank.... its not the number of words... its the way they are delivered!

Lu Zuckerman 2nd Jul 2002 23:18

What did he say? And, why did he say it?
 
To: Rotor Nut

Once again my words were either misunderstood or you did not follow the line of my post.

Firstly I explained why I placed the post. I knew it was promulgated several years ago but because of an experience I had working between the FAA and the CAA I found that there was in certain cases miscommunication between those two agencies. That miscommunication had nothing to do with the freewheeling unit problem covered in the AD. What it did deal with was the intent of the CAA to make certain information that the FAA considered as a recommendation as being mandatory. That information had to do with the causes of mast bumping and how to prevent it. If you are interested please E-mail me and I will send a copy of the document. Once received you could compare it to the same material contained in the POHs of CAA certified Robinson helicopters. This offer is available to anyone that wants a copy. The material covers about 20% of the posts I made on the previous Robinson threads.

Yes I am interested in safety (yours and every one else’s) and yes I am pedantic having four teaching credentials in the State of California and if I come across as being overbearing it is because of having 47 years in the aerospace industry watching educated people make mistakes

:eek:

Rotorbike 3rd Jul 2002 05:07

Lu

I believe you think a GASIL is something that it isn't.

This is what the GASIL is:

GASIL - General Aviation Safety Information Leaflet. Monthly safety and accident prevention bulletin for pilots and engineers published by the CAA.

If thats what you think it is then I'll head back behind the stone.

;)

Rob_L 3rd Jul 2002 09:30

FAA AD's are mandatory in the UK for aircraft and equipment of American manufacture.

HeliEng 9th Aug 2002 22:44

R44 Diagrams??
 
Good evening to you all,

I am hoping that some of you Robinson pilots/engineers/enthusiasts/haters :D out there will be able to help me.

I am looking for as many line diagrams of R44's as possible I have the two off of the Robinson website, but if anyone knows of anymore, I would be grateful if you could let me know.

Aslo, if anyone would happen to have an R44 picture/diagram in .3DS format, that would be fantastic.


Thanks for all your help





"Some days you are the pigeon, some days you are the statue!"

Helo 29th Oct 2002 08:38

R44 training materials, videos, CD Roms, ...
 
Does anyone know if there are any R44 training matierals on the market, in the form of books, videos, CD Roms, ... addressing the sort of areas that, I imagine, the Factory Safety Course, covers.

I've looked all across the Internet, and have only found a few R22 products, but nothing on the '44 - seems strange given it's now the best selling helicopter in the world. Is it a deliberate decision by RHC not to sell any of the safety course or similar videos, books, etc to persuade people to attend the course?

Am needing to hand out suggestions for Christmas presents and my family can't afford a helicopter, so I though the training material would be the next best thing :D

Cheers

Helo

The Pitched Link 30th Oct 2002 03:21

R44 stuff
 
Try helicopters.com, I know they have some R44 things.

Helo 30th Oct 2002 08:16

I've checked out helicopter.com but still haven't found anything - anyone else?

quidam 30th Oct 2002 20:48

No links/loyalties to them but as they're fairly near to me......

Have you tried contacting Heliair at Denham? They're a Robbo distributor. They might have some ideas or other suggestions about where to try.

Good luck.

Helo 31st Oct 2002 16:31

Thanks.

I checked with Heliair this morning and they're scratching their heads on this one - no immediate answers, so if any other PPRuNers can suggest information sources I'd be grateful. Possibly even a safer pilot as well :-)

Helo

nikki 16th Nov 2002 23:54

Raven II
 
Has anyone heard anything about ,good, bad or otherwise, Robinson Raven II. I heard that is was having some problems getting released for service but didn't get any details, was wondering if anyone know anything.

thanks.
nik.

ppheli 17th Nov 2002 06:33

A little bit early I guess. The first three are due in the UK in the next 7-10 days, to which you can add a few days for them to get them from crate to apron. Ships #5 and #11 at Wellesbourne and #7 at Sywell - and those numbers suggest to me not many are yet flying worldwide.

Having kept the same MSN sequence for all models of the R.22 (now around 3400), RHC have oddly started a new sequence at 10001 for the Raven II.

misterbonkers 17th Nov 2002 16:58

I believe one is bound for Sherburn Airfield, Yorkshire.

Have also heard that there are a few teething problems with the injection system causing a somewhat lumpy ride. Anyone else heard about it?

ShyTorque 17th Nov 2002 20:01

The injection system causing a lumpy ride? :eek:

Don't they have a proper seat? Or is that an injection seat? :D

misterbonkers 17th Nov 2002 23:29

i think i was being metaphoric, but had better check with my english tutor on that one.

Helo 18th Nov 2002 13:59

Someone must know!!!
 
Hi there - still no joy from Heliair on sources of R44 training material/books/Roms/etc.

Is it just me, or does this strike you as a little strange that the no-one has decided to support the world's best selling helicopter in this way?

Maybe this is a gap in the market that can get me out of my day job and retiring early ...

Helo

misterbonkers 18th Nov 2002 19:34

try Dick Sanford, he's the Robinson UK bloke. Runs the safety course (which is EXCELLANT) and is their accident investigator over this side of the pond.

Otherwise, just slip an experienced instructor some notes to give you a thorough day with the machine, or an engineer. Take the notes and produce something for the rest of us!

I thinks in this weather there will be lots of instructors willing to help you out!

nikki 19th Nov 2002 02:19

thanks for the replys.

does anyone know what type of problem there having with the fuel-injection?

nik.

Grainger 19th Nov 2002 08:22

What I've heard is that the injected engine can quit instead of idling, turning a practice auto into a real one :eek:

Helinut 19th Nov 2002 11:27

That's Progress ??!:( :eek:

handyandyuk 19th Nov 2002 12:27

That's not progress..... that's worrying!:eek:


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