Thanks Paul, great article! Yes, гв.мл.л-т Ляшин Иван Иванович was downed on April 16, 1945 in his Omsk-built Yak-9U, S/N: 42166063, engine: 437-716. 5 VA, 13 GvIAD, 151. GvIAP, 3. ea.
It is true, his regiment changed plane types very fast, but this does not mean they used only a single type of plane after a date. Usually new and old planes (and models) flew together in mixed flights until the old model was gone. So there was a specific transition time. Bad weather certainly affected all sides, not just the Axis.
On March 10, 1945 the 17 VA eg. lost only 1 IL-2 (S/N.: 18784100), while on March 14, 1945 they lost 18!!!! Spring weather helped missions...
During the final German tank offensive of WWII in March, 1945 the key word was: OIL. They wanted to keep the Zala oil-fields until the last bullet, so they brought tank forces even from the Western Front to push the soviets back in the Lake Balaton area, protecting the much needed oil. (6. Panzer Army, 501, 509. heavy SS panzer-division, etc.) The Panthers, Kingtigers caused huge losses among the soviet Su-76s, T-34s, Shermans, etc. Both the 5 and 17 VA tried to stop the advancing German tank forces and they also paid a very high price.
When the German offensive finally failed at Lake Balaton, the Axis resistance basically collapsed in Hungary and the rapidly advancing Soviets took the Austrian capital, Vienna very soon in April, 1945. See many great photos of destroyed German tanks in the Balaton area in March, 1945. Some of them were destroyed by the 5 and/or 17 VA planes:
http://www.battlefield.ru/photos/cat...oyed-afvs.html
Gabor