Actually the A-5 will out-climb the Yak up to 4k.
These are approximate climbrates I have observed with 100% fuel and max. power(100% in Yak, WEP in A-5).
Yak-9U.
Initial: 3600fpm.
At 6k drops off to 3200fpm at 8k.
8k to 15k improves slightly to 3300fpm.
15k drops off to ceiling.
Fw 190A-5.
Initial: 4000fpm.
4k drops off to 2800fpm at 10k.
10k to 20k improves to 3000fpm.
20k drops off to ceiling.
The Fw 190A-5 top speed is only about 400mph at 20k.
