BBC TU144 / Konkordski article - for interest

[Phoenix1969]

- BBC News (http://www.bbc.co.uk/news/video_and_audio/features/magazine-36398439/36398439)

Dunno that they lost the race just because of the 1973 crash, though. There were plenty of other things wrong with that plane!

[Shaggy Sheep Driver]

As John Farley intimates in the video, the TU144 was technically inferior to Concorde. In particular the engine intakes and wing shape were a far superior design on the Anglo French aeroplane. If the Russians really had copied Concorde, they'd presumably have got those right! The TU144 crash was not a factor in its commercial failure, even though the BBC imply that it was!

[India Four Two]

I found JF's comments, about a French "reconnaisance" aircraft causing the crash, very interesting.

Can anyone expand on that?

JF, where are you? ;)

[Phoenix1969]

Indirectly the crash happened because of its inferior design.....those canard wings behind the cockpit were an add-on precisely BECAUSE the shape of the main wing as it was didn't provide enough lift at low speed - Tupolev Tu-144 "Concordski" Discovered Hidden in Tatarstan (http://www.autoevolution.com/news/tupolev-tu-144-concordski-discovered-hidden-in-tatarstan-video-86365.html)

And it was the canard wings a French Mirage was above the TU144 trying to get a picture of when the TU pilot suddenly saw the Mirage and got startled, hence putting it into too steep a dive.

India Four Two - have just seen your comment; take a look https://en.wikipedia.org/wiki/1973_Paris_Air_Show_crash

Shaggy Sheep - re your comments on copying (or not) the Concorde, see this mention of how a Soviet agent called Pavlov got sent to collect tire scrapings off the runway from a Concorde test aircraft and ended up being fed 'something like bubble gum' ! http://www.pbs.org/wgbh/nova/transcripts/2503supersonic.html

[Coochycool]

I was lucky enough to get a look at one a few years back when I visited a very good, mainly civil aircraft collection in the city of Ulyanovsk. Highly recommended. The concierge guy was kind enough to open it up especially so I could get inside.

It was only then that I learned a notable point which can be distinguished from the video. The 144 had 5 abreast seating as opposed to Concorde's 4.

Remarkably curved wing too. What a brute of an aircraft!

Cooch

[Phileas Fogg]

A number of stories have circulated over the years regarding the Paris crash, perhaps the most believable being that the TU144 was being shadowed by an aircraft that got too close, the TU144 needed to take avoiding action resulting in a journalistic type that they had in the cockpit falling on to the controls and the rest is history.

Another story was that they did copy designs of Concorde that they sourced however deliberately flawed plans were provided which resulted in the TU144 being the piece of cr@p that it was.

[PPRuNeUser0139]

NOVA | Transcripts | Supersonic Spies | PBS (http://www.pbs.org/wgbh/nova/transcripts/2503supersonic.html)

NARRATOR: The TU-144 was scheduled to fly directly after Concorde. As it taxied for takeoff, the Russian pilot, Koslov, was told by the French air traffic controllers that his display time had been cut in half.

HOWARD MOON: The French, in my opinion, intervened into a scientific, technical spectacle for political reasons. This was a major piece of French prestige and honor. I think they simply wanted to showcase their bird. They wanted to show it off to the world and to push the Russians in the background.

NARRATOR: French test pilot, André Turcat, was watching the TU-144's display.

ANDRÉ TURCAT: We saw the whole movement, the whole presentation of the airplane from very close up. I must say, it was very well done. A 360-degree turn above the runway with good inclination. After this last pass, the plane climbed quite steeply.

NARRATOR: British pilot, John Farley, and his co-pilot, Andy Jones, were also watching.

JOHN FARLEY: Because there was no cloud, he could go up and up and up, and, I don't know, three and a half, four thousand feet. This thing was just going up, looking at it as we were, you know, going away from us like this. And then suddenly, it just very abruptly leveled off. I mean, really violently. And it did something that you never see big airplanes do, really violently change their pitch attitude. And both Andy and I went, "Ooooh!" You got this vision of this aircraft coming down. And it has to do with the angle, the speed, and the distance remaining when you think, 'That's not right.' And I said to Andy, "He's lost it." And at that point, with the aircraft still fairly well up, probably -- I don't know -- 1,500 feet or a bit less, it started to break up and had clearly been overstressed.

NARRATOR: Six Soviet crew members and eight French citizens died. One little boy playing in front of his home was decapitated by a piece of flying debris. Two other children were also killed. Sixty people were seriously injured and fifteen houses totally destroyed.

...

NARRATOR: Nearly 25 years after the event, what caused the TU-144 to crash is only now being revealed. Minutes before Concorde and the TU-144 were scheduled to fly, a French Army Mirage jet took off. A surprising departure, since at international airshows, competing pilots expect to have the skies to themselves. Regulations state that a five-mile column of airspace must be kept free for their display. Concorde's crew was warned that the Mirage would be flying. Jean Forestier, French accident investigator, was asked if the same courtesy had been extended to the Russian crew.

JEAN FORESTIER: No.

NARRATOR: Why not?

JEAN FORESTIER: Right. Listen. We're moving away from the subject. If this is the case, we will go round and round impossible issues. As far as I'm concerned, it's very clear. The conversation is going in such a way. It's quite clear. Right. It's over.

NARRATOR: Jean Forestier's revelation that the Soviet crew was not warned of the Mirage was excluded from the government statement. There is speculation that the French neglected to admit this breach of regulations because the Mirage was on a clandestine mission to photograph the TU-144 in flight. In particular, the French wanted detailed film of the canards, the insect wings behind the cockpit. Flying at a height of approximately 4,000 feet in and out of the clouds, the Mirage tracked the TU-144 through its routine. As the Soviet plane climbed on a trajectory which would cross the Mirage's flight path, the pilot, Koslov, was not aware that the French jet was flying directly above him.

YURII KASHTANOV: At the moment when the pilots saw the Mirage which was flying at roughly the same height as the TU-144, they couldn't tell whether it was coming towards them or moving away.

NARRATOR: To avoid colliding with the Mirage, Koslov was forced to pitch the plane violently downwards, causing gravitational forces of minus 1G, known in pilot's jargon as a bunt.

JOHN FARLEY: We talked to the Russian ground crew immediately after the accident, and they all said, as did a Rolls-Royce chap who was familiar with their engine, they all said, "Well, the engines would have not have taken that bunt." Now, what they meant by that was the compressors would probably have surged. This means that you lose thrust. The rotating machinery at the front of the engine, which is generating the pressure before it gets to the combustion chamber where you burn the fuel, that will have stalled. It's purely aerodynamic, and it would have stalled. So, he had one, two, maybe even all three or four of his engines misbehaving now. So, he's level. And you can almost see the question mark over the top of the airplane, you know, as it's going along level.

NARRATOR: At a height of 4,000 feet, Koslov had just one option -- to put the plane into a steep dive in an attempt to windmill-start his engines.

JOHN FARLEY: So, he's got to lower the nose, quickly get some speed up, get these engines blowing around, and then go through a few check lists, turn on the fuel, turn on the ignition, and so on. And I suspect that he did this and was completely preoccupied with it. Probably got one, two, maybe even all of them going in the end, and suddenly thought, "Oh! Look at the height!"

NARRATOR: In his effort to pull the jet out of its steep dive, Koslov over-stressed the plane, causing a structural failure. It is widely believed that the French and Soviet governments colluded to cover up the cause of the crash. With eight French citizens killed on the ground, the French government did not want the world to know that the Mirage jet was the precipitating cause of the accident. The official statement implied human error on the part of the Soviet pilot. Jean Forestier returned to defend the statement.

http://www.dailymotion.com/video/x3qo9c4 : relevant part starts at 27:10

[Shaggy Sheep Driver]

Shaggy Sheep - re your comments on copying (or not) the Concorde, see this mention of how a Soviet agent called Pavlov got sent to collect tire scrapings off the runway from a Concorde test aircraft and ended up being fed 'something like bubble gum' ! http://www.pbs.org/wgbh/nova/transcr...upersonic.html

Not sure how trustworthy that link is. I stopped reading it (it's pretty long!) when I came to :

At 1,400 miles per hour, wind friction quickly raises airframe temperatures beyond the boiling point of water

It's not friction that heats Concorde's skin to its limit of 127 degrees C (on the nose, a bit less elsewhere), it's dynamic heating caused by supersonic shock compression of the air.

[Just a spotter]

On a slight tangent, it always amuses me how the British press seem to feed the idea that the tu-144 was a copy of the Concorde, while ignoring the similarities between the French Super Caravelle and British Bristol Type 223, the two independently developed predecessor concepts to Concorde. Just who copied from whom? Or could it be that designing an SST using contemporary technologies meant that the aircraft was predestined to to look a certain way.

IMHO the aborted American Boeing 2707 looked more like a tu-144 than it did a Concorde.

JAS

[Phileas Fogg]

The B707 and the Russian equivalent, the VC10 ditto, wasn't the BAe146 supposed be be 2 engines whilst Antonov have achieved it, the B727, the DH121 and the TU154, the BAC1-11, the DC9 and the TU134, the Fk27 and the AN24, the C5 Galaxy and the AN124, the B757 and a Russian equivalent ... All of these are just too much of a coincidence that one party isn't copying another!

[Shaggy Sheep Driver]

Any SST, especially back in the '60s but probably today as well, would have to have been a thin winged narrow delta with a minimum cross section fuselage (hence Bristol 223, Super Caravelle, TU144, and Concorde).

The Americans tried variations on this with their proposed SSTs and failed miserably.

Concorde's wing is a far more complex shape than that on the TU144, and the engine intakes (the secret of its supercruise ability) far superior to the TU144 design. Not much copying going on there, then!

[DaveReidUK]

The B707 and the Russian equivalent, the VC10 ditto, wasn't the BAe146 supposed be be 2 engines whilst Antonov have achieved it, the B727, the DH121 and the TU154, the BAC1-11, the DC9 and the TU134, the Fk27 and the AN24, the C5 Galaxy and the AN124, the B757 and a Russian equivalent ... All of these are just too much of a coincidence that one party isn't copying another!Yes, you'd have thought that over the years the Russians would have thought of some new places to stick the wings, tail and engines, rather than the same old boring, conventional locations. :O

[Phileas Fogg]

you'd have thought that over the years the Russians would have thought of some new places to stick the wings

They did think::

the crash happened because of its inferior design.....those canard wings behind the cockpit were an add-on

[PDR1]

The Americans tried variations on this with their proposed SSTs and failed miserably.


To be fair, the reason why the American SST programme became unaffordable was that they targeted Mach 3 rather than Mach2(ish). The airframe temperatures at Mach 3 are higher, which drove materials (and other) requirements that were uneconomic and that's why they abandoned the project.

If you want to cite a "clever" US/Europe discriminator I think it would have been identifying that Mach 2.2 was the economic sweet-spot rather than any airframe configuration issues per se.

PDR

[DaveReidUK]

I recall having an aerodynamics lecture a couple of days after the Tu-144 crash where we naturally wanted to pick the lecturer's brain about the accident. He told us in no uncertain terms that presence of "moustache" aerofoils on an aircraft was a dead giveaway that it had severe aerodynamic/CofG issues. As a Pole, he could scarcely conceal his delight at the event, which struck me at the time (and still does) as extremely distasteful, if perhaps understandable given the history of the two nations.

[Brit312]

I would like to point out that if the Concorde type B had gone ahead it would have had Retractable canards also, so as to improve the aircraft's low speed operation.

[Shaggy Sheep Driver]

Yes, it's touch and go whether canards pay their way. They improve low speed handling... Consider a Concorde about to touch down; it was John Farley I think who described it as an upside-down flapped delta at that moment. All elevons up, forcing the TE down, and the nose up.

And consider T/O. Concorde's wing produces no lift until it is pitched to positive AoA on rotation. So just before that point the tyres are doing about 250mph (pretty much the limit of tyre technology) with all 185 tons of the aircraft's weight on them. Them the pilot pulls back to rotate, the elevons go up, forcing the TE down, and those stressed tyres get a big extra loading as they are forced into the tarmac as the aeroplane rotates. Canards would be very useful to raise the nose without the airframe puting that extra load on the tyres at rotation.

More efficient to have canards lifting the nose than elevons forcing the tail down. But the canards have to be retractable for supersonic cruise, and that means a lot of added weight. Not considered worth it on Concorde.

I think it is incorrect to assume a delta with canards indicates a poor aerodynamic design.

[Evanelpus]

The B707 and the Russian equivalent

Which was? The others I relate to but not this one.

[John Farley]

I was very disappointed with the programme because it did not include all the reasons behind my comments. But there we go, I am grown up and should have expected that.

Was it a copy of Concorde? Of course not. As anybody in the business knows it was a bigger machine had a different wing plan form (double delta) and a different engine layout. Was there spying? Yes. But this was to give both sides a better understanding of the opposition’s strengths and weaknesses when it came to the sales bit. (Just as we wanted to know all about the Alpha Jet when doing the Hawk – only newspapers would suggest it was to copy. There is more to the engineering and aerodynamics of any aircraft than a few drawings)

http://img.photobucket.com/albums/v145/johnfarley/Concorde%20Tu114%20comparison_zpsm5kq8eyf.jpg

I had met Valezi Moltchnov, one of the pilots who was flying it at Paris, at the Hanover show a year earlier when I was displaying the first development Harrier and Valezi had one of the Tu-144 prototypes minus the very important canards that appeared later at Paris. He had come up to me as I was nosing around under his aircraft and finished up giving me the complete tour. We had got on like a house on fire and his English was probably better than mine. As a result, we later talked aeroplanes for several days as we wandered around the show. He was as sharp as a tack as evidenced when I asked whether he had any hobbies and he replied “Reading Flight and Aviation Week”. However, one probably had to have lived through the height of the Cold War to appreciate just how meaningful that was coming from a Russian in 1972. One night Valezi and I went to a shooting club in Hanover with his boss, Tupolev CTP Edward Elyan and German WWII fighter ace Adolf Galland. Not surprisingly, Galland thrashed me at shooting. I would have liked a return match in a hovering vehicle but life is not always that fair.

Back to Paris 1973. On the Sunday and last day of the show, fellow Dunsfold pilot Andy Jones and I were watching the Tu-144 display with considerable interest. We had been amazed earlier in the week at how much slower the aircraft could land now it was fitted with the canards. These retractable mini wings, when extended during takeoff and landing, generated so much nose up force that on the approach the wing trailing edge control surfaces were now deflected downwards giving in effect a delta with flaps down. At Hanover, without the canards, the aircraft had been like Concorde, the HP115 and the T221 and needed the trailing edge controls to be up for the approach and landing flare. This meant these three aircraft were in effect fitted with flaps working the wrong way round and so reducing lift. The lower approach speed possible with this new ‘flapped delta’ allowed the Tu-144 to land on the display runway 03 and exit at the second turn-off, which was a distance of some 1,200 metres.

Their display sequence included a touch and go on 03, followed by an initial steep climb then an immediate turn onto the downwind for the final landing, a manoeuvre almost amounting to a wingover given the cloud base during the week was below 2,000 ft. On the Sunday however, there was not a cloud in the sky and their initial steep climb after the touch and go was continued straight ahead to perhaps 4,000 ft. Then suddenly the aircraft violently bunted to level flight. Both Andy and I gasped at seeing such a push in that class of aircraft. As we looked at the retreating aeroplane flying away level, we had time to say to each other that it looked as if they were going home and we were going to be denied watching another full stop landing. Then down went the nose and the aircraft made as if to descend and turn back to the downwind leg. When it was about half way to the ground and having rolled left through 90o, so giving us a side view of the dive, something made me say to Andy “He’s going in”.

Even though it was still a long way up, that something which suggested to me that the crew had lost it was a mixture of height, unchanging steep nose down attitude and rate of descent. Suddenly the picture looked wrong. I have seen many aeroplanes come to grief at air displays and, if you are a display pilot yourself, you develop a feel for when the picture is wrong. Just as I said that to Andy, the aircraft started to pull out of the dive and for a moment we both felt it might just miss the ground but it broke up at about 1,000 ft.

My belief is that whatever caused the bunt caused the accident because I don’t believe the engines could have swallowed the appalling flow into the intakes produced by that much negative alpha without surging. Some people noticed an orbiting Mirage above them as they climbed but I did not. (The mirage actually can be seen very briefly on the BBC programme video of the accident). However, if the crew had unexpectedly seen another aircraft not far above them, then the sudden push we saw would have been instinctive. If the engines did all surge, then this would have necessitated a shut down and relight which would have required a pretty determined dive to obtain the necessary windmilling rpm. My guess is that, as they were busy trying to get some engines restarted, they suddenly saw the ground coming up and overcooked the pull, possibly due to the very nasty view of some 230ft electricity pylons that were right across their flight path.

[Phoenix1969]

Wow - just revisited this thread and seen the flurry of replies, especially the last one from John Farley himself.

Thanks a lot, John - that really fills out the story.

Phoenix

[B Fraser]

Great response John, very insightful. I had not appreciated the hammering that the Concorde tyres had to endure. Am I right in thinking that much of the low speed lift on Concorde was achieved through the small "whiskers" ahead of the forward doors ? Do they help generate the low pressure vortex above each wing ? If so, then what amount do they contribute ?

[John Farley]

Hi B

I think they were there to locate the vortices so that their origin did not wander about fore and aft and cause big trim changes by doing so.

JF

[Shaggy Sheep Driver]

Strakes are there to generate vortices at high AoA (they do nothing in cruise). These vortices sweep up to the upper section of the fuselage and keep the airflow attached so the fin works in clean air at high AoA (landing and T/O). Some of the Concorde books show dye flow photos that illustrate this.

[B Fraser]

Thank you both, every day is a day in the classroom.

:ok:

[PDR1]

IIRC the small strakes are there to keep the flow attacked for the fin, while the extended leading edges (what we would now call "LERX") generate huge vortices over the top of the wing to increase the lift coefficient at high AoA to reduce approach/landing speeds (already discussed in much detail here (http://www.pprune.org/tech-log/353898-strongest-wing-tip-vortices-when-slow-clean-heavy-but-why-2.html#post5292022)).

PDR

[WHBM]

Yes, you'd have thought that over the years the Russians would have thought of some new places to stick the wings, tail and engines
Well they certainly did with choppers ...

[ferrydude]

The grandpappy of both of ems


https://en.wikipedia.org/wiki/North_American_XB-70_Valkyrie

[tdracer]

Yes, you'd have thought that over the years the Russians would have thought of some new places to stick the wings, tail and engines, rather than the same old boring, conventional locations. :O

If you've ever tried to design an airplane from scratch, you'll quickly realize there is a reason they all tend to look the same.

Back when I was in college, we had a class on aircraft design - a really interesting class literally taught by the guy who wrote the text book :ok:. For our grade, we had to design an aircraft - either individually or as teams of two. One guy took some promotional materials for a "new kind of airplane" - STOL using ducted fans and such - from a startup company trying to raise funding. Short story, he simply couldn't make it work - things like CG and CP were all wrong, it would have been extremely heavy and very fuel inefficient. At least the guy had a sense of humor - when he did his presentation at the end of the class he put up a slide of 'the vision' from the promotional materials, followed by a slide of 'reality' - literally a streamlined brick :E Not surprisingly the company quickly disappeared without a trace - it wouldn't surprise me if it was scam.:rolleyes:

[B Fraser]

At risk of straying too far from the topic, the Russians were accused of simply repeating the Space Shuttle Orbiter design with the Buran. If you wanted to design a re-entry vehicle with a payload bay which would be capable of performing "cross range" manoeuvres then it is very difficult not to come up with the same answer. A blended wing / body would be far more challenging.


Cross range was a US military requirement for Vandenberg single polar orbit launches. The plan was to launch a shuttle, retrieve an object from orbit and then land. The earth will have rotated 20 degrees or so east during the 90 minute flight hence the need to fly cross range on the return. I guess the Russians wanted to do the same so the design was a foregone conclusion.

[Phoenix1969]

@WHBM - Well they certainly did with choppers ...

What was the name/no of this pterodactyl-like Soviet machine?

[WHBM]

@WHBM -

What was the name/no of this pterodactyl-like Soviet machine?
Mil-12. A 4-engined helicopter. It is really two Mil-6 twin engine choppers bolted side by side. It was designed to carry ICBMs which had been distributed by the Antonov 22 heavy cargo aircraft onward into remote launch locations in the forest.


https://www.youtube.com/watch?v=hdiXJZjZ5Cs

[Phileas Fogg]

If you've ever tried to design an airplane from scratch, you'll quickly realize there is a reason they all tend to look the same.

Then why doesn't a VC10 look like a DH Comet like a B707/DC8, a F28 like a Bae146, a DC9 like a B737, a SF340 like a Do328 like a Shed360 like a DHC8, a DC10 like a B747 and WTF was a BAe ATP supposed to look like? :)

[tdracer]

Phileas, once someone comes up with a better idea, well it's hard to keep a secret when it's in plain view.
Boeing decided putting the engines on pods under the wing worked better back on the B-47. It's been a long time since anyone has designed a new subsonic airliner with the engines buried in the wing.
Similarly, putting engines in the tail works well so long as you precisely know the weight of the engine package. The problem is, engines have a bad habit of gaining weight - especially when the thrust ratings get bumped up. As a result, late production 727s carried several hundred pounds of ballast in the nose. The MD90 was much worse - fan blade out loads drove massive weight into the engines late in the program, and the required nose ballast was around a ton. That's a lot of lost payload/increased fuel burn and even ex McD engineers that worked on it admit the MD90 is not a very good airplane due to the extra weight. As a result, it's been decades since anyone designed an entirely new subsonic airline with engines in the tail (MD11, MD90, and MD95/717 all being derivative designs).
So, the A380 looks a lot like a 747 (but with an ugly fuselage), the A350 is hard to distinguish from a 787, and a 777 looks a lot like a 767 that got scaled up.


Until someone makes a new breakthrough that works - such as blending wing/body - it's going to be really hard to tell the difference between any new design twin engine aircraft from a distance, especially when there is nothing to gauge the size by...

[DaveReidUK]

Until someone makes a new breakthrough that works - such as blending wing/body - it's going to be really hard to tell the difference between any new design twin engine aircraft from a distance, especially when there is nothing to gauge the size by...

Some are a bit easier to tell apart. :O

http://www.aviastar.org/pictures/ukraine/an-158.jpg

and WTF was a BAe ATP supposed to look like? :)

The ATP is basically a warmed-over Avro/HS/BAe 748, which in turn was intended to be a DC-3 replacement (a role it only partly managed to achieve) and shared the same basic configuration.

[Phileas Fogg]

The ATP is basically a warmed-over Avro/HS/BAe 748

Besides them trying to market it as a STOL unpaved strips aircraft, I believe one or more incidents at Portsmouth Airport, the Avro 748 was a good aircraft, still flying today.

By comparison the BAe ATP looked, nor performed, anything like it and was a piece of .....

That said, I did do some contract work for one (one aircraft of the type) ATP operator and they remarked that per bum on seat the fuel economy was remarkably good.

[Phileas Fogg]

it's going to be really hard to tell the difference between any new design twin engine aircraft

Ahem:

http://tourweek.ru/upload/iblock/dff/1b.jpg

[B Fraser]

I am rather puzzled (it doesn't take much) why manufacturers have not adopted a canard layout. Having an upside down wing at the back seemed daft to me when I first learned about it as a spotty teenager. I hoped that airframe development would eventually see sense, swap the arrangement around and have a foreplane that generated lift instead of wasteful downward force. In general terms, having a vortex above the main aerofoil section appears to be a good thing e.g. the fin / strake / widget on Airbus engine cowlings. Could a lifting foreplane also generate a vortex at the tip which could then be used to enhance the performance of the main wing ? I would be grateful if a genuine expert would please explain to me why this has never been adopted for airliners. Mr Rutan's aeronautical carriages seem to do rather well.


To while away the time before we see blended wing airliners take to the skies and to keep the thread on track, here is another TU-144 article.


TU-144 Flying Laboratory | NASA (http://www.nasa.gov/centers/dryden/history/pastprojects/TU-144/index.html)

[PDR1]

Then why doesn't a VC10 look like a DH Comet like a B707/DC8, a F28 like a Bae146, a DC9 like a B737, a SF340 like a Do328 like a Shed360 like a DHC8, a DC10 like a B747 and WTF was a BAe ATP supposed to look like? :)

Because they were all designed to different sets of requirements at different times and different technology states.

PDR

[PDR1]

I am rather puzzled (it doesn't take much) why manufacturers have not adopted a canard layout. Having an upside down wing at the back seemed daft to me when I first learned about it as a spotty teenager.

The problem with the canard layout is making it intrinsicly safe when stalling whilst maintaining efficiency. With a tail-at-the-back design you can arrange the neutral point so that either the wing or the tailplane stalls first and still get safely close to maximum lift coefficient when needed. If the wing stalls first then the nose drops, reducing AoA and promoting recovery. if the tailplane stalls first then the nose drops, promoting recovery.

With a canard layout it's very different. It's ONLY safe if the foreplane stalls before the mainplane. If the mainplane stalls before the foreplane then the aeroplane pitches nose-up (or pedantically "tail-down") and drops into a deeply stalled condition with no available pitching forces that would pull the nose down. recovery would need to wait for it to drop into a tailslide which (hopefully) would then yaw around into a nose-down condition from which it could recover. This will take a LOT of height. To minimise the risk of this condition a canard must be restricted such that it can never get the mainplane close to Cl(max), and as a result a canard needs to carry more wing for a given loading and landing speed, so the drag is higher and the efficiency is less.

There are other, lesser, issues. The foreplane creates a downwash, and it must not be allowed to impinge on the mainplane because it changes the local AoA and stuffs up the efficiency of what should be the most efficient lift-generating area of the wing (the inner wing area). To avoid this you need vertical seperation, which either needs the foreplane to be about eight mainplane root chords higher than the mainplane, or about two below it. The former isn't achievable because of the effect it would have on forward keel area, and the latter is only achievable if the mainplane is mounted like the tailplane of a C5A or VC10. Aside form the weight penalty of a fuselage structure stiff enough to mount the mainplane up there, the result would place fuel tanks and engines a long way off the ground with consequent issues for refuelling and engine maintenance, never mind the required deep maintenance hangar design.

Finally, it's true that a canard generates lift, but you don't really want to generate much of the overall lift with a smaller surface because compared to the mainplane it either has lower aspect ratio, short chord, or both. And that means that the lift it develops comes at a much higher (drag) price than adding the same area to the mainplane would achieve - the same reason why biplanes fell from fashion as soon as we learned how to make cantilever wings that didn't need the extra moment of inertia available from braced-truss multiwing layouts.

There are other reasons, but those are the main ones.

Also "blended wing" configs are very popular as university student projects, but they're not really suitable for line service. One reason is that there's nowhere to put the fuel, but the main reason is that you can't design a "family" (like the A318/319/320/321) as there is nowhere to easily "stretch" then to adapt them for different mission profiles.

€0.03 supplied,

PDR

[Stanwell]

Thanks for that post, PDR. Things are now a little clearer for me too.

I think I'd mentioned it a while back on another thread, but a former Chief Project Engineer with BAe, Roy Braybrook, was firmly of the opinion that ..
"The best place for a canard is on someone else's aircraft".

[B Fraser]

Thanks for that PDR, I guess we are still some way off airliners becoming interesting to look at again. Sadly we have just two types, the 747 (plus the A380 ugly sister) and everything else.

[Phileas Fogg]

Sadly we have just two types, the 747 (plus the A380 ugly sister) and everything else.

Nope:

In the puddle jumper market there is the BN2, the DHC6 and the Do228.

The 30 something seat market is lacking but apparently RUAG are thinking of reinventing the Do328, Saab are long out of the civilian aircraft market and god forbid that Short Bros might reenter the civilian aircraft market!

50 (ish) seats then solely the ATR42 but orders are lacking.

Stretched turboprop then ATR72 and DHC-400

Puddle jumper jets then EMB135/145 and CRJ's

Commuter Jets then the F28 family, the BAe146 and the EMB175/195 mob, apparently Bombardier are to have a crack at this market also.

The smaller jets then the A320 and B737 families.

The medium jets then the B757, B767, B787, A330, A350.

The big and/or 4 engine jets then the B777-200/300, A340, B747, A380.

Far more than merely: just two types, the 747 (plus the A380 ugly sister)

[WHBM]

god forbid that Short Bros might reenter the civilian aircraft market
Shorts, in Belfast, are as much in the civil airliner market as they long have been, just producing major subcomponents like fuselages instead of final assembly. The new Bombardier CSeries has a lot made at Shorts, just like the De Havilland Comet did 60 years ago.

[Dr Jekyll]

Fascinating post PDR1, thanks. Why do the Rafale and Typhoon have Canards then?

[PDR1]

Thanks for that post, PDR. Things are now a little clearer for me too.

I think I'd mentioned it a while back on another thread, but a former Chief Project Engineer with BAe, Roy Braybrook, was firmly of the opinion that ..
"The best place for a canard is on someone else's aircraft".

Note that my remarks only apply to canard airliners where cost per seat mile and low cost of ownership are the primary concerns. Canards have their place.

One example is the supersonic fast jet, where various permutations of operational requirements can drive the design towards a slender delta mainplane - the use of a canard allows a slander delta to have HLDs like flaps & slats to reduce take off and landing speeds, while running at zero lift in high speed flight for minimum drag.

Another example is where absolute peak Cl is not needed, but a pusher propeller (for low speed acceleration and visibility) makes it difficult to achieve the desired CG win a conventional layout - the BAe SABA (especially in the initial P1233-1 config) is just such an example:

http://i9.photobucket.com/albums/a94/WtMiller/4.jpg

In this case it also gave a long straight wing with nine pylons whose position allowed the stores CGs to be bang on the aircraft CG, so there were no CG restrictions on what could be hung on the pylons.

I've got a copy of the original SABA concept study & brochure because this aeroplane fascinated me; and aeroplane the size and weight of a Sea Fury with a 5,000-7,000shp unducted fan would have been the ultimate aerial sportscar! I've always felt some wry amusement at the way it shows that future military needs can never be predicted accurately. SABA was cancelled in 1990 in response to the fall of the Berlin Wall, as part of the "peace dividend". At the time they said:

"With the threat of soviet tanks rolling across western Europe a dedicated anti-tank force multiplier won't be needed. The UK won't find itself in any major tank battles for the foreseeable future".

Of course history loves to bowl the odd bouncer [that means "throw a curve ball" for the colonials], and it was only months after that statement that the British army was in the biggest tank battle since El Alamein...

PDR

[DaveReidUK]

god forbid that Short Bros might reenter the civilian aircraft market!

Shorts did think about it, in the late 80s:

https://www.flightglobal.com/FlightPDFArchive/1987/1987%20-%202584.PDF

I remember the stunned expressions on the faces of the punters at Le Bourget. :O

[FlightlessParrot]

So, the A380 looks a lot like a 747 (but with an ugly fuselage)
Every time I recognise an A380 by thinking "Stubby looking thing, four engines" I realise that what is flying at the moment is the cut-down version, and it will look right if they ever stretch it to full length. No, I am not privy to Airbus secrets, but nobody could have designed something so abbreviated as the definitive aeroplane.

[megan]

Why do the Rafale and Typhoon have Canards then?The benefit of canards on a fighter might be explained why some operators of the Mirage III fitted them. Here are the reasons given by the Swiss.

The requirement was for better handling with reduced pilot workload, better turn rate, increased angle-of-attack (AoA), reduced minimum airspeed.

The canard produces two additional vortices which combine with the vortices on the delta wing. This gives an extension of controlled airflow up to a higher AoA and an unshielded fin and rudder. The vortex lift starts earlier, which results in reduced drag at a given lift. At a given AoA, the canard configuration gives more lift and less drag than the canardless delta configuration. The improved yaw stability permits higher AoA, and therefore lift and drag are approximately doubled with the canards. Overall manoeuvrability at low speeds is much improved. Minimum speed in 1g flight is down from 150kt IAS to less than 107kt.

Article here will give a primer.

https://www.flightglobal.com/pdfarchive/view/1982/1982%20-%200309.html

[B Fraser]

The Swedes came up with the Viggen. I was looking for a photo and stumbled on this one which will be a familiar sight to many.


http://www.vintage-airfix.com/images/Type%204%20Saab%20Viggen.jpg




In response to Mr Fogg - the small turboprops do have a certain element of individuality and I would add the Twin Otter. However, to me the E-195, 737, A-320 family and larger twins are all very similar, apart from their size of course. There will be excellent engineering and economic reasons for this but to the inner youth in all of us, the same overall shape does appear rather dull. I had forgotten about the A-340 ..... as have much of the industry.


I guess that most of us grew up in that magical age where we had Concorde, VC-10's, Harriers, Vulcans and Americans tootling off the moon. Happy days but now we have the accountants in charge.

[PDR1]

I guess that most of us grew up in that magical age where we had Concorde, VC-10's, Harriers, Vulcans and Americans tootling off the moon.

Don't talk about the Vulcans going to the moon in public, for cripes sake, it's classified! If you start talking about that they'll realise how they were used mask the demolition of the WTC...

PDR

[El Bunto]

Shorts did think about it, in the late 80s:And also the FJ-X project for a 50-seat regional jet powered by CF34s.

Sounds ahead of its time? Fokker were keen to proceed with the project ( would have slotted nicely between the F50 and F100 ) but their bid for Shorts was passed-over in favour of Bombardier who promptly shut-down the FJ-X work in order to protect their concept for an RJ based on a stretched Challenger...

[DaveReidUK]

And also the FJ-X project for a 50-seat regional jet powered by CF34s.

I don't think the project got as far as selecting an engine supplier (Shorts was looking for a risk-sharing partner, rather than just an OEM), though it could well have ended up with the CF34, had it gone ahead.

Sounds ahead of its time?Not according to one wizened Air Canada exec, who sat through the presentation on the FJX and then went to his filing cabinet and pulled out a dusty brochure from 1949 ...

https://upload.wikimedia.org/wikipedia/commons/1/1c/Avro_Canada_C-102_Jetliner.jpg
https://en.wikipedia.org/wiki/Avro_Canada_C102_Jetliner#/media/File:Avro_Canada_C-102_Jetliner.jpg

[Phoenix1969]

Wow - I don't think ANY thread started by me on any forum has EVER had this many responses.

Thanks a lot, guys - very educational.

Feenics

[Stanwell]

Feenics,
Once Dave Reid's attention is drawn to such a thread, no stone shall be left unturned. :ok:

[Phileas Fogg]

During the mid 90's I recall working with a Mr Norman whose father, Desmond, was then working on something that he best described as a 3 engined Shed360 type aircraft.

Clark-Norman Triloader proposal for a 3 engined transport aircraft With an engine configuration almost identical to that of the Trislander but with three 45kW(600 hp) turboprops. Preliminary performance figures indicated a take-off run at sea level of just 740 ft (225m); long-range cruise speed of 155kt (290 km/h); and a range of 580 km (315 nm) with a payload of 3,000 kg. The large hold could have accommodated up to five LD3 containers. Side doors were proposed for palletised cargo and a front-loading door for containers and bulky goods. Wingspan was 24.4m and length 19.05m.

[Haraka]

PF. I think that was the "Mainlander".

[ferrydude]

Haraka, don't think so, the Mainlander (BN-4) was a 4 engine design, all wing mounted.

You can see a conceptual drawing here.

http://www.ivanberrymandirect.com/BNAPS_Images/BNAPS_News-November_2012.pdf

[treadigraph]

Triloader (https://books.google.co.uk/books?id=94ChDS0EutEC&pg=PA35&lpg=PA35&dq=Clark-Norman+Triloader&source=bl&ots=AmHyiHjjkt&sig=do_3ZTp5uhqpdQSm8IQ_RTZg7OI&hl=en&sa=X&ved=0ahUKEwiMkZ2c1ZjNAhWoB8AKHS4kBW8Q6AEIQzAF#v=onepage&q=Clark-Norman%20Triloader&f=falsehttps://books.google.co.uk/books?id=94ChDS0EutEC&pg=PA35&lpg=PA35&dq=Clark-Norman+Triloader&source=bl&ots=AmHyiHjjkt&sig=do_3ZTp5uhqpdQSm8IQ_RTZg7OI&hl=en&sa=X&ved=0ahUKEwiMkZ2c1ZjNAhWoB8AKHS4kBW8Q6AEIQzAF#v=onepage&q=Clark-Norman%20Triloader&f=false)

[Haraka]

Some pictures of the Mainlander visioned in BAF scheme with a 3-View can be found on Google:
Fairey Britten Norman Mainlander:
Fairey Britten-Norman proposes a Hercules-size Bristol Freighter replacement with a Trislander-type layout:
"The aircraft was designed to carry 100 passengers or ten tons of freight or vehicles over 250 miles, 400 km at 200kt, 370 km/hr. At the maximum take-off weight of 62,5001b, 28,500 kg and sea level, ISA plus 20 °C, the unfactored take-off distance to 35 ft is 2,250 ft, 685m. It was to be powered by three Rolls-Royce Dart RDa7s rated at 2,280 t.e.h.p.(wet) arranged in a layout similar to that of the company's Trislander design."

This is not to say of course that the 4 engined version of the Islander as illustrated in ferrydude's reference wasn't also included in a study under the same title. ( The BN4 looks like being inspired by "Dove to Heron" and bears no resemblance to the three turboprop scheme ).
Treadigraphs Triloader is a much later design from 1991 ( and new to me), indeed looking a lot like a cross between a big Skyvan and a Trislander.
All interesting concepts.

[cyclic35]

I was very disappointed with the programme because it did not include all the reasons behind my comments. But there we go, I am grown up and should have expected that.

Was it a copy of Concorde? Of course not. As anybody in the business knows it was a bigger machine had a different wing plan form (double delta) and a different engine layout. Was there spying? Yes. But this was to give both sides a better understanding of the opposition’s strengths and weaknesses when it came to the sales bit. (Just as we wanted to know all about the Alpha Jet when doing the Hawk – only newspapers would suggest it was to copy. There is more to the engineering and aerodynamics of any aircraft than a few drawings)

http://img.photobucket.com/albums/v145/johnfarley/Concorde%20Tu114%20comparison_zpsm5kq8eyf.jpg

I had met Valezi Moltchnov, one of the pilots who was flying it at Paris, at the Hanover show a year earlier when I was displaying the first development Harrier and Valezi had one of the Tu-144 prototypes minus the very important canards that appeared later at Paris. He had come up to me as I was nosing around under his aircraft and finished up giving me the complete tour. We had got on like a house on fire and his English was probably better than mine. As a result, we later talked aeroplanes for several days as we wandered around the show. He was as sharp as a tack as evidenced when I asked whether he had any hobbies and he replied “Reading Flight and Aviation Week”. However, one probably had to have lived through the height of the Cold War to appreciate just how meaningful that was coming from a Russian in 1972. One night Valezi and I went to a shooting club in Hanover with his boss, Tupolev CTP Edward Elyan and German WWII fighter ace Adolf Galland. Not surprisingly, Galland thrashed me at shooting. I would have liked a return match in a hovering vehicle but life is not always that fair.

Back to Paris 1973. On the Sunday and last day of the show, fellow Dunsfold pilot Andy Jones and I were watching the Tu-144 display with considerable interest. We had been amazed earlier in the week at how much slower the aircraft could land now it was fitted with the canards. These retractable mini wings, when extended during takeoff and landing, generated so much nose up force that on the approach the wing trailing edge control surfaces were now deflected downwards giving in effect a delta with flaps down. At Hanover, without the canards, the aircraft had been like Concorde, the HP115 and the T221 and needed the trailing edge controls to be up for the approach and landing flare. This meant these three aircraft were in effect fitted with flaps working the wrong way round and so reducing lift. The lower approach speed possible with this new ‘flapped delta’ allowed the Tu-144 to land on the display runway 03 and exit at the second turn-off, which was a distance of some 1,200 metres.

Their display sequence included a touch and go on 03, followed by an initial steep climb then an immediate turn onto the downwind for the final landing, a manoeuvre almost amounting to a wingover given the cloud base during the week was below 2,000 ft. On the Sunday however, there was not a cloud in the sky and their initial steep climb after the touch and go was continued straight ahead to perhaps 4,000 ft. Then suddenly the aircraft violently bunted to level flight. Both Andy and I gasped at seeing such a push in that class of aircraft. As we looked at the retreating aeroplane flying away level, we had time to say to each other that it looked as if they were going home and we were going to be denied watching another full stop landing. Then down went the nose and the aircraft made as if to descend and turn back to the downwind leg. When it was about half way to the ground and having rolled left through 90o, so giving us a side view of the dive, something made me say to Andy “He’s going in”.

Even though it was still a long way up, that something which suggested to me that the crew had lost it was a mixture of height, unchanging steep nose down attitude and rate of descent. Suddenly the picture looked wrong. I have seen many aeroplanes come to grief at air displays and, if you are a display pilot yourself, you develop a feel for when the picture is wrong. Just as I said that to Andy, the aircraft started to pull out of the dive and for a moment we both felt it might just miss the ground but it broke up at about 1,000 ft.

My belief is that whatever caused the bunt caused the accident because I don’t believe the engines could have swallowed the appalling flow into the intakes produced by that much negative alpha without surging. Some people noticed an orbiting Mirage above them as they climbed but I did not. (The mirage actually can be seen very briefly on the BBC programme video of the accident). However, if the crew had unexpectedly seen another aircraft not far above them, then the sudden push we saw would have been instinctive. If the engines did all surge, then this would have necessitated a shut down and relight which would have required a pretty determined dive to obtain the necessary windmilling rpm. My guess is that, as they were busy trying to get some engines restarted, they suddenly saw the ground coming up and overcooked the pull, possibly due to the very nasty view of some 230ft electricity pylons that were right across their flight path.
Watched the BBC4 Witness Programme, where John Farley mentions the crash. This kind submission really supplies interesting detail. If you read this John, thank you again. Michael.

[MrSnuggles]

Re: Canards

Everyone should have a few of these:

http://www.aerospaceweb.org/aircraft/fighter/gripen/gripen_02.jpg

http://www.ipmsstockholm.se/home/wp-content/uploads/2012/11/jas39_04.jpg

Yes I am Swedish. :-) Aren't they beautiful? And they work! And they can be bought already! Twenty of these and you have money left for a hangar, personnel, spare parts, and gold watches for the whole pluton, instead of one lousy F-35 with questionnable performance. Just kidding. The F-35 isn't even ready yet. ;-)

[megan]

Our skies will be graced with some examples this week by visiting Thai aircraft MrSnuggles. Tearing up the skies until 17 August.

[Volume]

The grandpappy of both of ems
https://en.wikipedia.org/wiki/North_...XB-70_Valkyrie

And his brother
https://en.wikipedia.org/wiki/Sukhoi_T-4
Air Force Museum - Monino, Russia (http://www.moninoaviation.com/24a.html)
Already with an interesting fixed canard design, so that detail was already known some years before the 144.
The view from behind (http://static1.squarespace.com/static/565a2a6ee4b0f33a7ada25b9/t/565b98eee4b022a251120bdf/1448843504521/Art-of-Monino-Sukhoi-T-4-rear-view-by-Kent-Miklenda-1920x1200.jpg?format=2500w)with the 4 grouped engine exhausts looks line a Star Wars battleship to me... Especially if you see it live on a grey and frosty day in Monino.