R22 Engine and Rotor RPM Overspeed(past red line) - Help!
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I had a similar situation with a 30 hour student I took on from another school. I was not in the helicopter as the exercise was a solo one practising basic skills a few miles form the airfield.
Previous school instructors always turned the gov off on the ground and when I was not in the helicopter the student had reverted to type and turned it off whilst running up. You all know where this is going - well he managed to take off with out the gov on and shortly after take off realized his mistake and flicked it on. No problem he thought and off he went - some 5 minutes later he realized the engine and rotor needle was no where to be seen and after doing some trouble shooting he slowly retarded the throttle and then all of a sudden the gov pulled the RPM back to the normal green range. Student believing all was now ok, continued the exercise for a further 35 minutes before returning to the airfield.
Thankfully I have a no blame culture and open approach to all mistakes so he fully explained what happened. Whilst there are many lessons to be learn't here the I grounded the helicopter immediately and had it check - 3 weeks later and $36000 out of my pocket (I also own the heli) found very little wrong and is a testament to how these little machines are made. Worst thing was the helicopter was brand new and had 98 hours on the clock at the time of overspeed.
Lessons learn't - gov stops governing at 116%, never assume that just because a student has over 30 hours with another school that he know the very basics of pre-lift and post lift checks, always brief on the what to do if any unusual situation occurs durning any part of the solo exercise (done before every solo flight until they are responsible for themselves.
Thankfully, no one hurt and a very valuable lesson - student now has 500 hours and owns his own Jet Ranger which we also use for some commercial work.
Previous school instructors always turned the gov off on the ground and when I was not in the helicopter the student had reverted to type and turned it off whilst running up. You all know where this is going - well he managed to take off with out the gov on and shortly after take off realized his mistake and flicked it on. No problem he thought and off he went - some 5 minutes later he realized the engine and rotor needle was no where to be seen and after doing some trouble shooting he slowly retarded the throttle and then all of a sudden the gov pulled the RPM back to the normal green range. Student believing all was now ok, continued the exercise for a further 35 minutes before returning to the airfield.
Thankfully I have a no blame culture and open approach to all mistakes so he fully explained what happened. Whilst there are many lessons to be learn't here the I grounded the helicopter immediately and had it check - 3 weeks later and $36000 out of my pocket (I also own the heli) found very little wrong and is a testament to how these little machines are made. Worst thing was the helicopter was brand new and had 98 hours on the clock at the time of overspeed.
Lessons learn't - gov stops governing at 116%, never assume that just because a student has over 30 hours with another school that he know the very basics of pre-lift and post lift checks, always brief on the what to do if any unusual situation occurs durning any part of the solo exercise (done before every solo flight until they are responsible for themselves.
Thankfully, no one hurt and a very valuable lesson - student now has 500 hours and owns his own Jet Ranger which we also use for some commercial work.
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For those who are wishing to learn from these threads it may be a good idea to relate a bit about the whirlmode RPM as well. I don't have the book in front of me so rather than guess maybe someone else who has can look it up.
For the newbies, the onset of whirlmode is very sudden and is where the T/R drive shaft goes out of whack so far that it self destructs, taking half the tail boom with it. It probably is a sort of eye watering, ear wax popping excitement experience, followed by a quick stop from the vertical terminal descent speed approach profile. Your arrival airspeed of course will depend upon the height of entry, but any higher than ten feet is most likely academic
At every hundred hourly inspection, the run out limits on the T/R drive shaft are checked to ensure someone hasn't been doing something that they should have spoken about.
Now tell me, are you still dithering about marching right into the CFI right now, and talking it over.
yessir, the red line is there to be not abused and if done so accidentally, please make a breast of it.
all the best tet
For the newbies, the onset of whirlmode is very sudden and is where the T/R drive shaft goes out of whack so far that it self destructs, taking half the tail boom with it. It probably is a sort of eye watering, ear wax popping excitement experience, followed by a quick stop from the vertical terminal descent speed approach profile. Your arrival airspeed of course will depend upon the height of entry, but any higher than ten feet is most likely academic
At every hundred hourly inspection, the run out limits on the T/R drive shaft are checked to ensure someone hasn't been doing something that they should have spoken about.
Now tell me, are you still dithering about marching right into the CFI right now, and talking it over.
yessir, the red line is there to be not abused and if done so accidentally, please make a breast of it.
all the best tet
For those who are wishing to learn from these threads it may be a good idea to relate a bit about the whirlmode RPM as well.
60% and 132% RRPM are the relevant numbers in the R22 according to RHC. (The first number is, of course, far less dangerous, although this is the reason for the yellow arc on the tachs).
There are cases where the entire tailboom separated during a severe overspeed.
Is it not common practice for the instructor and the student to discuss the flight either beforehand or at the start of the flight what exercises are to be covered and what if any emergency drills (may) be carried out.
This would seem particularly important if it's not your regular student/instructor relationship.
Yes I get that once you have your license you need to be able to identify problems quickly and go into auto on your own (and quickly in a 22) but it does seem form the initial account that some of the panic (probably the wrong word but you get the idea) was caused by the student's lack of expectation of needing to do an auto or low rotor RPM recovery.
For my non-instructor two-pennyworth initiating an auto/low rotor RPM recovery at 300ft with someone you haven't flown with much does seem to be getting a bit close to the line. Was it also over a built up area?
IFRESH21 - Interested to know if that conversation did take place beforehand ??
CC
This would seem particularly important if it's not your regular student/instructor relationship.
Yes I get that once you have your license you need to be able to identify problems quickly and go into auto on your own (and quickly in a 22) but it does seem form the initial account that some of the panic (probably the wrong word but you get the idea) was caused by the student's lack of expectation of needing to do an auto or low rotor RPM recovery.
For my non-instructor two-pennyworth initiating an auto/low rotor RPM recovery at 300ft with someone you haven't flown with much does seem to be getting a bit close to the line. Was it also over a built up area?
IFRESH21 - Interested to know if that conversation did take place beforehand ??
CC
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Having seen first hand a set of spindles from an oversped 44, I would not hesitate reporting an O/S. Very dangerous situation that can hide for a long time after the event with no apparent symptoms.
I bent wrenches for 10 years in the Military before starting to bend helicopters, a world very critical on mistakes, and spent many a late night doing inspections and troubleshooting trivial issues to avoid a pilot having to get in hot water for admitting they exceeded the rather conservative 30deg/sec yaw limit or being called a complainer because they didn't like how the flight controls felt during a travel check. A good mechanic can find out if you have broken something very quickly, and the aircraft will be sorted accordingly, without having to put your neck out for what is right. Good rapport with your mechanic is worth its weight in gold, and all it will cost you is a case of beer. Yeungling is preferable.
Mike
I bent wrenches for 10 years in the Military before starting to bend helicopters, a world very critical on mistakes, and spent many a late night doing inspections and troubleshooting trivial issues to avoid a pilot having to get in hot water for admitting they exceeded the rather conservative 30deg/sec yaw limit or being called a complainer because they didn't like how the flight controls felt during a travel check. A good mechanic can find out if you have broken something very quickly, and the aircraft will be sorted accordingly, without having to put your neck out for what is right. Good rapport with your mechanic is worth its weight in gold, and all it will cost you is a case of beer. Yeungling is preferable.
Mike
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cl12pv2s
I do believe I may have been that very student, much water has passed under the bridge since then 
Even now as an R22 Instructor with many thousands of teaching hours I recount that story to all of my new instructors for 3 reasons;
1) Beware of students you havent trained yourself, they will do things you dont expect when you least expect it.
2) Do the right thing!! If you screw up, someones life can depend upon your integrity as a Flight Instructor. My Instructor's professionalism and subsequent actions / reaction (both to me and the company) to that incident were formative in my flying career.
3)Always fully brief a student prior to flight about low RPM recovery and autoration power recoveries so you are both on the same page and one of you isnt winding on the throttle whilst the other is pulling an armpit full of collective - sure fire power on overspeed. It is the instructor's job to prevent this happening NOT the student.
Geoff
Even now as an R22 Instructor with many thousands of teaching hours I recount that story to all of my new instructors for 3 reasons;
1) Beware of students you havent trained yourself, they will do things you dont expect when you least expect it.
2) Do the right thing!! If you screw up, someones life can depend upon your integrity as a Flight Instructor. My Instructor's professionalism and subsequent actions / reaction (both to me and the company) to that incident were formative in my flying career.
3)Always fully brief a student prior to flight about low RPM recovery and autoration power recoveries so you are both on the same page and one of you isnt winding on the throttle whilst the other is pulling an armpit full of collective - sure fire power on overspeed. It is the instructor's job to prevent this happening NOT the student.
Geoff
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Mr Sanford - I thank you for your comment and whilst I don't doubt that you may have had many discussions with Mr Robinson regarding low RRPM recovery I wasn't quoting the R22 manual but rather the R22 Safety Awareness video in which he specifically states the actions must be simultaneous. If you would like me to quote the manual then I in turn refer you to Safety Notice SN-10 which says, in part:
"No matter what causes the low rotor RPM, the pilot must first roll on
throttle and lower the collective simultaneously to recover RPM before
investigating the problem. It must be a conditioned reflex."
Rgds.
"No matter what causes the low rotor RPM, the pilot must first roll on
throttle and lower the collective simultaneously to recover RPM before
investigating the problem. It must be a conditioned reflex."
Rgds.
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Last comment ref Low RPM recovery in a Robinson helicopter (R22 & R44)
Why do you need to add throttle before lowering the lever?
You can lead a horse to water but you cannot make it drink. Having conducted the European R22/R44 safety course for 15 + years, perhaps i'm wrong.
Why do you need to add throttle before lowering the lever?
You can lead a horse to water but you cannot make it drink. Having conducted the European R22/R44 safety course for 15 + years, perhaps i'm wrong.
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So I called the school like the day after the "well call you back" call. I talked to my real instructor who is beast and most experienced at the school. He was like I heard you had an overspeed? He is like ok well we grounded the aircraft. He sounded like he knew his shiz he was talking about removing the rotors and checking spindles and stuff.
He didn't even ask what happened - he said wed talk about that later after he talked to instructor... I was away without cell service so i haven't talked to him since. Im hoping they did a full maintenance and everything. I will talk to him today - any questions I should ask?(about the maintenance etc.) Hopefully the instructor explained that it was an engine overspeed also. That does require additional maintenance, right?
Thank you again everyone - I will keep you guys updated
choppperchappie: It wasn't panic at all, I was calm the whole time. I just did what the book says - that is all. I didn't do it perfectly either - there was a big pause. If it was real I prly would have stalled it lol. Thank god he was smart enough not to do a throttle chop.
We were on final parrallel to a runway over grass.
We talked about the flight generally before hand. He was good to take the time to do that. But in no way shape or form did he mention a low rpm warning test lol. We also did 180 autos for my first time and we didn't discuss those before though. So yea we talked but he missed a few things
He didn't even ask what happened - he said wed talk about that later after he talked to instructor... I was away without cell service so i haven't talked to him since. Im hoping they did a full maintenance and everything. I will talk to him today - any questions I should ask?(about the maintenance etc.) Hopefully the instructor explained that it was an engine overspeed also. That does require additional maintenance, right?
Thank you again everyone - I will keep you guys updated
choppperchappie: It wasn't panic at all, I was calm the whole time. I just did what the book says - that is all. I didn't do it perfectly either - there was a big pause. If it was real I prly would have stalled it lol. Thank god he was smart enough not to do a throttle chop.
We were on final parrallel to a runway over grass.
We talked about the flight generally before hand. He was good to take the time to do that. But in no way shape or form did he mention a low rpm warning test lol. We also did 180 autos for my first time and we didn't discuss those before though. So yea we talked but he missed a few things
Last edited by ifresh21; 5th Apr 2011 at 17:46.
Being 16 years doing both fixed and rotorwing license at the same time,(impressive) I would recon you must be a smart fellow, therefore I think you should know what to ask your instructor about next you see him.
Your last post reminded me of ''Little Britain'' by the way
Your last post reminded me of ''Little Britain'' by the way
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Dick / reversethrottle
You roll on throttle BEFORE lowering collective because...lowering the lever naturally closes the throttle via the corrollator, ie: the lever and throttle are connected.
Simultaneously lowering and rolling raises the possibility that your amount of throttle rolling will be at least partially cancelled out by your amount of lever lowering, ie: the former will trail the latter.
Thus, to be sure, it is better to at least get the engine power recovery process started by first rolling on throttle that little bit BEFORE. Of course, getting the lever down is also very important, hence the 's' word tends to get used. We are talking milliseconds, here.
Bring back the old days, eh Dick?
You roll on throttle BEFORE lowering collective because...lowering the lever naturally closes the throttle via the corrollator, ie: the lever and throttle are connected.
Simultaneously lowering and rolling raises the possibility that your amount of throttle rolling will be at least partially cancelled out by your amount of lever lowering, ie: the former will trail the latter.
Thus, to be sure, it is better to at least get the engine power recovery process started by first rolling on throttle that little bit BEFORE. Of course, getting the lever down is also very important, hence the 's' word tends to get used. We are talking milliseconds, here.
Bring back the old days, eh Dick?
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Isn't it more important to worry about lowering the collective? Cause what if there is engine trouble anyway - full throttle might not do much for you.
I think it should be simultaneous - any hesitation waiting for the throttle to go full could be deadly. I did it and its not that hard to go full throttle while lowering the collective . lol.
You guys know wayy more than me probably though(besides maybe actually doing it), so thats just what it seems to be from my pov.
I think it should be simultaneous - any hesitation waiting for the throttle to go full could be deadly. I did it and its not that hard to go full throttle while lowering the collective
. lol.You guys know wayy more than me probably though(besides maybe actually doing it), so thats just what it seems to be from my pov.
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Now i'm not a very sharp helicopter pilot but I'm pretty sure that I can roll and lower at the same time.
Good question about the cause of RRPM decay; not something I'm personally diagnosing when the buzzer kicks in.
Good question about the cause of RRPM decay; not something I'm personally diagnosing when the buzzer kicks in.
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So I finally got in touch today. The aircraft was inspected and nothing was wrong. I asked they said it was grounded a few days.
So everything is good to go I guess. He said I can talk direct to the maintenance guy when I come in- that is something I would like to do. It also interests me just so see like a disassembled R22 and how they do things if they let me do that. Maybe I can get some preflight advice and stuff.
Thank you to everyone for all the help and stuff. You guys are beast.
So everything is good to go I guess. He said I can talk direct to the maintenance guy when I come in- that is something I would like to do. It also interests me just so see like a disassembled R22 and how they do things if they let me do that. Maybe I can get some preflight advice and stuff.
Thank you to everyone for all the help and stuff. You guys are beast.
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Oversped an R22 engine yesterday on strartup. I could have sworn the throttle was in the detent, but I don't see how an overspeed would be possible like that on startup without the throttle butterfly open. I must have not had it closed all the way. In any case it was reported immediately and the engine is being pulled for inspection.
Any idea how much this costs to inspect for an engine overspeed? I am feeling really guilty about it and want to help pay for the inspection, but I need to have an idea of cost. Anyone have any insight?
Any idea how much this costs to inspect for an engine overspeed? I am feeling really guilty about it and want to help pay for the inspection, but I need to have an idea of cost. Anyone have any insight?
If the engine has to be removed, with parts and labour, you're up for at least $15,000 to pull, bulk strip, inspect, reassemble and refit.
As for repayment, these things happen, the school will understand this. Just continue to do your license with them and whatever you do, don't go next door to the competition.
As for repayment, these things happen, the school will understand this. Just continue to do your license with them and whatever you do, don't go next door to the competition.