109s and Flaps

[Krusty]

I think you're over-reacting there gyrene...

The manuals are talking as if theres only one setting: full. The reality is the pilot could move the lever to whatever setting he wanted. If he wanted to crack them open just a bit, he could.

We had a similar issue with Bf109 flaps many years back, and evidence was produced from outside-of-manual sources showing the safe-to-deploy speeds for bf109 flaps being much higher for just a 10-degree flap setting, than for the normal flaps.

The fact that the P-40 has more than one flaps setting is to simulate this ability to deploy flaps to whatever angle you want. Otherwise it would be like the Spit1's flaps.

Also, you seem to be picking up on "do not retract below 160" -- this was not a mechanical limitation. The flaps were not blown back by windpower. This was a safety order to prevent green pilots from creating some turbulence or loss of lift without sufficient speed to stay in the air. I've seen footage of P-40s on the ground and on jack-stands raising and lowering their flaps (rather rapidly, as fast as the hand can push the hydraulic lever in the cockpit) again and again.

[gyrene81]

i'm not over reacting krusty and i know how the flaps work. just answering fls questions without opening a bigger can of worms.

my point of contention is mainly the manner in which the current speed setting was extrapolated and decided upon, with less evidence than you're saying was presented for the 109 long ago, yet to this day the 109 cannot deploy even 1 degree of flap at combat speeds.

[FLS]

I recall that POHs are a primary source when they are available and that other official documents are also used.  I also think it's possible that 109 pilots were better off not using combat flap settings because they had the slats. Why deploy flaps for a Cl that you can achieve with AOA and/or slats? But not knowing the actual difference between them I can only guess. Hitech would know since he programmed it but my main point is that we don't know what documents HTC is using and stating that they they are guessing the speeds is just speculation.

[gyrene81]

I recall that POHs are a primary source when they are available and that other official documents are also used.  I also think it's possible that 109 pilots were better off not using combat flap settings because they had the slats. Why deploy flaps for a Cl that you can achieve with AOA and/or slats? But not knowing the actual difference between them I can only guess.

you're still thinking the slats do something they don't. i take it you don't fly the 109 often. take a p-51 in ah and get it into a turn at 250mph without flaps, then do the same thing with 1 notch of flaps, see how much difference there is in a 180 degree turn.

Hitech would know since he programmed it but my main point is that we don't know what documents HTC is using and stating that they they are guessing the speeds is just speculation.

well, hitech has repeatedly stated the poh is the primary source used in making such determinations. and look at pyro's statement again.

[FLS]

you're still thinking the slats do something they don't. i take it you don't fly the 109 often. take a p-51 in ah and get it into a turn at 250mph without flaps, then do the same thing with 1 notch of flaps, see how much difference there is in a 180 degree turn.


well, hitech has repeatedly stated the poh is the primary source used in making such determinations. and look at pyro's statement again.

I'm pretty confident that I understand slats, flaps, and turn rate but I'm always happy to learn more.

I agree that the POH is a primary source. Hitech has also stated that primary sources can be unclear. Pyro or Hitech posted that 140 mph was a bug in the update where the full flap landing restriction was applied to all flap settings. You haven't supported your statement that HTC models performance based on a lack of evidence of non-usage. You don't know what they used to set the P-40 flap speeds or the BF109 flap speeds. The P-40 POH only shows a landing restriction that is likely for full flaps. This is clearly shown by the other manual showing 160 as the minimum flaps up speed with a drop tank. You are using your lack of information on their decisions to speculate that they didn't have necessary information on flap restrictions.

[Krusty]

i'm not over reacting krusty and i know how the flaps work. just answering fls questions without opening a bigger can of worms.

I think you are... The following keeps becoming a theme...

yet to this day the 109 cannot deploy even 1 degree of flap at combat speeds.

This is false. The 109 CAN deploy flaps at combat speeds. You simply disagree how fast you want them to deploy. Just because the P-51 can do it doesn't mean the Bf109 could. If you want the flaps to start coming down at 400mph you have another thing coming to ya.

[gyrene81]

didn't realize the two of you were a mind readers...i'm not the one who brought this crap up, just answering the questions. if you don't like the answers, not my problem.

i dare either of you to prove that a clean undamaged 109 could not actually deploy even 1 degree of flap over 190mph tas at 15,000 feet or below.

[FLS]

didn't realize the two of you were a mind readers..

I knew you were going to say that. 

...i'm not the one who brought this crap up, just answering the questions. if you don't like the answers, not my problem.

i dare either of you to prove that a clean undamaged 109 could not actually deploy even 1 degree of flap over 190mph tas at 15,000 feet or below.

I'm simply going by what you posted Gyrene. If you can justify your criticism of HTC's flight model fidelity in the Help forum please go ahead and do so. A new player reading that, and unaware of your habit of shooting from the lip, might actually believe you. So far your answers to me have just indicated that you're read some things a little too quickly. If you think I don't know how slats work be specific and tell me what it is I don't understand. Maybe I'll learn something.
 
Since I never claimed that any 109 couldn't deploy 1 degree of flap at 190 mph I'll take a pass on your request for proof.

[gyrene81]

   come on fls...i just passed the information to you. you kept asking the questions and well, simply put if you're going to continue asking me rather than investigate for yourself, i'm going to give you exactly what i think and it is not "off the lip". i've spent the time digging and translating manuals written in german. where the 109s are concerned, there is no concrete evidence either way that states max safe speed for anything except full flaps with landing gear down and the deployment speeds in ah reflect an estimation of deployment speeds from low to high based on full flaps with landing gear down. and as krusty said, the pilot could move the lever to whatever setting he wanted, but that is not possible above the speeds htc determined were acceptable. nothing to criticize, it is in plain english.

The data posted is not mutually exclusive.  Some planes will have a different max speed for deploying the flaps than the max speed for having the flaps down.  In AH we only have one speed per flap setting, so we have to bridge those differences as best we can.

[Tank-Ace]

I think you are... The following keeps becoming a theme...

This is false. The 109 CAN deploy flaps at combat speeds. You simply disagree how fast you want them to deploy. Just because the P-51 can do it doesn't mean the Bf109 could. If you want the flaps to start coming down at 400mph you have another thing coming to ya.

Krusty, I've read 109 manuals, and I haven't ever come across a sentence stating "the 109 cannot deploy flaps at speed above 310km/hr".

Theres a difference between "shouldn't" and "couldn't".


A6M couldn't drop flaps at 350mph

P-47's weren't advised to drop flaps while doing 375mph, but they could.

109 shouldn't drop flaps at 300, but they could

See? Its a matter of if HTC has decided the "shouldn't" number is a limitation of the aircraft, or just is what is advisable.

[gyrene81]

If you think I don't know how slats work be specific and tell me what it is I don't understand. Maybe I'll learn something.

forgot to answer this. higher cofl is created from angle of attack and speed, leading edge slats change the (i believe) camber of the wing to increase the cofl at slower speeds and thus allow the plane to fly at slower speeds than it could without them, not 400mph. the 109 used automatic slats (unlike some modern aircraft) that deployed when aerodynamic forces on the leading edge of the wings decreased to the point where they could deploy, still not 400mph. is that a sufficient answer?

[morfiend]

 I'm sure I dont have to tell you knowledgeable guys that the 109's used a wheel to lower flaps,above deployment speeds the wheel just turned and the flaps would not lower! It had a built in "slip" mechanism in the linkage so the pilot could lower flaps and break them! I believe little is written about the actual speed but it seems to be in the 300 to 350 KM per hour,300 kn is 186 mph which is around the speed that you can drop the first notch flaps in AH.

 Remember a kilometer is 5/8ths of a mile every 80 km is equal to 50 mph,100 km is 62 mph!


  YMMV



  

[Tank-Ace]

Even 350km/hr would be helpfull. Just so long as its at a speed seen in combat other than the "oh crap, I'm caught in a low speed turning game" situations.

[gyrene81]

I'm sure I dont have to tell you knowledgeable guys that the 109's used a wheel to lower flaps,above deployment speeds the wheel just turned and the flaps would not lower! It had a built in "slip" mechanism in the linkage so the pilot could lower flaps and break them! I believe little is written about the actual speed but it seems to be in the 300 to 350 KM per hour,300 kn is 186 mph which is around the speed that you can drop the first notch flaps in AH.

 Remember a kilometer is 5/8ths of a mile every 80 km is equal to 50 mph,100 km is 62 mph!


  YMMV


  

where did you find that information sir? unless i missed something in the ugly translation process, none of the manuals i have from the 109b to 109k4 show anything like that. and 350 kph would be much better than the current setting.

[morfiend]

where did you find that information sir? unless i missed something in the ugly translation process, none of the manuals i have from the 109b to 109k4 show anything like that. and 350 kph would be much better than the current setting.

 Actually read it on a site that was about myths and facts on the 109 series,had both Finnish and German pilot comments! Oh and I meant to say couldn't lower the flaps to break them. Gyrene,I simply googled 109 flap deployment speeds and waded through 14 or 15 pages of google,I went to many sites so I dont recall which 1 stated about the slip mechanism,but I'm pretty sure it was the myths site I mentioned.

  Interestingly several Finish pilots report going over 850 KM per in dives which was more than 100 KM above VnE!!!! I believe those were G6's

 Tank,350km is roughly 200 mph,or close enough to deployment speeds in AH,also from what I read it stated between 300 and 350 KM,50 KM is only 30 mph,ok 31.5