[HGabor]

17 VA also has written off at least 2 trainer-version Yaks in March, 1945:

UYak-7 (Yak-7V), S/N: 2615323 in 17 VA, 18 OUTAP - written off by March 18, 1945 - crashlanding damage
UYak-7 (Yak-7V), S/N: 3115336 in 17 VA, 136 IAD - written off by March 29, 1945 - WW, as being too old

As you see, both from Novosibirsk, Factory No.153. (Zavod 153)

Gabor