skippo,

So the next question has to be how quickly does carb icing melt with full carb...
Drop an ice cube on a radiator and I bet i doesn't melt in under 10s!
Does full heat literally blast the carb icing out of the carb in a few secs?

PS Whirlybird, Do you recon if it happened to you, you could pull it off without anyone knowing (fellow instructors)... Just imagine the T.L. student on the way home "Yeah...he really cut the engine...and we just floated down!!!":confused:

MADY

My Lady cfi drummed it into me that Carb heat FULL ON before any other item or action if going to practice any Auto's on the R22,

However that will not give you a cast iron guarantee that your carb will NOT ice up, under certain Wx conditions it will.

The secret is to pull full heat and watch the temps climb, then at least you know heat is there, but God, or Allah will still be watching ready to catch you
shalt thou fail!:E

Vfr

yeah the trick is to not pull carb on and then enter , make sure ya put it on on your downwind landing checks . When giving Throttle chops on student fly with the heat on for a bit before ya do it, The student will expect a Chop when he see's ya go for Heat , so put it on and them you will get the full effect .

Another trick is to crack the thottle out of idle to about 60-70% when passing 300' on Auto's the reason for this is that it gives you more reaction time in case yer power is gone due to ice and you have more vital seconds to perform yer best full down Touch .

10 secound melt time?
 

Mady
I bet it takes more than 20 seconds to melt carb ice to! I said some time in advance, most do it on downwind checks. Also if you are to throttle chop a student, leave it on for a longer time. This will make the chop safer and give the student mor element of suprise:} . When it comes to how quikly ice already acumulated melts i have no idea. BUT if you use the carb temp gauge this can give you an idea of if some ice already acumulated.

In other words if youre been close to or in the yellow band, i would wait longer before doing any autos after applying carb heat:ok: Think ahead, dont put a student and yourself in a world of !!!!...

Proper carb heat procedures do work...

If you're flying R22's DO NOT DO THROTTLE CHOPS!!!!!

Safety Notice 27 I believe

MD902man
 

well said, NO THROTTLE CHOPS IN R22,
heard a story about that once,
it goes like this:-
exerienced instructor does one with ab initio at about 1,000 agl,
entry hgt very lucky,
student:- they think didn't push down on the old life-saver but they think he threw in a boot full of left pedal. Instructor scared so much does not remember
Result flick roll inverted,
instructor completes hlf roll and hlf loop or something and lands asap,
note entry hgt,
instructor is last seen heading to change room at a higher speed than loop pull out speed.

machine passed fit to fly after thorougth look over, and clean off oil from ALL over underside of whole A/C

ab-boy still none the wiser.

maybe someone should start a thread, F--- NSTB

What if the R22 is the only machine you have ever flown and a student gets an actually engine failure on a solo flight? If every practice auto they have ever done was a 3-2-1 countdown, then they won't have the reaction time needed to get the collective down before the rotor stalls!:eek: The instructor that used to chop me in the R22 had a rule of thumb for students until he knew how well they would react to it; always chop below 20in on newbies since there is less drag and more time to react compared to pulling full power.

While I was on the Robinson safety course last year, one point that was highly stressed to instructors was to "never chop the throttle" as a new student may react totally wrong, i.e. freezing on the controls. :yuk:

inthetin
 

thats right, at least in the '47 students would learn without preps, or you had time to undo harness stand up and puch p--- out of him while the scenery didn't change much outside.

R22 QUESTION
 

Apologies fellow aviators for a dumb question that I should be able to remember (and I am expecting to get some grief, so give it your best shot).

How many degrees of slope is the R22 limited to for sloping ground detail?
Is it 15 degrees of slope in either direction? Haven't got my books with me so I can't look it up.

Ta & safe flying.

RV

:eek: The thought of a 15 degree slope in an R22 will haunt my dreams forever!

IIRC (I'm sure some kind soul will correct me if necessary) you have 9 degrees of cyclic authority to the right, and 11 degrees to the left

From that, interpret your own safe limits! - there is nothing in the manual

We use 5 degree slopes for training at my school, although I'm sure nobody has actually measured the slope we use! :}

Nose Up: 10 degrees
Left Skid on: 5 degrees
Right Skid on: 7 degrees

No limits are published for the R22 on sloping ground, however there are wide used "recommended limits".

Hope it helps you,

TiP:ok:

I hate the feeling when you are slope landing nose up and waiting for the back of the skids to touch ground. As you can't see the surface behind you, it is just a question of hoping the skids hit before the tail, or that's how it feels anyway.

Wind speed limits for starting an R44/R22?
 

Hi Folks
I'm looking for some information or advice regarding the limitations for start-up and shutdown of an R44/R22 with reference to blade sailing. There is currently no limitations within the POH.
Cheers

If you lose the back end of the tail boom, then it was too windy . . . :ouch:

If you put the wind at your 4 - 5 o'clock, you can start them in any wind you would consider flying in. The pick-up might be a little exciting.

Wind limits
 

R22/R44 start up/ shut down limits,

I have seen it in the POH, either in the safety notices or as a CAA supplement, limit is 26Kts i think. The best wind position to avoid a tailboom strike is to have the wind at 10 - 11 o'clock which means you have the blade rising on the left side of the A/C and at a high point as it goes over the tailboom and falling on the right side and at a low point as it passes the nose.


Regards BC

The only wind limitation I can think of in the R22 manual is that for low-experience pilots.
This was a result of AD95-26-04, which is now included (in part) in the POH.
The relevant text is copied below.
LIMITATIONS SECTION
The following limitations (1-3) are to be observed unless the pilot manipulating the controls has logged 200 or more flight hours in helicopters, at least 50 of which must be in the RHC Model R22 helicopter, and has completed the awareness training specified in Special Federal Aviation Regulation (SFAR) No. 73, issued February 27, 1995.
(1) Flight when surface winds exceed 25 knots, including gusts, is prohibited.
(2) Flight when surface wind gust spreads exceed 15 knots is prohibited.
(3) Continued flight in moderate, severe, or extreme turbulence is prohibited.
Adjust forward airspeed to between 60 knots indicated airspeed (KIAS) and 0.7 Vne, but no lower than 57 KIAS, upon inadvertently encountering moderate, severe, or extreme turbulence.
Note: Moderate turbulence is turbulence that causes: (1) changes in altitude or attitude; (2) variations in indicated airspeed; and (3) aircraft occupants to feel definite strains against seat belts.
I don't believe there is a limitation for starting, but the advice that has been posted previously about the best azimuth is good (notwithstanding the obvious error, as pointed out by Flingwing below, which I admit I missed at first!)
cl12pv2s

If the wind is from forward-left as you describe, the the blade advancing from the right side will reach maximum upflap at the 1 - 2 o'clock point, the retreating blade will reach maximum downflap at the 7 - 8 o'clock position. The tailboom is at the 6 o'clock position. You do the math

Agreed. That description is 180 degrees out. Have the wind in your back right hand jeans pocket with your wallet is how I remember it.

"limit is 26Kts i think"
Better keep them out of the Grand Canyon. 26kts is a nice day......

When we first got R22's many years ago, we asked Robinsons for the reasons for the 26 kt bit for starting and stopping. Answer - the CAA said there had to be a reference in the Flight Manual so we said oh, er, ok, 30 mph. When we conducted some trials, we found the R22 was more resistant to blade sailing by a long way than other types and with better tailboom clearance in gusts. Whether you want to train in wind speeds much above 25 kt at ground level is another matter.

Composite blades and the R22
 

Just a question I would like to ask.With the previous blade problems,and the new bonding problems arising in the dash 4's.Could,or would a composite blade be a better option for the R22?It could extend blade times,and solve the structural integrity of such a small blade!

Yes but it would mean a huge price increase in a new set of blades, which would eventully have to be passed on to the customer, making hire rates more expensive.

The Robinson does a good job in its Current format in allowing the pleasure of flying to more and more common folk. An increase in prices would make that gap increase and stop more people taking up flying.

R22.

True!They would be more expensive in the first place.But the timex would probably at least double,possibly triple.That is a huge saving at O/H.I am no tech guru, just a jockey.What is the life span of say a squirrel blade?

I agree that over a long term they would probably work out more cost effective but the initial outlay would put off alot of people and also the abuse they get in large training schools would make them and expensive nicety.

Just recently at our school, one of the R22's had new blades fitted and then after 100 hours of use, a line service guy twatted one as he was pushing the heli out of the hanger!

Expensive mistake, even more expensive if they were composite!

I don't thing that a composite blade is necessarily more expensive. A lot of the blade's cost will depend on the production rates over which the fixed costs can be amortized and the automation or mechanization of the variable costs.

A decrease of new craft sales, or a longer blade life, or the eventual end of R-22 production have probably been considered by Robinson when evaluating this option.

20,000 hrs for the squirrel blades i think. Do you have to be common to fly a Robinson ?:E

How do the weights of composite vs aluminum work out for rotor blades? I imagine since rotor weight/inertia is fixed by auto response time, the only advantage is extended fatigue life from lower root stresses. Initial tooling would favour composite, but i imagine the R22 jigs are long since payed off.

Dave, how is your blade work progressing? It looked like you were making great progress, so i'd like to follow up.

Mart

Not so much common, just skint!! Like me!!!

Most Robbies are shake-rattle-and roll. Some of them could shake your fillings right out.

But it doesn't have to be that way. The one I flew today was sm-o-o-o-o-th. I mean really, it could have been a three-bladed system.

Which gets me to thinking - how much of the problems are caused by poor set-up. Stands to reason that a machine with poor tracking and high vibration levels is going to suffer more wear and tear than one that's all set up and smooth.

Perhaps that's the answer - a well set-up machine is much less likely to shake itself to bits. Question is, how achievable is it ? Some machines just seem harder to keep in track and balance than others.

Graviman,The composite blade is lighter, while at the same time the profile can be improved, and the rotational inertia can be maintained or improved by adding back a little of the weight at the very tip of the blade.

Ref. Sikorsky S-61 blades; http://www.ainonline.com/Publication...endingpg2.html

Currently debugging the controller. Then to build the frame and mount the hardware. It's not as much fun as Aerodynamics.

Dave

Lock nuts and overspeeds
 

Pre flighted the club 22 today and when i got to the cooling fan the locking wire was not in line with the painted lines (a good 30% out).

Didn't fly it and reported to the engineers who said that when you take off the cooling fan for maintenance it doesn't always line back up again and that they didn't repaint the line as the a/c was only a few hours of its 100 hour check.

I have to say i have a few problems with this answer, but as a 100 hr newbie (aka know nothing) and a non engineer I don't want to make a prat of myself.

Would welcome the pprune collective wealth of experience, specifically;

1. Is a misaligned nut always a sign of an engine overspeed or does their explanation have merit.
2. If their explanation has merit then if the nut is put back on to the prescribed torque values then why doesn't it line up.
3. Can the nut slip without the wire breaking (this was also given as a reason why my concerns were unfounded).

Suffice to say that at present I am avoiding this a/c like the plague :eek:

thanks in advance

Mr R Biggles

Mag check may be cause
 

Mr Biggles,

The fan is on a tapered shaft.

If a pilot (student?), turns off both mags during the pre flight runup check, then human nature is that we immediately flick it back on ....... the engine almost stops and then bursts back to life.

A great stress is placed on the fan and it can slip on the shaft, so misaligned marks can mean a fan which has moved.

Can anyone else help here?

Find a new Engineer !

E

I would want to know what maintenance was being carried out and why it was being done out of sequence. If there was there something wrong with the machine that couldn't wait a few hours, I think you should be told !

(How long does it take to repaint the line anyway?)

Pre-flight checklist says it should be in line because that's how you know if there's been an engine start with throttle open or other problem. It's a safety feature leaving a tell-tale if a problem has occurred.

Letting it go from maintenance without lining up and repainting the marks precludes the pilot from knowing if such a problem has occurred.

I'm picky, but I would absolutely refuse to fly an R22 without the nut and marks in line. If I was the owner (and I do own one), I would also consider moving the a/c's maintenance unless I got a very good answer as to why an engineer would release the a/c to service with this safety feature effectively disabled - from a non-engineer's viewpoint, it gives an impression that the person did not do a full and complete job - so what else was not done fully and completely?

BW

All good advice thanks.

The "marks don't always line up after the fan has been off" argument that was given by the engineers just seems wrong.

Interesting point from BW, but I had always assumed the thread and nut will always start at the same position of the thread when it first "lines up". Thus if it is always set to the same torque value with the wench it will always end up in the same place.. i.e in line with the white marks. Maybe i'm missing something here.

If true then any deviation must mean slippage hence some sort of overspeed, mag jolt, overtourque etc (all bad regardless of the original issue).

I have joined a syndicate which has different engineering (of the reasuringly picky kind..) but it does make you think given that Uncle Frank (not a man to waste words or pages in the POH) makes it part of the checklist