1.5.1.46722 P-51D changes

[GrapeJam]

Solty,

 

What you quote from yo-yo does not contradict what these modern pilots describe: 90lbs of force for a 5g turn. It is interesting if it actually decreases past that point, and a non-linear force/g curve cannot be desirable in a fighter.

One of the main reasons the P51D had light was because of rear after CoG thanks to the aft tank, most modern P51D had them removed, so, yeah.

[AG-51_Razor]

It's not detonation as we understand in engineering terms - i.e cylinder related and very bad for the engine. It's actually exhaust popping.

 

Unburnt fuel/air mix being allowed to escape the cylinders and hits the very hot exhaust manifold and combusts with a popping sound. This is often heard in Merlin engined aircraft as they cut power immediately prior to touchdown.

 

I do believe that DD_Fenrir is absolutely right and, although I have never flown a P-51, I think it's a bit overdone and corny sounding. All these big bore engines will snap and pop with a rapid decrease in throttle but it doesn't sound like a drummer practicing with a wooden spoon on a desk top. I would almost rather they did away with it.

[Redglyph]

Its a dream of mine that one day we will get FFB sticks with extreme strengths.Just look at the new high torsion racing wheels and how they make the racing sims so much more realistic.Watch the end wehere he drives with the wheel.

 

 

That'd be great! Hopefully less expensive though ;) I've always been horrified how much Accuforce or even Fanatec hardware cost.

 

Isn't that a patent issue, for the FFB joysticks?

[gavagai]

Isn't that a patent issue, for the FFB joysticks?

 

No, Microsoft successfully defended itself against that lawsuit. There is nothing stopping them from making more ffb joysticks, except the profit motive.

[Dirkan]

About the so called heavy controls in the mustang. Page 66 in the reprint of the pilot's training manual says this.

Edited November 17, 2015 by Dirkan

[Solty]

Thank u dirkan. That's what I've read many years ago.

[Yo-Yo]

About the so called heavy controls in the mustang. Page 66 in the preprint of the pilot's training manual says this.

 

This text must be stuck to the first forum page... :)

[gavagai]

Very interesting. Thank you.

[Crumpp]

About the so called heavy controls in the mustang. Page 66 in the preprint of the pilot's training manual says this.

 

It is not a static quality.

 

You can think of the CG limits in terms of stick force per G.

 

The forward CG limit equals the maximum stick force per G the design can accept.

 

The rearward CG limit equals the minimum stick force per G the design can accept.

 

The POH is discussing the movement of the rearward limit of the CG due to radio and fuel tanks.

 

The minimum stick force per G limit has changed from a normal 6lbs per G to a much too light 1 1/2lbs per G and the pilot will experience longitudinal instability in the form of stick force reversals.

 

Nothing in the clip says a thing about the maximum stick force per G found at the forward limit.

[Crumpp]

Here is an idea of the P-51's Stick Force per G range:

 

 

You can see at a mid range CG location of 25.5% MAC, the Stick Force Per G is 8.3lbs/g. With that you are going to experience some two handed dive recoveries. That is a not a bad though.

 

At the forward limit of 21.5% MAC, the Stick Force per G would be even larger and one could easily experience stick forces in excess of 90lbs.

 

what these modern pilots describe: 90lbs of force for a 5g turn. It is interesting if it actually decreases past that point, and a non-linear force/g curve cannot be desirable in a fighter.

 

That article is a great piece of work.

 

At face value some things are not representative of a World War II Operational aircraft but data points do give us some very good measured data points which can be converted to other conditions.

Flight test comparison_P-47_P-51_Corsair_Hellcat (1).pdf

[AG-51_Razor]

Keep in mind though that, with full wing tanks and fuselage tank, you could fly around the outer edge of this map a couple of times! I doubt if very many fly in this sim with any fuel in the fuse tank at all, much less full.

[Crumpp]

Keep in mind though that, with full wing tanks and fuselage tank, you could fly around the outer edge of this map a couple of times! I doubt if very many fly in this sim with any fuel in the fuse tank at all, much less full.

 

Absolutely.

 

Yo-Yo's interpretation of the P-51 is fantastic.

[Anatoli-Kagari9]

BTW,

 

did the p51d, with fuselage tank not filled, also so neutral positive pitch stability, being speed stable (positive) for negative pitch inputs ?

[Dirkan]

Here is an idea of the P-51's Stick Force per G range:

 

 

You can see at a mid range CG location of 25.5% MAC, the Stick Force Per G is 8.3lbs/g. With that you are going to experience some two handed dive recoveries. That is a not a bad though.

 

Where did you get that image from? I'd like to read the source material, please.

 

At the forward limit of 21.5% MAC, the Stick Force per G would be even larger and one could easily experience stick forces in excess of 90lbs.

 

 

 

That article is a great piece of work.

 

At face value some things are not representative of a World War II Operational aircraft but data points do give us some very good measured data points which can be converted to other conditions.

The article also mentions that they removed the fuselage tank. Which in the original ww2 manual, states that it made a huge difference, and with stick forces reversing after 4Gs, pulling more isn't going to be difficult. Edited November 17, 2015 by Dirkan

[Dirkan]

Something else that's interesting. Installation of bobweight in the mustang and the effect on lbs/G.

 

Given the results, removal of the fuselage tank but not the bobweight could render the stick forces really heavy. That's maybe what's happening in the article pdf crumpp linked.

60J-28.pdf

Edited November 17, 2015 by Dirkan

[gavagai]

Keep in mind though that, with full wing tanks and fuselage tank, you could fly around the outer edge of this map a couple of times! I doubt if very many fly in this sim with any fuel in the fuse tank at all, much less full.

 

IIRC, the fuselage tank was the one pilots drained first because it had a bad effect on the P-51D's pitch stability.

 

----------

 

Thank you for the pdf Crumpp! I'd never seen the original article before.

[Crumpp]

IIRC, the fuselage tank was the one pilots drained first because it had a bad effect on the P-51D's pitch stability.

 

----------

 

Thank you for the pdf Crumpp! I'd never seen the original article before.

 

You are most welcome.

 

The P-51 flown in that article is a dual seat modification. The rear tank/radio equipment is replaced with a rear seat and I believe the normal pilot seating position is moved forward.

[Anatoli-Kagari9]

You are most welcome.

 

The P-51 flown in that article is a dual seat modification. The rear tank/radio equipment is replaced with a rear seat and I believe the normal pilot seating position is moved forward.

 

Yes Crumpp, and if I'm not wrong, at least after the latest patch we do get a rear seat too in the TF51.

 

Thx for another excellent source of data !

 

We must fly a mission online one of these days!!!

[Dirkan]

Keep in mind the data is misleading if you don't read under what conditions they were tested. A lot of the aircraft are modified in the test. Removal of a 100 gallon auxiliary tank and turbocharger in the P-47, and removal of the 85 gallon fuel tank in the P-51 to name a few.

 

So the data is not representative of ww2 combat performance.

Edited November 19, 2015 by Dirkan

[Solty]

Keep in mind the data is misleading if you don't read under what conditions they were tested. A lot of the aircraft are modified in the test. Removal of a 100 auxiliary tank and turbocharger in the P-47, and removal of the 85 gallon fuel tank in the P-51 to name a few.

 

So the data is not representative of ww2 combat performance.

 

I agree. Those tests bring only confusion and prove nothing I am afraid.

Edited November 19, 2015 by Solty

[Crumpp]

Keep in mind the data is misleading if you don't read under what conditions they were tested. A lot of the aircraft are modified in the test. Removal of a 100 auxiliary tank and turbocharger in the P-47, and removal of the 85 gallon fuel tank in the P-51 to name a few.

 

So the data is not representative of ww2 combat performance.

 

Much of that data is representative. The stick forces growth in the P-51 is correct in that it has much higher forces than many modern pilots are used too.

 

A P-51D in world war II could have pull forces in excess of 90 lbs.

 

That is not a bad thing and keeps the pilot from killing himself.

 

:thumbup:

[Crumpp]

The forward CG limit which is the maximum stick force per G the aircraft can accept is determined by the elevator design and arm of the fuselage.

 

Moving the seat forward on a two seat mustang does nothing to change that relationship.

[Crumpp]

Yes Crumpp, and if I'm not wrong, at least after the latest patch we do get a rear seat too in the TF51.

 

Thx for another excellent source of data !

 

We must fly a mission online one of these days!!!

 

You are most welcome and I would love to link up and fly online with you, Jcomm!

[Crumpp]

It is not a static quality.

 

You can think of the CG limits in terms of stick force per G.

 

The forward CG limit equals the maximum stick force per G the design can accept.

 

The rearward CG limit equals the minimum stick force per G the design can accept.

 

The POH is discussing the movement of the rearward limit of the CG due to radio and fuel tanks.

 

The minimum stick force per G limit has changed from a normal 6lbs per G to a much too light 1 1/2lbs per G and the pilot will experience longitudinal instability in the form of stick force reversals.

 

Nothing in the clip says a thing about the maximum stick force per G found at the forward limit.

 

Extremely important fact to understand in this discussion. Stick Force Per G is not a static quality.

[BSS_Sniper]

And did you notice the new detonation effects if you lower the throttle way too much inflight ?

 

Yes and it sounds awful the way it is today.