Posts about: "Tu-144" [Posts: 25 Page: 1 of 2]¶

Just wondering: does anyone know if a Concorde driver ever flew the Koncordski (Tu-144) ?

Lurking SLF
An interesting post Darragh, but with the greatest respect I think that you may have missed the whole point of this thread. As wonderful as the Boeing 747 is (personally I think that the 744 is one of the finest commercial aircraft ever built), I think anyone would agree that there is no comparison at all, as far as technical achievement goes, between the 747 and Concorde. So many boundaries had to be crossed with the Concorde design, and technical problems were overcome that had defeated many of the world's leading designers. I do have a vague idea what I am talking about here; although I was directly involved with Concorde for 30 years, I am also licensed on both the 744 AND the 777, and although I hold Boeings with the greatest respecect and admiration, nothing so far in the realms of commercial aviation can really compare with the technological marvel that was Concorde.
I think that most of the posters here will be sorrry that you felt you wasted 2 hours reading through these pages, I feel most of us have thoroughly enjoyed reading each others posts.
The YouTube links were great though.
atakacs
To the best of my knowledge no. The original TU144 was an extremely crude attempt by the Soviets at commercial supersonic aviation, and the political climate at the time would not have permitted such a thing. The TU144D used in the 1990's as a joint NASA/Russian experiment was a different beast altogether however, with far better engines and systems, but as far as I am aware the only western pilots to fly it were American chaps.

Dude

Well, it was essentially a development airframe pressed into premature service for the sake of beating a western project into the air. One wonders whether the story would have been different if the designers had been allowed to take their time and develop it properly.

This is off-topic, so I ain't going to bang on this subject after this post, but I wouldn't be so quick to denigrate former Soviet technology in all cases. Those "agricultural" fighters can mix it up with the best the west has to offer (until - or if - the F22 comes online) in terms of manoeuvering ability, if not in terms of weapons. Elements of their rocket technology were in advance of what we had at the time, and the solutions they came up with to put the Tu-144 in the air may have been crude, but they were to some degree effective, which can denote an elegant solution in itself.

That said, this thread is about an aircraft which was the result of - unarguably - some of the best engineering in aviation history, and I'd much rather talk about that!

To conclude this slightly o/t story :

The Tu144D was the last production model of the Tu144.
With improved engines and other refinements, it was capable of supercruise (Mach 2 without afterburners). Only five were built, and they came too late ; the aircraft went out of service, and were put into storage.

Tu-144D s/n 77114 was brought out of mothballs (with less than 83 hours "on the clock") for the joint NASA/Russian program in the '90s and modified, with completely new more powerful engines (same as those of the 'Blackjack' Tu-160 bomber) and a fit of sensors and test equipment, to become the Tu-144LL (flying laboratory). A total of 27 flights were made.

The entire "High Speed Civil Transport" study indeed cost over $300M, but the actual work on the Tu-144LL reputedly cost less than $20M, although it's not known exactly what that bill represents.

CJ

DozyWannabe
Good point I suppose, but you could say that the six Concorde prototypes, Pre-Production and Production Series Test aircraft were also development aircraft, and yet more or less worked just as it said on the tin', where the TU144, in spite of all the facilities of Andrei Tupolev's design bureaux, not to mention more or less unlimited Soviet state funds produced a machine that in my opinion really BELONGED in a tin can. (I know this is all off topic, honest guys, I won't mention this stuff again ).
In reality the Soviets really lacked both propulsion technology as well as the systems expertise required to build an aircraft with even a remote hope of Mach 2 cruise, let alone safe and comfortable enough for fare paying passengers. The original aircraft had all for engines in one giant nacelle, and the landing gear retracted into the engine inlet duct itself, great for an undistorted flow path to the engines . The variable inlets were manually operated by the flight engineer as well, no automatics here. In the mid 1970's the Russians even approached PLESSEY to build a digital engine control unit for the TU144. A similar PLESSEY unit had been VERY successfully flight trialled on production series aircraft 202 (G-BBDG) and only lack of funds prevented it being used on the production aircraft. As this unit could obviously be used for Soviet military applications, there was objection from the UK government, and more than just a little trans-Atlantic pressure applied, and so this venture never happened.
Until the advent of the Mig-29 and Sukhoi SU-27 this really was not the case. I'm afraid I'm with galaxy flyer on this; If you look at the air war over Vietnam, when an F4 met a MIG 19 or MIG 21 in an even air-to-air combat, the MIG was going down. (OK this could be partially down to superior US pilot traing etc, but if you look at the handful of skirmishes where the 1960's/1970's Soviet aircraft were engaged in Combat against US or French built fighters, the MIGs never really did very well at all). However, the aircraft that the Russians have been producing from the Mig 29 onwards seem to be in a completely different class now; hope they really are the good guys now.
ANYWAY, back on topic
Lurking SLF
No problem at all Darragh, please keep visiting us and post here also anytime.
Nick Thomas
I'm not sure that I can describe the DEBOW process remotely as eloquently as my friend Bellerophon did, I particularly loved the 'out of balance tumble-drier' bit, but starting a hot or even warm engine, even at DEBOW, you could certainly 'feel' the noise on the flight deck, until the shaft distortions evened out.
Now for the PFM bit, equally eloquently alluded to by Bellerophon:
DEBOW itself was maintained by a special sub-idle datum in the electronic Engine Control Unit, and once the engine was accelerated towards normal idle (61-65% N2, depending on the temperature of the day) even if the switch described by Bellerophon was accidently re-selected, an electronic inhibit gate in the ECU prevented this sub-idle datum from being used again that engine cycle.
You're welcome Nick, actually the roll and yaw trims operated in a similar manner to the pitch, although of course these was applied by a manual trim wheel only. (No French bike bell either ). Rotation of either wheel (more a giant knob actually) merely shifted the neutral datum of the relevant artificial feel unit, which in turn shifted the rudder pedals or control yoke; the resolvers for the FBW system would in consequence demand this 'trimmed' control surface movement.

Dude

Yes indeed.
That sort of discussion belongs in the Military Aircrew forum.

One could say that the Tu-144, and also the Boeing 2707 and Lockheed L2000 were part of the background against which Concorde was born.

But "F-4 v a Mig 19/21" is not really part of that context...... so please?

CJ

Forgive me for butting in again, you're in part quoting me but I wasn't the one that brought the F-4 into the debate in the first place. If the Concorde fanclub brings the F-4 vs MIG 19 into the debate and then glibly uses it as an example of the superiority of Western technology then I feel there's a right of reply from those of us who have actually flown the aircraft ( 1000 hours F-4 in my case) and used the technology, irrespective of wether or not it's a military or civil forum....or do you just want to argue in the abstract?

As a general point many in the West have almost always believed in the superiority of Western designers and engineers and whilst Concorde may be one shining example of what the West did right we should not forget that on the evidence of Sputnik, Vostok, Luna 9, Lunakhod and even the MIG21 Russian ( or German ) engineers can achieve worldbeating results with minimal resources.

But, to summarise, yes, it would seem the TU-144 was a dog , does that get us back on thread?

Nick Thomas
This of course is one for one of my pilot friends to answer properly again, but as galaxy flyer says, it's an 'eye to wheel' issue here when compared to other aircraft.
galaxy flyer
Again best answered by learned gentlemen such as my friends EXWOK or Bellerophon, but to the best of my feeble knowledge a resounding NO, at least as far as CRUISE flying was concerned. As the majority of the flight was carried out between FL500 and FL600 there was really no weather as such to avoid during supercruise. (As has been previously posted, at Mach 2 you would invariably be above FL500). Only at extremely low latitudes where the tropopause could theoretically extend up to around 70,000' was there ever any chance of seeing any cloud anywhere near your cruise altitudes. The only turbulence as such you would ever encounter was as the result of a temperature shear, but these never felt to be too much in the way of 'bumps' to me. And again, only at very low latitudes did you encounter severe shears anyway; anything encountered on the North Atlantic was generally very mild and civilised.
A CONCORDE PARADOX
The tropopause issue here is an interesting one, in that the coldest stratospheric temperatures we ever encountered were close to the equator, whereas the WARMEST temperatures possible are over the POLES , where the tropopause can be as low as 22,000'. This is just one of the many paradoxes involving Concorde, and the reason why the aircraft would never be routed over the poles, BECAUSE THE DARNED TEMPERATURES ARE TOO HIGH, in terms of the stratosphere. The result here would be that the aircraft is temperature (Tmo) limited all the time to 127 deg's C. (I previously mentioned in another post in this thread that only 5 deg's C above ISA, -51.5 deg's C, would mean Tmo being reached at Mach 2; any warmer and we HAD to slow down) The relatively high polar temperatures mean that we are unable to fly anywhere near Mach 2. Another paradox would then come into play, the slower your cruise speed, the HIGHER your fuel burn. It was originally proposed in the early 1970's that Concorde would fly from London to Tokyo, and the routing for that needed two things: It could not be polar, and possibly just as important , you required a refuel stop. The Soviet Union amazingly proposed granting a supersonic corridor over Siberia, refuelling at the Siberian city of Novosibirsk. This was hardly an ideal routing (definitely far from a great circle) but was arguably one of the very few that was possible at all. This by the way was not some early iteration of glasnost, but the Soviets fully expected that flying thoroughbred, the TU-144 (bad dude ) to be a success, and could compete side by side with Concorde.
ANOTHER CONCORDE PARADOX
If anyone wonders why when you flew faster you burned less fuel, it was primarily down to drag, actually a thing frighteningly termed as 'pre-entry spill drag'. As most people (???) are aware, the Concorde engine inlet utilised a series of carefully controlled and focused shockwaves to slow the air down entering the engine; in 14 feet of engine intake you lost in the order of 1,000 mph of airspeed! Now most of these different shocks varied with a combination of intake variable surface angle, intake local Mach number and also engine mass flow demand. However the oblique shock coming off the top lip of the intake produced a shock that varied with Mach alone, and would project downwards, just forward of the intake bottom lip. Due to the air downstream of this fairly weak shock still being supersonic, a measured amount of this air spills downwards, away from the intake. If you can possibly picture it, we have this wall of air spilling downwards over the lower lip of all four intakes, the combined effect of this supersonic forespill is a fair amount of drag. The faster we go, the more accute the angle of the shock and therefore the less air is spilled, and in consequence the lower the spill drag. Remembering that cool temperatures could produce a higher Mach number, temperature really could either be our friend or enemy, but cool was COOL
I hope this explanation does not sound like too much gibberish, but it really was a fact that 'More Mach = Less Fuel'. Hope it makes some sense.

Dude

I've only seen photos... but judging from some recent ones they seem to maintain 'FB rather well, same as its companion, the Tu-144.

CJ

LOL !

True though... they're little more than two small flat surfaces... clearly marked " NO STEP ", so they're not even any use for standing on to clean the windows.

They look pretty insignificant, compared to the 'canards' of the Tu-144 or the big foreplanes on some other deltas, or the long forward wing extensions on aircraft like the F-16 and F-18, none of which have the same function.

And to be perfectly honest, I myself didn't know about their real function until after 2003, when I started delving into a lot of other technical aspects of 'our Lady'.

CJ

I would say that the SR-71, and the Tu-144, are in a way honorary members of the Concorde family, so I don't mind if they fly into the discussion every now and then.

The full list of names (up to 2002) for both BA and AF can be found in "The Concorde Story" by Chris Orlebar. For BA, a quick count shows about 170 names. That book also mentions, that the maximum number of crews qualified at any one time was 28, in 1980, and that the average was about 20 crews.

Photos can lie.... or rather, they are rarely close-up enough to show clearly where corrosion has set in.

As an example, F-BVFC at Toulouse, which was the last one to remain at least taxyable, now has some patches of corrosion starting to show, when you know where to look. Not to mention the nasty smell of damp and mould in the cockpit which bodes no good for what's going on underneath the floor.

And even F-BTSD, kept "live" to some extent at Le Bourget, leaks some hydraulic fluid (like all Concordes did on the ground), so it's easy to imagine the dried-out hydraulic and fuel seals on the other museum aircraft.




And yes, that's kitty litter...
The composite material of the floor and the hydraulic fluid don't agree too well.

I'll leave M2dude to answer that one.

CJ

galaxy flyer
Well the RAT was 'advertised' to be able to maintain 4000 (ish) PSI on Green and Yellow systems down to around 200 KTS, so IN THEORY you'd be ok (ish), refering to Brit312's post. Incidently, one of the prime reasons that the engines were housed in twin nacelle pairs, rather than the original TU144 'monobloc' style was to eliminate the chance of a severe ripple surges flaming out all four engines. (But as the thing had half of the engine air passing over the massive stowed main undercarriage, they had other problems to worry about anyway).
I have to echo your point GF about carrying on asking questions, even if they may seem dumb at the time. It's all about how we all had to learn in the first place; Personally I'm happy to answer any questions at all here (the questions may not be stupid, but some of my answers........... ).
Regards to all

Dude

CliveL , correct me where I'm wrong.

* Most deltas develop some vortex lift, and there were several deltas flying long before Concorde, so the phenomenon was not unknown.
Shaping the wing, and in particular the leading edge, optimised the effect on Concorde.

* The ogee (slender delta) wing was original proposed by NASA (possibly still NACA at the time) as best suited for a supersonic transport. The information was in the public domain by the time the "BAC223" and "Super Caravelle" were first revealed (they later "merged" into the Concorde design).
The Tu-144 design used the same information, which is a major reason for its resemblance to Concorde, rather than espionage...
How much the full advantages of the 'vortex lift' were understood at the time, is still an open question, IIRC.
I'll have to look for the original NASA TN (Tech Note)... it may be on the web somewhere.

* I would think the Handley Page HP115 slender-delta low-speed test aircraft must have contributed some details about vortex lift.

Sorry, I can't find my own photos of the beast.
It's now in the Fleet Air Arm Museum at Yeovilton (UK), together with Concorde 002 and the BAC-221.
It still has the "smoke tube" on the left wing leading edge, that was used to visualise the vortex over the wing (not yet fitted when the photo above was taken).

CJ

Christiaan

Quite true, and I hope I didn't give the impression that it was otherwise. On this side of the Atlantic France had the Mirage series, UK the Javelin, the two Avro aircraft and of course the FD2. However these all had relatively rounded leading edges which reduced the effect somewhat.

I must admit that I was not aware that NACA had proposed an ogee wing for supersonic transports, although all the US SST designs featured 'double deltas' . Ken Owen's book says that US firms had been working on SST research and design studies since the late 1950s, and since the UK equivalent, the Supersonic Transport Advisory Committee (STAC) ran from 1956 to 1959 and definitely included sharp-edged slender wings amongst their studies, I would say UK work was at least in parallel.

But to be frank, the basic idea sprang from German research done during WW2. They were well ahead in knowledge of the aerodynamics of delta wings as part of their research into aircraft suitable for the higher speeds that went with those new-fangled jet engines. Then, after the war's end, the German scientists migrated to either the UK and US (if they were lucky) or got carried off to Russia. They brought with them all the knowledge they had gained (and of course there were specific trained teams whose job it was to search the German research establishment records for any useful data. On the UK side certainly the idea of exploiting vortex lift for use on an SST was generated by German researchers working at the RAE (Kuchemann and Weber in particular). My guess (I don't know for sure) is that similar things happened in the US, although "their Germans" seemed to be more interested in rocketry.

Not as much as you might think, because like the 221 it was too late to have much influence and it also was built to study slender delta handling, in particular a possible problem known as 'Gray's oscillations' rather than vortex lift as such.

Clive

Earlier this week I had the great pleasure of a late afternoon followed by a full day at the Sinsheim technical museum near Heidelberg. Highly recommended and much more than just a museum; just ask my children what they thought of the helter-skelter from elevated Ilyushin IL-18 back down to the ground, or the twisting and turning stainless steel tubular slide from museum roof mounted DC3, through a hole in the roof, and back to the ground level entrance! The staff I encountered were all friendly and informed and I now look forwards to a day at the sister museum in Speyer - replete with 747-200 on the roof on which visitors can walk the wing.

Anyway, of relevance to this thread I thought I'd shared some of my photos of Concorde F-BVFB and Tupolev TU-144 77112. It was tremendous to be able to walk backwards and forwards between the two, directly comparing design features and relative elegance of execution. Both are achievements for mankind but I have to say that to me not being an aeronautical engineer, Concorde won every time - dreary Air France cabin notwithstanding - with the larger Tupolev coming over as somewhat clumsy; let alone knowing engine technologies to be a world apart, just compare the wheel bogies as one example, and then the cleanliness of wing design as another. Yes, the Tupolev canards were a novel feature, but I understand they were only necessary in the first place because of lower speed control issues as a result of more basic aerodynamics.

Like any aircraft on static display exposed to the elements both airframes could do with some TLC, but here are the photos:











Concorde aft cabin door


TU-144 aft cabin door










TU-144 No 4 engine location viewed from exhaust towards inlet (and directly in to the sun!)






To be continued in separate post as I have hit the photo count ceiling in this one.

...and the second post to conclude the photos and ask a question:

Concorde cockpit (through hazy perspex screen)


TU-144 cockpit (also through hazy perspex screen)


A sign that made me chuckle









I hope that these pictures were of interest and can spark some further discussion in this amazing thread. If I can have the temerity to start the ball rolling with a TU-144 question, I was intrigued to notice the following tiny vane situated on the fuselage base between engines 2 and 3. Closer inspection revealed an adjacent hole, perhaps indicating pressure measurement? Anyway, ideas or proven fact welcome!

As observed


Cropped

I think the TU144 needs an entirely new thread. Oooh questions questions....

The late XV105

Dunno about the source of your info on this but it may have got a bit garbled in the telling.

With a plain slender delta on the approach the trailing edge control surfaces will be slightly up and as speed is reduced this angle will increase slightly. If you want to raise the nose in the flare then even more stick back will be needed. This gives - if you like - a wing with a negative flap angle and so rather less lift needing a higher speed than you miught wish.

If you add some canards to give a big nose up force then to trim the aircraft the trailing edge surfaces will all be down a bit - giving a flapped delta with considerable benefit in terms of reduced approach speed.

The Tu144 with canards was able to land on the display runway at Le Bourget and take the second turn off right to the aircraft park - a quite remarkable demonstration of its modest speed on finals.

One of the guys on the Save the TU144 Facebook page says that the thing in that picture on the TU144 is connected to the Air Conditioning.

There is also a TU144 website now. Format donated by Gordons ConcordeSST

TU-144 SST - Flying Forever on the Internet