Behaviour at high alpha

[VTB_Ray]

Good way to get down quick is power off, full flaps, prop full foward and put it into a turning slip with full rudder deflection. For a slip to the right it would be left rudder, right aileron to control ground track. Keeps your speed under control with a massive sink rate.

 

Not sure if you'd see anyone do that in real life in a P-51 but I do it all the time in the Super Cub!

 

I feel the way it handles when landing feels very good - no problem with wheel landings or 3 points, the key to a wheel landing is carrying enough excess speed/power to maintain enough speed to keep the tail in the air as you're working to touch the mains gently on the ground.

 

The amount of forward stick required to "stick it" is proportional to the sink rate at touch down. The harder you touch down the more downward momentum the tail has that's trying to rotate the wing and fly/bounce you back into the air.

 

You don't have to hold the foward stick, but a rapid application is needed initially to stop the downward momentum of the tail, once that's arrested you can hold just what you need to keep the tail flying and begin to gently fly it onto the runway as your speed decreases.

 

The key is managing your sink rate and I like to think of it as trying to fly as close as possible to the runway without actually touching it.

Edited June 25, 2012 by VTB_Ray

[MaverickF22]

Have you guys ever head of laminar airfoils? They stall violently with no or very little warning (vibration/shaking)...! Although we have a 15% times the chord lenght, as an airfoil thickness for the P-51..., there still is some vibration due to a partial airflow separation over the wing, yet that isn't high enough..., although when it stalls, it stalls violently due to an abrupt and complete airflow separation from the top of the wing (if we talk about positive alpha).

 

Think of what would've happened if it were a 5% thickness airfoil or 4% (like the F-104 Starfighter has)..., it would snap in a spin with no warning at all (except for a stick shaker or alpha limit audible warning)...! Aerodynamics baby!

 

So the way the wing's stall and any other aerodynamic surface (empennage) stall is simulated, is simulated as realistic as possible from my opinion, so not the stall is the problem with P-51, but the way it transfers the center of lift in horizontal plane (along the aircraft's XoY plane), from one wing to the other and closer or further from the leading edge as the aircraft travels through the alpha (angle of attack) and beta (angle of sideslip) angles..., that's where the devs have to revise the aero tables, for the P-51 alone (so far).

 

 

Have a good day!:thumbup:

Edited August 4, 2013 by MaverickF22

[sobek]

The effect is intentionally overmodelled in DCS to account for the absence of other cues. IRL, this is apparently even less obvious.

[MaverickF22]

That article pretty much described DCS P-51D.

I did wonder if it was really this difficult to lose speed. A hung of metal this size doesn't want to slow down? This can't be realistic! Good job, ED.

 

 

This is the P-51's airfoil's aerodynamic test data, and as you can see, that drag bucket is the region where this airfoil (which is a laminar one) has the lowest drag coefficient values as shown in the picture, between -1.5 AoA and +4 AoA (the drag variation is very low between these values), while the lift coefficient will vary from -0.05 to +0.45 (which is more than what a regular airfoil can provide)..., so when you're at 4 deg AoA having a 0.45 lift coefficient (which is quite good), you'll have a very good lift to drag ratio there, and that's the reason why you feel that it has a lot of lift for so little drag...! That's what a laminar airfoil is also meant to do!

 

Learn2Aerodynamics!

 

 

Good day!:thumbup:

Edited August 2, 2013 by MaverickF22