[Arsenal VG-33]

Hello Birgir

Sorry for being so late, a lot of job here!
Happy new year anyway!

About sources in other languages. How good is the french Polikarpov I-16 book by LELA press? (Cony, Ledet, Cerda, Louie & Kulikov). I guess sources have become rapidly outdated recently, so you should always look for the latest.

Avoid it as much as you can, a very low level of knowledge, too much errors. The same for Polikarpov Fighters in action, squadron signal n° 162.
Polikarpov I-16 Fighter from Gunston and Dexter, is a little better but less than average in all and...quite boring.

In my opinion the best book for the I-16 in english translation would be the J Kytka editions one, because il’s the closest to the original Mikhail Maslov’s book:
http://www.aerostories.org/~aerobiblio/article18.html
but there is a very little information about the I-18/185.

Now, specific topics that you might be able to shed further light on. Re. the M-88 engine. Had the problems been solved in the USSR, at say, decision-time of july 31 1940, (or november for that part.) That is to say, did engine supply questions affect (or determine, if you want to word it more strongly) the aircraft production plans in late 1940/early 1941.

AFAIK, the M-88 was "put in production" again on automn 1940, after it had passed with success the second batch of state tests on previous summer. In fact, no production was stopped, only deliveries during the state investigation due to numerous complaints from VVS units.

Do you know if the M-88 was a copy of the Gnome-Rhone 14N or a seperate line of development of the 14K. Bearing in mind, the strength of the french communist party, and the fertile ground for soviet espionage in France, either direct official technology transfer, or "industrial espionage" could easily have passed information from France to Russia. (And, yes, let no-one hijack this thread to discuss interwar french politics

)
M-88, was different since soviet engeeners ware ambitious and developped it on a different way. Even too much ambitious... Blum governement idea was to exchange french technology against soviet production in 1936. Not a bad idea, but unfortunatly with no continuation.

And on a similar theme, and prompted by your nom-de-plume, Do you know if there is any connection between the french interest in "non-strategic materials", (wood), which produced among others the Arsenal VG series in France, and the soviet efforts that led to the Lagg series? Was there anything common in either material, or process of production between the wooden aircraft projects?

I only know that zavod 301 in Khimki was preparing (slowly) the Caudron 690 production in Russia (and about the high opinion of Yakovlev for french wood designs) , when it was roughly occupied by Lavotchkin bureau and quckly turned to the LaGG production. But the later was rather a composite plane, than a wood one because of the delta D materials.

A third point of interest. If you compare two designs with a common(?) engine, the Polikarpov I-180, and the Bloch MB 152, the I-180 is much superior in every respect (except, arguably, firepower). Yet the Bloch is a "modern" all-metal monocoque design, the I-180 an obsolete mixed construction. How could that be?

In fact I-18 was tremendously small, see its dimensions. Even with an equivalent or slightly worse Cx value it would be faster. Moroever, it was light: there is no interest in the “modern” or “obsolete” definition, but only on the strenth vs weight ratio. The highly stesses stainless steel 30Kh GSA used on the I-18 airframe (120-140 kg/mm²) was very effective on that way. “Modernity” is a kind of industrial problem, and technically not always the best. In 1939, light alloys were giving 40 kg/mm² resistance, at best. And they were riveted, not glued or welded, with certain loss of resistance on stress lines.

How credible are the I-180 performance figures? In Gordon and Khazanov´s book, Soviet Combat Aircraft, the tables at the end give the preproduction 180s superior performance to the third prototype, (albeit with no range information). Yet it seems the pre-production planes were closer to the second prototype than the third.

There is nothing to discuss about, it’s only physicall measurements. As for the Eiffel tower lengh or weight. I don’t understand your question. Furthemore, The plane was equipped with the M 88 R (R for reductor) engine that was calculated for 3.6m propellers. The use of propellers less than 3.2m was generating an important loose of the output.

(I must confess that I have never been able to figure out just what was so wrong with the MB 152).

There is nothing specially wrong with the MB-152, it was not worse than the american curtiss H-75 (P-36). Of course, it had some developpement problems as for all planes in the world but finally it could withstand without substantial modification the powerfull 1500-1700 hp Gnome le Rhone engine (MB 157).
Polikarpov, was obliged to design a new plane for the use of M 82 and M 71 engines: the I-185.
I-180 itself, had no no more developpement opportunities, except for the Shvetsov M-89 engine.

Best wishes