This crew revealed a problem with this plane by going closer to the test limits. Unfortunately they had to offer their lives, but probably saved a lot more lives by doing so. May they rest in peace!
@dquincecrowell6729
2 жыл бұрын
Kk
@thatguyalex2835
2 жыл бұрын
May all folks who have sacrificed their lives for the betterment of safety RIP. Safety rules and checklists are truly written in blood, as MACI said. Now don't get me wrong, I love t-tail aircraft, but would a set of small retractable canards in the front of the plane prevented the stall from becoming an accident, so that t-tails can recover from severe stalls? That would cost a lot of money though.
@Maven0666
2 жыл бұрын
Do all planes gave shadow spots?
@Ztbmrc1
2 жыл бұрын
@@Maven0666 When you mean as a consequence of stall? Yes, but since a plane pitches up when about to be stalled, the tail goes down. Planes with conventional elevators, these elevators move downward with the tail and stay below the shadow. However T-wing elevators are already several meters above the tail, and when the tail moves downward, the higher elevators now move exactly into the shadow, thus making the elevators non functional. The plane can now longer be leveled or pitched down to prevent it from stalling: deep stall.
@Maven0666
2 жыл бұрын
@@Ztbmrc1 Oh okay. Thank you.
@whoever6458
2 жыл бұрын
When I was in fire academy, we had to memorize certain rules for when you're on a fire line. Near the beginning of us trying to memorize them and none of us really had, they yelled at us about how every single one of those rules had been adopted because a firefighter had lost their life that way.
@foxman105
2 жыл бұрын
I'm quite sure I heard it in English as well but when I was doing a training on how to use oxy acetylene torch, some people bitched about overkilling it on the safety measures. The old guy just came in, turned off their equipment and told them " The rules of safety are written in blood." and sent them away. I don't think some of them understood what that phrase met...
@Dargesh890
2 жыл бұрын
That last point is so important. So many of our safety features and rules are there because someone died or got seriously hurt
@pooletrainboy
2 жыл бұрын
Indeed as the saying goes the rules of aviation are written in blood.
@rattlyy
2 жыл бұрын
checklists are written in blood
@Bertrand146
2 жыл бұрын
Yes and if my mum had wheels we would call her a bike....
@nztv8589
2 жыл бұрын
yes. When I learned to fly my instructor said " you won't live long enough to make all the mistakes others have made and learn from them. So take the easy option which is to follow the rules and procedures.
@Bertrand146
2 жыл бұрын
@@nztv8589 Yeah like "plan your flight and fly accordingly to your plan" and all that bs.... So now you think you'll never make mistakes and that your plans will always be right?
@michaelschwartz9485
2 жыл бұрын
It's very sad so many pilots sacrificed their lives for all of us. I wish there was a way to personally thank those that gave their lives to help keep us safer. My thoughts and prayers are with you brave pilots and your families.
@sharoncassell9358
Жыл бұрын
I met test pilots in the service. They are dedicated daredevils. I realize the chances & scarifices they take. S few told me they ejected when the plane did not react as expected. Or it caught on fire. What guts.
@tedsmith6137
2 жыл бұрын
The angle of INCIDENCE is the angle between the wing chord line and the fuselage datum line. This is fixed by the design of the aircraft. You should be referring to the angle of ATTACK, which is the angle at which the air meets the wing.
@Lozzie74
2 жыл бұрын
Thank you. I found it painful to hear this term used incorrectly. I commented similar to you but your comment was much better stated.
@kolasom
2 жыл бұрын
Exactly. You saved me a comment.
@grahamj9101
2 жыл бұрын
There is a difference in terminology between the two sides of the Atlantic in respect of 'angle of incidence' and 'angle of attack'. This was recognised way back in the 1940s by Langeweische in his book 'Stick and Rudder'. In a career lifetime in the design of gas turbines here in the UK, I can tell you that the term 'angle of incidence' has been used to define the difference between the air/gas angle onto the leading edge of an aerofoil, relative to the local angle defined by the leading edge at which the angle of incidence would be zero. 'Angle of attack' has typically been used to define the angle of an aircraft relative to its direction of flight.
@109-w7v
2 жыл бұрын
Angle of attack is the angle of the aircrafts flight path with reference to the relative airflow. The chord line is the reference on the wing. Hence you can be in a stalled condition at any pitch attitude or any speed.
@grahamj9101
2 жыл бұрын
Further to my previous comment, some years ago, I had an argument on KZitem with one of our American cousins. He just could not accept that a difference in terminology from that in use in the USA was valid - even though it was recognised by Langewiesche in 'Stick and Rudder'. I even quoted him the page number of the reference.
@LanceHKW
2 жыл бұрын
"Written in blood." That is a very profound statement.
@Bertrand146
2 жыл бұрын
The "writting" is a never ending process....
@frank_av8tor
2 жыл бұрын
The deep stall phenomenon was unkown at the tine! All T-Tail aircraft are prone to it and therefore aircraft like the B727 and the DC-9 family all have pushers.
@Trashhauler
2 жыл бұрын
I’ve flown DC-9 and 727, neither of them have stick pushers
@109-w7v
2 жыл бұрын
All swept wing jets are prone to deep stall. Not all T tails have pushers. The only jet I’ve flown with a pusher was the EMB 145.
@mauricedavis2160
2 жыл бұрын
Right on thank you for the great information 🙏👍🛫
@momchilandonov
Жыл бұрын
There was one russian plane literally not able to recover from a stall by design due to it's massive T shape. Quite worrying to fly it on low energy/speed :D.
@johnhill8529
Жыл бұрын
Mike Lithgow survived a ditching in a Fairey Swordfish in 1942. He and my grandfather were very good friends and fellow test pilots. My middle name is Mike because of him. I was a year old when he died. Through my career as a pilot I carried my grandfather’s navigation computer, a few years ago I took it apart for cleaning and found Mike’s name on the inside, it may have been his to start with, but I don’t know. I did however fly 3000 hours on BAC1-11 very safely.
@ProfVaharrak
2 жыл бұрын
Amazing video, as a chemistry teacher I always emphasize to my students the fact that safety features and regulations exist bc no matter how small or insignificant they may sound, someone most likely has lost their life. I will be happy to show my senior students this video as a real life example. Thanks for your content! Love from Mexico
@jasonwhite1069
2 жыл бұрын
@Hal Mash What is wrong with you?
@Bertrand146
2 жыл бұрын
As a taxi driver, I always emphasize to my clents (to keep them quiet and therefore make my day easier) the fact that safety features and regulations exist bc no matter how small or insignificant they may sound, someone most likely has lost and will lose their life.
@Bertrand146
2 жыл бұрын
@Hal Mash lol
@johnjaeger4804
2 жыл бұрын
I flew the BAC111 in the 1980s it had a stick pusher system to avoid this problem.
@AEMoreira81
Жыл бұрын
As a direct result of this incident in testing. They died so that many others could live.
@TCPUDPATM
2 жыл бұрын
Congrats on 150k! The last statement made on this video is so profound. Hats off to these brave souls.
@johannesbols57
2 жыл бұрын
I've never been a nervous flyer. But, March of 1986 I was flying ELP - ABQ on a Western Airlines 737-200. The distance between the two cities is minimal, so we were not that high. Between El Paso and Albuquerque is the Franklin Mountain range. It was choppy. How choppy was it, you ask? The stewardess at one point was collecting bevvies. She hit the deck on both knees and, holding onto an arm rest (this is where flight attendant training shows), she raised her voice (not shouted, not screamed), "HOLD ONTO YOUR DRINKS!!" She didn't say that not holding onto them would endanger your life because they could become airborne and lodge themself into your skull. I began to freak out. Looking out the window, I realized that the test pilots put these airframes through torture that nearly breaks the airframe apart before the FAA certifies them as airworthy. At that moment I relaxed.
@emielvanderwel5200
2 жыл бұрын
Interesting
@melodiefreshour4257
2 жыл бұрын
Oh yeah- I was on that same flight!
@cageordie
2 жыл бұрын
Right. I've been on test flights from RAE Bedford. We weren't doing anything to test the limits, we just weren't as concerned about not upsetting the paying passengers and had two ETPS graduates at the controls. On one occasion that resulted in one of my friends floating back down the plane in a zero g pushover. In another it resulted in all of us feeling like we'd spent an hour in a tumble dryer. It's funny when you turn up to the plane in office clothes and the pilots turn up in full survival gear, but they were serving RAF officers and they could be hauled off to Wales to a survival exercise any time they went out to fly. When we were bouncing through turbulence I was in the jump seat, at first I was really concerned, then I noticed that the two pilots were chatting about video games. Ah. No problem then. Live tests never come near the ultimate load limits of the aircraft, most people will never experience even half the ultimate design load. The static tests aim to reach 150% of designed ultimate load. Normal g limits for commercial aircraft are +2.5 and -1. China Airlines 006, a Boeing 747SP reached +5g which broke the APU off its mount, broke some overhead bins, and gave the wings a permanent set.
@ianoswald1605
2 жыл бұрын
It was reported that one of the test flight.observer had written on his paperwork that they were in a deep stall and couldn’t recover. I also heard that BAC fitted a tail parachute to pull the tail up until they fitted the stall stick shaker and stall pusher. I also remember Mike Lithgow used the fly the Supermarine Swift fighter at the then annual Farnborough air show at supersonic speed by putting it in a dive while aiming at the airfield resulting in a loud sonic boom. Those were the good old days of British aviation.
@stephenpage-murray7226
2 жыл бұрын
My father flew the Swift FR5 in Germany. No longer here or I’d ask him about them…
@ianoswald1605
2 жыл бұрын
S
@claycassin8437
2 жыл бұрын
Wow. I worked that plane as a crewmember hundreds of times...in the late 80's. They were originally Mohawk Airlines...if you know your airline genealogy, then you will know who I worked for. I had no idea about this flaw, thank God.
@ChrisCooper312
2 жыл бұрын
It's the same "flaw" with all T Tail aircraft, including the DC9, MD80, Boeing 727 and many more.
@claycassin8437
2 жыл бұрын
@@ChrisCooper312 All of which I have worked. And the Fokker 100 too. As I said, I'm glad I didn't know this. We had a tragic history with the Boeing 737-300, as well. Don't even ask me how many flights I worked on that plane...before the uncommanded rudder flaw killed three of my friends. I tried to avoid it...working our T-tail equipment and the 75 and 76 instead! Even the jack screw challenged MD-80. By the way, a flaw is a flaw. No quotation marks are required.
@Milesco
2 жыл бұрын
@@claycassin8437 * quotation marks
@claycassin8437
2 жыл бұрын
@@Milesco Oops. Thanks. My brain is faulty. I have corrected my error.
@timhancock6626
2 жыл бұрын
My first jet flight was on a BAC 111 and I flew on them a few times. Thanks for the accuracy of your reporting of this very unfortunate incident and its causes.
@phishbill
2 жыл бұрын
Once again, fantastic job. You are uniquely great at what you do.
@Ronin4614
2 жыл бұрын
Thank you lads!! Rest In Peace.
@TheFULLMETALCHEF
2 жыл бұрын
When I was a kid I built a balsa/paper model of the Wright Flyer. Noticed that at certain angles that it would always enter an unrecoverable stall. This was due to two factors-drastic changed thrust vectoring, but most importantly no airflow over the elevators assembly due to blockage of the wings and body of the plane. Bad design that unfortunately has been repeated ever since.
@brucebaxter6923
2 жыл бұрын
Wasn’t it canard?
@TheFULLMETALCHEF
2 жыл бұрын
@@brucebaxter6923 yeah, and IMO made it more prone to stall at shallower angles
@brucebaxter6923
2 жыл бұрын
@@TheFULLMETALCHEF You balanced it wrong. Canards need that front loaded up, way up.
@TheFULLMETALCHEF
2 жыл бұрын
@@brucebaxter6923 except that at too steep a attitude you now have two surfaces creating drag instead of just one, and like the jet that was lost does not have variable pitch to compensate
@brucebaxter6923
2 жыл бұрын
@@TheFULLMETALCHEF Missing the point. Two surface creating lift and stall proof, What you lose by increased drag on the front you gain by increased lift overall.
@sactu1
2 жыл бұрын
I was with 34SQN RAAF in the mid-80s - we flew the BAC-111 in VIP configuration. The stick shaker/stick pusher test flights were the scariest, considering we all knew about the unrecoverable deep stall. However, the stick pusher occurred well above the stall speed and it was nearly impossible to pull against it. Oh yeah, it also had a loud claxton horn that went off just prior to stick pusher, which scared the hell out of you. Rule number one - keep the airspeed above stall.
@thoralexander9387
2 жыл бұрын
Beautiful video, for the basics and more advanced knowledge alike. As excellent as normal. Also, your English is almost perfect (from a native speaker), and you are very good at explaining complex topics in ways that the average viewer can understand. The video complements the commentary very well.
@Al-ih1en
2 жыл бұрын
Very good video. It's sad to see they couldn't exit the plane and use the parachutes. Elevators failed just when they needed it most.
@MiniAirCrashInvestigation
2 жыл бұрын
Really sad 😞
@jimmyyu2184
2 жыл бұрын
Wow, just wow. (Another) Great episode full of info. Things that we (now) take granted came from the lives of others. Big big thumbs up on this.
@mathis8007
2 жыл бұрын
The angle of incidence doesn’t change, its the angle of attack
@hotrodmercury3941
2 жыл бұрын
I think the most true quote I can ever quote from a teacher that I knew. He was talking about a NASCAR wreck that lead to restrictor plates. A very famous one you are sure to know, Bobby Allison. He said "It takes someone to die before anything changes" And time and time again I see it happen every once in awhile. The reason we have so many safety features or safety precautions is because of someone passing away or getting severely injured.
@voiceforthevoicelesstruth5480
2 жыл бұрын
Your content is excellent
@noneofyourbizness
2 жыл бұрын
2:46 in fact that would be an understatement !
@williamgeorgefraser
2 жыл бұрын
I haven't flown many times in my life but most were in a BAC 1-11. I always felt safer in that than in a Boeing.
@thamesmud
2 жыл бұрын
The blistering acceleration was what always got me, they used to go like scalded cats compared to the modern jets.
@johannesbols57
2 жыл бұрын
And? A gratuitous swipe at Boeing. How original.
@hoagy_ytfc
2 жыл бұрын
Why? Based on jingoism or something scientific? High-tail plans have terrible stall characteristics. (like the Trident crash at Staines). These planes were also disgracefully noisy.
@Arthion
2 жыл бұрын
@@hoagy_ytfc So were most aircraft of the era. It's only with more modern engines and designs that noise was significantly reduced
@hoagy_ytfc
2 жыл бұрын
@@Arthion but the 1-11s were bad even by the standards of the day, was the point I was trying to make.
@jeffphillips6993
2 жыл бұрын
My father was shocked when the prototype One-Eleven crashed as he worked on it as an aircraft fitter at Hurn Airport Bournemouth. When the internet became widely available I found an article on the crash. Apparently there was a stall system which operated in part by a hydraulic tab on the tailplane. The pump was undersized and failed plus the pitch reading was incorrect. When the pilot realised he was in a stall he was not aware the pitch was greater than the reading. Being a WW2 fighter pilot he tried a few manoeuvres but it was too late. On impact the forward movement was 75ft. The exit door was still in place as all the bolts had not been fired. The final comment was that military aircraft undergoing stall tests could deploy a tail parachute to bring the nose down. I’m not saying the article was correct but it is how I remember it.
@dodoubleg2356
2 жыл бұрын
Just an FYI...You wouldn't say, "To say that he's one of the few people who knew the plane best would NOT be an understatement." Saying he knew it best WOULD be an understatement. No biggie, just some constructive criticism from a faithful subscriber is all...Another great video BTW. 😉✌️
@rebeccahylant7695
2 жыл бұрын
Grammar
@paulbrouyere1735
2 жыл бұрын
Thanks for another great video. As a former RC pilot in the 80’s it’s not always necessary to die to learn how to fly safer. We trained on getting out of spins and stalls and aerobatics. In this situation I would try to roll out using the ailerons to allow the tail catching some wind. If nothing seems working, try something else
@achalbhoir1359
2 жыл бұрын
Landing gear extansion may provide some pitch down nose as per other incidents videos
@geonerd
2 жыл бұрын
T-tail deep stall had been a known issue for decades before the plane was built and flown.
@cageordie
2 жыл бұрын
It's called a super stall because the tail gets captured in the wind shadow of the wing.
@stevevet3652
2 жыл бұрын
What is really sad, the problem was found after the crash. I wonder if budgets had anything to do with not completing more test.
@Nimmo1492
2 жыл бұрын
Deep stall is what brought down BEA 548, too.
@BobbyGeneric145
2 жыл бұрын
I think you meant Angle of Attack. Incidence is the angle formed between the body and the wings.
@jossdionne9810
2 жыл бұрын
I loved this plane, for it took off so fast, and could land on very short runways. Also loved the DC3, and the 747.
@kolasom
2 жыл бұрын
For those who haven't worked on aircraft let me tell you -- the stick shaker is not very subtle. It is a violent movement designed to get your attention!!
@cyber25573
8 ай бұрын
The narrator of this did not explain why the nose went back up when the pilots put in maximum power. The deep stall phenomenon was not known very well at all in those days, and the pilots probably did not realize if they accelerate the air underneath that tail by going to high power, then the air pressure under the tail is reduced, and the air pressure above the tail is higher, will shove the tail down, putting the nose back up in the air. Kind of a counterintuitive thought, but they needed to keep those throttles back until the nose was down. So that airflow could be restored and airspeed increased. I flew both the DC9/MD80, and the Lear35. Both of those aircraft had a very strong stick pusher that would shove the nose down . in the case of the MD80, It’s a force of 80 pounds on the column and it will shove the yoke forward violently when you activate the stall warning. It’s activated several knots above the actual stall so you still have airflow over the tail when the elevator starts coming back down. it does that by a hydraulic circuit in the down elevator. That’s the only hydraulic flight control for pitch. Otherwise the elevator is cable operated with servo tabs. Douglas actually put an additional device called ventral strakes, underneath the nose on each side to help energize airflow over the tail at high angles of attack. That gives even more control in an extreme pitch situation. Just one more thought. The only thing that would’ve got the nose down quickly with no airflow would be a weight shift system that would allow weight to be moved forward very quickly from a cockpit control. If they could’ve moved a couple thousand pounds forward in a matter of seconds by using a weight shift system in the cabin that would’ve put the nose down. I’m guessing they had no such system installed . It’s obvious to me if they had known all of the dangers of the deep phenomenon they would’ve taken additional steps to get the nose back down in a loss of control situation.
@kristensorensen2219
2 жыл бұрын
Drag chute is needed to break a flat spin. This being a test plane should have had one. ERAU 80 CFIA&I ret.
@TJ-USMC
2 жыл бұрын
Great Aircrew !! "Semper-Fi"
@stevehall5299
2 жыл бұрын
I remember this, I recall vividly my mum calling up the stairs one afternoon, to tell me of the accident, awful business.
@gsmdo8836
2 жыл бұрын
Didn't a HS Trident deep stall and crash after take-off at Heathrow in 1972? BEA Flight 548 - in the days before CVR, so they weren't cetain, but that was the inverstigators' best guess, if I remember correctly.
@CharlesStearman
2 жыл бұрын
One of the Gloster Javelin jet fighter prototypes (which also had a T tail) was lost to a 'deep stall' 10 years before this accident so it seems surprising that the designers of the BAC-111 did not anticipate the problem. However, the Javelin had a much broader delta wing, so they may have thought the BAC-111's narrower wings would make it less prone to a 'deep stall'.
@Lozzie74
2 жыл бұрын
Angle of incidence is a static angle. Angle of ATTACK is what you were referring to.
@gordonmutten1750
2 жыл бұрын
Sounds like a similar issue to the Dehaviilland Trident in which a test also caused the plane to crash onto the airfield at Hatfield. I think the engines flamed out. As an apprentice there in 1972 I remember seeing the crater it had left near the edge of the airfield. I don't know if that incident was before or after the 111 one.
@stephenlittle7534
2 жыл бұрын
As being a British person. I THANKS THOSE WHO TOOK PART IN THAT EST FIGHT AND SADLY LOST THEIR LIVES TO SAVE ALL THAT FOLLOWED. THANK YOU.
@kevgermany
2 жыл бұрын
And there was a Trident full of passengers that stalled the same way. And if you recall, the Beech staggerwing had the same issue with its upper wing.
@roadsanctuary
2 жыл бұрын
I wonder if briefly activating the thrust reversers while in the deep stall on this rear engined airframe could have pulled the tail up enough to regain elevator control.
@nadernowzadi1
2 жыл бұрын
Very good thought and question Alex 🙏
@johnmanson4166
2 жыл бұрын
@Alfred Weber Two Tridents stalled, and crashed, one on a test flight in similar circumstances to this.
@johnmanson4166
2 жыл бұрын
They were only available on the ground on the 1-11.
@MarkPMus
2 жыл бұрын
Rear engined planes are more vulnerable to stalling than wing-mounted ones I have heard. I’ve never heard of BAC, we’re they a British company, and what happened to them?
@tow1709
2 жыл бұрын
British Aircraft Corporation --> British Aerospace --> BAE Systems
@chrismanspeaker9372
2 жыл бұрын
Brings up Chernobyl similarities, pushing something to the limits. Also, while these folks death did lead to safety improvements, they technically sacrificed themselves for money as this was a commercial airplane that went into service.
@HuNtEr-rd9lb
2 жыл бұрын
Video request: Investigation of N8097W.
@SGTSnakeUSMC
2 жыл бұрын
I wonder if they tried asymmetric thrust to try to turn or bank it to see if the nose would drop and possibly pick up speed? RIP
@iansinclair521
2 жыл бұрын
my recollection is that at least one Boeeing 737 may have been lost to a deep stall before they were well umderstood
@kentdavies1988
2 жыл бұрын
What's the proper way to get out of deep stall? Rudder?
@tomriley5790
2 жыл бұрын
Being a test pilot is not something to be taken lightly, such a shame they came so close to getting out of the stall and also to abandoning the aircraft (although bailing out of a freefalling civil aircraft would be alot harder than it sounds...)
@paulsmith843
2 жыл бұрын
Angle of Attack and the relative airflow is what you mean NOT angle of incidence. Deep Stall.
@ttnyny
2 жыл бұрын
2:46 Would not be an "understatement"? Or should that be "overstatement"?
@vicoastdog
2 жыл бұрын
Angle of attack, NOT angle of incidence.
@pjford1118
2 жыл бұрын
I've seen spin chutes used during flight testing for spin recovery. It's a shame they didn't do something similar.
@Purlee100
2 жыл бұрын
They did! But it too caused a crash, see my other comment.
@IARRCSim
2 жыл бұрын
Do they use fluid dynamic simulations and flight simulators to test planes before physically flying them now? That obviously wouldn't have helped in 1963 but such a flaw should show itself if the flight simulation was very accurate and without endangering the test pilot and team.
@momchilandonov
Жыл бұрын
Couldn't they figure out that the power caused the nose up and stop all power immediately? I feel like they still had plenty of time to react to this.
@leojennings2438
2 жыл бұрын
I think you were referring to angle of attack, not angle of incidence lmao
@SuzukiRider93
2 жыл бұрын
i wonder if they initially had enough altitude to roll out of it, if they had known what was happening
@mohamedshidane9155
2 жыл бұрын
Were the families at least compensated?
@nipuniperera9918
2 жыл бұрын
I just don't understand how they didn't realise this is wind tunnel testing.
@emjay9280
2 жыл бұрын
Is this the plane that hit Emmerdale?
@NeonVisual
2 жыл бұрын
Full flaps, reverse thrust.
@alhanes5803
2 жыл бұрын
Reverse thrust would push the tail down further.
@alhanes5803
2 жыл бұрын
Only hope would have been to use hard rudder and ailerons to roll past 90, and let the nose drop.
@slavix
2 жыл бұрын
Russian TU-154 got same issue. They call it "flat spin". Its impossible to get out the plane from this type of stall.
@colettechenal6852
2 жыл бұрын
but there is a really good video about it on Mentour pilot's channel
@AugustDwight
2 жыл бұрын
This was not a sacrifice. A sacrifice is a deliberate act, performed willingly and with full knowledge of what the result will be. This was an accident initially caused by cocky test pilots who assumed they could recover the aircraft from a stall condition well beyond the bounds of the planned test, and compounded by the second mistake of increasing engine thrust to attempt to recover. This was a tragedy, sure, and a lesson which led to innovations that saved many lives...but it was not a sacrifice.
@MrSuzuki1187
2 жыл бұрын
The correct term is angle of attack, not angle of incidence.
@matsv201
2 жыл бұрын
Its not only that its a T-tail... its also that tis rear engined thst make it so the wing is far bsck
@Spyke-lz2hl
2 жыл бұрын
I hate it when people mis-use the term “deep stall”.
@ruscador1
4 ай бұрын
i have flown on one british caledonean airways
@anhedonianepiphany5588
2 жыл бұрын
We owe test pilots a lot. Let’s hope that those who lose their lives in the pursuit of safer aircraft are rewarded by having their families well taken care of (suitably compensated).
@rebeccahylant7695
2 жыл бұрын
My thoughts exactly
@rickstone8592
2 жыл бұрын
Perhaps has already been mentioned, but you mean angle of attack, not angle of incidence.
@markusthl
2 жыл бұрын
You mistook angle of attack for angle of incidence, otherwise great video!
@ЕвгенийКукелев
2 жыл бұрын
Углы атаки под лоб загнали, итог плоский штопор
@Max.railways
Жыл бұрын
my favourite aircraft :/
@legomindstormsfan1
2 жыл бұрын
During flight tests of the Fokker 70 (also t-tail), they installed 3 rockets under the tail to push the nose down during a deep stall. You can see them in action here @2:53: kzitem.info/news/bejne/24uNvIKDnal8i6g
@datopperharlee2628
2 жыл бұрын
Passengers expect 'cutting edge technology' and airline manufacturers need to sell planes so theyre always at the cutting edge. That's why flying will never be safe.
@em1osmurf
2 жыл бұрын
NSTM: the naval safety "bible". all through my career i heard that every regulation was written in blood. if you sat down and read some of them, your blood would run cold thinking how that particular rule got inserted. one i investigated: "cargo lifts or elevator door interlocks must be fully operational." yeh--bad. closed casket bad.
@andrewnorris5415
2 жыл бұрын
Brave men, just wish they had bailed a little earlier.
@curt3494
2 жыл бұрын
RIP
@CHESSmaster69SH
2 жыл бұрын
I think you meant to say "Angle of Attack". Angle of incidence is fixed and cannot be changed. Keep up the good work. I really enjoy your channel.
@daszieher
2 жыл бұрын
Angle of attack, not incidence.
@s87343jim
2 жыл бұрын
The bitter sweet is that it happened in the test flight and gave us the safety feature that has saved countless lives. I have a question though since everything is mechanically linked on that aircraft, wouldn't the stick shake regardless? I remembered in my flight training days the yoke would shake as the airflow over the wing is being separated.
@EneTheGene
2 жыл бұрын
Nice to hear of these less talked about accidents.
@ihateusernamesgrrr
2 жыл бұрын
Probably the wrong word. It's not an accident, it's a testing incident. An accident implies the actions that lead to their death were unintentional, but they were deliberately testing the stall, and a stall is exactly what they got. They just weren't planning on not being around to see the following day.
@MothaLuva
2 жыл бұрын
Great video, as usual. May I suggest something? What you were calling „angle of incidence“ is actually angle of attack. The angle of incidence is the angle between the aircraft longitudinal axis and the airfoil reference line (basically, how the wing is attached to the fuselage). It’s usually something which on most airplanes cannot be changed, unless being extremely destructive. One airplane which could vary that is the F-8 Crusader, because it’s geometry didn’t allow sufficient angle of attack (and thus, lift) to be produced during take off and landing from carriers. So, the guys at Vought built in a hydraulic jack where the front end of the wings could be raised a few degrees for that purpose. The angle of attack is the angle between the airfoil reference line and the approaching air.
@toddsmith8608
2 жыл бұрын
^^^ What Johnny said. Angle of incidence can be altered slightly by flap/ slat extension but OP needs to be saying angle of attack. Also, many people confuse aoa with deck angle.
@toddsmith8608
2 жыл бұрын
Also, "airfoil reference line" is called the chord line and is basically a line from leading edge of wing to trailing edge.
@MemphisBBQ640
2 жыл бұрын
What we in America call "angle of attack" is called "angle of incidence" in Great Britain.
@MothaLuva
2 жыл бұрын
@@MemphisBBQ640 And how is the angle called at which wings are mounted to the fuselage in Britain?
@toddsmith8608
2 жыл бұрын
@@MemphisBBQ640 well that's strange. Cookies and biscuits, chips and fries, I suppose.
@lhw.iAviation
2 жыл бұрын
If at least 1 pilot made it, just imagine about how much more we could’ve learnt. RIP
@TimothyChapman
2 жыл бұрын
So that's how we discovered the deadly weakness of T tails. Never really thought about it until now. But now that I know how we learned this, I'm wondering what else we learned through someone else's death.
@ricardokowalski1579
2 жыл бұрын
The discovery of deep stall made McDonnel-Douglas add pilon flaps to the DC9 kzitem.info/news/bejne/16mI3oupqYaFfX4
@AviationHorrors
2 жыл бұрын
This wasn't the first T tail aircraft, nor one with problems: the F-101 Voodoo first flew several years earlier in 1954.
@Bertrand146
2 жыл бұрын
Back in those days, pilots didn't even know T Tails existed....
@MemphisBBQ640
2 жыл бұрын
Many advances in aviation technology, especially in the early days, were paid for in blood.
@the_rakan
2 жыл бұрын
@@AviationHorrors I remember that. Thank u
@michaelbuckers
2 жыл бұрын
Due to T-tail stalls being unrecoverable by normal means, T-tail planes require special stall recovery procedure, such as using a tail drag chute or tail pitch rocket where available, or banking as high as 90 degrees to exchange deep stall for a steep dive which IS recoverable.
@Steveman61
2 жыл бұрын
Great video, as always, many thanks for sharing it with us! I know that problem from the DC9 my dad was flying for decades and I was working on it as an engineer in the 80's. On the DC9 a locked in deep stall situation could occur as well. That is why the DC9 's had among other things an elevator power system allowing an elevator nose down command even when the t-tail had almost no air flow. As far as I can remember the "elevator pwr on" light was one of few blue/green indication lights on the annunciator panel. The system was checked during pre flt check by pushing the steering column full forward. Kind regards from Vienna, Austria
@AviationHorrors
2 жыл бұрын
Interesting, thanks for sharing!
@marcmcreynolds2827
2 жыл бұрын
The DC-9-10 was literally on the drawing boards when this crash happened. In the late 70's, I was told by a senior DAC engineer that the area of the DC-9's horizontal stabilizer was increased by "50% overnight" after the crash. I don't know whether the chord/span literally got bumped up by 22%, but nonetheless an indication of the effect this crash had on airliner design going forward. IIRC the MD-80 also experienced persistent deep stall during flight testing, but as expected from analysis was able to recover by the time it reached thicker air around 10k feet. Or maybe it was higher than that, and 10k was the designated bail-out altitude if the stall persisted? The test aircraft was outfitted for quick egress by the minimal crew, with the forward cargo door rigged to open when the first person jumped down a hole in the cabin floor above it. Also don't know whether the powered elevator for recovery had been developed at that point, or was turned off for the test, or ??. So a fuzzy and incomplete memory, but I'm passing it on with that caveat. Maybe someone who was actually involved with the flight testing can chime in.
@Steveman61
2 жыл бұрын
@@marcmcreynolds2827 Yes I have heard about that but when I started we had a DC9-30 fleet, so can't say a lot about the series 10. Over the time we got 50's and 80's.
@nigo1787
2 жыл бұрын
@@marcmcreynolds2827 yes I really think they didn't know that was possible at the time, and learned the hard way. I can only imagine what not being able to do anything and falling like a rock feel like. I wish they were able to escape the plane to tell the tale
@marcmcreynolds2827
2 жыл бұрын
@@nigo1787 My understanding is that they did stay in radio contact all the way to the ground. I'm fuzzier on specifics, like whether control movements for recovery attempts were being relayed in real time, but it seems there was a good technical account as to what was going on. That would have gone a long way towards dispelling questions afterward of for example whether hardware failure had been the cause, thus allowing the engineers to zero in on corrective action.
@ulin4226
2 жыл бұрын
It’s the Angle of Attack (AoA) which was exceeded and got them into the stall - not the Angle of Incident! The Angle of Incident is a fixed value and denotes the angle between the chord line of the airfoil and the longitudinal axis of the plane. It is a designed feature and cannot be changed by the pilots! The elevator controls the Angle of Attack, i.e. nose up or down.
@paulkasden9758
2 жыл бұрын
Wow. U did such a great job on this one bro.
@MiniAirCrashInvestigation
2 жыл бұрын
Thank you!
@phuketexplorer
2 жыл бұрын
Your 'Investigations' are amongst the best on KZitem - not too long and boring, and not too short with missing information. Well Done. I'm Subscribed!
@BestEachDay
2 жыл бұрын
Wow. I wish there were some way to accomplish these types of changes without death being part of the equation.
@AlessandroGenTLe
2 жыл бұрын
No other deep stall on this plane, but if you look at the story of the MD80, which has an identical configuration, you'll find them, and much later than 1963, like the West Caribbean Airways Flight 708 in 2005
@fliegenistdassicherste8828
2 жыл бұрын
8:16 But other planes than the BAC-1-11 crashed due to a Deep Stall during test flights, like a Trident in 1966 and a CRJ-100 in 1993.
@AviationHorrors
2 жыл бұрын
Yeah, and other planes like the F-101 had these issues prior to the 1-11's testing.
@reformCopyright
2 жыл бұрын
In hindsight, the danger of deep stall with a T tail seems obvious. I guess it wasn't that obvious at the time.
@AviationHorrors
2 жыл бұрын
True, but there are also benefits to the T tail design. And designers can always convince themselves that the problem is a "corner case" that will "never happen".
@wahyudyatmika5119
2 жыл бұрын
I mean, it was in the 1960s, the aerodynamic phenomena was not understood as much as we know today. They did not fully understand the limit of those phenomena. I think it is one of the driving factors of those BAC pilots exceeding the limits, to obtain more understanding to the aerodynamic characteristics. Sadly, it resulted in a dire consequences.
@Bertrand146
2 жыл бұрын
Back in those days, pilots didn't even know T Tails existed....
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