Realy? a moving bolt is operating and at the same time holding the hole tailwing with no second safety whats so ever hahaha this is crazy lazy design. You need to constantly lubricate a bolt or else the whole plane will fall out of the sky.
There are electric grease guns. Mount one in a strategic place with a couple applicators and have a sensor that indicates low grease in the sump. Done. That torque tube nut prolly got so hot from the motor spinning it... in an attempt to move the stabilizer....it just melted off.
LMAO. You obviously have never worked on an airplane. I have. 27 years now. That stabilizer doesn't move fast enough to 'heat up' the Acme nut in any meaningful way. Grease gun blasting grease randomly? Hilarious. This accident was cause by lazy maintenance practices. The Acme nut was probably 1000 hours past it's useful life.
@@dbcooper7477 Laughing your ass off?.... Glad you're not my mechanic....You can't even interpret what you read. Here, try again.... That (as they label it) "torque tube nut" was the last piece of hardware holding the stabilizer from disconnecting completely. (Keep in mind that stabilizer is as big as a small house.) Probably 100's of ft-lbs against it while the servo-motor was attempting to to utilize the (already stripped out) jack-screw. Eventually smoked that nut off. (Get it yet?) You post: "Grease gun blasting grease randomly?" (What are you? Some farm boy?) Incorrect, It distributes grease where you want it...could save 100's of lives from (as you call them) lazy maintenance workers like yourself. You make all these calls after the accident. (easy) It's called "hind-sight...." I prevent them from happening...it's part of my job. (challenging) You have 27 years in....name some preventative measures you've brought to the table.
@@readmore3634 Stabilizer big as a small house?? C'mon man you're not even close bud. I've lived in some small houses...all bigger than any narrow body stabilizer. You're obviously are out of your element and trying to interject your opinion into something you know nothing about. The jack screw wasn't stripped, THE ACME NUT WAS, genius. BTW, "prolly" isn't a word. Even a 'farm boy' knows this! LMAO
@@dbcooper7477 I've been flying since I was 14... Pitts special, Decathlon, Rv-4, Extra-300, Cessna 172,182, Citation 1,2 and 3, no stick time in my friends Citation 10 yet (fastest civilian, production plane made (Mach .8 ) and even a Bell 206 Jet Ranger 4. My late Uncle, a 35yr old career USAF Colonel took me flying and golfing once a week when he retired in 1976....I was 15. I come from a fairly large circle of pilots. And yea...I guess over estimated the control area surface of the MD-80's stabilizer....I've seen some pretty big ones tho. So to say "I'm out of my element" might be true....but I know what fly's well and what struggles to fly....what I don't know is why you're so angry...talk about that. BTW....My grease gun rant was only because I read an article that said : "The jack screw is hard (pain in the ass) to get to"....so I thot maybe, just maybe have a sump. But nooooo....you won't have that...(and people die in preventable crash) all your fault...maybe.
@@readmore3634 Lol. I'm angry?? You attacked me. Called me a bad mechanic and a farm boy. I just get tired of "keyboard mechanics" telling me how airplanes work. I will never claim to know everything, but I know plenty after nearly 30 years. Good day. Have fun flying.
@@JustRememberWhoYoureWorkingFor manual cable system could have moved the stabilizer without the need of jackscrew, but then again the entire thing seems to hold steady thanks to jackscrew th-cam.com/video/rxPa9A-k2xY/w-d-xo.html manual cable system would require a lot more mechanical parts and gears for disabling jackscrew and enabling manual control, difficult, expensive but it's possible.
Using jackscrews on the horizontal stabiliser is used on a lot of large aircraft. They are used on the trailing edge flap system aswell. It works well if it’s maintained correctly
more redundancy would have been better... 2 jackscrews in parallel --- however without maintenance that would eventually fail too... LUBE and 'end play' sensors could have helped alert trouble
You can only idiot-proof things to a certain degree. An airline that refuses to properly maintain its equipment will eventually manage to kill people...
Paul Wescott it wasn’t the nut.. to save money airline beancounters failed to allow proper maintenance and lubrication to the screw.. thus causing the threads to wear out and stripped.
The fact that none of those engineers thought of a safety system in place to provide support in case this system failed is insane, it's like with the 737 Max disaster, sometimes one wonders if those set engineers should be looking for a desk job instead, these are faults so obvious even for an average person...
Actually that jackscrew is reliable if maintenanced regularly and properly. All Airliners horizontal stabilizer work that way. But I agree with you with the 737 MAX. They did a very bad job.
A mechanic named John Liotine recommended the jackscrew to be replaced two years before the crash. He was over-ruled. He filed a complaint to the FAA. Liotine was placed on administrative leave. He was working with federal investigators before the crash happened. Alaska Airlines attacked him in the press. He sued the airline for libel. He settled for 500,000 dollars.
@@TrFusion So how come it came loose then? How come there wasn't any structure in place to take some load and prevent the jack screw from traveling further than it should? We've seen this too many times in aviation where they rely entirely on one assembly point, this is ridiculous, makes one really question the competence of these set engineers.
The system is very primitive and poorly designed and therefore prone to failure. There should be multiple layers of redundancies and a much more robust and strong mechanism other than a jack screw.
The statistics of air travel do not support your assertion. The mechanism is apparently simple yes but not primitive. How many layers of redundancy do you suggest? The mechanism failed because of extreme neglect. Take a look at the NTSB accident report. www.ntsb.gov/investigations/AccidentReports/Reports/AAR0201.pdf Page 21 and 22 give some insight into anticipated failure modes. Your "Prone to failure" statement needs a rethink.
Exactly: so many times in a system-malfunction scenario, there's nothing to fall back on. In the case of hydraulic failure (which isn't unlikely), a plane's crew may be unable to control the plane's flying-surfaces and engines because there's no other way to access them.
@@johnhardman3I’m not trained on the MD-80 but in general most large aircraft have multiple layers of redundancy if a system fails. All aircraft I work on have 3 or more systems of hydraulics. If one fails the others can do the job of the failed system
Those poor people, I can't imagine the terror they must have felt. The event lasted a long time too. I think my heart would have stopped before the plane hit the water
Could the free moving stabilizer have been pitching the opposite of the elevator input. The elevator could have be acting as a large servo-tab reversing the pilots inputs.
Look at where the pivot of the stab trim is located - right next to the elevator hinge. I would guess that the stab trim and elevator actuator must remain isolated from each other. If the pilot pushes the stick forward, the elevator would go down but the direction the floating stab would move would depend on several factors. So no, I don't think it would respond in a way that would make the plane flyable.
Most of its costumers are equally willing to cut corners in order to get a "good deal" on a ticket. When faced with the choice of an expensive fare with a reliable airline and a cheap one with an unknown low-cost operator, many people don't think twice about choosing the latter. Granted, this is often due to the fact that they simply can't afford the costlier flight, but let's be honest: people love cheap things and reward this kind of practices by patronising these companies. The boom of low-cost airlines and the regional operator phenomenon were the biggest double-edged sword to hit the aviation industry: it made flying accessible to all, at the cost of safety and quality standards.
What junky design
What pathetic engineering.
Thanks for your work, easy to understand, nice to know.
Why no comments after all this time for such a good knowledge?
Realy? a moving bolt is operating and at the same time holding the hole tailwing with no second safety whats so ever hahaha this is crazy lazy design. You need to constantly lubricate a bolt or else the whole plane will fall out of the sky.
There are electric grease guns. Mount one in a strategic place with a couple applicators and have a sensor that indicates low grease in the sump. Done. That torque tube nut prolly got so hot from the motor spinning it... in an attempt to move the stabilizer....it just melted off.
LMAO. You obviously have never worked on an airplane. I have. 27 years now. That stabilizer doesn't move fast enough to 'heat up' the Acme nut in any meaningful way. Grease gun blasting grease randomly? Hilarious. This accident was cause by lazy maintenance practices. The Acme nut was probably 1000 hours past it's useful life.
@@dbcooper7477 Laughing your ass off?.... Glad you're not my mechanic....You can't even interpret what you read. Here, try again.... That (as they label it) "torque tube nut" was the last piece of hardware holding the stabilizer from disconnecting completely. (Keep in mind that stabilizer is as big as a small house.) Probably 100's of ft-lbs against it while the servo-motor was attempting to to utilize the (already stripped out) jack-screw. Eventually smoked that nut off. (Get it yet?) You post: "Grease gun blasting grease randomly?" (What are you? Some farm boy?) Incorrect, It distributes grease where you want it...could save 100's of lives from (as you call them) lazy maintenance workers like yourself. You make all these calls after the accident. (easy) It's called "hind-sight...." I prevent them from happening...it's part of my job. (challenging) You have 27 years in....name some preventative measures you've brought to the table.
@@readmore3634 Stabilizer big as a small house?? C'mon man you're not even close bud. I've lived in some small houses...all bigger than any narrow body stabilizer. You're obviously are out of your element and trying to interject your opinion into something you know nothing about. The jack screw wasn't stripped, THE ACME NUT WAS, genius. BTW, "prolly" isn't a word. Even a 'farm boy' knows this! LMAO
@@dbcooper7477 I've been flying since I was 14... Pitts special, Decathlon, Rv-4, Extra-300, Cessna 172,182, Citation 1,2 and 3, no stick time in my friends Citation 10 yet (fastest civilian, production plane made (Mach .8 ) and even a Bell 206 Jet Ranger 4. My late Uncle, a 35yr old career USAF Colonel took me flying and golfing once a week when he retired in 1976....I was 15. I come from a fairly large circle of pilots. And yea...I guess over estimated the control area surface of the MD-80's stabilizer....I've seen some pretty big ones tho. So to say "I'm out of my element" might be true....but I know what fly's well and what struggles to fly....what I don't know is why you're so angry...talk about that. BTW....My grease gun rant was only because I read an article that said : "The jack screw is hard (pain in the ass) to get to"....so I thot maybe, just maybe have a sump. But nooooo....you won't have that...(and people die in preventable crash) all your fault...maybe.
@@readmore3634 Lol. I'm angry?? You attacked me. Called me a bad mechanic and a farm boy. I just get tired of "keyboard mechanics" telling me how airplanes work. I will never claim to know everything, but I know plenty after nearly 30 years. Good day. Have fun flying.
didn't this plane have manual controls like on boeing?
Do you mean string control?
Yeah, it has cables
I don't think a manual control would have prevented this accident
@@JustRememberWhoYoureWorkingFor manual cable system could have moved the stabilizer without the need of jackscrew, but then again the entire thing seems to hold steady thanks to jackscrew th-cam.com/video/rxPa9A-k2xY/w-d-xo.html manual cable system would require a lot more mechanical parts and gears for disabling jackscrew and enabling manual control, difficult, expensive but it's possible.
@@wlfgangthe B737 has a jack screw with a cable system. It does exist
That is piss-poor design. Failure is imminent.
No, design is not piss poor. Maintenance was. Anything not maintained will eventually become piss poor.
Using jackscrews on the horizontal stabiliser is used on a lot of large aircraft. They are used on the trailing edge flap system aswell. It works well if it’s maintained correctly
more redundancy would have been better... 2 jackscrews in parallel --- however without maintenance that would eventually fail too... LUBE and 'end play' sensors could have helped alert trouble
You can only idiot-proof things to a certain degree. An airline that refuses to properly maintain its equipment will eventually manage to kill people...
737 MAX 8 - flies for a MAXimum of 8 minutes
The Acme nut, go figure. Acme never made anything of quality just ask Wile E Coyote.
Paul Wescott it wasn’t the nut.. to save money airline beancounters failed to allow proper maintenance and lubrication to the screw.. thus causing the threads to wear out and stripped.
No lubrication on the thread bolt Good design with a cotter pin or welded nut on end just piss poor maintenance planning
Why not weld the torque nut onto the all thread? Probably not cost efficient on the maintenance end $
And everyone got to experience a horrible death as a result!
Today's episode of "Why is it on my recommended"
Same here... But maybe because of the Boeing 737 Max crashes
The fact that none of those engineers thought of a safety system in place to provide support in case this system failed is insane, it's like with the 737 Max disaster, sometimes one wonders if those set engineers should be looking for a desk job instead, these are faults so obvious even for an average person...
Actually that jackscrew is reliable if maintenanced regularly and properly. All Airliners horizontal stabilizer work that way. But I agree with you with the 737 MAX. They did a very bad job.
A mechanic named John Liotine recommended the jackscrew to be replaced two years before the crash. He was over-ruled. He filed a complaint to the FAA. Liotine was placed on administrative leave. He was working with federal investigators before the crash happened. Alaska Airlines attacked him in the press. He sued the airline for libel. He settled for 500,000 dollars.
@@AWildBard Sad
Not really like the max crashes though.
@@THYB737 yeah but if it loses power no way to fly the plane, everyone dies
This jackscrew may have been the trouble with the Boeing 737 Max 8 planes... according to th-cam.com/video/Mdi3f9H1hqQ/w-d-xo.html
No safety wire or cotter pin? What was stopping the nut from just unscrewing? Something doesn't add up.
@@TrFusion Yeah, that's crazy. You're right.
@@TrFusion So how come it came loose then? How come there wasn't any structure in place to take some load and prevent the jack screw from traveling further than it should? We've seen this too many times in aviation where they rely entirely on one assembly point, this is ridiculous, makes one really question the competence of these set engineers.
@@HansensUniverseT-A They're under pressure to cut costs, and so cut corners and so cut safety-margins.
@@johnhardman3 Oh they're cutting corners alright.
HansensUniverse it was under aerodynamic force it simply was not designed to take. It broke through everything
Good video, which program did you use?
The system is very primitive and poorly designed and therefore prone to failure. There should be multiple layers of redundancies and a much more robust and strong mechanism other than a jack screw.
The statistics of air travel do not support your assertion. The mechanism is apparently simple yes but not primitive. How many layers of redundancy do you suggest? The mechanism failed because of extreme neglect. Take a look at the NTSB accident report. www.ntsb.gov/investigations/AccidentReports/Reports/AAR0201.pdf Page 21 and 22 give some insight into anticipated failure modes. Your "Prone to failure" statement needs a rethink.
Exactly: so many times in a system-malfunction scenario, there's nothing to fall back on. In the case of hydraulic failure (which isn't unlikely), a plane's crew may be unable to control the plane's flying-surfaces and engines because there's no other way to access them.
@Xarifa Lee It's far from fool proof.
@@johnhardman3I’m not trained on the MD-80 but in general most large aircraft have multiple layers of redundancy if a system fails. All aircraft I work on have 3 or more systems of hydraulics. If one fails the others can do the job of the failed system
They never should have fucked with those trim motors at 30,000+ feet.
Those poor people, I can't imagine the terror they must have felt. The event lasted a long time too. I think my heart would have stopped before the plane hit the water
Could the free moving stabilizer have been pitching the opposite of the elevator input. The elevator could have be acting as a large servo-tab reversing the pilots inputs.
Look at where the pivot of the stab trim is located - right next to the elevator hinge. I would guess that the stab trim and elevator actuator must remain isolated from each other. If the pilot pushes the stick forward, the elevator would go down but the direction the floating stab would move would depend on several factors. So no, I don't think it would respond in a way that would make the plane flyable.
Good point
It sickens me how an airline is willing to cut corners in these areas. Don’t give a damn about human life at all. Negligence to manslaughter.
Most of its costumers are equally willing to cut corners in order to get a "good deal" on a ticket. When faced with the choice of an expensive fare with a reliable airline and a cheap one with an unknown low-cost operator, many people don't think twice about choosing the latter. Granted, this is often due to the fact that they simply can't afford the costlier flight, but let's be honest: people love cheap things and reward this kind of practices by patronising these companies. The boom of low-cost airlines and the regional operator phenomenon were the biggest double-edged sword to hit the aviation industry: it made flying accessible to all, at the cost of safety and quality standards.
737 Max, do i need to say more...
@@HansensUniverseT-A Alaska 261 was a MD-83
@@elliottstewart8745 I think he refers to the general practice of giving priority to money over safety