109s and Flaps

[gyrene81]

It's not a question of what anyone should be able to do. The question is what were the pilot's operating instructions. Anecdotes are not evidence. A lot of players would like a higher flap deployment speed but that's a different issue.

pilots operating instructions were for full "landing flaps" and landing gear with full "landing flaps"...there are no instructions that pilot's had to avoid deploying 10 degrees of flap above a certain speed.

You didn't answer about the slats.  Do you think they planned for both slats and combat flaps?

the leading edge slats were for low speed stability not high speed combat maneuvers.

[Tank-Ace]

Slats/flaps aren't the same thing, and don't serve the same purpose.

Anecdotes aren't evedence, but that doesn't mean they don't support evidence.

[gyrene81]

from a 109g-6/u4 manual - rough translation

Aircraft made genugten the building regulations of the dla and strength of december 1936 and the last special assumptions on this. It is intended for the use of Group H and comply with the requirements of the stress groups 5 and 4, depending on the load.

maximum speeds

employed in full flight landing flap - 250km/h
flight with landing gear - 350km/h

landing flap deflection was 40 degrees.

[FLS]

pilots operating instructions were for full "landing flaps" and landing gear with full "landing flaps"...there are no instructions that pilot's had to avoid deploying 10 degrees of flap above a certain speed.

the leading edge slats were for low speed stability not high speed combat maneuvers.

Slats and flaps are both high lift devices. The difference is slats don't work like landing flaps, slats only work like combat flaps. I'm not saying you can't have both. I just wanted Tank-Ace to realize that they solve the same problem from different ends.

[gyrene81]

i don't know man, those leading edge slats were designed for high angle of attack under low speed conditions...whereas combat flaps would produce different results at higher speeds. can't see where they would be useful except near stall conditions.

[Tank-Ace]

Notice the slats don't usually deploy unless you're at low speed  .


And note: landing flap speed: 250km/hr (about 155mph), 40 degrees deflection. Nothing mentioned about lesser deployment of the flaps. 10 degrees would likely be available upto ~250mph, perhaps 275 or even 300mph at a strech.

[FLS]

Do you guys both think that it's incorrect when the slats deploy at 400 mph in Aces High as you pull G and they act just like auto combat flaps?

The slats always deploy at the same AOA. They deploy just when you need more lift. It's pretty clever. You just don't want them to deploy asymmetrically.

[Owlblink]

Do you guys both think that it's incorrect when the slats deploy at 400 mph in Aces High as you pull G and they act just like auto combat flaps?

I do.

Again, the slats are coming out simply because of the reduced air pressure on the tip of the wing. Slats are designed to give you a larger wing surface to procude more lift at slower speeds; flaps are designed to produce more lift but it has the effect of changing your AoA by diverting the airflow downwards.
Slats tend to be momentarily distabalizing when they pop out, not always nice to happen in a high G turn, and I'm not sure if it has any benefits on the turn rates or radious.

[FLS]

I do.

Again, the slats are coming out simply because of the reduced air pressure on the tip of the wing. Slats are designed to give you a larger wing surface to procude more lift at slower speeds; flaps are designed to produce more lift but it has the effect of changing your AoA by diverting the airflow downwards.
Slats tend to be momentarily distabalizing when they pop out, not always nice to happen in a high G turn, and I'm not sure if it has any benefits on the turn rates or radious.

The lower air pressure above the leading edge of the wing that deploys the slats results from the wing reaching a specific AOA. High AOA is more likely at low speed but it is also possible at high speed. Increasing lift while maintaining your speed increases your turn rate and decreases your radius.

[Owlblink]

Good to know, thanks for the education

[gyrene81]

i get what you're saying fls but, 2 things...the slats don't deploy at 200+ in a high g turn let alone 400 and when they do deploy they don't do anything remotely like what 10 degrees of flap would do,

[FLS]

i get what you're saying fls but, 2 things...the slats don't deploy at 200+ in a high g turn let alone 400 and when they do deploy they don't do anything remotely like what 10 degrees of flap would do,

Lift and G loading comes from AOA and speed. When your speed is high enough you can black out while still at an AOA that doesn't deploy the slats. Anytime you establish the required AOA the slats will deploy. I can deploy slats at 400 mph in the BF109. Any time the slats deploy they increase lift and G loading. I don't know the actual difference in coefficient of lift between 10 degrees of flaps and slats.  If you have some data on that it would be interesting to see it.

[Tank-Ace]

You're the one saying slats are just as effective as flaps. Burden of proof rests with the accuser.

[FLS]

You're the one saying slats are just as effective as flaps. Burden of proof rests with the accuser.

The proof of the pudding is in the eating.

[Tank-Ace]

Yeah, you can know pudding is vanilla if you eat it, and know that it isn't chocolate.

But you're trying to say that slats are just as effective as flaps at 10 degrees deflection when at high speeds, which is akin to trying to tell what ingredients are in the pudding.



Once again, burden of proof rests with the accuser. I'm interested to see what your source of information is.