Robinson R22 Corner [Archive copy]
Join Date: Nov 2003
Location: Drishan Mor.
Posts: 36
Likes: 0
Received 0 Likes
on
0 Posts
Absolutely right Vfrpilotpb and with the schools charging the students or instructors for the overspeeds I'm almost sure this, in most cases, will make it even harder (more expensive) to be honest.
I used to teach in school with R22's and Schweizer 300's (about 20 aircraft in total) and the boss always encouraged honesty by never charging for damage to aircraft. On the other hand everybody knew an unreported overspeed would be the fastest way out of the school and rightly so.
I used to teach in school with R22's and Schweizer 300's (about 20 aircraft in total) and the boss always encouraged honesty by never charging for damage to aircraft. On the other hand everybody knew an unreported overspeed would be the fastest way out of the school and rightly so.
Join Date: Jan 2004
Location: stand by one
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
r22 rotor stall
I have a question that has been bugging me perhaps you guys can help.
In the R22 POH it states that “In the event of low RPM (indicated by horn and light I presume) the pilot must first roll on throttle and lower collective simultaneously to recover RPM before investigating problem”
I can not understand why the manual does not tell you to enter autorotation immediately as I thought that you only had 1 second to react to an engine failure. A low RPM horn and light could also indicate an engine failure. Why not enter auto and then investigate?
My question is
1 In flight how do decide whether to enter autorotation or roll throttle and lower collective given that you have one second to make your mind up?
2. How many of you have experienced the low RPM and light activating in flight? What were the conditions? How often have you experienced it?
Thanks
Raven2
In the R22 POH it states that “In the event of low RPM (indicated by horn and light I presume) the pilot must first roll on throttle and lower collective simultaneously to recover RPM before investigating problem”
I can not understand why the manual does not tell you to enter autorotation immediately as I thought that you only had 1 second to react to an engine failure. A low RPM horn and light could also indicate an engine failure. Why not enter auto and then investigate?
My question is
1 In flight how do decide whether to enter autorotation or roll throttle and lower collective given that you have one second to make your mind up?
2. How many of you have experienced the low RPM and light activating in flight? What were the conditions? How often have you experienced it?
Thanks
Raven2
The Original Whirly
Join Date: Feb 1999
Location: Belper, Derbyshire, UK
Posts: 4,326
Likes: 0
Received 0 Likes
on
0 Posts
I'll pass on what I still remember Dick Sanford saying on the R22 Safety Course.
In the event of engine failure, you will get a violent yaw to the left. That is apparently the most obvious sign, so if you get that AND the horn, then enter auto-rotation immediately. But what Dick said was that there are other reasons for low rotor RPM. The most common one is over-riding the governor. He gave a likely scenario...you're on a cross country, the weather starts closing in, you're not sure where you are and perhaps a bit worried about your endurance. You start to worry and get tense, which means you grip the collective too hard and inadvertantly over-ride the governor. The next thing you know is the horn goes off. Already stressed, you enter auto-rotation...
He said there had been accidents from unsuccessful attempted forced landings in this sort of situation. So what he told us was: if the horn goes off, with no other indications, roll on throttle and flare. The flare will raise the RPM anyway, thereby giving you slightly longer to see if it works, or if you really do need to enter auto-rotation.
The only time I've experienced the horn and going off in flight is during governor-off training. You might say that doesn't count. However, it is also a good thing to practise (with an instructor, not allowed otherwise), just so that you don't immediately panic as soon as the horn goes off. Governor failure is of course another possible cause of low RRPM, and I gather is not unknown...if something can fail, then one day it will.
I hope that helps. And if you haven't been on a Robinson Safety Course, I'd highly recommend it; one of the best things I've ever done.
In the event of engine failure, you will get a violent yaw to the left. That is apparently the most obvious sign, so if you get that AND the horn, then enter auto-rotation immediately. But what Dick said was that there are other reasons for low rotor RPM. The most common one is over-riding the governor. He gave a likely scenario...you're on a cross country, the weather starts closing in, you're not sure where you are and perhaps a bit worried about your endurance. You start to worry and get tense, which means you grip the collective too hard and inadvertantly over-ride the governor. The next thing you know is the horn goes off. Already stressed, you enter auto-rotation...
He said there had been accidents from unsuccessful attempted forced landings in this sort of situation. So what he told us was: if the horn goes off, with no other indications, roll on throttle and flare. The flare will raise the RPM anyway, thereby giving you slightly longer to see if it works, or if you really do need to enter auto-rotation.
The only time I've experienced the horn and going off in flight is during governor-off training. You might say that doesn't count. However, it is also a good thing to practise (with an instructor, not allowed otherwise), just so that you don't immediately panic as soon as the horn goes off. Governor failure is of course another possible cause of low RRPM, and I gather is not unknown...if something can fail, then one day it will.
I hope that helps. And if you haven't been on a Robinson Safety Course, I'd highly recommend it; one of the best things I've ever done.
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
Raven,
The reason for your confusion is your predisposition to think that the rpm is low because the engine failed. Remember that rpm drops when the demand for power is more than the power you have.
The demand for power is determined by many things, but collective setting is primary. As written, the rpm recovery procedure is telling you to demand less power (lower collective) and be sure you are at high throttle (increase throttle).
This procedure has nothing to do with autorotaion, in other words. The British term for the condition is overpitching, a really good way to say you are asking for more power than the engine can deliver, and so you are dragging the rotor down.
In a hover, this is a nice way to start an LTE event (I do not like that term, but it is with us). This means you are likely to hit the pedal stops during an overpitch because you have now demanded max power (max main torque means max tail torque to counter it) and at the same time you have limited the tail rotor thrust because the rpm is reduced (and rotor thrust is reduced by the square of the rpm).
The reason for your confusion is your predisposition to think that the rpm is low because the engine failed. Remember that rpm drops when the demand for power is more than the power you have.
The demand for power is determined by many things, but collective setting is primary. As written, the rpm recovery procedure is telling you to demand less power (lower collective) and be sure you are at high throttle (increase throttle).
This procedure has nothing to do with autorotaion, in other words. The British term for the condition is overpitching, a really good way to say you are asking for more power than the engine can deliver, and so you are dragging the rotor down.
In a hover, this is a nice way to start an LTE event (I do not like that term, but it is with us). This means you are likely to hit the pedal stops during an overpitch because you have now demanded max power (max main torque means max tail torque to counter it) and at the same time you have limited the tail rotor thrust because the rpm is reduced (and rotor thrust is reduced by the square of the rpm).
Join Date: Mar 2000
Location: UK
Posts: 5,197
Likes: 0
Received 0 Likes
on
0 Posts
Helibiggles
Judging by a recent discussion in this forum about training in the UK, the R22 rental price you quote doesn't seem very different from prices in the UK.
Training in an R22 here costs about £210 pr/hr plus tax.
Fuel is very expensive because of our extremely high fuel tax, and FI costs are about £40 pr/hr even for a newly qualified QFI with nothing like the 17000 hours you mention.
£170 for an R22 + £40 for the FI plus tax @ 17.5% = £246.75 per hour.
Not surprisingly, if family/work commitments allow, many Brits train in America where fuel is much cheaper and FI hourly rates are less than half here.
Judging by a recent discussion in this forum about training in the UK, the R22 rental price you quote doesn't seem very different from prices in the UK.
Training in an R22 here costs about £210 pr/hr plus tax.
Fuel is very expensive because of our extremely high fuel tax, and FI costs are about £40 pr/hr even for a newly qualified QFI with nothing like the 17000 hours you mention.
£170 for an R22 + £40 for the FI plus tax @ 17.5% = £246.75 per hour.
Not surprisingly, if family/work commitments allow, many Brits train in America where fuel is much cheaper and FI hourly rates are less than half here.
Iconoclast
Join Date: Sep 2000
Location: The home of Dudley Dooright-Where the lead dog is the only one that gets a change of scenery.
Posts: 2,132
Likes: 0
Received 0 Likes
on
0 Posts
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
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
Join Date: Mar 2002
Location: Queensland Australia
Posts: 267
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
Join Date: Dec 2003
Location: Australia
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
Join Date: Sep 2002
Location: Australia
Posts: 103
Likes: 0
Received 0 Likes
on
0 Posts
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
The Original Whirly
Join Date: Feb 1999
Location: Belper, Derbyshire, UK
Posts: 4,326
Likes: 0
Received 0 Likes
on
0 Posts
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! 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.
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!
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.
Join Date: Apr 2003
Location: 18 Degrees North
Posts: 699
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
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.
Join Date: Nov 2003
Location: New York
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
