206L Crash on YouTube
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206L Crash on YouTube
Anyone know anything about this?
YouTube - Helicopter Crash
Looks like a heavy water impact...
My take on it was that the aircraft was overloaded and the pilot knew it so they tried to get airborne by spinning with the torque, then screwed up the transition, drooped the RPM and that was that.
YouTube - Helicopter Crash
Looks like a heavy water impact...
My take on it was that the aircraft was overloaded and the pilot knew it so they tried to get airborne by spinning with the torque, then screwed up the transition, drooped the RPM and that was that.
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Makes me think of the Twinranger in Spain that crashed - also overweight I recall ..
Part I - outside view: YouTube - Stadium Helicopter Crash Part I
Part II - inside view: YouTube - Stadium Helicopter Crash Part II
- madman
Part I - outside view: YouTube - Stadium Helicopter Crash Part I
Part II - inside view: YouTube - Stadium Helicopter Crash Part II
- madman
Well he certainly was light enough to pull up into that big, high hover! Also looked like he had enough room to accelerate through ETL and spiral up if he had to.
Making right pedal turns is counterproductive. Might work in a recip, but not in a 206. The governor senses this as an *increase* in N2 rpm and reduces fuel flow accordingly. So yeah, you get a little more torque from the reduction of left pedal, but pulling further up on the pole only makes things worse, not better.
Low time 206 guy, I'd say. Sad.
Interesting to me...maybe I'm seeing things...but does it look like some of the things in the baggage compartment came right the floor and right out the bottom of the tub with that high vertical impact?
Making right pedal turns is counterproductive. Might work in a recip, but not in a 206. The governor senses this as an *increase* in N2 rpm and reduces fuel flow accordingly. So yeah, you get a little more torque from the reduction of left pedal, but pulling further up on the pole only makes things worse, not better.
Low time 206 guy, I'd say. Sad.
Interesting to me...maybe I'm seeing things...but does it look like some of the things in the baggage compartment came right the floor and right out the bottom of the tub with that high vertical impact?
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We have seen that video for at least three or four years at Bell during recurrent training. High DA in South America, as I recall.
The pilot would probably have liked to have a high altitude tail rotor.
George
The pilot would probably have liked to have a high altitude tail rotor.
George
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I have seen a lot of crash videos but must admit this is the first time I have seen this one. It is sickening to watch but interesting in terms of learning a few things.
I don't know what the official report said but IMO the pilot did not put in right pedal intentionally. He could have been overweight and/or attempting to come to a hover downwind (note he transitions off in the opposite direction ?), either of which would have demanded greater power requirements. This may have prompted the pilot to raise collective, droop MR rpm and induce LTE in the high DA. Or maybe he just did a spot turn the wrong way (yawing to the right).
His corrective action was correct, in that he tried to halt the spin with left pedal - the chopper stopped yawing to the right for a short period while he tried to transition into wind to weathercock the tail back to where it belongs (note he even had more airspeed and height than the Spanish one). This is when the chopper disappears momentarily off the right hand side of the screen.
The horror sets in when it doesn't work (possibly due to high DA) and you can hear the engine slowing down as he tried to maintain altitude with collective, possibly overpitching the main blades. The chopper starts yawing to the right again with LTE to the inevitable crash.
I have conducted extensive research into the LTE phenomenon and spoken to many instructors about how to save these situations like milking the collective and transitioning in the direction of the yaw but at the end of the day these are all theories. This video proves how quickly things can go wrong even if you are doing all the right things.
The video does not show the liftoff but in my experience once the right yaw begins to take off on a mind of its own, don't attempt to fly away. Roll off throttle while you are still have HIGE and do your best to cushion the touchdown with collective. You may spread the skids but at least the landing is more than survivable.
I don't know what the official report said but IMO the pilot did not put in right pedal intentionally. He could have been overweight and/or attempting to come to a hover downwind (note he transitions off in the opposite direction ?), either of which would have demanded greater power requirements. This may have prompted the pilot to raise collective, droop MR rpm and induce LTE in the high DA. Or maybe he just did a spot turn the wrong way (yawing to the right).
His corrective action was correct, in that he tried to halt the spin with left pedal - the chopper stopped yawing to the right for a short period while he tried to transition into wind to weathercock the tail back to where it belongs (note he even had more airspeed and height than the Spanish one). This is when the chopper disappears momentarily off the right hand side of the screen.
The horror sets in when it doesn't work (possibly due to high DA) and you can hear the engine slowing down as he tried to maintain altitude with collective, possibly overpitching the main blades. The chopper starts yawing to the right again with LTE to the inevitable crash.
I have conducted extensive research into the LTE phenomenon and spoken to many instructors about how to save these situations like milking the collective and transitioning in the direction of the yaw but at the end of the day these are all theories. This video proves how quickly things can go wrong even if you are doing all the right things.
The video does not show the liftoff but in my experience once the right yaw begins to take off on a mind of its own, don't attempt to fly away. Roll off throttle while you are still have HIGE and do your best to cushion the touchdown with collective. You may spread the skids but at least the landing is more than survivable.
It starts out as not enough TR thrust i.e pedal
As it progress's and the aircraft starts to drift off to the left and you think he is going to straighten it out as the fin starts to become effective, the TR is at max pitch and being pushed perpendicular to the airflow (think vortex ring) and also possibly some wake now from the main rotor has joined in, the power required to keep the tail rotor turning helps to top the engine out and you can hear the loss of RRPM.
This is a trap on L3's. If the governor was a little dopey or the RRPM was not at the top of the green to start with.
Begs the question about the departure as it nearly had OGE hover capability.
Technique was definitely lacking. Ticked all the boxes to get LTE.
Spent a day with an L3 once pouring concrete at 9000' DA. Trick was to keep full left pedal and steer with the collective. Don't fly sideways to the left or let the nose drift right though.
Helicopter is definitely too big for the TR!
As it progress's and the aircraft starts to drift off to the left and you think he is going to straighten it out as the fin starts to become effective, the TR is at max pitch and being pushed perpendicular to the airflow (think vortex ring) and also possibly some wake now from the main rotor has joined in, the power required to keep the tail rotor turning helps to top the engine out and you can hear the loss of RRPM.
This is a trap on L3's. If the governor was a little dopey or the RRPM was not at the top of the green to start with.
Begs the question about the departure as it nearly had OGE hover capability.
Technique was definitely lacking. Ticked all the boxes to get LTE.
Spent a day with an L3 once pouring concrete at 9000' DA. Trick was to keep full left pedal and steer with the collective. Don't fly sideways to the left or let the nose drift right though.
Helicopter is definitely too big for the TR!
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RVDT
Thanks for the window into the murky world of the L3. I was wondering if it was an L3 thing - it was odd to me that he had the power to hover OGE but still managed to droop it.
During the transition I assumed he was trying to recover RPM by getting off the left pedal, I never considered that the poor sod was pressing left pedal and drooping it more due to LTE in forward flight.
He should have just lowered collective a bit and dumped the torque, as ReverseFlight said. He had the height.
Easy to say watching a video rather than being in the spin cycle though. I experienced moderate LTE during OGE with a student about 3 months back and the helo had completed a 180 by the time I'd managed to lower the collective and get forward cyclic in.
Kris
Thanks for the window into the murky world of the L3. I was wondering if it was an L3 thing - it was odd to me that he had the power to hover OGE but still managed to droop it.
During the transition I assumed he was trying to recover RPM by getting off the left pedal, I never considered that the poor sod was pressing left pedal and drooping it more due to LTE in forward flight.
He should have just lowered collective a bit and dumped the torque, as ReverseFlight said. He had the height.
Easy to say watching a video rather than being in the spin cycle though. I experienced moderate LTE during OGE with a student about 3 months back and the helo had completed a 180 by the time I'd managed to lower the collective and get forward cyclic in.
Kris
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It took place in Ecuador . . .
On the 206 L4 you will hit the left pedal stop with about 85% torque when you are heavy and at altitude, I know because I flew L3 and L4 models at DA 8000+ feet during years, actually I still do at least ones every 15 days.
The 206L4 and to a lesser but still considerable degree the L3, has a small rotor that doesn't produce enough thrust to counter MR torque at higher altitudes with high power settings, (I think it's just certified to 17 knots of crosswind) as I said before, in calm wind with a DA of about 8 or 9 thousand feet YOU WILL hit the pedal stop with about 80% torque applied, now if you decide to apply even the slightest amount of power beyond that, or any sort of tail or wind from the left comes, you will spin.
If you dare take off too heavy at altitude on the L4, once those skids are airborne and you start spinning, you either try to depart with usually fatal results, or you come back to the ground spinning, which in some terrains can mean disaster.
Thus the High Altitude Tail Rotor Kit.
Some people call this LTE, but it's no mysterious phenomenon, it's just an underpowered tail rotor, poor design.
Nick Lappos used to point this all the time, but as he now works for Bell H, I doubt he's able to do so now, I probably wouldn't if I were in his place.
This is another video of a 206L3 suffering from the same poor design at altitude, on this one I am flying the other 206L3 that you can see on the video . . .
206L LTE.
On the 206 L4 you will hit the left pedal stop with about 85% torque when you are heavy and at altitude, I know because I flew L3 and L4 models at DA 8000+ feet during years, actually I still do at least ones every 15 days.
The 206L4 and to a lesser but still considerable degree the L3, has a small rotor that doesn't produce enough thrust to counter MR torque at higher altitudes with high power settings, (I think it's just certified to 17 knots of crosswind) as I said before, in calm wind with a DA of about 8 or 9 thousand feet YOU WILL hit the pedal stop with about 80% torque applied, now if you decide to apply even the slightest amount of power beyond that, or any sort of tail or wind from the left comes, you will spin.
If you dare take off too heavy at altitude on the L4, once those skids are airborne and you start spinning, you either try to depart with usually fatal results, or you come back to the ground spinning, which in some terrains can mean disaster.
Thus the High Altitude Tail Rotor Kit.
Some people call this LTE, but it's no mysterious phenomenon, it's just an underpowered tail rotor, poor design.
Nick Lappos used to point this all the time, but as he now works for Bell H, I doubt he's able to do so now, I probably wouldn't if I were in his place.
This is another video of a 206L3 suffering from the same poor design at altitude, on this one I am flying the other 206L3 that you can see on the video . . .
206L LTE.
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BlenderPilot, it must have been a shock to see the other L3 go into LTE.
RVDT, I think there is a distinction between getting into LTE and getting out of LTE. Pilots get themselves into LTE by making mistakes but recognising LTE and taking timely corrective action is the real test. My discussion is limited to the remedial action after LTE has begun to set in.
I have experienced full LTE too and, speaking to senior instructors and other high-time pilots who have suffered LTE, an interesting fact emerges. No matter whether the spin set in slowly to start off with (like the Ecuador video) or happened suddenly and quickly, the only practical way to survive is to roll off throttle and (height permitting) reduce collective. I have yet to meet someone who managed to pull it off by flying away with cyclic and pedals.
RVDT, I think there is a distinction between getting into LTE and getting out of LTE. Pilots get themselves into LTE by making mistakes but recognising LTE and taking timely corrective action is the real test. My discussion is limited to the remedial action after LTE has begun to set in.
I have experienced full LTE too and, speaking to senior instructors and other high-time pilots who have suffered LTE, an interesting fact emerges. No matter whether the spin set in slowly to start off with (like the Ecuador video) or happened suddenly and quickly, the only practical way to survive is to roll off throttle and (height permitting) reduce collective. I have yet to meet someone who managed to pull it off by flying away with cyclic and pedals.
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A totally heart stopping moment for any pilot, resulting in a sharp intake of breath no doubt regardless of their hours.
If I understand what has been written correctly then possibly the sensible thing to do is reduce torque by lowering collective? (if you have the height) thereby having more power available to the TR for it to have better effectiveness increasing thrust. Reducing torque also has the benefit of reducing the spin .... even slightly?
Stage 2 after you recognise what is happening and gather your thoughts for a moment is to Cyclic forward to gain airspeed (subject to height) and transition forward picking up speed to get the airflow over the fin thereby keeping you straight negating the need for pedal so much?
Would love to know how this logic stacks up?
Thanks KDDDD
If I understand what has been written correctly then possibly the sensible thing to do is reduce torque by lowering collective? (if you have the height) thereby having more power available to the TR for it to have better effectiveness increasing thrust. Reducing torque also has the benefit of reducing the spin .... even slightly?
Stage 2 after you recognise what is happening and gather your thoughts for a moment is to Cyclic forward to gain airspeed (subject to height) and transition forward picking up speed to get the airflow over the fin thereby keeping you straight negating the need for pedal so much?
Would love to know how this logic stacks up?
Thanks KDDDD
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KDDDD,
Dont think of it as a lack of power to the tail rotor, think of it as the torque of the main blades overpowering the tail rotor, so you lower collective to take away the torque from the mains, not allow more power to the tail, its is all about reducing the torque of the main blades if you are on the left pedal stop.
Dont think of it as a lack of power to the tail rotor, think of it as the torque of the main blades overpowering the tail rotor, so you lower collective to take away the torque from the mains, not allow more power to the tail, its is all about reducing the torque of the main blades if you are on the left pedal stop.
Hi Guys,
I know I am going to waste a valuable posting space - but I cannot help meself!!
THIS IS NOT AN LTE ACCIDENT. IT HAS NOTHING TO DO WITH LTE. THE PILOT DID NOT SUFFER LTE.
Please do a search on the 100s of thousands (ok, a little exaggeration here) of posts about this distinction. He ran out of left pedal - no question about it - but HE DID NOT SUFFER LTE.
It is important that we do not label it so incorrectly. By doing so we are merely perpetuating a myth that there was nothing that could be done. We are ensuring that less experienced pilots will grow up with a false understanding of what is actually happening - and thus false actions on the recovery required.
Still think that is not true, or maybe that I am confused? I cannot get the audio to work, and I am not very experienced in the 206L, but.......I think hoverbover is on the mark.
I know I am fighting a losing battle, but humour me....
I know I am going to waste a valuable posting space - but I cannot help meself!!
THIS IS NOT AN LTE ACCIDENT. IT HAS NOTHING TO DO WITH LTE. THE PILOT DID NOT SUFFER LTE.
Please do a search on the 100s of thousands (ok, a little exaggeration here) of posts about this distinction. He ran out of left pedal - no question about it - but HE DID NOT SUFFER LTE.
It is important that we do not label it so incorrectly. By doing so we are merely perpetuating a myth that there was nothing that could be done. We are ensuring that less experienced pilots will grow up with a false understanding of what is actually happening - and thus false actions on the recovery required.
Still think that is not true, or maybe that I am confused? I cannot get the audio to work, and I am not very experienced in the 206L, but.......I think hoverbover is on the mark.
I know I am fighting a losing battle, but humour me....
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If he has enough power to climb up and away like that then to me it just looks like the T/R is not up to the job. We are always flying to one limit or another and on this occsion it was the T/R limit of thrust and it's ability to hold the nose straight. As others have said if you pull any more power beyond that it is going to end in tears.
Is LTE just a myth put about as an excuse for a poor T/R covered by a whacking great big fin?
Is LTE just a myth put about as an excuse for a poor T/R covered by a whacking great big fin?
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KDDDD
Yes - the main thing is to reduce collective to reduce the torque that is causing the helicopter to spin.
Once the spin is under control I would personally get airspeed asap for several reasons:
1. The rotor system experiences translational lift so you won't lose (what is probably now low) altitude as quickly.
2. Forward airspeed reduces t/r power requirement due to weathervaning.
3. You could get into settling with power if you've lowered collective a lot and are descending vertically fast.
4. As a last resort it gives you another form of energy you can use to flare and reduce ROD, instead of a vertical hard impact like this poor guy.
5. I feel less personally jumpy with 20kts+ of forward airspeed, mainly for the reasons outlined above!
Kris
Yes - the main thing is to reduce collective to reduce the torque that is causing the helicopter to spin.
Once the spin is under control I would personally get airspeed asap for several reasons:
1. The rotor system experiences translational lift so you won't lose (what is probably now low) altitude as quickly.
2. Forward airspeed reduces t/r power requirement due to weathervaning.
3. You could get into settling with power if you've lowered collective a lot and are descending vertically fast.
4. As a last resort it gives you another form of energy you can use to flare and reduce ROD, instead of a vertical hard impact like this poor guy.
5. I feel less personally jumpy with 20kts+ of forward airspeed, mainly for the reasons outlined above!
Kris
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LTE is simply a term used to describe the condition of flight that occurs when one applies more torque to the main rotor than the tail rotor is capable of counteracting. I have personally had LTE in two types or AC, the B206 and R44.It isn't some mysterious condition that occurs out of the blue and if its recognized early enough and with sufficient altitude it is easily overcome. But it is just another term same as vortex ring, and you don't hear anybody arguing about what that's called.
In the video the guy lifted off and started yawing to the right pretty much right away(my guess is he had the left pedal to the stop), As he gained a little altitude( and pulled more power)( left pedal still to the stop) the yaw rate increased, Then at one point the AC seemed to transition to a very slow forward flight and stop yawing for a short time. The AC then seemed to pitch up loose apparent airspeed and then start yawing again (spinning now) losing RRPM ( by the sound of it) until it hit the water. A rough ratio for modern helicopter Main to tail rotor RPM ratio would be 7:1, so as the main rotor lost RPM the tail rotor lost 7 times as much, and became that much more inefficient, causing the increasing rate of yaw and the sh!ty ending.
From my experience and my opinion, the corrective action cold have only been reduce collective(reducing Tq) and regain RRPM and even beep it up if possible and get some airspeed. Of course this is all assuming that there was no mechanical failure.
just my opinion
In the video the guy lifted off and started yawing to the right pretty much right away(my guess is he had the left pedal to the stop), As he gained a little altitude( and pulled more power)( left pedal still to the stop) the yaw rate increased, Then at one point the AC seemed to transition to a very slow forward flight and stop yawing for a short time. The AC then seemed to pitch up loose apparent airspeed and then start yawing again (spinning now) losing RRPM ( by the sound of it) until it hit the water. A rough ratio for modern helicopter Main to tail rotor RPM ratio would be 7:1, so as the main rotor lost RPM the tail rotor lost 7 times as much, and became that much more inefficient, causing the increasing rate of yaw and the sh!ty ending.
From my experience and my opinion, the corrective action cold have only been reduce collective(reducing Tq) and regain RRPM and even beep it up if possible and get some airspeed. Of course this is all assuming that there was no mechanical failure.
just my opinion
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Kflexer said . . .
"LTE is simply a term used to describe the condition of flight that occurs when one applies more torque to the main rotor than the tail rotor is capable of counteracting."
I would add LTE is a term created by Bell, to justify and blame the effects of underpowered tail rotors on some of their helicopters, and make it seem like the tail rotor is affected by mysterious phenomena that makes it be magically uneffective under certain conditions.
"LTE is simply a term used to describe the condition of flight that occurs when one applies more torque to the main rotor than the tail rotor is capable of counteracting."
I would add LTE is a term created by Bell, to justify and blame the effects of underpowered tail rotors on some of their helicopters, and make it seem like the tail rotor is affected by mysterious phenomena that makes it be magically uneffective under certain conditions.
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As I understand it, LTE is simply vortex ring of the tail. Hence the control problems with a crosswind from the left in an American helicopter. Is this incorrect?
To me, the take off looked achievable, if only the pilot had kept the nose forward. The fin seemed to be coping without the need to reduce collective.
To me, the take off looked achievable, if only the pilot had kept the nose forward. The fin seemed to be coping without the need to reduce collective.
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BHenderson,
I was taught that LTE comes in four different flavours:
1. Main Rotor disc interference (wind from 10-11 'o' clock; that happens here as he transitions with the nose cranked over to the right)
2. Tail rotor VRS (wind from 9 'o' clock)
3. Weathervane stability (wind from the 6 'o' clock)
4. LTE at altitude (tail rotor is affected by DA in a big way, another contributing factor to this)
Note that the above is for a US helicopter, for French helos it's wind from 1-2 'o' clock for M/R disc and wind from 3 'o' clock for T/R VRS.
Cheers
Kris
I was taught that LTE comes in four different flavours:
1. Main Rotor disc interference (wind from 10-11 'o' clock; that happens here as he transitions with the nose cranked over to the right)
2. Tail rotor VRS (wind from 9 'o' clock)
3. Weathervane stability (wind from the 6 'o' clock)
4. LTE at altitude (tail rotor is affected by DA in a big way, another contributing factor to this)
Note that the above is for a US helicopter, for French helos it's wind from 1-2 'o' clock for M/R disc and wind from 3 'o' clock for T/R VRS.
Cheers
Kris