Ranges from:-

50hr £280 - £600 (plus consumables/ parts)

100hr £360 - £800 (as above)

Annual £1400 - £2000 (as above)

Plus VAT and any unexpecteds

Where are you based and why do you ask?

Robinson rotor head question.
 

Chiplight. What conditions exist at the point where the blades are directly fore/aft. Surely at this point in their rotation they lose the effect of incoming foreward airloads and for a split second are only suject to the torque? Bug.

Lead lag and rotor tilt.
 

To: chiplight

As I previously stated the blades are offset in front of the mast relative to the pitch change axis. This is done to minimize inplane bending of the blade. The purpose of this offset is to try to align the blade pitch axis (CG) with the center of pressure. Or, is it the aerodynamic center (I forgot which). Since this is the case it would be difficult to draw a straight line through the teeter hinge and align with the blade CG.

Because of the underslinging of the rotorhead there is minimal if no lead and lag when the pilot introduces cyclic pitch. The blades will maintain the same degree of cone relative to each other and the cone angle will remain the same as when the pilot first introduced collective pitch. When the blades flap about the cone hinge it will deviate from the original cone angle and with this change in position the blades will lead and lag. On a conventional flex rotor with offset hinges or on the more modern helicopters with elastomeric bearings when the pilot introduces cyclic pitch the blades will lead and lag in direct proportion to the degree of cyclic pitch input by the pilot.


:E :E

What does a 50 hourly service entail?

I haven't heard of a 50 hourly service (apart from change the oil and do inspections of frame and blades - which are pilot allowed actions). Does the CAA in Britain mandate further services?

bug,

In a teetering rotor, the torque isn't much different when the blades are fore and aft than when they are at the adv/retreating position.
Why? because the advancing blade sees higher velocity air which WOULD increase lift and drag, but flapping equalizes lift (I should say moment) between the blades by reducing AoA on the adv blade and increasing AoA on the ret blade. When lift is equalized, so is drag, since most of the drag is induced drag, which comes from lift.

Lu,
the aerodynamic center of lift is often 25% back from the leading edge, so thats where the cg of the blade is located to avoid flutter and other probs. That's why the feathering axis is not in the center of the blade. Since each blade is facing the opposite way, the line bewteen the cgs of the blades will cross through the center of the mast, ideally at the teeterbolt. Ther coned rotor can tilt any way it likes with cyclic and the cg of the cone will stay near the teeter bolt if the undersling is correct.

Robborider
Unlike Australia, some Foreign Civil Aviation Authorities request that all maintenance including oil changes are only performed by LAME, hence the cost of a 50 hourly.
It makes life interesting when you have a breakdown somewhere in the Jungle....Thanks God for Aussie training ;)

R22 Performance Graphs
 

Hi all,

I'm confused (as always!) about a certain aspect of the R22B IGE/OGE Hover ceiling vs gross weight charts. My instructor tells me thet the temperature lines on this chart are ISA lines. The way I read it, there is only one ISA line on these charts and that is the 'standard day' line. The rest are OAT lines.
If you were to use them as ISA lines your'e calculations would be incorrect ...... wouldn't it?

Hi,

looking at the R22 charts in the POH which is on my desk, my interpretation is that there are two types of temperature lines on each chart.

There is a dashed line and there are unbroken lines.

The dashed line indicates a standard day temperature. This is what your instructor is probably talking about. During certification a lot of the performance calculations are referenced to a "standard day" set of conditions. They then workout from there what effects temperature has on the performance. Infact if you have a look at the introduction to section 5 of the POH it states:


The unbroken lines are temperature lines. The higher temperature lines are closer to the bottom of the chart, which follows from higher temperature = less performance for the same weight.

If your instructor still has problems with this then I suggest that he goes back to school for a while until he understands what the charts actually state.

Tinkicker....

Thanks TK

I believe my instructor is definately refering to the solid lines as ISA lines! It was explained to me that if, for example, it was 20 degrees C at SL, it would be an ISA +5 day. You would therefore follow the up from your max weight, say 1300lbs to +5 (solid line) and follow accross to read your max hover ceiling - appx 6300ft PA in this example (OGE). I get appx 6000ft using the method I thought was correct prior to that conversation. Not a huge difference I guess but still ........

R22 Servicing Costs
 

Quichemech.

Ever herd of Anonymity! Isn't this what Pprune is all about?

I want to know because I'm interested.

No offence intended but you don't need to know where I'm based.

Musket097.:confused:

Hey Musket,

You are right of course, if you want to remain anon then I feel we will all respect your wish!


But Come on GUY get real, the Uk has 63,000,000.5 people living in some 6500 towns and villages plus some 30 + counties and Metro areas,, so why the pricky reply !

Normally being anon could mean several things,:-

You are a member of the IRA
" " " Al-Qeada
" " " Royalty
Or you could be a Whistle Blower, or some other murky type

We all have some sense of being able to help each other, on this particular Rotorheads Forum, and help is available in truckloads, but I am afraid snappy answers more often than not will get you a great big ZERO, Kapisch!

Have a nice day somewhere

Peter R-B From Lancashire

Hiding behind Vfrpilotpb!!

Almost whenever I meet anyone in the aviation world and mention I'm a helicopter instructor from North Wales - and they can see I'm female - they go, "Oh, you're Whirlybird". And much as I enjoy the instant fame, sometimes it would be rather nice to be an anonymous one of 63,000,000.5 people again. Of course, I could remove some details from my profile...but it's probably too late now - everyone knows me. :{ :)

So, Musket097, I for one quite understand. ;)

Whirly, You cannot go under cover, your World Famous!!

PeterR-B
Vfr;)

Sneetch - just because it is 20 degrees C at sea level (ie an ISA + 5 day), doesn't mean it is an ISA + 5 day at 6000'. That is why the temperature lines are there so you can enter at a pressure altitude and an OAT at the height you want to hover at and see if you can do it at the AUM you will be at.

An ISA day assumes a lapse rate of temperature with height of 1.98 degrees C per 1000 ft - in the real world the lapse rate can be much more or less than this and can reverse if there is an inversion.

If you know it is + 8 degrees C at 6000 PA (ie an ISA +5 day then you can use the ISA + 5 line on the graph, you cannot assume that the lapse rate from SL to 6000 is as per ISA.

Vfrpilotpb

I didn't think Musket097 was being snappy or pricky (whatever that means) and has every right to query why someone should want to know where they are based or why they are asking.

And as for your comment, and I quote you directly," Normally being anon could mean several things:- you are a member of Al Qeada/IRA/Royalty" beggars belief. Whatever you're taking I suggest you don't fly for the duration.

Get a life and don't be so ridiculous.

Ewe Turn

Chiplight
 

As you state the opposite blades evenout most of the lift/drag differences which are for individual blades quite different at different positions.
This is also graphically shown in the drag curves I published in other posts.

Delta3

I should just like to confirm that I am not a member of royalty (although I'd like some royalties)

:p

Part of the fun of Pprune is guessing who is who. Some are not as anon as they think, Eh Ed.

If you post often enough your anonymity becomes compromised.

Mind you, I do have a second, really anonymous persona for those most controversial posts.

Do you mean 'Editor' ?

NB have you seen me in a dress ???

;)

Why do Al-Qeada need to know about R22 servicing costs?

Oops! Didn't mean to start something.
 

No No No you've got it all wrong! Didn't mean to start something.

If 'Vfrpilotpb' wants to give up his anonymity that's fine and thats his choice.

But anonymity is my choice for what ever reason.

Yours Sincerely,

Musket 'Osama Bin Laden' 097
:E

Lets ask this question and narrow it down a bit. Of the 63,000,000.5 people living in some 6500 towns and villages plus some 30 + counties and Metro areas how many are flying helicopters?:ok:

Redeye
No
Is that an offer or a chat up line????:ooh:

No I just wondered if I'd got drunk sometime and ended up in a dress. happens during dark months ...:p

Hey Ewe turn,


I meant like a Hedgehog, not like the friendly weapon!

Peter R-B
Vfr;)

Ah the humble hedgehog! My second favourite animal:O

I asked where and why for the plain and simple reason that as an engineer I could have supplied some phone numbers for organisations that would happily let you know their costs.

A simple midlands area(for example) because I've just bought one or am thinking of buying one or am doing some research would have been more than enough information. However feel free to keep your valuable identity and find out for yourself:p

Well I have no hang ups about identity. I am in Derbyshire and am about to buy one so I would like the same info if you have it.

OOps sorry M, I said I'd give you the data I had anyway. I'll post it a bit later for R22 and R44 based on sample of five companies that I asked to tender for the work.

h-r

Anti Redeye day. I just posted the data and the system bombed. I see it has not landed so I'll type it all in again tomorrow .......

:{

Here is the data (having typed it out again, grr, and even then the tables do not come out 'right') - and me in IT.

R22 Data

R22 R22 R22
50hrs 100hrs Annual
Maintenance provider #1 £276 £621 £1,242
Maintenance provider #2
Maintenance provider #3 £275 £551 £1,362
Maintenance provider #4 £195 £480 £950
Maintenance provider #5 £270 £585 £1,530

R44 Data

R44 R44 R44
50hrs 100hrs Annual
Maintenance provider #1 £368 £736 £1,472
Maintenance provider #2 £315 £540 £1,080
Maintenance provider #3 £360 £763 £1,415
Maintenance provider #4 £250 £575 £1,000
Maintenance provider #5 £360 £585 £1,620


Labour Rates
Labour Rate
per hr
Maintenance provider #1 £46
Maintenance provider #2 £45
Maintenance provider #3 £45
Maintenance provider #4 £32
Maintenance provider #5 £45

I should add that all were 'plus VAT' and the rates may have changed from when I gathered the data in the service provider tender (assume prices have gone up not down).

Also consumables are usually excluded so what you are looking at in quoted prices is an estimated labour rate alone (plus maybe some oil and the off filter/ lock wire/ washer. etc.

The most expensive shown may thus not be the most expensive in practice. I would note that the actual amounts paid were rarely these. There were always 'extras' to account for so only by adding up two or three years worth of real invoices can you get close to the real cost of running a 22 or 44 in the rela world (the Robinson website figures are WAY off.



h-r





:{ :\ :*

R22 startup - advise please
 

I have just read through:

http://www.aaib.dft.gov.uk/cms_resou...pdf_024586.pdf

a report concerning an R22 lifting of during horn/light check with a subsequent roll over. The report states:

Since the reasons why the pilot had difficulty in maintaining and regaining control of the helicopter
stemmed from the friction applied to the collective and cyclic controls, it is recommended that the
Operator amends his procedures for the Low RPM check, after engaging the rotors, to reflect the
manufacturer's procedure.

In the checklist I use, I see no change in the frictions procedures. have they changed or am I misreading something?

Any advice and comments welcomed.

Cron
Read the report again. there is no change to the POH, the problem was the operators checklist differs from the manual insofar as it allows for the horn check to be carried out with frictions on, - the correct procedure is carried out with frictions off. check your checklist and make sure you don't fall into the same trap as that unfortunate student.

He would surely have had to move the collective a fair bit to get to take-off power - I found that just moving the lever off the stop would prompt the horn, friction or no friction.

The laminated check list provided by the operator I use also leaves the frictions on during the horn check. I personally take them off - I can't see the benefit in having them on at that stage.

would it take a major wind gust with a light load to let it start to turn on the skids? possibly not...

They have changed it to reflect the new governor-on prior to run up over 80%.

BW

!? I agree w/ Hilico, the horn comes on at <= 97% RRPM, and the collective needs only be slightly up -- nowhere near power needed to pick up, 20"-ish MP.

Yes Dash
The horn does come on at 97% with the collective only slightly raised but remember the problem really started during the students second attempt, and with the friction tightly locked maybe he was unsure as to the position of the collective (relative to the down stop) also he said that during the first attempt he lowered the RRPM to 90%. Why?
Two points to consider (on 1st attempt)
One --Surely when when the RRPM dropped below 96% it was time to stop staring at the RRPM gauge and look elsewhere rather than continuing down to 90% and hoping that eventually the machine will decide to change it's mind and produce the correct result.
Or two perhaps he is prone to overcontrolling.

Either way it seems to me that he was concentrating to much on the RRPM gauge and was not sufficiently aware of the conseqences of raising the collective to much.

This leads to the mistake on the second attempt. Whilst Still staring at the the RRPM did he then continue to pull collective 'til the machine changed it's mind or did he overcontrol?- At the same time not having sufficient control over the collective due to the friction.
Either way he suddenly he finds himself trying to fly an R22 with the govenor off and frictions on- and then it was too late.

The accident report seems fairly conclusive insofar as it recommended that the operator changed it's procedure.

I'm personally not in favour of changing a procedure unless the old one is flawed/dangerous- even if the change comes from the manufacturer (why frank now tells us to turn the governor on twice is beyond me)

Also in this case the student may have had some chance of avoiding an accident if the govenor was on and frictions were off.

So as I dive for cover can I just ask what is the advantage of changing the checklist to friction on and govenor off? -Or has hindsight given everbody 20-20 vision on this one?

Thanks
 

Thanks for the R22/R44 data really helpful.

Thanks to everone for there input, costs and anonimity.

Cheers,

Sadam! :}

R22 Dash 4 Blades
 

We operate a number of R22's at our school, the feeling is that on machines that have had blades changed to the dash 4 series the machines now appear to be less powerful.

Any thoughts on this?

We have recently had blades changed too on our machines. I thought one was less powerful afterwards, however knowone else believed me!

Are the new -4's heavier perhaps?