Flaps deployment

[SchniX]

I know it's an old thread, but this question about the P-51D flaps is still concerns me till today

and maybe today someone knows more about it?

 

The big question for me is: do the flaps in the P-51D can be lowered at high speeds and stay extended or the airflow pushes the flaps inside like it's in DCS?...because in 2 another pretty realistic simulators it's not like in DCS, i'm talking about mainly A2A P-51D, but also about the P-51D in IL-2 Great Battles series. and in every sim it's modeled different, and i want to know which is more correct and how it's in real life.

 

1. DCS P-51D - flaps are depressed inside by the airflow at high speeds and cannot be jammed or break.

 

2. A2A P-51D - flaps can be extended at high speeds and at certain point the flap rod will be jammed and the flap will stuck and if you continue, eventually the flap rod will be break and the flap will remain attached to the wing, but moves freely.

 

3. IL-2 GB series P-51D - flaps can be extended at high speeds and at certain point the flap rod will be jammed and the flap will stuck as in the A2A P-51D, but the afterwards is different, the flap will also break, but in the way that it's completely cut off from the wing.

 

Also, we have real life combat reports of P-51 pilots and in some of them they said that they used flaps at high speeds in order to not overshoot the enemy aircraft, even in very high speeds..for example: "I had to put down 20° flaps to keep from overrunning him, indicating above 500 m.p.h." and in DCS when i tried lowering flaps at 500 MPH they barely extend, something like 5 degrees.

 

You can see the source here(near the bottom under: Use of flaps in combat): http://www.wwiiaircraftperformance.org/mustang/combat-reports.html

 

Off course we don't want it to be tested in real flight and to risk the pilot and the plane, but maybe someone with an access to a real P-51 can invenstigate how the system looks like inside the plane?

 

Thx

[grafspee]

Yes, after action reports aren't 100% legit data sources.

But pilot said that he put 20 degree flaps to avoid overshoot at over 500 IAS, ok lets assume that this exactly happen.

But pilot didn't say how flaps reacted to this command, maybe flaps extended only couple degrees he for sure didn't look at flaps at this point.

At 500 ias even 5 degree flaps make enormous drag. I think that flaps are fine in DCS. Extending flaps to 20 degrees looks quite impossible to me at 500 IAS.

Same with for example elevator at low speed you need big deflection to pitch up but at high speed you need only tiny tiny movement and you are in 9 G pull up :)

Edited December 6, 2019 by grafspee