Can someone enlighten me on maximum performance turn?

[AKA_Relent]

Looking at the Aircraft Flight and Technical Specifications and Operational Details page, I see the following comparisons between the Bf-109F-2 and the Yak-1:

 

Bf 109 F-2:
Maximum performance turn at sea level: 23.6 s, at 270 km/h IAS. 
Maximum performance turn at 3000 m: 29.0 s, at 270 km/h IAS. 

 

Yak-1:
Maximum performance turn at sea level: 19.2 s, at 270 km/h IAS. 
Maximum performance turn at 3000 m: 24.6 s, at 270 km/h IAS. 

 

Can someone tell me exactly what "maximum performance turn" means?  It seems to indicate that if both aircraft at the respective altitude and with similar speed and energy were flying at/maintaining 270 kph indicated in a horizontal turn, that in a clean configuration (i.e. no bombs, rockets, and no flaps deployed) the Yak-1 should be able to out-turn the Bf-109F-2 (by 6 seconds at sea level, and 4.4 seconds at 3000 meters) in a full circle.

 

But when would you (if ever) use a maximum performance turn in combat?  I can't remember the last time I've been able to out-turn (horizontal turn) an F-series Bf109 in a Yak-1, unless upon entering the fight I had a better energy state (e.g. higher altitude or speed).  The Bf109 with it's leading edge slats and ability to drop partial flaps vs the full up/down flaps of the Yak-1 appear to give the Bf-109F2/4 a serious advantage.

 

So I guess I'm asking how best to utilize this information in a combat situation.

 

Thanks.

[LeLv76_Erkki]

You are likely facing mostly F-4. It has much more power than F-2, has listed best turn time similar to Yak-1 and is likely to enter a turn fight at higher initial E than you. Also at lowest speeds the 109 does turn better. Remember you can also drop flaps in the Yak, they dont fully extend at speeds above 230-ish km/h IAS. Yak-1's main advantage is in ability to maintain speed through maneuvers better(lower wing loading, no leading edge slats) and it achieves its best rate of turn at slightly higher speed.

 

Quote

But when would you (if ever) use a maximum performance turn in combat?

 

You dont, the data is there just so you can compare the planes to each other and to give an idea on speeds where you turn best so you know to not go below unless it gives you firing solution or makes the enemy to overshoot you.

[AKA_Relent]

Thanks for the reply Erkki - it was a Bf109F2, confirmed from stats.  In any case, interesting perspective, I hadn't realized that the Yak-1 will only drop partial flaps at higher speeds, so they will work like combat flaps until your speed drops... good to know.

[JtD]

The figures aren't accurate in the first place. While they are supposed to mean what you are saying, they are painting a wrong picture. Testing these two aircraft myself a while ago I could get the following sustained turning performance at sea level:

Bf109F-2: 22.4s @ 250IAS

Yak-1S67: 19.5s @ 280IAS

 

Which means that while the Yak-1 is still faster at completing a 360° turn, but not as much as the developer figures suggest. Also, the minimum sustained turn radius of the two is very similar, and if you don't use the flaps on the Yak-1, it's quite possible that the other guy can slow down quicker and turn tighter than you do, owing to flaps and LE slats.

 

[AKA_Relent]

Thanks JtD - yes, that’s sort of what I was trying to figure out.  I.e. would “not” dropping flaps and going with the mentioned indicated IAS (270) somehow equate to being better than dropping flaps - thus slowing down and getting a tighter turn (possibly for a short time as you ride the edge of a stall) - vs maintaining a sustained turn at the higher speed.

 

Was initially just wondering what to make if the information.