Re: Soviet Aircraft

From:         spagiola@FRI-nxt-Pagiola.Stanford.EDU (Stefano Pagiola)
Date:         14 Apr 93 14:31:14 PDT
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h andrew chuang <chuang_hsin@ae.ge.com> writes
> I simply won't believe that there wasn't any
> "plagiarism" in the Soviet designs.  I don't have any
> documented evidence, but the law of statistics tells me
> that there are way too many occurances to be
> coincidental.

OK, lets list them.  The Tu-134 looks like the BAC 111, DC-9, and  
Caravelle; the Tu-154 looks like the 727 and HS-121 Trident; the  
Il-62 looks like the VC-10, and the Tu-144 looks like the Concorde.   
I suppose one could add that the An-24/26 look like the F27.

Of course, the Tu-134 and Tu-154 both have negative dihedral on the  
wings, which none of their Western counterparts have (can any of the  
engineers out there tell us why this feature might have been  
adopted?).  The Tu-144 has a cranked delta wing compared to  
Concorde's ogival delta; the initial Tu-144 designs also had their  
engines grouped together under the fuselage rather than out on the  
wings as on Concorde.  Details, details.

I was chided by one person for saying that the 767 was similar to the  
A300 because of, among other things, the difference in fuselage  
width.  Has anybody compared the widths of the Tu-134 and the DC-9?   
(Hint: you can only seat four abreast, even at Aeroflot comfort  
levels, in the Tu-134).

You'll notice that saying that the Tu-134 looks like the BAC 111,  
DC-9, and Caravelle also means that the BAC 111, DC-9, and Caravelle  
look like each other (we should probably add the F28 to this list,  
too).  Were the 111 and DC-9 `plagiarized versions' of the Caravelle?   
Some people thought so (or found it useful to argue so): in the early  
1960s, when BAC started producing the 111 and Douglas the DC-9,  
Sud-Est, manufacturers of the Caravelle, ran a series of ads showing  
two astonished kids reading an aviation magazine and saying "Look!  
They've copied Caravelle!"  Knowing what we know of BAC and Douglas,  
do we think this statement is correct?

> Having similar set of requirements does
> not mean the designs will be visually similar.  For
> example, When the SST effort first started, the US
> airframers came out with different designs based on
> similar requirements. 


True.  But Lockheed's design, for one, looked a heck of a lot like  
Concorde and Tu-144.  And in fact all SST designs looked extremely  
similar in profile view.  In plan view, they do not, because of  
different choices on wing geometry.  But that is equally true of the  
Tu-144 (the only cranked delta in the set, if memory serves).

> Other than being a bigger plane
> with the canards, the Tu-144 looked too much like the
> Concorde.

As pointed out above, this is simply not true except for very general  
appearance.  The wing planform is different.  The engine placement is  
different.  


> (Shahid Siddiqi pointed out the Tu-144 flew
> before the Concorde, but that was only because the Soviet
> rushed through the process.  ...  Does anyone
> know if Rolls' bankruptcy delayed the Concorde program,
> too?) 


Rolls' bankruptcy didn't help, but the main reason Concorde was  
delayed was continual bickering between France and England, including  
several attempted cancellations of the whole thing.

> Also, when the Air Force gave the aircraft manufacturers
> a same set of requirements for the ATF (Advanced Tactical
> Fighters), the two teams came up with two distinctive
> designs, the (Y)F22 and YF23; even the engines, (Y)F119
> and YF120, were distinctively different. 


The point is not that identical requirements lead to identical  
designs, but that they CAN do so.  Compare the DC-10 and L-1011.   
Compare the A330 and 777.  Given similar requirements and a finite  
set of possible configurations that will meet those requirements, why  
are we surprised that designs look similar?  Short-haul jets need at  
least two engines.  These can be placed in pods on the wing (under or  
over it), embedded in the wing roots, or on the aft fuselage.   
Boeing, Dassault, and Airbus chose the pod-under-the-wing  
configuration for the 737, Mercure, and A320 (as did Douglas and  
Fokker for various design studies).  VFW placed them in pods over the  
wing on the VFW-614.  De Havilland had them in the wing roots on the  
Comet, as did Tupolev on its Tu-104 and Tu-124.  Sud-Est, BAC,  
Douglas, Fokker, and Tupolev chose the aft-fuselage position.  Both  
the pod-under-the-wing and the aft-fuselage arrangement have been  
spectacular failures (Mercure: 11 built) and great sucesses (737:  
going on 2,500; DC-9/MD-80: over 2,000).  So neither is obviously  
`wrong'.  Why are we surprised that some Soviet designs can be found  
in some of these groups?  Considering that Soviet designs often put a  
premium on rough-field performance, are we surprised they didn't  
adopt pod-under-the-wing designs?  Why is the Tupolev the only one of  
5 manufacturers of airliners with engines on the aft fuselage accused  
of plagiarism?

> Then, why does the resemblance only occurs in
> the commercial transport?

I've heard many people describe the MiG-29 as a `virtual copy' of the  
F/A-18.  Tom Clancy, for example, uses those very words.  I would  
disagree with him on the same grounds that I'm advancing here for  
commercial aircraft, though, unless evidence other than external  
similarity is presented.

> Moreover, there is a very good reason (other than the national
> pride like flying the first commerical SST flight with the
> Tu-144) why the Soviet wanted to build airplanes that had
> similar specs as the Western planes: they wanted to make sure
> that the airlines in the Soviet-bloc nations would not buy
> Western planes.

First I fail to see how a cosmetic similarity to Western designs have  
this desired effect in the face of substantial performance  
differences.
Second, compared to Aeroflot, the Eastern Bloc countries were a  
negligible market for Soviet-produced airliners anyway.  Poland's LOT  
had, what, 10 Tu-134s?  Compared to several hundred in Aeroflot  
service.

> Correct me if I am wrong, JAT of Yugoslavia was the
> only Soviet-bloc airline that had bought American jets in the 70's.

Actually, you are wrong.  Romania's TAROM had 707s (as well as BAC  
111s).  Earlier, LOT flew Viscounts and CV-240s.  If you count China,  
they've used Viscounts and Tridents for a long time, and 707s and  
then 747s since the early '70s, alongside their Tupolevs and  
Ilyuschins. In any case, I would submit that soviet bloc airline  
purchasing decisions were more likely driven by politics than  
marketing considerations.  Witness the rush by ex-Soviet bloc  
airlines to buy Western aircraft once the Soviet-bloc collapsed.

> Unless you can show me hard evidences that there was no significant
> Western influence on many of the Soviet designs, I have as much
> right to say that the Soviet "plagiarized" as your right to say
> otherwise.  Don't we all make our conclusions based on our
> perception?

Was there influence in the sense that Western designs showed that  
this or that configuration `worked?'  Sure.  But then, one can  
equally say that Airbus showed that the large twin worked (there was  
a LOT of skepticism about that configuration when it first came out),  
which probably influenced Boeing in pursuing that approach for the  
757 and 777.  Ditto with the Caravelle and other aft-fuselage  
designs.

I would submit that the best evidence that there was in fact little  
copying is provided by the Tu-134 and Tu-154.  Take the Tu-134, blow  
it up by about 30% in all dimensions, add a third engine in the tail,  
and you have a Tu-154.  General appearance (that distinctive Tupolev  
nose and those downturned wings), wing geometry, etc, are all the  
same.  That Tupolev took an existing design and expanded it to make a  
new, larger one (and had to add a third engine to get the necessary  
thrust) is much easier for me to believe than that they first copied  
the DC-9, and then sat down and decided to copy the 727 for their  
next project.

Sure, the Trident and 727 would have told them that an S-duct for the  
third engine could be designed.  Heck, maybe they even copied the  
technology for that particular piece of the aircraft (although I  
doubt that simply lifting a 727's S-duct and pasting it onto a Tu-134  
would have worked).  But that doesn't make the Tu-154 a copy of  
either.

--
-
Stefano Pagiola
Food Research Institute, Stanford University
spagiola@frinext.stanford.edu (NeXTMail encouraged)
spagiola@FRI-nxt-Pagiola.stanford.edu (NeXTMail encouraged)