Down on The Hudson

Loss of Tailrotor Effectiveness


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luvflyin said:
LTE ???
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Loss of tail rotor effectiveness. You can hear the wind whipping in those vids. All it took was the pilot to get slow, increase that collective (high torque), dirty air or vortex ring going through the tail rotor and with all that torque, it’s gonna spin. Classic case of LTE.

If you notice, once he got the collective down and increased his descent, the nose starting to slow it’s rotation. Just not enough altitude for a recovery.

I don’t know what it is with the Hudson and helicopters. She just seems to gobble them up.
 
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Velocity173 said:
Loss of tail rotor effectiveness. You can hear the wind whipping in those vids. All it took was the pilot to get slow, increase that collective (high torque), dirty air or vortex ring going through the tail rotor and with all that torque, it’s gonna spin. Classic case of LTE.

If you notice, once he got the collective down and increased his descent, the nose starting to slow it’s rotation. Just not enough altitude for a recovery.

I don’t know what it is with the Hudson and helicopters. She just seems to gobble them up.
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Thinking there has to be a loss of power, also. Just one soul on board shouldn't tax the aircraft too much - should have enough out of ground effect (OGE) power. Look at the blades coning before impact.

edit: watched again -- tail rotor malfunction?
 
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Piperonca said:
Thinking there has to be a loss of power, also. Just one soul on board shouldn't tax the aircraft too much - should have enough out of ground effect (OGE) power. Look at the blades coning before impact.
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I don’t know. Initially he seemed to be climbing while spinning and the engine sounds OK. Could very well be a tail rotor failure but judging by the vid, it looks like it’s still spinning fine.
 
The way the aircraft starts spinning makes me think TR failure, then he chops the throttle to get it under control. That's when things get really sporty. Firing the floats was the cherry on top.

Even if the TR wasn't driven any more, it would continue to spin for a while. If you notice the sync with video, the TR is changing rpm on the way down.
 
Velocity173 said:
Loss of tail rotor effectiveness. You can hear the wind whipping in those vids. All it took was the pilot to get slow, increase that collective (high torque), dirty air or vortex ring going through the tail rotor and with all that torque, it’s gonna spin. Classic case of LTE.

If you notice, once he got the collective down and increased his descent, the nose starting to slow it’s rotation. Just not enough altitude for a recovery.

I don’t know what it is with the Hudson and helicopters. She just seems to gobble them up.
Click to expand...
VRS sort of like this?

 
RyanShort1 said:
VRS sort of like this?

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Yeah, only it’s happening with the tail rotor. Strong wind from the left overcomes the normal thrusting state of the tail rotor. The air gets recirculated through the tail rotor causing a vortex to form in the middle, thereby reducing the amount of thrust (effectiveness) of the tail rotor. Once the right rotation developes past 90 degrees, the strong wind from that side (weather cock region) can exacerbate the problem and continue to assist in spinning the aircraft. If not reacted to quickly at the first sign of LTE, it can become uncontrollable if there’s not enough altitude to recover.

Kind of like settling with power or VRS, you need a fair amount of altitude to recover. That Vuichard recovery is a new thing. Maybe in the last 5 years or so they came up with that. The common practice that was taught used to be a nose over. Now, they’ve determined that a slide out of it is the most effective way of getting out of VRS with the least loss of altitude.
 
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Velocity173 said:
Yeah, only it’s happening with the tail rotor rotor. Strong wind from the left overcomes the normal thrusting state of the tail rotor. The air gets recirculated through the tail rotor causing a vortex to form in the middle, thereby reducing the amount of thrust (effectiveness) of the tail rotor. Once the right rotation developes past 90 degrees, the strong wind from that side (weather cock region) can exacerbate the problem and continue to assist in spinning the aircraft. If not reacted to quickly at the first sign of LTE, it can become uncontrollable if there’s not enough altitude to recover.

Kind of like settling with power or VRS, you need a fair amount of altitude to recover. That Vuichard recovery is a new thing. Maybe in the last 5 years or so they came up with that. The common practice that was taught used to be a nose over. Now, they’ve determined that a slide out of it is the most effective way of getting out of VRS with the least loss of altitude.
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Yeah, we had a big safety seminar deal on helicopter stuff at one of the aerial photography conferences because of the tendency for newer helicopter pilots to try too hard to please a photographer and sit in a spot to get the perfect shot...
 
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