R44 down Rio de Janeiro
Thread Starter
R44 down Rio de Janeiro
Last edited by HeliHenri; 1st Jan 2012 at 11:43.
Join Date: Nov 2007
Location: Yellow Brick Road
Posts: 1,127
Likes: 0
Received 0 Likes
on
0 Posts
Quite a rare but instructive video of how quickly LTE bites if the chopper is slow and the wind is wrong and there's very little height to recover from except try and do one or more of the following:
1. closing the throttle and reducing collective
2. "milk" the collective
3. flying into the direction of the turn
4. doing an auto once there is any airspeed
but I think none of these would work for this poor guy.
It's all very easy to say one should never get oneself into this position but what other escape methods does one have ? I'd be keen to hear from anyone who has done extensive research into this area (as I have) or has been through a similar situation.
Thanks in advance.
1. closing the throttle and reducing collective
2. "milk" the collective
3. flying into the direction of the turn
4. doing an auto once there is any airspeed
but I think none of these would work for this poor guy.
It's all very easy to say one should never get oneself into this position but what other escape methods does one have ? I'd be keen to hear from anyone who has done extensive research into this area (as I have) or has been through a similar situation.
Thanks in advance.
Join Date: Dec 2008
Location: N/A
Posts: 845
Likes: 0
Received 0 Likes
on
0 Posts
Dangerous mis-understanding
LTE (Education) - LTRED
Presuming there was no mechanical fault (loose article in control run?)
This appears to be a classic case of 'the education problem'.
I hope no-one was injured.
The Airspeed becomes negative (due to the classic accidentally downwind app)
The weathercocking is unexpected
a small and timid input is ineffective
the pilot becomes confused
despite the input he has made the helicopter appears to be responding in the wrong direction.
The pilot makes drastic and confused control inputs and sometimes crashes.
- most pilots suffer this educational stage at some point and learn to be authoritative.
There are many examples of this (class) of accident/incident (LTEd):
Australian film pilot (looses 2000ft whilst confused)
Irish wedding squirrel
EC120 Redhill (more or less)
Gazelle in Yorkshire (fatal)
The R44 does not run out of pedal at zero A/S - you just need to use the pedals.
At Airspeed the situation is improved - with the worst pilot screw up the most you'd have to turn is 180 deg.....
- the action suggested by RF might be a little drastic for a serviceable helicopter, where the pedals just need 'subtle manipulation' to arrest yaw.
Presuming there was no mechanical fault (loose article in control run?)
This appears to be a classic case of 'the education problem'.
I hope no-one was injured.
The Airspeed becomes negative (due to the classic accidentally downwind app)
The weathercocking is unexpected
a small and timid input is ineffective
the pilot becomes confused
despite the input he has made the helicopter appears to be responding in the wrong direction.
The pilot makes drastic and confused control inputs and sometimes crashes.
- most pilots suffer this educational stage at some point and learn to be authoritative.
There are many examples of this (class) of accident/incident (LTEd):
Australian film pilot (looses 2000ft whilst confused)
Irish wedding squirrel
EC120 Redhill (more or less)
Gazelle in Yorkshire (fatal)
The R44 does not run out of pedal at zero A/S - you just need to use the pedals.
At Airspeed the situation is improved - with the worst pilot screw up the most you'd have to turn is 180 deg.....
- the action suggested by RF might be a little drastic for a serviceable helicopter, where the pedals just need 'subtle manipulation' to arrest yaw.
Join Date: Nov 2007
Location: Yellow Brick Road
Posts: 1,127
Likes: 0
Received 0 Likes
on
0 Posts
Thanks AnFI for your input. As a matter of fact, I agree with your comments:
You control it, and not the other way.
that is true too, and if all else fails, try my aforementioned "drastic actions" !
Cheers.
learn to be authoritative
R44 does not run out of pedal at zero A/S
Cheers.
Join Date: Jan 2006
Location: Redondo Beach
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
R22LTE
I got into it at 400 agl(photo flight), completely my fault. 
I WAS trying to stay above 20 kts, but I failed to do that. Spun 3 times in 3 seconds, full left pedal, and it felt like I was holding a tiger that wanted to break free. Fighting to keep it from spinning, with full left pedal, and that sorta worked, pulled a bit of collective, got a low RPM horn, OK that didn't work, down collective, while fighting the pedals again, tail rotor sounds like I had never heard before, nosed it over to get forward airspeed, with no response, nosed it over again to about a 60 degree down angle, yawing back and forth, and finally got it back at 50 agl over the beach. Got out of the 22 10 min. later at the airport, and the seat was still attached to my behind! THEE LONGEST 15 SECONDS OF MY LIFE. My photog hit my knee and said GOOD JOB, that was FUN! IF he only knew!
I WAS trying to stay above 20 kts, but I failed to do that. Spun 3 times in 3 seconds, full left pedal, and it felt like I was holding a tiger that wanted to break free. Fighting to keep it from spinning, with full left pedal, and that sorta worked, pulled a bit of collective, got a low RPM horn, OK that didn't work, down collective, while fighting the pedals again, tail rotor sounds like I had never heard before, nosed it over to get forward airspeed, with no response, nosed it over again to about a 60 degree down angle, yawing back and forth, and finally got it back at 50 agl over the beach. Got out of the 22 10 min. later at the airport, and the seat was still attached to my behind! THEE LONGEST 15 SECONDS OF MY LIFE. My photog hit my knee and said GOOD JOB, that was FUN! IF he only knew!
Join Date: Jan 2010
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
I WAS trying to stay above 20 kts, but I failed to do that.
Was it 20kts downwind or reducing airspeed to possibly being in the negative? Did you make large collective inputs due to losing ETL (with big change in torque as a result) with feet not being able to follow?
Happy to learn,
Helldog
Join Date: Jan 2006
Location: Redondo Beach
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
Yes, for me 20-23 kts airspeed would have been ideal....
What would you say would be the main reason for losing tail rotor control in your case?
Was it 20kts downwind or reducing airspeed to possibly being in the negative? Did you make large collective inputs due to losing ETL (with big change in torque as a result) with feet not being able to follow?
Was it 20kts downwind or reducing airspeed to possibly being in the negative? Did you make large collective inputs due to losing ETL (with big change in torque as a result) with feet not being able to follow?
Unless I am directly into the wind, will I drop it below 20 kts forward airspeed to get a shot. I know I introduced it to myself, and I've since forgiven myself for it, but I will never forget that experience, and lesson learned! Hope this helps!
Rob
Join Date: Nov 2003
Posts: 185
Likes: 0
Received 0 Likes
on
0 Posts
Flag in background appear to support the LTE. Brisk wind away and slightly to right of camera. The acceleration and deceleration of the turns. Interesting 'high pitched' whine down just at onset of spin. Pilot induced?
That low over people? Duh!
Full left pedal, lower collective to gain airspeed and reduce torque in the altitude you have. Not much option. In fact, don't be there in first place is only option.
Sorry for the kids who didn't get their turn on the bouncy castle.
That low over people? Duh!
Full left pedal, lower collective to gain airspeed and reduce torque in the altitude you have. Not much option. In fact, don't be there in first place is only option.
Sorry for the kids who didn't get their turn on the bouncy castle.
Last edited by cl12pv2s; 5th Jan 2012 at 05:30.
Join Date: Oct 2010
Location: Tacoma, WA
Posts: 46
Likes: 0
Received 0 Likes
on
0 Posts
1. closing the throttle and reducing collective
2. "milk" the collective
3. flying into the direction of the turn
4. doing an auto once there is any airspeed
but I think none of these would work for this poor guy.
2. "milk" the collective
3. flying into the direction of the turn
4. doing an auto once there is any airspeed
but I think none of these would work for this poor guy.
Join Date: Nov 2007
Location: Yellow Brick Road
Posts: 1,127
Likes: 0
Received 0 Likes
on
0 Posts
Why would you want to close the throttle?
Join Date: Nov 2003
Posts: 185
Likes: 0
Received 0 Likes
on
0 Posts
Quote:
Apologies for regurgitating the FM. At the rate of rotation in the video, there is no need to close the throttle. Agree.
Why would you want to close the throttle?
The idea is of course to REDUCE TORQUE. If that means reducing pitch, you must lower collective, which in turn should be accompanied by an appropriate closing of the throttle.
However, it is important that the 'throttle' is not the cause, and so cutting the engine completely is NOT necessary. More importantly, and Rotor RPM droop will result in tail rotor RPM droop. This is undesireable. Keep RPM up.
LTE recovery is simple and systematic.
FAA Rotorcraft Flying Handbook
If a sudden unanticipated right yaw occurs, the following recovery technique should be performed.
Apply full left pedal while simultaneously moving cyclic control forward to increase speed. If altitude permits, reduce power. As recovery is effected, adjust controls for normal forward flight.
Collective pitch reduction aids in arresting the yaw rate but may cause an excessive rate of descent. Any large, rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate and decrease rotor r.p.m. The decision to reduce collective must be based on your assessment of the altitude available for recovery.
If the rotation cannot be stopped and ground contact is imminent, an autorotation may be the best course of action. Maintain full left pedal until the rotation stops, then adjust to maintain heading.
If a sudden unanticipated right yaw occurs, the following recovery technique should be performed.
Apply full left pedal while simultaneously moving cyclic control forward to increase speed. If altitude permits, reduce power. As recovery is effected, adjust controls for normal forward flight.
Collective pitch reduction aids in arresting the yaw rate but may cause an excessive rate of descent. Any large, rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate and decrease rotor r.p.m. The decision to reduce collective must be based on your assessment of the altitude available for recovery.
If the rotation cannot be stopped and ground contact is imminent, an autorotation may be the best course of action. Maintain full left pedal until the rotation stops, then adjust to maintain heading.
*Edit* - You say your 1-4 response is regurgitating the FM? Is that really what the R44 manual says? I'm surprised. FAA certified aircraft!
FAA Advisory Circular - AC 90-95 - Unanticipated Right Yaw in Helicopters
Last edited by cl12pv2s; 5th Jan 2012 at 06:02.
Join Date: Nov 2007
Location: Yellow Brick Road
Posts: 1,127
Likes: 0
Received 0 Likes
on
0 Posts
Collective pitch reduction aids in arresting the yaw rate but may cause an excessive rate of descent.
The decision to reduce collective must be based on your assessment of the altitude available for recovery.
1-4 response is regurgitating the FM?
Cheers.
Join Date: Dec 2008
Location: N/A
Posts: 845
Likes: 0
Received 0 Likes
on
0 Posts
Use the controls for their purpose....
He only needed to move the left pedal forward ... to prevent the rotation to the right.
The R44 does not run out of left pedal - but pilots do get confused - as is clear from this thread..... many questionable solutions proposed here.
Most pilots learn this - most often by being caught out, and then becoming more authoritative.
There are many accidents from this cause - the fatal Gazelle accident in Yorkshire was most probably an example....
The R44 does not run out of left pedal - but pilots do get confused - as is clear from this thread..... many questionable solutions proposed here.
Most pilots learn this - most often by being caught out, and then becoming more authoritative.
There are many accidents from this cause - the fatal Gazelle accident in Yorkshire was most probably an example....
Join Date: Nov 2003
Posts: 185
Likes: 0
Received 0 Likes
on
0 Posts
ReverseFlight,
Dude. You listed four recovery actions. One of them was 'closing the throttle'. While your post explains that these are 'beyond' the recommended techniques for use in low altitude / airspeed situations, you clearly caused some confusion for others. Some people asking why the 'throttle must be closed'.
Instead of explaining and clarifying your list, you replied with what I can presume was an attempt at poorly written sarcasm, which caused more confusion. I think you'd better read YOUR post more carefully.
The recovery techniques I listed (in italics) were directly copied from the Rotorcraft Flying Handbook, a training book. Not the FM. You will also find the same recovery technique listed in the FAA Advisory Circular 90-95.
You'll note that those techniques therefore state a complete recovery chain, rather than scenario specific actions. It also provides warnings regarding LTE at low altitude.
Since it is important to keep the entire section together, so no one can take any part out of context (as you have done), I'll repost it all here.
It is important that the steps above are learnt as the recovery techniques. They may have saved this pilot alone. Step 1 - APPLY FULL LEFT PEDAL!
If you have other techniques from dusty old videos, then be very clear, or you'll have people less learned than you closing throttles and milking collectives when all they need is APPLY FULL LEFT PEDAL.
cl12p2s
Dude. You listed four recovery actions. One of them was 'closing the throttle'. While your post explains that these are 'beyond' the recommended techniques for use in low altitude / airspeed situations, you clearly caused some confusion for others. Some people asking why the 'throttle must be closed'.
Instead of explaining and clarifying your list, you replied with what I can presume was an attempt at poorly written sarcasm, which caused more confusion. I think you'd better read YOUR post more carefully.
Someone Asked:
Why would you want to close the throttle?
ReverseFlight said:
Why would you want to close the throttle?
ReverseFlight said:
Apologies for regurgitating the FM. At the rate of rotation in the video, there is no need to close the throttle. Agree.
You'll note that those techniques therefore state a complete recovery chain, rather than scenario specific actions. It also provides warnings regarding LTE at low altitude.
Since it is important to keep the entire section together, so no one can take any part out of context (as you have done), I'll repost it all here.
FAA Rotorcraft Flying Handbook
If a sudden unanticipated right yaw occurs, the following recovery technique should be performed.
Apply full left pedal while simultaneously moving cyclic control forward to increase speed. If altitude permits, reduce power. As recovery is effected, adjust controls for normal forward flight.
Collective pitch reduction aids in arresting the yaw rate but may cause an excessive rate of descent. Any large, rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate and decrease rotor r.p.m. The decision to reduce collective must be based on your assessment of the altitude available for recovery.
If the rotation cannot be stopped and ground contact is imminent, an autorotation may be the best course of action. Maintain full left pedal until the rotation stops, then adjust to maintain heading.
If a sudden unanticipated right yaw occurs, the following recovery technique should be performed.
Apply full left pedal while simultaneously moving cyclic control forward to increase speed. If altitude permits, reduce power. As recovery is effected, adjust controls for normal forward flight.
Collective pitch reduction aids in arresting the yaw rate but may cause an excessive rate of descent. Any large, rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate and decrease rotor r.p.m. The decision to reduce collective must be based on your assessment of the altitude available for recovery.
If the rotation cannot be stopped and ground contact is imminent, an autorotation may be the best course of action. Maintain full left pedal until the rotation stops, then adjust to maintain heading.
If you have other techniques from dusty old videos, then be very clear, or you'll have people less learned than you closing throttles and milking collectives when all they need is APPLY FULL LEFT PEDAL.
cl12p2s
Join Date: Dec 2008
Location: N/A
Posts: 845
Likes: 0
Received 0 Likes
on
0 Posts
cl12pv2s
you must lower collective, which in turn should be accompanied by an appropriate closing of the throttle.
you don't mean the pilot should partially close his twist grip do you?
I think you must mean(?): "....and the correlator will close the throttle (butterfly valve) by the appropriate amount - reducing the torque but leaving the RRPM unaffected." ???
Join Date: Nov 2003
Posts: 185
Likes: 0
Received 0 Likes
on
0 Posts
can I double check that with you...
you don't mean the pilot should partially close his twist grip do you?
I think you must mean(?): "....and the correlator will close the throttle (butterfly valve) by the appropriate amount - reducing the torque but leaving the RRPM unaffected." ???
you don't mean the pilot should partially close his twist grip do you?
I think you must mean(?): "....and the correlator will close the throttle (butterfly valve) by the appropriate amount - reducing the torque but leaving the RRPM unaffected." ???
Yes, that is exactly what I mean. In an LTE situation, RPM must be maintained, but power reduced.
Lower the collective, and maintain RPM.
Someone else might chip in more, but that's how I learnt it.