Too much pitch is a bad thing.
 

The rigging procedure for the R-22 might influence the pitch setting on the blades when high collective pitch is applied. Before you say“Duh” hear me out.


In rigging the basic pitch setting the cyclic is neutralized and the control tubes are adjusted to position the swashplate in a level position. This is common to most helicopters. In rigging fore and aft pitch the mechanic sets forward pitch range which is governed by the fixed pitch stops. When he hits that stop the pitch setting on the blade is adjusted to get a determined pitch setting. Since the cyclic starts at the neutral position the fore and aft travel is the same. In setting aft pitch setting the pitch angle should be the same due to equal travel. In the case of the R-22 the mechanic must adjust for a different pitch setting which changes the setting for forward cyclic. He is then told to check if the forward pitch setting has changed. The pitch setting will change but the mechanic is not told what to do. If he changes the pitch setting for forward travel it will change the aft pitch setting. If he then resets the aft pitch setting he will be left to chase his tail.

In setting left and right pitch settings he will change the fore and aft settings. In one case the mechanic is told to adjust one of the two lateral tubes to position the swashplate in order to get the required pitch setting. This action can possibly result in a binding of the swashplate when collective is added.

In a normal helicopter the swashplate is neutralized, the control linkage is pinned and neutralized and all of the tubes are adjusted to attach to the pinned and neutralized control linkage. The basic pitch setting is set on all of the blades and then control stops are used to limit the control range for left ands right and fore and aft. The FAA design guidelines specify that the control ranges be limited by adjustable stops. The R-22 either did not comply with those requirements or, they got special dispensation. All control ranges on the R-22 are either adjusted at the pitch links or the control tubes which alters all of the originally adjusted control positions so there is no knowing what the pitch settings are when the cyclic or the collective controls are moved to the stops

The rigging of the tail rotor is equally bad. The man that designed the tail rotor and its’ controls is/was a tail rotor guru but in this case it is extremely difficult to rig the tail rotor and the entire process for both the main and tail rotors leaves a great deal of room for errors.

All of the above : IMHO


:E :E

Thanks Whirly and Nick for your practical advice, food for tought! Sorry Lu Z. but your post is way over my head!!

raven2
:confused:

Nicks summary is a most useful way of understanding it.
Whirly's point about the yaw is a most useful point about deciding what to do about it.


I have had lights/horns come on about four or five times in seven years none assosiated with any yaw. All but one associated with being heavy, high D/A with high outside air temps (OAT) in the order of 35 - 39 degrees celcius.

Two or three have been while pulling up at that last little bit of the hover before landing. Prelanding power check at about 500 feet AGL suggested sufficient power to land at a hover - but when I got down to ground level the OAT had climbed, maybe the wind had dropped off a little etc and as I slowed down and looking out at the trees/rocks etc I was landing among the RRPM had sagged and the horn went off. Answer to that was stop mucking around and just land it. Air Temp 39 degrees at about 2000 ft ASL, two blokes of about 75 kg each and half or more tanks of fuel. No Yaw.

One other time was on turn for base leg, OAT in high 30's about 2500 ASL, again two blokes more than half full tanks, had to do a tight turn due hills all around, less experience than now - pulled a bit too much pitch while banking to maintain height - light came on - no yaw. Rolled throttle and a smidgen of lower collective and it fixed itself. I wouldn't let myself into that situation again now though.

Most unusual and hard to explain time was very early after I got my licence. Flying across a ridgeline (about 3500 ft ASL) with some descent, as I expected an updraft on the other side as we crossed. Airspeed crept up and so I flared a bit and lowered collective. After that I nosed over again and I think, pulled pitch again and horn and lights came on and the RPM gauge was down in the 80's%. No yaw ( but I didn't think about that at the time) Assumed an engine failure and put it into an auto and made a mayday call. Then realised that everything was sorting itself out. Gradually increased collective to arrest the descent rate and the engine (which had never missed a beat the whole time) merrily kept us flying. Debated about landing or continuing on but decided to continue as everything had been OK since the event.
I have to assume the reasonably quick change from a flare with the dropping collective back to a nosed level with pulled collective in combination was enough to increase drag on the blades and correlate the throttle back. Temp wasn't that high the maybe high 20's, two blokes and half tanks.

Whirly's scenario may have happened as well - stressed firm grip on collective - suddenly seeing the airspeed going up etc - and over-rode the governor.

These responces all sound fantastic but my experence in R22 see's them as a very capable and forgiving machine, in my opinion their is no reason for any overpitching provided you fly the aircraft at the corret profile bearing in mind weight, wind,temp, altituide and avaiable landing space. Even with a high, and dare I say it a over weight situation you should be able to do it in a tight area.

Having said that I should add, that getting in is no problems, Its the getting out you should worry about. I have found the old trim R44s do have a definite tenendancy to over pitch it has to do with the govonors slow reaction to the power required, I can't remember the exact reason.

If you do overpitch their is no reason to dump collective and grab at throttle, just gently in a relaxed fashion reduce a little collective (perhaps a inch at a time)while squeeeeezzzing on a little throttle. I find the best way is to hold my hand half on the lower portion of the throttle (maybe thumb and first two fingers) and the lower part of my hand on the actual collective stick itself, this provides me with a much more accurate technique of throttle control.

In flight you may need to reduce collective rapidly, and I teach students to be quick if this does happen inflight (low warning horn), refer straight away to the rpm guage both enjine and rotor and use this to govern the amount and to what degree you have to adjust throttle and collective. If you get a sudden right yaw expect the worst and enter auto.



In summary, do what you have to,

In-flight----Reduce collective and roll on some throttle.

If you get a uncommanded yaw get in to auto real quick as you have nothink to play with....believe me.

Approach ---- roll on throttle should fix it.

Take-off ------Roll on throttle and reduce collective as required.

In time you will know the sound of you helicopter at 104% with a happy enjine churning away behine you, and you will naturaly adjust throttle to suit, this is probably one of the most important survivel techniques for all helicopter flying.

In summary the R22 if maintained by good organisation should not have any such problem. The older trim machines can have this problem mainly during the summer months and at sea level.

Hope this helped in some way......

Sorry thats left yaw "I think"?????

Don't want to sound mean but if youve left it that late that LTE is next, I'd take up fishing.

The R22 tail rotor is fantastic even at reduce rpm NOT TOO MUCH though, you should have it fixed by then.

Sorry don't want to sound mean but if youve got LTE coming into it , probably could do with a polish up. The R22 Tail rotor is still very efficent at reduced rpm but not Toooo much.

At sorry I thinks it left yaw if I remember.

Point to note: When recovering from a low rrpm situation in a Robbo, always lead with the throttle before lowering the collective. If the collective is lowered first, the correlation will close the throttle, making the problem worse before it gets better. This is not a place you want to be if bordering on rotor stall:ok:

oxi,

Just in case you get tail rotor failure, maybe you should remember which way is which in terms of yaw. ;) :)

Being a simple soul with the memory of a goldfish, the way I work it out is to start with my anti-clockwise rotating rotors - I don't forget that, somehow. OK, so that causes the fuselage to want to turn the other way, ie clockwise. So the tail rotor pushes it back again, ie anticlockwise. So if you engine stops and you only have the tail rotor, it'll push it anti-clockwise, ie left yaw. If you have tail rotor failure, it'll go clockwise, ie right yaw. Hope you don't mind me putting it in overly simple terms, but that's the way I understand it, and I guess I'm getting used to explaining it to students who are even less technically minded than I am.

However, since you really really REALLY don't want to be working that lot out if either happens, in the event of a violent yaw, I think I'd enter auto-rotation, then try and troubleshoot. By that point I think I'd know whether it had gone all quiet, or whether I had trouble flying straight, or what.

raven2,
When you asked if any of us had ever had the horn come on, I forgot about high altitude flying. When I was in California I flew with an instructor to Big Bear, at nearly 7000ft. We worked it all out, and should have been OK for an IGE hover. But conditions must have changed by the time we got there. As we pulled in collective to come to a hover, the RRPM dropped, and the horn and light came in. The RRPM gradually got lower and lower, and the only thing we could do was land. For someone who'd never flown outside the UK it was an education I can tell you; no amount of reading the books really prepares you for a situation where the poor little R22, quite lightly loaded with two smallish people and about half fuel, just can't fly! :eek: By the time we came to leave the wind had picked up, or something, as we had no real problem...thought I'd get to do my first running take-off in earnest, but I didn't have to.

identical aircraft of the same type can also have different characteristics also.

I reguarly fly 2 different R44's (both hydraulic) in flight instruction mode.

the procedure I follow before I recover from an autorotation is to leave the governor on and to set engine RPM with throttle to about 75% then raise the lever for the climb and the needles join as the governor will take over at 80% and the a/c climbs away with needles at top of green.

one a/c responds very sluggishly and the Low RPM horn comes on very easily if you raise the lever too fast, so roll on throttle and lower lever a bit to sort it out.

the other a/c no matter how fast you raise the lever you will never get the horn on.

in all other respects they fly and act the same, and have similar lever setings in autorotation all other things being equal.

to go back into autorotation in this situation would obviously be ill advised.

Raven2

In the R22 I was heavy, right on MAUW and lumbering through about 30 feet on takeoff at about 40 Knots under max power when one of the magnetos failed. MP went way offscale, RRPM dropped rapidly and the horn went off. Had I immediately entered auto then it probably wouldn't been pretty as the terrain in front of me had obstacles and the airspeed was low. Straight on with full throttle, lowered the lever as much as I could and lost height but RRPM recovered and I managed to fly away and return to land no problem. Had I flared in that situation by the way I wouldn't have been able to maintain flight either, with no airspeed.

Another time in the R44, hot 40+ degree day and heavy, air taxying at about 25 feet and turned downwind too fast on a windy day. Bingo it fell out of the sky and horn goes off, this time with bushes underneath. Same thing, full throttle, lowered the lever as much as I dared and then milked the RRPM back. Right pedal helped, and managed to stay out of the bushes.

Once more in a H300CB, over total jungle in the cruise when it starts to run very rough and RRPM drops. Lowered the lever and RRPM recovers, full carby heat and about a minute later it comes good. Off we go with the hearts beating but much relieved, looking for a safe place to land (and smoke a cigarette!), which was a fair way off.

Last one, in a H500C, again hot and heavy, trying to lift vertically out of a tight clearing and lose RRPM at about 25 feet. Only solution there was to lower the lever and milk the RRPM back and try not to hit the ground hard. Only just managed to pull that one off, despite it being a fairly firm landing.

Moral of the story is in any of those situations if I had totally dumped the collective the aircraft would have landed heavily and/or no doubt been significantly damaged.

You'd be amazed how quickly your instincts can kick in and a complete engine failure rapidly becomes very obvious.

It is important to realised that engines may not fail totally, but due to some other malfunction (turbo failure, carb icing, stuck valve etc) can significantly but not totally lose power.

And of course it may just be bad piloting and overpitching. Don't forget as RRPM drops in an overpitching situation, so does engine RPM, and horsepower is related to the number of bangs in the cylinders per minute.

It is vital in pilot training that you are not only taught autos and forced landings, but correct recovery from low RRPM situations, and how to land safely when you are majorly but not completely limited in power.

In any emergency, when time is tight, you MUST have an awareness of what your RRPM is doing at all times.

Hope this helps make you realise there is not just black and white, but a whole lot of grey in between.

South of France, with instructor and fuel:
R-22: 390 Euros (~ $490)
R-44: 600 Euros (~ $750)
EC-120: 800 Euros (~ $1000)

It's interesting that in the same conditions, an EC 120 is just 30% more than the R44 in France. In the US (at least where I fly) the EC 120 is about 3 times the cost of the R44. The relative value of Robbies over the rest just isn't there in France.

Rotorboy

With the uk £ being very strong against the US Dollar £1 = $1.81 this makes training in the US relativly cheap!


:*

today I experienced a miracle......
 

Being used to pay a equiv. of 561 USD for an hour dual R22 and an equiv. 449 USD solo I never thought that I would experience the day.....

A local JAR workshop seems to have a 300C for rental for only a equiv. 210 USD + fuel. And I need not to go 2,5 hours drive one way for helicopter rental - the workshop is only a ten minute drive from my home.

Fuel is approx. 0,65 USD per liter overhere.

Hi Raven,

everyone has a good point (except Lu Zu, if you are around a while in this forum, you will find out that Lu has some weird "love affair" with Robinson's....)

Short answer to your question is Robinson specific:

The R22 does not only have a governor, but also a throttle correlator that works of the collective and is rather powerful compared to the governor. If you just lower the collective without rolling on full throttle first you might loose more rpm as the correlator turns the engine towards idle.

Remember your governor off training:

Once you got to 18" MP you hardly have to do anything to keep rpm in the green or even at 104% up to about 24" MP.

If you are running 104% with the collective at the bottom and you start to raise it you will overspeed rpm if you don't roll off some throttle.

If you are running 104% at about 18 to 20 MP and you lower the collective without rolling on some throttle you will loose rpm.

If you have low rpm (for any reason) first reaction is mostly to lower the collective substantially. Specifically in the R22 (...also in the R44) you must roll on full throttle first to avoid further rpm decay (if your engine died it doesn't hurt....if not, better for you!)


Even if you have the governor on, the collective down and you are running at 104%:
If you raise the collective fairly quick, you still get a raise in rpm, as the governor is not fast enough to reduce the throttle against the correlator,......vice versa if you lower the collective too fast from around 18"MP you will get some low rpm until the governor catches up.
It is a correlator/governor setup matter.

3top

;)

Yeah but my point was...
 

To: 3Top

The point that I was making was that the rigging procedures for the Robinson are very vague and misleading and could result in both excessive pitch at full collective and the possibility of binding of the swashplate which really does not apply to over pitching. I would strongly suggest that as pilots of Robinson helicopters that you familiarize yourselves with the rigging procedure for both the main and tail rotors. Ask your mechanics about the rigging procedures and find out if they are able to follow those procedures without being a bit confused.

If your mechanic has experience in rigging other helicopters ask him/her what the differences are because there are many.

:E :E

What's the reason of this?

Aser:

Because between that range of power setting the correlator is extremely efficient.

Just yesterday I flew a circuit governor off and the only adjustments required were small, and below 18" and also when pulling power again coming back to the hover.

In case any other R22 pilots didn't do governor-off training during their PPL - and I know I didn't.....

Below 18" MAP the correlator overcompensates. So if you raise the collective you need to CLOSE the throttle a little, and vice versa.

From 18-23" the correlator works well.

Above 23" it can't quite keep up, you as you raise the collective you need to OPEN the throttle, and vice versa.

This is in the PPL syllabus, but I know for a fact that not everyone does it even in theory, never mind practising it. They should.

Robinson Quiz
 

1. Where are the two nuts you cant see that carry the helicopter. 2 Are the legs on the skids steel or alloy 3. Is the top belt pulley steel or alloy. 4 Are the skids all one piece of tube. 5. What is the weight of the blade tip weights. All questions to be answered without looking at a machine. No cheatin please

Why? What's the prize?

Who gives a stuff?

Sounds like the sort of stuff a wannabe spits out to impress somebody at the bar.....

mmmmmmm
 

dunno but i can see two nuts pushing a helicopter!
everythings alloy and the tubes come apart:ok:

Charlie


So. Falling down doesn't impress someone at a bar ???

Harsh words charlie!

Ok I'll Bite
1. What Nuts?
2.Legs are 4130 chrome moly
3. A-188-1 is anodised aluminium, A-188-2 is metal sprayed aluminium
4. No the heels can be removed
5. Dunno

I think I need to get out more!:(

I would guess the nuts are 1 on the bottom of the main shaft in the gear box below the drive pinion gear and 1 possibly above the gear. then there is 1 on the top of the shaft holding the rotor head to the shaft. only guessing though, as I aint an engines ear.

Ah, correlators....
The one in the Sioux (Bell 47) seemed to have a mind of it's own - it was called the analog randomizer - sometimes it was add throttle as you lowered the collective, sometimes it was take it off.
Kept you on your toes.

Robinson Quiz
 

No prizes, no self gratification in posing the questions just for amusement on a wet january night! Interesting about the different attitudes towards a simple quiz though.

The Jesus nut is sitting on top of the Mohammed nut. Neither can be seen since the Jesus nut must be protected from harsh reality and the Mohammed nut is enclosed in a cage.

:D :D :D

This post has been sanitized to make it politically, sexually and religiously correct. :ooh:

Robinson Quiz
 

Dave Jackson. What a wonderfull description. Your answer tells me you have gone where lesser men would not venture.

5./ The two nuts that you cant see: Is it the two that are on the end of the spindle bearings in the M/R blades?!? :confused:

How about a 6th question (though this has probabily been done before.....)

How many 'split' or 'cotter' pins are there on the R22?

PA 3,2,1
:ok:

bugdevheli,Oh! Oh! You were in the woman's washroom also??? :O

Ascend Charlie, check your PM's please.


--
Michael.

The blade tip weights weigh 1.6 pounds (or 0.72 kg). I seem to remember that from the safety course.

Number of pins will depend on how many you put in the doors. We only use one per door as that is all that is required but you can put two per door.

Anyone out there who have survived an R22 enginestop?
 

Just out of sheer curiosity I had to ask the question. I´ve read lot´s of reports on helicopters (others than the R22) which suffered enginestop and made an autorotation which was succesfull.

However, I have not read to many reports where a where a R22 had suffered enginestop and made an succesfull autorotation.

I am not after starting som R22 bashing thread. Just curious as I said.

Lots!! No reason why it should be different to any other single engined machine provided you are actually FLYING the machine and it's not 'in command'.

Know one personally - had fuel problems although can't recall details as it was a couple of years back. Landed in one of CA's many (empty) flood areas, waited for mechanic and flew it out same day.

Only injury was to his pride of many years incident free flying! And the student wasn't put off either - he's a CFI now.

PW

Kates,

You perhaps ought to define what you mean by engine stop, but I have "survived" a real autorotation and forced landing initiated by an engine problem - so did the aircraft and the other occupant, without injury or damage other than a briefly raised heart rate.

I had a share in an aircraft that suffered an engine failure due to a problem with the breather pipes to the fuel tanks. It suffered a complete and sudden engine stop and down it went. The solo pilot carried out a successful landing subject to cutting the tail boom clean off just before the strobe light. Not bad considering he was extremely low time and hadn't flown for almost 5 months

Yep, I survived two in the R-22 (one right after the other). Both were on MX flight tests and were just in the hover. Both were kinda expected, so was only hovering at the time, and therefore no big deal. The aircraft acted as expected, just like you train for.

Trailering an R22
 

We are purchasing a new R22 and would like to know what experience others have had in doing the same. We would like to pull the helicopter behind the motorhome when we go to various fly-ins so that we have all of the comforts of home and the helicopter at the same time.

Avoid potholes
 

To: Helocfi

Trailering a helicopter for any distance can cause problems such as brinelling the bearings and gears in the transmission. It could also expose the blades to excessive flexing due to the undulating motion of the trailer. You would also exposes the skid gear attach points on the fuselage to repetitive shock loads. And your instruments would not fair very well due to the vibration.

If you are serious then I would suggest the following. Build a floor for the helicopter to rest on and attach this floor to the trailer with springs. Someone a lot smarter than me would have to select the proper springs or shock isolators so that the helicopter would in fact be detuned or isolated from all of the repetitive shock loading

Good luck.



:E :E

Considering they are charging me $900 for only liability insurance on my 1976 motorbike this year....have you considered the cost of insurance and the ramifications?