Bell 429 crash in China

[HeliHenri]

Today in China, minor injuries :

pic.twitter.com/j3sw5mErMo (https://t.co/j3sw5mErMo)
.

[gulliBell]

My operative in China reported 3 fatal + 1 minor injury (young female pilot). Perhaps reportee was mistaken because the post accident cabin looked survivable.

The aftermath here:
http://www.news.com.au/video/id-5348771529001-5815582003001/Pilot-'steered-helicopter-from-crowds'-before-Beijing-crash

For my money, there wasn't a whole lot of pilot steering going on there.

[500e]

Witnesses said the helicopter spun around a number of times before plummeting nose-first to the ground at about 11am, does not look nose first to me
From VR news today
https://www.scmp.com/news/china/society/article/2157470/helicopter-crashes-nose-first-beijing-car-park-no-casualties?utm_source=vertical-daily-news-news-from-the-web&utm_campaign=vertical-daily-news&utm_medium=email&utm_term=news-from-the-web&utm_content=V1 (https://www.scmp.com/news/china/society/article/2157470/helicopter-crashes-nose-first-beijing-car-park-no-casualties?utm_source=vertical-daily-news-news-from-the-web&utm_campaign=vertical-daily-news&utm_medium=email&utm_term=news-from-the-web&utm_content=V1)

[Flying Bull]

My operative in China reported 3 fatal + 1 minor injury (young female pilot). Perhaps reportee was mistaken because the post accident cabin looked survivable.

The aftermath here:
http://www.news.com.au/video/id-5348771529001-5815582003001/Pilot-'steered-helicopter-from-crowds'-before-Beijing-crash

For my money, there wasn't a whole lot of pilot steering going on there.

Well, was my first thought as well, should have used the short period straight to recover for a planed emergency landing.
But on the second thought, being tossed into the harness during the first rotations, how much coolness is left to try to continue flying? May be seeing the carpark and aiming for it was all what she was able to do at that moment.

Will be an interesting accident report....

[SASless]

....on the second thought, being tossed into the harness during the first rotations, how much coolness is left to try to continue flying?

Education, Training, Experience....and Mindset determine that!

Having learned and understanding what you have been taught, doing the same during your training and embracing what you were shown and practiced, and having the attitude of never giving up.....(assuming all of the teaching and instructing was adequate and proper of course) then the flying would continue until well into the crash.

[Flying Bull]

Education, Training, Experience....and Mindset determine that!

Having learned and understanding what you have been taught, doing the same during your training and embracing what you were shown and practiced, and having the attitude of never giving up.....(assuming all of the teaching and instructing was adequate and proper of course) then the flying would continue until well into the crash.

Hi SASless,
I wrote, „was all she was able to...“
Donˋt know, how much Sim-training she had, or „fly away“ training?!
Lowering the collective and pushing the nose down to gain speed is something you have to have trained to have the experience, that you can fly away, if you have enough height an react fast enough.
It was quite a thrill with the instructor „just kicking the pedal to the floor“, simulating the failure.
But it worked out 😉

[Tiger G]

Didn't see this one posted on here, but if it's an oldie, I'll delete ??

https://www.liveleak.com/view?t=9oH3c_1532974694

[gulliBell]

Does anybody here think that China 429 crash had anything to do with a TR drive failure?

[SARWannabe]

Does anybody here think that China 429 crash had anything to do with a TR drive failure?

It didn’t look like a drive failure to me - she seemed to get it momentarily under control with power applied and low airspeed, for say 2 seconds until it started yawing again...

[Flying Bull]

The Liveleak Video shows a little more, as soon as she reduced speed and started to turn, the turnrate increased.
Dropping out with a little forward speed the bird seems to stabilse,
Then, with reduced airspeed, the turning starts again.
Possible LTE? No idea about the weight/winddirection/DA conditions.

[SASless]

First thought upon seeing the Live Leak video was the same....with what looks like a second onset as the aircraft begins to come to a hover after the initial recovery.

The Investigation will determine if there was a mechanical failure and if none....then perhaps.

[Keepitup]

Maybe not a TRDS failure, but with everything that's recently come out, what about TRGB fitting failure ?

[Fareastdriver]

My operative in China reported 3 fatal + 1 minor injury (young female pilot).

Xinhua showing only four injured.

4 injured as civilian helicopter crash-lands in Beijing - Xinhua | English.news.cn (http://www.xinhuanet.com/english/2018-07/30/c_137357530.htm)

[Ascend Charlie]

Possible LTE? No idea about the weight/winddirection/DA conditions.

LTE only applies to the older B206 with the small tail rotor, and if it REALLY existed, the bird would emerge from "LTE" after maybe 90 -180 degrees of turn, when the relative winds have changed.

Bell spin from the early 70s, but still propagated today - how sad. Gurgle up Nick Lappos with his post about helicopter urban myths.

[SASless]

Note what the nice Lady has to say early on in the video.

https://www.youtube.com/watch?v=TYmtRbn2vw4

[tartare]

That is a quietly chilling video.

[Ascend Charlie]

Sassy,
The lady repeated the mantra "ALL single-rotor helicopters are susceptible to LTE" - doesn't mean it's true. Check what Nick says.

The video then goes on to describe how the pilot stuffed up an approach, coming in downwind, 100% torque, pedal on the stops, RPM drooping, and he calls it "UNANTICIPATED YAW"??!!

What kind of idiot would NOT anticipate yaw in that situation. This video is plain and simple, loss of pilot awareness, running out of pedal. But call it LTE and suddenly it is not your fault. (Cue the mantra)

If LTE existed, it would be a snap yaw while the pedals are nowhere near the stops.

[Delta Torque]

Easy to be an armchair expert, but I believe I'd have aborted the approach very much earlier, At 100% tq, and no reserve, AND starting to fall through. You know that it's only going to get worse.

[Bell_ringer]

What kind of idiot would NOT anticipate yaw in that situation. This video is plain and simple, loss of pilot awareness, running out of pedal. But call it LTE and suddenly it is not your fault. (Cue the mantra)

If LTE existed, it would be a snap yaw while the pedals are nowhere near the stops.

LTE and Vortex Ring are not well understood, primarily as they are badly taught.
Where you see an aircraft losing the battle with gravity or the tail overtaking the pilot it is immediately blamed on Vortex or LTE, as if the poor person up front was a passenger to the events, when it is in most cases the aircraft being taken beyond it's limits through flawed technique.

[Flying Bull]

LTE only applies to the older B206 with the small tail rotor, and if it REALLY existed, the bird would emerge from "LTE" after maybe 90 -180 degrees of turn, when the relative winds have changed.

Bell spin from the early 70s, but still propagated today - how sad. Gurgle up Nick Lappos with his post about helicopter urban myths.

its not just old Bell helicopters.
It can happen with bigger newer machines as well, if you are to slow to push the pedal, don‘t push it fast enough far enough and have a high AUM with high DA.
Even Eurocopter has an handout about undemanded yaw, stating, what „mishandling“ leads to - and what you have to do then.
Don‘t make this an discussion about LTE
Analyzing the video you can see reducing the airspeed led to turns, dropping out with a little speed seemed to cure the problem until speed was bleed of again.
For a complete tailor failure the „cure speed“ is way to slow so other causes contributed to this accident.
When I have a little spare time I might look up Nicks Myth, a link would be nice.
But I also have videos in mind, which I have lo look up, where pilots went to close to the performance limits and ****** up, if you call it LTE or not, they were just spinning to the crash...

[[email protected]]

Agree with AC and DT - just a poor piece of piloting and decision making. Who could have envisaged performance problems on a mountain site at just below MAUM? And in an aircraft known to have TR performance issues! I can't believe he didn't throw the approach away far sooner but at least he is still around to tell the tale - more by luck then judgement!

Back to the 429 accident - looks like a TR control issue - stuck pedal type scenario - since the yaw is affected markedly by airspeed. Could be a physical restriction in the yaw controls or a thrust bearing or a TRGB mounting problem.

[Flying Bull]

Let’s use another wording, instead of
LTE - loss of tailrotor effectiveness
let us use
RTRA - reduced tailrotor authority 😉
reduced can be anything from a little to nothing left 😉
Hmm, or we have to come up with another wording, cause the problem can also arouse with NOTAR
Notar. crash
added weight resulted in not enough authority left....
similarities, altitude, weight....

[Ascend Charlie]

"Reduced Tail Rotor Authority" or just simply "Running out of tail rotor"?

Don't confuse a poor technique with some real or imaginary series of unavoidable events. Perhaps I am just lucky, having flown for 45 years and 15000 hrs, of which over 8000 were in that pesky 206, and never ran out of pedal. Always was aware of where my feet were, the rate at which that left foot was moving forward, the position of the collective, the power available, if any, the relative winds, and always keeping an escape path to fly away. LTE is horsefeathers. An invention to cover a lack of tail rotor power from the design stage. Despite what some FAA publication says, it is horsefeathers. Remember that those same publications tell you that "gyroscopic effect" is real, that "flapping to equality" is happening in forward flight, and that there is a "ground cushion" of higher pressure under the rotor in the ground hover.

All designed to allow the most rockape of student to understand his rockape instructor who only has 100 hours more than he does, and to grasp some basic concepts.

[SASless]

LTE is horsefeathers. An invention to cover a lack of tail rotor power from the design stage.

Now that did not take long.....clearly and accurately stated!

Sometimes pprune fishing can take a while...sometimes not so long!

As is being said.....be very careful when saying "LTE" as it might be caused by something other than the other and thus it is not "LTE" per se.

Brother Lappos was very clear in his discussion of the issue.


Here is an archived exchange including Brother Lappos.


Please note he does include "all" single rotor helicopters.

https://yarchive.net/air/loss_of_tail_effectiveness.html


On a less serious note....


http://www.chickenwingscomics.com/comics/2014-11-21-cw0758.jpg

[gulliBell]

..The Investigation will determine if there was a mechanical failure and if none....then perhaps.

Yeah, right. It is China. Loss of face. They will find any excuse to pin it on somebody other than the person sitting in the pilot seat.

[Flying Bull]

Txs for the link.
interesting reading.
With no experience on the 429, just looking through the numbers of tailrotor diameter and all up mass, is it comparable with the 206 in tailrotor authority? (more than double the mass of a 206 with nearly the same diameter, but 4 instead of 2 tailtotorblades.)

[SASless]

Part of what Nick has to say about the issue has to do with Certification Requirements...and Demonstrated Cross Wind capability.

That in turn determines the parameters that must be met when operating the aircraft.

Unless the Tail Rotor has a surplus of thrust in excess of that required to meet the Certification Requirements then Tail Rotor Control issues might arise if the aircraft encounters situations beyond the envelope the Certification approved.

[gulliBell]

I didn't following the Nick Lappos reasoning. My way of thinking, if you need to baby the helicopter because the tail rotor margin is what it is, well, baby it. And if you don't baby it and you get stung because of it, well, to me, blame that on the pilot. Don't blame it on the design, and don't solve the problem by using a helicopter with better design (unless of course it's practicable to do that). You just have to use the tools you are given, in such a way as to remain within the safety margin. Using as much baby as you need to.

[SASless]

What part of poorly constructed Certification Criteria do you not understand?

Should we continue to live with plastic fuel tanks knowing they are not crashworthy and incur needless death and maiming as a result.....or do we as we learn....improve the Certification Criteria (using a much simpler but analogous example for you)?

[[email protected]]

Gullibell - if you fly your helicopter outside its certification limits or RFM and you get LTE, you can blame the pilot - if you fly it within the RFM and certification and get LTE, you can blame the aircraft.

[Flying Bull]

@gullibell,
accidents happen, cause there is a chain of events, failures.
If you need to nurse a helicopter cause it was designed so, every unexpected gust can lead to desaster, cause you’re already operating at the edge of its envelope.
With a proper safety margin from design, even a unintended excursion outside the envelope would only scratch your pride but won‘t take your live.
and I can tell you, once you‘ve operated a powerful machine and have felt the advantages, you won‘t like to go back to a bird you have to nurse to get things done!

[Fareastdriver]

Yeah, right. It is China. Loss of face. They will find any excuse to pin it on somebody other than the person sitting in the pilot seat.

We have no evidence that this was NOT a control failure problem. In my experience Chinese pilots are taught to fly by numbers and they will fly to those numbers regardless. Should they be taught that they have to have a certain airspeed to carry out a manoeuvre they will have it.

The problem comes when something happens that is not in the script.

All in all the fact that she and the passengers survived should be applauded.

[Bell_ringer]

Gullibell - if you fly your helicopter outside its certification limits or RFM and you get LTE, you can blame the pilot - if you fly it within the RFM and certification and get LTE, you can blame the aircraft.

Didn't airbus (or whatever they were called back then) blame the loss of some gazelles (operated within the RFM and certification) on pilot error, ie poor technique. Insufficient pedal, too late and so on and so forth?
You can't always blame the aircraft, even within its limits.
It is fair to say that perhaps some aircraft are more crashable than others, but when there is a warning on the tin should you blame the designers? (Robinson's being the exception to the rule) :E

[[email protected]]

Bellringer - we had a few incidents that were put down to Fenestron Stall - a condition that didn't exist and Aerospatiale proved it. Not a design issue, just a lack of awareness about the handling characteristics of a Fenestron equipped aircraft.

I should have qualified my earlier comment with 'as long as you don't fly it like a drongo;:)

[Jimmy.]

Txs for the link.
interesting reading.
With no experience on the 429, just looking through the numbers of tailrotor diameter and all up mass, is it comparable with the 206 in tailrotor authority? (more than double the mass of a 206 with nearly the same diameter, but 4 instead of 2 tailtotorblades.)

Maybe you should look through the numbers of blade chord, profile and tail rotor NR as well.

[gulliBell]

..If you need to nurse a helicopter cause it was designed so, every unexpected gust can lead to desaster, cause you’re already operating at the edge of its envelope...


If I'm doing high altitude heavy sling loads to mountain tops in a 206 (or 212, or whatever helicopter), I nurse it in sensible ways so the unexpected does not lead to disasters. And it's real simple, slow down to a speed that maintains stable load in flight, keep it pointed outside the critical wind azimuth on arrival, keep the NR at 100, keep the sink rate near zero, keep the apparent closure rate until you have arrived where you need to put it. And if you can break the loads up into lighter sorties, do it. We all know these things. Short of the donk stopping at the perfectly wrong time, which would be a disaster, nursing a helicopter so it can safely complete a task is just basic operational airmanship.

[Flying Bull]

If I'm doing high altitude heavy sling loads to mountain tops in a 206 (or 212, or whatever helicopter), I nurse it in sensible ways so the unexpected does not lead to disasters. And it's real simple, slow down to a speed that maintains stable load in flight, keep it pointed outside the critical wind azimuth on arrival, keep the NR at 100, keep the sink rate near zero, keep the apparent closure rate until you have arrived where you need to put it. And if you can break the loads up into lighter sorties, do it. We all know these things. Short of the donk stopping at the perfectly wrong time, which would be a disaster, nursing a helicopter so it can safely complete a task is just basic operational airmanship.

GulliBell,
you don’t catch the point.
Sure you can baby a helicopter, like most of us do or have done.
Itˋs the question of reserves available, when the last chainlink tries to spoil your day.
May be the lack of scan, cause a flu is on its way and you missed the creeping in decendrate, the f... big bird which surprises you and you instinctively try to avoid, the gust you haven’t anticipated or the fool, who hasn’t seen you and flies over you giving you just an extra bit of downwash to play with.
Thatˋs when reserves, pulling power AND having tailrotor authority, comes in handy.
As long as you stay lucky through your career, everything seems ok. It´s interesting, when luck isˋt with you all the time.