US Army Huey Tail Rotor Failures
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SAS
If I had a friend that crashed 13 times I would be in awe at his ability to survive ...... but I would not be too enthusiastic about going for a ride with him.
I agree with your assessment of the laws of probability but you can stack the odds against you if you explore the limits of the envelope (and sometimes beyond) on a regular basis.
FDR/HUMS has an excellent record when it comes to recording exceedances but it is, and will continue to be the case that identifying the vibration signature of an impending failure for the first time against a myriad of background vibrations is very very challenging.
I could not agree more that pilots should get to know how to handle their machine but as long as we have a plethora of accidents caused by poor handling and poor judgement I will be troubled by the continued reliance of the industry on instructors who originate from the CFI/CFII system that permits newbies to gain flight hours teaching the next generation. But that's another thread creep too far and may need a new thread to take the subject on.
G.
I agree with your assessment of the laws of probability but you can stack the odds against you if you explore the limits of the envelope (and sometimes beyond) on a regular basis.
FDR/HUMS has an excellent record when it comes to recording exceedances but it is, and will continue to be the case that identifying the vibration signature of an impending failure for the first time against a myriad of background vibrations is very very challenging.
I could not agree more that pilots should get to know how to handle their machine but as long as we have a plethora of accidents caused by poor handling and poor judgement I will be troubled by the continued reliance of the industry on instructors who originate from the CFI/CFII system that permits newbies to gain flight hours teaching the next generation. But that's another thread creep too far and may need a new thread to take the subject on.
G.
The military crashes resulted from various forms of FOD....mostly 7.62mm sizeds chunks of fast moving lead....less one occasion where it was half inch sized pellets. The civvie end was a tail rotor failure when a Sea Gull committed Hari-Kari in the small fan....and the othere was an engine failure following that lovely engine named after a Female choked itself on some compressor blades. Amazingly enough the two civvie landings were minor damage only as in his words...".there was someplace to go and it was all getting to be old hat by then."!
Practice must make perfect I guess. Oddly enough he has never hit the Lottery!
Practice must make perfect I guess. Oddly enough he has never hit the Lottery!
Little Difference Between Models
Over the years I was provided with the opportunity to teach and evaluate varying levels of pilots from initial qualifiers to test pilot trainees in the U/TH-1E and L series (Bell 204) UH-1D/H Bell 205 and the AH-1G/J/S and T. The profiles were all very similar with little change between models. At Whiting Field in Milton, FL (Boo Weekley’s home town) our Squadron Flew approximately 50,000 flight hours per year. It may sound like a lot but we had more than 100 machines with approximately 60 flying each day. We wrecked 1 machine each year doing tail rotor malfunction training. I don’t believe that the unit ever had an actual tail rotor malfunction emergency.
We utilized a procedure very similar to that trained by our brethren at Ft. Rucker. We flew a flat power on approach to a long smooth landing area. As the aircraft decelerated we would keep close track of the yaw angle with respect to our ground track. Typically, the nose would be cocked out to the left. If it stayed left we would continue to slow the aircraft until the nose began to move to the right or we came to a hover. In the case of stuck pedal high power situation we may elect to land with the nose turning to the left. If the yaw rate was considered too excessive we had the option of beeping the governed RPM down to the lowest achievable speed. This would increase the torque required while simultaneously reducing tail rotor thrust. If the nose began to move right of our track we would reduce the twist grip to check the yaw rate and land. Once the twist grip was moved we were committed to land.
We utilized a procedure very similar to that trained by our brethren at Ft. Rucker. We flew a flat power on approach to a long smooth landing area. As the aircraft decelerated we would keep close track of the yaw angle with respect to our ground track. Typically, the nose would be cocked out to the left. If it stayed left we would continue to slow the aircraft until the nose began to move to the right or we came to a hover. In the case of stuck pedal high power situation we may elect to land with the nose turning to the left. If the yaw rate was considered too excessive we had the option of beeping the governed RPM down to the lowest achievable speed. This would increase the torque required while simultaneously reducing tail rotor thrust. If the nose began to move right of our track we would reduce the twist grip to check the yaw rate and land. Once the twist grip was moved we were committed to land.
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T/R problems
Yes Geoffers ... right on, as two of the three failures occurred during a max power manoeuvre with firm left pedal on ... (Enstrom) although the type's slack T/R cable rigging and oil-softened T/R blade flapping stops enhanced the situation allowing the upgoing blade to intercept the left hand control cable. Following the Cranfield incident, the Menominee factory re-positioned the control cable outlet position further inboard to increase clearance twixt cable and the upgoing blade. I now only display the type with cable rigging re-tensioned to maximum MM limits AND with replacement flapping stops fitted when required. The 3rd Biggin Hill occurrence was due to this not being done. Positively my fault.
Crosswind situation ... I completed the BH landing with a 3 0'clock breeze and a touch down on the right skid which helped maintain landing direction til around 40 knots when left yaw took over and the A/C finishing some 150 degrees left. And just to emphasise as Geoffers points out, my notes are only applicable to the light piston types with T/R cable control and a sizeable keel surface. Dennis Kenyon.
Crosswind situation ... I completed the BH landing with a 3 0'clock breeze and a touch down on the right skid which helped maintain landing direction til around 40 knots when left yaw took over and the A/C finishing some 150 degrees left. And just to emphasise as Geoffers points out, my notes are only applicable to the light piston types with T/R cable control and a sizeable keel surface. Dennis Kenyon.
Where's 35 Year Pilot?
You started out asking about tail rotor failure practice by military operators, got good replies from respected people and disappeared. A bit of explanation wouldn't go astray.
You started out asking about tail rotor failure practice by military operators, got good replies from respected people and disappeared. A bit of explanation wouldn't go astray.
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Explanation
I am sorry to respond so late. Thank you everyone for the replies - they are truely inspiring accounts.
My enquiry was to see if the USA Huey pilots trained to the ground stopped because a friend of mine had a tail rotor failure (in the cruise) in the Sinai Desert (El Gorah) and had a lot of US observers on board. The observers believed that their US pilots never trained the recovery to the ground and so they (observers) expected to die when the chopper was slowed on approach.
It turned out the Australian pilot was well versed in the technique and pulled off a great landing. The US observers bought beers at the bar for a month!
Your answers have cleared up this story. It was the observers who were mistaken about their US bretheren's skills.
Thank you!
I am sorry to respond so late. Thank you everyone for the replies - they are truely inspiring accounts.
My enquiry was to see if the USA Huey pilots trained to the ground stopped because a friend of mine had a tail rotor failure (in the cruise) in the Sinai Desert (El Gorah) and had a lot of US observers on board. The observers believed that their US pilots never trained the recovery to the ground and so they (observers) expected to die when the chopper was slowed on approach.
It turned out the Australian pilot was well versed in the technique and pulled off a great landing. The US observers bought beers at the bar for a month!
Your answers have cleared up this story. It was the observers who were mistaken about their US bretheren's skills.
Thank you!
Nice well sourced question.....and full explanation of what you were really trying to achieve but failed to accomplish. Back under the bridge lad!
Jack Carson: Whiting Field, TH-1E and L, was where I earned my wings. (HT-18, CDR Tilt was CO ... always thought that was a great name for a helicopter squadron CO that flew a semi rigid rotor system ... )
Good training there, I recall the stuck pedals training as being one where the IP's were very, very careful. (I was there when a Huey had the tail boom fall off and all of the Huey's were grounded due to them finding corrosion in those magical four bolts on more than a few of the birds in the hangar. No Xs until new bolts could be had).
Good training there, I recall the stuck pedals training as being one where the IP's were very, very careful. (I was there when a Huey had the tail boom fall off and all of the Huey's were grounded due to them finding corrosion in those magical four bolts on more than a few of the birds in the hangar. No Xs until new bolts could be had).
Only Fond Memories
Lonewolf 50.
I was there from April, 1975 through October, 1978 and have nothing but fond memories of my tour. The TH-1Ls were relatively new at the time. The fleet was augmented with tired Marine UN-1Es and Army UH-1D/Hs. Stuck pedal training and full touchdown autorotations were the high light of the tour. To this day, I am always amazed when I run into one of my old students, even now, 30 plus years later
All the Best
Jack
I was there from April, 1975 through October, 1978 and have nothing but fond memories of my tour. The TH-1Ls were relatively new at the time. The fleet was augmented with tired Marine UN-1Es and Army UH-1D/Hs. Stuck pedal training and full touchdown autorotations were the high light of the tour. To this day, I am always amazed when I run into one of my old students, even now, 30 plus years later
All the Best
Jack
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UH-1 T/R Fail
I had a cargo door come off of a Huey in the Nam thing. Took off the tail rotor and gear box completely.
A battery in the nose and 5 Grunts on board. Put it down in a rice paddy without another scratch.
Believe me, THAT was to the ground...you bet!!
A battery in the nose and 5 Grunts on board. Put it down in a rice paddy without another scratch.
Believe me, THAT was to the ground...you bet!!
Care to give us a detailed account of that bit of fun? It would be interesting to hear all about it! Being a Chinook driver....we did not care to even think about Tail Rotor failures!
Although it must have been pretty eye-watering for you, it's good to know that losing the T/R and gearbox doesn't necessarily mean it's going to pitch down uncontrollably with the C of G change, as some people have said to me at times.
Were you airborne for much time after it happened, and did you have much rearward cyclic left? What did you do? Good on you for putting it down safely.
Were you airborne for much time after it happened, and did you have much rearward cyclic left? What did you do? Good on you for putting it down safely.
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Thank you!
What a fantastic discussion!
I have the fondest memories of my very modest military 2,000 hrs in Hueys and the highest respect for any rotary pilot who can survive a career in the machines with the stress of low flying, (limited) performance, wire strikes, gearbox chip lights, tail rotor failures, vortex rings, PIOs .. blah blah.
I am an ex military "jack of all trades - master of none" pilot (Caribous, Hueys, small jets) but had a recent fixed wing incident where some of the basic skills of chopper flying (flying at the limit - not beyond) and respecting the machine proved to be a great asset on the day.
I only did it for 2,000 hrs on the Huey - you guys did it for a career. I loved my time on choppers and think I am so much the better for it.
I have the utmost respect for you all. Thanks for the discussion.
Safe flying!
Rich
I have the fondest memories of my very modest military 2,000 hrs in Hueys and the highest respect for any rotary pilot who can survive a career in the machines with the stress of low flying, (limited) performance, wire strikes, gearbox chip lights, tail rotor failures, vortex rings, PIOs .. blah blah.
I am an ex military "jack of all trades - master of none" pilot (Caribous, Hueys, small jets) but had a recent fixed wing incident where some of the basic skills of chopper flying (flying at the limit - not beyond) and respecting the machine proved to be a great asset on the day.
I only did it for 2,000 hrs on the Huey - you guys did it for a career. I loved my time on choppers and think I am so much the better for it.
I have the utmost respect for you all. Thanks for the discussion.
Safe flying!
Rich
