Helicopter crash; Servo Control Transparency
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- เผยแพร่เมื่อ 5 ต.ค. 2024
- for explanation go to • Video . AS350 BA heli-skiing at Bear Creek Lodge gets into servo control transparency when pilot buzzes the lodge and then eases back on the cyclic, which loads up forces on the rotor disk. The aerodynamic forces on the blades now exceed the ability of the hydraulic servos to control them and servo control transparency occurs. We hear the intermittent beeping of the high rotor horn as the aircraft pitches right and into the mountain. No serious injuries. I'll explain further. SCT happens at high disk loading and high speed. VNE in an ASatr is 155 kts minus 3kt/1000' so if they are at 6,000', it's now at about 135 kts. In addition, adding a ski basket on the side causes more drag, so more pitch is require to reach that same 135 kts and that means you'll hit the SCT limit even sooner. The hydraulic system has a pressure relief valve that opens and sends fluid back to the reservoir at 40 bars or about 600 PSI. The low pressure light and horn comes on at 30 bars or 450 PSI so that the working range. We found pilots complaining about one AStar where they were getting SCT in cruise flight, so the training department had the engineers test the pressure relief valve. They come from the factory with no life limit and no test interval. We had valves that were opening at 32-35 bars instead of 40, so those systems were running at 3/4 to 7/8 of what the pressure was supposed to be. As a result our company added something to the maintenance manual where these valves were checked on a regular basis to make sure they were running at 40 bars.
One second you’re in the air looking at the scenery and the next you’re in the scenery looking at the air
Show off some more
“Look what I can do”.
😂
That’s why you need to fly high to have time to react and recover
Very poethic
Former mountain rescue/search and rescue member here. I hope those passengers realize that they are the 1 in a million when it comes to walking away from a crash. At that speed and in the mountains I’m unaware of anything similar happening with basically no injuries. Awesome miracle in some ways. The pilot should count his blessings that everyone walked away.
indeed! there is only one reason they survived this crash and that was the sheer luck to crash in to very deep snow.
That deep snow really helped cushion impact
OMG you are understating their good fortune.
A helicopter is a whirling maelstrom, brought under glorious control by only the hand/eye coordination of the pilot. They are marvelous machines and I love them.
But, I knew a Huey pilot who crashed a long time ago. The spike in torque that occurred when the rotor hit the ground broke his neck. Sometimes the vertical impact breaks your back. These crashes are profoundly violent and were always on my mind (especially when flying passengers).
Cameraman always survive. Passanger should more use their cameras 👍🏼
Not "one in a million" though. People survive helicopter crashes all the time and 1 million helicopters have not crashed since its invention. You have hundreds of people alive today that have been in helicopter crashes. So not that rare.
Landing was softer that most Ryanair flights.
🤣
Nice dude....
this joke died already of old age...
This comments so annoying
Have you ever flown with other airlines?
For those curious, servo control transparency in helicopters refers to a situation where the forces from the helicopter's controls (like the yoke pilots use to steer) directly reflect the aerodynamic forces acting on the rotor blades, rather than being dampened or modified by the hydraulic systems typically used to make controlling easier. Normally, hydraulic systems help pilots move the rotor blades with minimal effort, but if these systems fail or are overpowered by strong aerodynamic forces, the pilot might feel the raw force of the air pushing against the rotor blades through the controls.
This can happen during aggressive maneuvers (as seen in the video) or in strong gusts of wind, making the helicopter harder to control. The pilot might feel as if they are fighting against the controls, which are trying to "push back" due to the direct feedback from the rotor's interaction with the air. It's like trying to hold a door closed during a windy day; the stronger the wind (or aerodynamic forces), the harder it is to hold the door (or helicopter) steady.
Probably why it’s not a good idea to dive without having an altitude buffer. The pilot is lucky he didn’t kill everyone with that stunt.
@@fizlianI thought the dive was part of the issue starting not intentional.. so this was avoidable? I wonder why they would post it
So it’s essentially like power steering for a helicopter?
@@adambell2068basically yea and it controls the pitch control allowing for more AOA
@@freedomfox8183Nah, he was following the rolling hillside, but partway through leveling off it twisted right and dropped
The person who uploaded this and created the description is being extremely kind regarding the pilots actions in the lead up to, and during, the crash sequence.
Thankfully the snow was soft and everyone is alive 👍🏽
👌🏻
What's wrong with the pilots actions? Those manevaurs look pretty gentle
i would say it was the actions of the mentioned "relief Valve" to blame for this one, how absolutely ridiculous is it to have such a system in place???!!!! Its just begging for accidents to occur, especially when they are known to be faulty!!!.
@@mrbrianbrushwatch the stick.... he started giggling pulling some g's and it was too stressful for the heli. He did a hell of a save at the end which corrected its momentum back vertical enough to soften the impact for us all to see. But it's moments like those that you have to not listen to the intrusive thoughts
@@sirseven3 Is he not trying to counter the actions of the faulty servo or am i being dumb cause id have thought with the cyclic in the position before the loss of major control it would have ripped the tail off?
This is one of those maneuvers you save for the sim and video games.
The best way to impress your passengers and watchers is to land safely and finish your mission. For thousands of times throughout a whole career without an accident. Now that's impressive. Now that's a responsible pilot.
Then why did he go into that ravine, everything was smooth up until then.
Pilota responsabile? Questo pilota è stato solo molto fortunato
@@cbr416 pilot pushed his luck . . . attempted aggressive high-speed flight maneuver under less-than-ideal conditions as was pointed out by can_shawn in one of above comments . . . think of a car going into a tight turn really fast where suddenly the tires lose traction; the driver will lose control and the car will at the very least slide off of the road and at the very worst flip and roll over . . . in the this case the car was driven in a way and under conditions where the driver couldn't maintain control . . . the same sort of thing happened to the helicopter pilot . . . too fast, too aggressive, too close to the ground, maybe close to the gross-weight limit, in high winds and at an altitude where the air was very dense . . . all things that contributed to the loss of flight control by the pilot
Pilot did everything wrong according to this quote on Skybrary: "To prevent servo transparency, pilots should avoid abrupt and aggressive maneuvering with combinations of high airspeed, high collective pitch, high gross weight, and high-density altitude."
I was about to says how it was 100% dumbassery that caused the crash but your explanation sums it better. It was 0% because of the aircraft or the environment. He flew like a jackass.
I had to search what servo transparency was as I didn’t know this flying R22s
Yup. Pilot error.
easy to say while you are comffy sitting on your sofa eating chips and drinking coke btw
@@pepethefrog2176 Nope. You clearly see him fly like its a video game in a dangerous place with many "souls" on board. Your argument has been declined.
I don’t know anything about this, but that landing was surprisingly soft.
yeah they hit the snow really fast, if it had been rocks or trees, this video would be on liveleak.
@timarc9895 when the helicopter is closer to the ground, the lift force from the rotor is greater.
When helicopters lose power they dive towards the ground to keep the rotor spinning, and pull up near the ground to get more lift
@@emersonsnyder369 Except your forgetting this isn't an autorotation and they were nose down partially inverted when they hit the ground. Any lift vector they would've had would've been horizontal at best, or downwards at worst.
@JoshuaPlays99 it looks like he pitched up while rolling and turning right in the last second.
And I think the servo transparency means they have loss of and effective use of rotor collective output. Doing an auto rotation when exceeding VNE renders the blades useless. @@JoshuaPlays99
I can't believe the rotor appeared to stay in one piece... Holy moly.
The video description can easily be boiled down to "Reckless jockey flying his aircraft out of the envelope, to encounter a jock stall, and still being able to walk away from his mess".
RIP, Colin McRae
Yup, as soon as I saw him go into that dive, it was obvious this wasn’t going to end well.
Truth to that
He was showing off to the Heli-Ski Brosephs
Without fail, every time I've heard someone make these kind of comments I hear them at the local aero club bar counter two weeks later telling everyone how they cut down trees with their rotor blades to land troops in nam.
why say rip for a guy who killed two children while trying to show off?
Awesome upload! THis will be used for years to come. I don't fly but when i drive my car, I drive quite differently when I have passengers. If you ever tried to showboat in your car, you noticed the differences in weight when bodies are on board.
It feels more like a boat than a car. In fact I don't think my loaded car feels anything like my plane when heavy.
The snow saved them by softening the landing, and by not allowing the door to open, because the passengers were about to run 🏃🏽♀️ out into the spinning blades!😳😳😳😨😨
Just what I was thinking. You can see they were trying to bolt!
Okay emoji lover
It happened to me: descending from 13.000 feet (Testa Grigia Zermatt) with full fuel, full Pax and full ski basket: so max take off weight. At about 10.000 feet when descending into the valley with max speed, SCT happened. If you have never experienced it feels like a “normal” hydraulic failure. BUT with a hydraulic failure you would ease back and then switch the hydraulics off. With SCT you “just” ease back and the hydraulics come back.
It was an awful feeling, but I had plenty of ground clearance. Ever since I leave plenty of speed and torque margin when flying high (and hot) and heavy…
I have to add: at the point when SCT happened I made NO excessive cyclic inputs! “Just” descended too fast for being so high and so heavy and with a ski basket.
You did handle it correctly, and you did learn from it ❤
So are we to understand that the Vne in a helo is mainly calculated to avoid that SCT issue ?
So understanding the mechanics from a hydraulics point of view, the relief valve does exactly that! It will relieve at the bar pressure set, and your controls will turn to mush until that relief valve stops relieving and the system builds pressure again. So the other alternative by design is allowing the pilot to continue stressing critical components until a failure occurs, and then there's no chance of recovery !!!
Holy smoke....there's never been a more important time to read the flaming manuals guys !!!
In this particular instance on the video, could have it been avoided if he didn't try to push left on the cyclic and the pedals, and just straightened up and maybe gained some height before making the next manouver? I know there's not much space left in the front, but with some extra altitude he might have cleared it.
I'm not a pilot (yet), just fascinated with helicopters and interested in how situations like this could have been avoided at the last second.
I heard this is more likely to happen when the heli is full of weight but man ive never seen such excessive cyclic inputs before from a pilot. that would be terrifying to go through, they lucky
It's cause by disk loading. Happens at high speed, too fast. He pulled the cyclic back at too high a speed. clowning, putting on a show. Now the show is for us.
you can see the moment the hydrauliucs fail and the cyclic jolts aft aggressively. Thanks relief vAlve, glad you had my back on that one. P.O.S system
so my understanding from this is the hydraulic system has an over-pressure relief valve??? so when you're in a situation when you need to over stress the system it depressurizes itself? is that only in the a star? That seems ludicrous, why would it not be a progressive pressure relief instead of a full dump. If so I agree what a shitty system. @@macfly4649
@@martinsinclair55 Was he clowning, or trying to have fun and get the adrenaline up before a ski session? I was voting latter. Unfortunate outcome, but it seemed very soft. I assume and hope nobody got hurt.
@@mstrickk1 you can't see from the video but he was buzzing the ski lodge and then pulled up, inducing the event 😮
just from the video description I can say: Helicopters are one hell of a complicated flying machines
excellent example of how fast things can go wrong. They were flying very low, so the pilot had about 2 seconds to recover, which he obviously didn't.
recovered enough for the crash landing that they could all walk away from though. so that is the silver lining.
Another example of what happens when your taking chances when you are already taking chances.
you're*
I teach a risk and decision making class sometimes and i am stealing that phrase. Important concept, very well put.
Stacking the odds
that would be a great video to use in the classroom environment... thanks for sharing!! 👍
It no doubt will. Exhibit A- why the manufacturer publishes limitations in the POH 😂
Definitely a huge difference in the way civilian helo's are built compared to military. I have over a decade of flying military helo's. From the Mighty Chinook down to the little Bell 58 A/C and have never heard of this EP. Glad I had 3,000psi in my ILCA's and zero relief valves installed!
This is something I've never encountered in civilian helicopters. Seems the H125 has a very weak hyd system!
Yes, valve opens way too fast
I never heard of or was taught "Servo Control Transparency" When I was at rotorcraft flight school and my helicopter flying handbook makes no mention of it. This video looks like retreating blade stall and it looks like he continues to push forward to go faster into that decent (the airbus has a clockwise rotation meaning the retreating blade is on the right side of the helicopter).
I have no idea what you just said but 👍
@@EncrypticMethodslook up similar Astar/squirrel accidents. Most likely contributing factor in McRae's crash too.
I was in a car crash where the car “ricocheted” off the wall of the tunnel when the driver fell asleep, crossing through three lanes, and it felt way more brutal than it looks like when this helicopter literally falls down from the sky. A miracle.
Very interesting Martin, thank you for posting this. Glad everyone made it too.
Every AS 350 i know (including myself) have given themselves servo transpsrencey. Ususlly a right, nose low turn that is aggressive is when it happens. It REALLY hard to relax control pressure to regain control... we've all been there.
like experiencing anti-lock brakes for the first time
@@frez777more like being a young lad grown up with newer cars with abs and esp trying to show off with a real old car.
Is this from a hydraulic release valve? I'm starting flying this year and trying to get to the bottom of this situation as it concerns me a lot. my understanding is over speed and overloading the rotor caused the hydraulic system to depressurize. Why wouldn't the as 350 have a progressive depressurization system where it limits system pressure but does not render the controls ineffective. Correct me if I'm not making sense.
no, we have not all been there, don't fly like bozos
@@were562there is no depressurization occuring. What happens is that you don't have enough pressure/ hydraulic power to overcome the aerodynamic forces on the rotor system.
It's like a tug of war between the rotor and the servo, and the rotor wins, but the servo never stops trying to fight.
Dude knew what was up. Had his camera out because he knows the camera man never dies
Is it the camera man never dies or is it just the camera the dead guy is holding doesn’t break?
@@MichaelSuperbacker my friend, you may have just asked the million dollar question. I'm going with the camera man never dies because a lot of videos you can hear them talking afterwards and for some reason the point the camera at themselves
It just seems like the camera man never dies because you only see their footage. Dead camera men rarely upload
@@alexbernier6154false the camera man NEVER dies
Servo control transparency sounds like an attemp to avoid a lawsuit bc the pilot felt like being cool and f ing around in a mountainous environment.
yup looked like that for me also
Servo control transparency is a specific condition which is typically caused by pilot error. If they had just said "he crashed it" you'd be sitting there wondering how, the pilot was the cause of servo control transparency in this case. This crash would be similar to a pilot of a fixed wing aircraft causing an accelerated stall, you wouldn't sit there going "yeah he just crashed" you'd wanna know what the pilot did, if a similar video was posted saying "Aircraft Crash; Stalls" you already know a plane isn't gonna just stall on its own 99% of the time, the pilot had to do something to exceed the critical AoA. It doesn't sound like an attempt to avoid a lawsuit to me, anyone of those guys with a strong enough will to sue the pilot would have a pretty good case here with a competent enough lawyer.
Woo! What a pilot! That couldn't have gone better. It seemed like such a soft landing compared to what it could have been.
This is a quote from a SKYbrary Aviation Safety article. I had to look this up to better understand what I witnessed.
"The Servo Transparency phenomenon, also known as Servo Reversibility or Jack Stall, can be encountered during abrupt maneuvering of any single hydraulic system equipped helicopter, particularly at high speeds. The phenomenon marks a flight envelope boundary.
This aircraft phenomenon occurs smoothly and is not dangerous if properly anticipated by a pilot during an abrupt or excessive high-load maneuver such as a high positive g turn or pull-up. The factors that affect Servo Transparency are airspeed, collective pitch input, gross weight, "G" loads and density altitude.
How does it Happen? Because of the higher control forces in larger helicopters, hydraulically boosted servo actuators are used to assist the flight controls. The maximum force that these servo actuators can produce is constant and is a function of hydraulic pressure and servo characteristics. Engineers design the hydraulic system to adequately handle all aerodynamic forces required during approved maneuvers. Some manufacturers state that the design of the flying controls hydraulic system is to limit its power so as to protect the helicopter from excessive flight loads. So, with certain aggressive maneuvering it is possible for the aerodynamic forces in the rotor system to exceed the maximum force produced by the servo actuators. At this point, the force required to move the flight controls becomes relatively high and could give an unaware pilot the impression that the controls are jammed. To prevent servo transparency, pilots should avoid abrupt and aggressive maneuvering with combinations of high airspeed, high collective pitch, high gross weight, and high-density altitude.
Note that the effects of Servo-Transparency are generally pitch-up and a roll towards the retreating side of the rotor disk. In this respect the phenomenon presents similarly to Retreating Blade Stall."
I am not positive but I think a bell pilot told me this is a known issue on the a-stars? The correct response is actually to turn even more into the bank to release it but instinct is to do the opposite.
Long story short, don't ride in a helicopter.
This is also known as pilot error. Yanking and banking a likely overloaded helicopter high in the mountains. Oh geee, why did we crash??? 🙄
Thank you 👍👍🙏🤲
@@1BillyPetersonor get in a car, or go swimming, or get on a boat, or cross the road. You get the idea.
looks like a crazy pilot
Horn work perfectly
20 yr whirlybird pilot (but not in this type) - Seems like the pilot caused this with the aggressive cyclic adding too much G load. Had he maintained stable forward flight, instead of diving down that valley and then pulling back abruptly, this likely wouldn’t have happened. When traveling fast, low, heavy, and at high density altitude, bad stuff can happen. Also, a bit confused on the high right bank angle going into the autorotation, but I can’t tell what he saw or felt that may have influenced that. Seemed messy, but these things happen in an instant and he was already flying low, so not much time to really do much. Atleast everyone can walk away.
Would you trust this pilot with flying you somewhere?
see the tattoos on his hand?
@@sankarnath don’t really know him, but I’d probably just fly myself
@@frez777 nah, what’s up?
Seems a bit reckless IMHO, but it’s super hard to judge with just a short clip - flying in the mountains can be hard, especially in such conditions
Best part of the video is the 1,325 different descriptions about what caused the accident. Who knew TH-cam had so many experienced helicopter accident investigators! 😂
There's 7 billion people in the world, alot of people have experience with helicopters you hack.
Not just are you a hack... it's obvious what he did. An over aggressive maneuver
@@d.jparer5184 loser
Incredibly lucky to stay upright/rotors, fresh dence powder, someone was looking out for them this day.
wasn't the pilot
must have had some hot chicks in there @@DarkstarNovembr
@@DarkstarNovembr You beat me to it.
Due to high altitude, speed exceeded VNE - 155kt, less 3kts per 1000ft.
at 10000' thats 125 knots and a dramatic difference in available airspeed!
True
And don’t forget they likely have a ski basket on the side.
Strange.In my 11000 hours of flying helicopters I have never heard this term.
And that’s how you lose your license
easy and fast
"Never fly a helicopter again with this one cool trick!!!"
This is literally the first thing they teach you in helicopter flight school for what NOT to do.
This happened in 2016, the TSB Canada accident report is available online:
Aviation Investigation Report A16P0045
Loss of control and collision with terrain
Airbus Helicopters AS 350 FX2, C-FBLW
TRK Helicopters Ltd.
Smithers, British Columbia, 82 nm NW
16 March 2016
The cause was determined as the pilot placing the helicopter into a flight regime where it experienced servo transparency while at unsufficient height to recover.
Damn, i live in Smithers
@@smiley847loserrr
That went from woohoo, to oh sh1t! In a real hurry.
Hot Dogged it right in!
What’s your Vne at that altitude…?
155 minus 3 kts/1000' u needn't be at VNE if disk loading high
Heavy in the mountains then at about 1:05 there is a really big forward cyclic input which unloads the disc which will cause the aircraft to roll.
"Because of the higher control forces in larger helicopters, hydraulically boosted servo actuators are used to assist the flight controls. The maximum force that these servo actuators can produce is constant and is a function of hydraulic pressure and servo characteristics. Engineers design the hydraulic system to adequately handle all aerodynamic forces required during approved manoeuvres. Some manufacturers state that the design of the flying controls hydraulic system is to limit its power so as to protect the helicopter from excessive flight loads. So, with certain aggressive maneuvering it is possible for the aerodynamic forces in the rotor system to exceed the maximum force produced by the servo actuators. At this point, the force required to move the flight controls becomes relatively high and could give an unaware pilot the impression that the controls are jammed. To prevent servo transparency, pilots should avoid abrupt and aggressive maneuvering with combinations of high airspeed, high collective pitch, high gross weight, and high-density altitude."
Servo Transparency SKYbrary.
And another perfectly good helicopter takes a not so good pilot to the scene of the crash.
That, was frekin awesome, I did not expect an ending where everyone walked off with nothing more than an incredible story.
Sometimes you think you’re good! Then there’s times like this when you thought you were good!
Looks like retreating blade stall to me. He pushes the nose over and accelerates. The pull-up at the bottom followed by uncommanded pitch/roll is classic RBS.
When I flew the gazelle years ago we called it 'jack stall' you would think that later generations of helicopter would have learned of the problem and designed it out!!
They sort of did. The AS350 B3e has available dual hydraulics and also a warning light system when you are close to entering servo transparency.
Funny I flew the Lynx, Sea King and Wasp as well as the Gazelle and not of them had the problem - all Westland products!@@betztechnikindustriesltd.8901
Right, you'd think every helicopter relying on hydraulics would have at least dual pumps!
You don't need dual pumps to avoid jack stall The Wasp only had one pump and never had it@@JohnDoeWasntTaken
1:06 "yee-haw!!!" - the ultimate warning sound of imminent danger in aviation! 😅
Play stupid games, win stupid prizes.
the description is very clear about various mechanical wear and tear but it looks like a sudden altitude drop before the alarms sounded. at least no casualties and scheduled maint had more to check
So if I'm reading the description correctly, the accident was result of 100% pilot error?
Stay out of helicopters is the best piece of advice I ever received.
But not after a crash lol, better to stay inside and wait until the rotor stop spinning.
Agree: Stay out AND away from them.
This is the first helicopter crash I've ever seen in which anyone survived.
You must not watch many of them then
@@keithturgeon5448 Only a few hundred. Why, what counts as a lot?
@@aaronmicalowe You've watched hundreds and this is the first time you've seen anyone survive? I've only seen a handful and most of those had survivors. I think you are being disingenuous about the number of crashes you've seen, the amount of crashes which have survivors, or both.
@@miked7728 It's probably because people and MSM are more likely to upload videos when there's a fatality. Accusing someone of lying isn't nice (yes, that's what disingenuous means, unless you're being disingenuous about what you mean when you use the word disingenuous).
well, tbh there probably haven't been hundreds of helicopter crashes not to mention all of them being recorded... @@aaronmicalowe
This feels a lot more like blade stall but then again, I wasn't there
these comments surprise me, it seems very apparent from the video alone that they were at the top end of the functional speed range from vibration alone
congratulation on writing one of the stupidest comments yet.
Plot twist: they actually smashed into a fluffy cloud ☁️
Absolutely the softest crash you'll ever see!
Controll. Will be fine during this time
This is the luckiest crash I have ever seen: aircraft steered itself directly into a powder face, belly first, with like 60 degrees of bank. If told that you HAD to crash land there and asked to do it intentionally, the pilot couldn't have done it better :D Amazing-- don't even see any damage on the blades afterwards-- like they didn't even hit the snow. Absolutely crazy lucky.
Servo transparency looks scary a/f. That was certainly over quickly...
There’s one even better out there, in which a Bell Huey entered LTE in mountainous terrain, and was pretty much inverted but managed to pull away from it? Craziest thing I’ve seen from a helicopter video.
@@crazyralph6386 Hahaha I know the one. They failed to crash, though :D :D :D
Well that de-escalated quickly!
A great lesson in not overloading the rotor/controls. High altitude, high speed, high g loading trying to pull out of a dive at high gross will overload the servo usually takes 2 seconds to recover from but flying that close to to terrain would make it almost impossible…
ah, you only got to worry about that on flat farmland! This is mountainous and freezing cold!
Looks like it flared out a little before hitting the snow, that might have scrubbed of some speed. Lucky the blades didn't seem to hit anything too hard and could slow down after impact.
GREAT PILOT HAS A GREAT ANGEL GUARDING THEM
In spite of the description stating a mechanical issue, judging by the video, the pilots maneuvering most certainly contributed to this accident.
Servo transparency is not a mechanical issue. It is a condition that this type of helicopter can get into when flown inappropriately. Pilot error and only pilot error.
Pilot was pretty aggressive in the little thrill dive. Being what looks like high in the mountains in dense air the helicopter needs more time to recovery from change of direction and altitude. Total pilot error from what I saw.
As an experienced fixed-wing mountain pilot, I'm quite surprised that a helicopter can't handle such a maneuver.
This is a unique issue only to the A-Star (H125) or EC130 series. The hydraulics don't have this same issue in any other helicopter in the world
@@Alan-hr5luwhat is it that it does/doesn't do that is out of the ordinary to cause this?? And why/how has it not been corrected by this point??
**NVM.... Found a few great videos explaining the phenomenon **
@@james94582 video explains it here th-cam.com/video/U7sc2BodDHo/w-d-xo.html
Manufacturer won't fix it because there's technically nothing wrong with the aircraft. Don't fly past limits and you won't encounter the problem,
@@james94582, there is no problem with the servo system when you don`t exceed the limits of the helicopter. Except in the case described in the video description, where apparently the pressure relive valves can open at a pressure to low for the system. The AS 350 is one of the most flown helicopters worldwide, and servo transparency is known to be there, but not to be an issue when you stay inside the approved flight envelope.
Ikr. If the hydraulics can't overcome the aerodynamics then why the hell is that thing in the air?
Yep. Got to the Find out stage real quick after the initial FA. Lucky lucky guys. Unreal they got out of that.
2 passengers in the front??
lucky that snow was light pack and not icy/rock... This is why I firmly believe you must have a solid grasp of the engineering and limits of when operating machinery of any sort. Without it you are just pressing buttons and moving levers only knowing what they do, not why or their limit
When I took my pilot license for helicopters, we called this hydlock.
He went too fast and tried a maneuvre that is fine at lower speeds and lower altitude but not in the mountains.
Legend has it that this pilot now works at McDonalds
Burgers are less expensive to flip!
Everyone very lucky! Total armchair nerd but I cannot believe the pilot would not have been aware of the likelihood of this happening if he flew this way with load, at altitude etc totally down to ‘Human Factors’.. Amazing outcome considering..
CAMERA MAN NEVER DIES
@1:10 you can practically hear the Vne limit exceeded from the air passing over the windscreen!!! Can’t believe guys are still doing this cowboy stuff, especially when 90% of the time it’s being recorded? You simply don’t mess around with somebody else’s multi million dollar piece of equipment, fully loaded with pax…..in the mountains no less! Guaranteed it wasn’t his first rodeo either.
It was at that moment he knew he ……….. up 😂😂😂😂
As an average guy, my first instinct would be to escape the heli before it bursts into flames! I never really thought about the blades still spinning! Wow, I learned something new today.
Engines on a liner too. They pull you right off the slide and make confetti. It's why you shouldn't evacuate before the command is given. Unless it's obvious, half are dead and the aircraft is on fire then yes, go ahead and run. If you still can. One of the main points of the evacuation checklist is securing the engines.
That "landing" deserves a thumb up.
Holy S is right dam glad u all are ok thank god for that fresh snow saved u all
Perfect landing , any crash landing you can walk away from is a good landing , now if your talking about his flying skills thats another story ...
Had nothing to do with his skills, the pilot was not trained and the information was not contained in any training manual on servo transparency. Read the TSB report on this accident to understand
@@rfcdgaf "the pilot was not trained" Doesn't that pretty much mean a lack of skill for this model of helicopters?
Aka 'settling with power'? I have a secret valve in my brain. It opens at 20 bars... when I push hard on things and realize that I should not, or... Well done guys on staying alive! Very educative video!
I think settling with power is a bit different
@@ScreamingElectron Agreed. It just looks like if you take hydraulics out of eqution. Please excuse me oversimplyfing and have a good day. So glad for survivors!!!
Very 350 has this issue except the B3 (dual hyd pumps). Any pilot with ASTAR experience has found this out, either purposefully or accidentally. High G loads, it’s going to bank right and pitch down.
Its even possible B3e... very low powered hyd. system, a lot better than a B3, but it still can happen.
what? the issue is the pilot nose diving the helicopter and flying way above vne then trying to pull up at 180 kts or whatever bs he got up to. I've flown the astar for a decade and NEVER ran out of hyd. Stop flying like dipshits.
Dual Hydraulic system won't stop this from happening but they introduced the LIMIT system so it warns you before this can happen.
Never heard of servo control transparency. The more I learn about helicopters the more ways I learn they can kill you.
interesting, I've experienced similar issues with remote models when the cyclic servos are pushed harder than they can take.
It was a "retreating blade stall". The pilot increased the speed of the helicopter in a high mountain and high weight situation, causing a loss of lift on the side where the blade was retreating (right).
no. read comments
@@martinsinclair55 I'm helicoper pilot since 20 years ago, I know what I said.
@@MI17-HK then I'm guessing uve never flown an A Star because every A Star pilot knows what it is and how u get it. Look it up🧐
SCT Whaaa? I've flown bell 206LIIIs for years, been to Bell recurrent training several times, never heard this term before. Like A-Stars, they have servo assist/boost but you can still fly them if hydraulics fail. Anyone here have experience in both aircraft and care to enlighten me?
Ps. My (paying) pax never got the hotdog flight swooping just above the trees unless it was on a takeoff or landing. So I have never felt the hydraulics run up against their limit and didn't know this was possible (at least in BHT helicopters).
I have 700 in the 206B3 and 500 in the AS350B3e. While technically possible in a variety of hydraulic systems, its considerably more known/common in the Astar than the Ranger, to the point where there is a light for it and it's in the manual. I used to be flying the Astar heavy and high (10,000ish), and would see the light flicker even from the SAS just holding a level cruise through light/moderate turbulence. Typically just backed off on the speed when that happened, and made sure not to fly like a jackass.
Thank you.
Hydraulic Jack stall, essentially overloaded the hydraulic system which can happen on the AS350. Very poor pilot control, you can see pilot uses forward cyclic to descend after he clears the trees instead of lowering collective creating a low g situation. My guess he is at high gross weight, high airspeed and high ROD through the valley, so due to clockwise rotation of blades helicopter turns to the right and he is unable to recover at low altitude. One very lucky pilot and passengers!!!
Yep, how they didn’t plow into a rock cut at 130kts, is anyones guess? The ship even appears salvageable at the end of it all too?
You are talking about Vne being reduced by altitude to 135kts, but if he had a basket on, most of those have a Vne of 100kts (at least the ones from Dart) so his real Vne may have been much less.
Does the Vne of a basket has anything to do with servo control? I don't know, just asking.
@@NightIntruderPL Yes, the basket will add significant drag to the helicopter, and therefore put more force on the hydraulics at a given airspeed.
@@jimrogers907 Oh, understood. Thank you for the explanation!
Thanks for sharing
They were being reckless yelling yeeehaw
It looks like they hit the snow nose down but I think what actually happened was the helicopter uprighting itself at the last second slowing down the descent greatly, it is hard to notice because of the snow making look like they went in nose first
Softest crash ever
It looks like the helicopter dove and then spun around and impacted right side up facing backward from flight direction, which probably helped survivability. That and the deep snow.
01:04 he pushes the cyclic forward causing negative Gs and consequent departure from controlled flight as the blades lose purchase on the air and consequently the aircraft then yaws to the right and rolls to the right.
The pilot then tried to correct by pulling back and to the left which aggravated the situation.
The pilot did everything he should not have done and this was completely the pilot's fault.
False. The AS350 is rated to -1G. It is equipped with a starflex fully articulated rotorhead. The phenomenon you are referring to affects teetering rotor heads like R-22, R-44, early Bell helicopters, and others.
Also the tail rotor would roll it to the left not the right.
Wrong, wrong, wrong. Fully-articulated head retains some low-G roll authority. There's no negative G: the loose objects on the guide's side stay put on the shelf the whole time. Astar has a clockwise rotor and would tend to roll left in a zero-G situation anyway (that's the way the T/R thrust pushes). Zero G even in a teetering rotor doesn't cause yaw.
Wrong.
Im no expert but it looked like the pilot broke the heli while trying to show-off with his sudden, unnecessary maneuvers. Would love to know what the investigators had to say about this!
what a crash landing. The softest, most graceful crash i've ever seen.
ignoring the fact that this crash was caused by pilot error, that crash landing couldnt have been any better.
The snow may have helped survivability..
I can't quite believe the valves have no manufacturer designated test interval or flight hours/years flown expiry. Seems highly negligent to me especially on a chopper.
Awesome capture! May I feature this incident in one of my next episodes? Of course with a link back to your original video. Cheers!
Still stealing other peoples content for profit huh?
Thanks for sharing!
cant believe someone was beeping their horn, so rude
Learn something new everyday. When I was a kid I learned how to fly single engine fixed wings, and yeah, read all the tech manuals and treat what they say like the Bible. Keep Safe to Stay Safe.
Hot doggin and showing off usually leads to bad news.
That snow probably saved their lives.