40,000 in a nosedive

[fatchance]

I tried and tried to get the plane into a state of compressibility where the controls start to lock up. I never get much past 500ias and maintain very good control especially at lower altitudes. At higher alt's it's very hard to get the ball centered for some reason. Is that because it's still in beta?

 

I also find the engine has no power at 40k down to maybe 25k. I think that's probably my ignorance of high alt engine management though.

 

PS I love the P51 and I don't get all the critical comments about DCS's decision to add it. I can spend hours just practicing take offs and landings. I have had to un-learn many ham handed habits I've picked up with other high end sims just to land and take off. THANK YOU DCS!!

Edited June 15, 2012 by fatchance
added praise

[Sceptre]

Yes it is because the P-51 is still in Beta. A few switches in the cockpit don't work and the Flight Model is not finished yet. IMO, the state of DCSM right now is absolutely amazing for Beta and I agree with you, I do not understand the negative comments about a new plane to learn!

 

I spend hours trying to get a direct hit with rockets on an tank and I still can't!

[effte]

Rudder hinge moments are on the list of unfinished work. That's the fancy name for control forces increasing at high speed. I'm hoping this means we will see rudder effectiveness decrease significantly with speed in future releases. Right now, you can put everything on the stops at all speeds. Not even the strongest among us could do that in the real thing. :)

[G-Lock91]

Rudder hinge moments are on the list of unfinished work. That's the fancy name for control forces increasing at high speed.

 

You just couldn't resist could you? :thumbup:

[Jona33]

You just couldn't resist could you? :thumbup:

 

He couldn't resist what?

[Tango]

Embrace technical nomenclature. ;)

 

On topic: Does the P-51 simulate roll torque? e.g. you're on approach at low power and slam the throttle wide open. The real thing will roll inverted with insufficient aileron authority to stop it.

 

Best regards,

Tango.

[Sceptre]

Embrace technical nomenclature. ;)

 

On topic: Does the P-51 simulate roll torque? e.g. you're on approach at low power and slam the throttle wide open. The real thing will roll inverted with insufficient aileron authority to stop it.

 

Best regards,

Tango.

 

Yes it does:)

[G-Lock91]

He couldn't resist what?

 

Eff is an Einstein when it comes to planes and how they work. I've learned quite a bit from just reading his posts. He's hard to understand if u don't have a Doctorate in Engineering :thumbup: I just have to give him a hard time about it is all.

[sobek]

On topic: Does the P-51 simulate roll torque?

 

Yes it does, although the effect is comparatively unpronounced until you are close to a stall (given that you are in yaw trim).

[Weta43]

"I never get much past 500ias "

 

What counts as "much past 500ias"

[fatchance]

much past 500ias means right around 500ias on the air speed gauge in the cockpit. I'm mostly trying to keep the ball centered to max out the speed so maybe 510ias is the max speed I've reached.

 

Can someone else try to get a faster speed and post it?

[macedk]

Yep and its a ¤#%¤"#% when u adjust throttle up on landing hehehe

[effte]

You just couldn't resist could you? :thumbup:

 

But I did include an explanation this time! ;)

[Weta43]

560...

Suspect there's more to get if you're carefull about keeping the ball centred.

[Strut]

I got about 550, first go, il mess around some more, see what happens.

[159th_Viper]

Speed-Bar prior to pulling out of dive with screenshot indicating successful recovery.

 

[Strut]

Good work Viper, whats that in MPH ?

[159th_Viper]

Good work Viper, whats that in MPH ?

 

575 or thereabouts.

[Strut]

Bloody fast, well done, i bow to your greatness.....@ Viper

[159th_Viper]

Bloody fast, well done, i bow to your greatness.....@ Viper

 

Hahaha no nothing great about it - just point the nose down and hang on :D

[rextar]

Is 40000 max altitude?

If so whos flyin in the dcs world load up screen at over 200 thousand feet! Lol

[fatchance]

Two questions. Why is it so hard to center the ball? What is the best way to manage the engine to get the most power.

[sobek]

Why is it so hard to center the ball?

 

Because you lack haptic feedback from the airframe. The behaviour itself is perfectly normal for a big prop plane.

 

 

What is the best way to manage the engine to get the most power.

 

The engine manages itself, mainly. Just stick to the timesinks for the power ratings.

 

5mins - WEP (not implemented yet)

15mins - 61inHg@3000RPM

max cont - 45inHg@2700RPM

max cruise - 35inHg@2400RPM (off the top of my head)

[TimmyD]

Make sure the trim, throttle and prop settings are correct. If you're pushing everything forward you won't get as much as you think.

 

Try throttling back to 45" mp and prop set to just over half way forward.

[effte]

Why is it so hard to center the ball?

 

It's physics. Those inclined to stop reading at the mention of the P word can skip forward to the third last paragraph at this point. :)

 

The ball is normally pulled down by the normal force (n_z), i e the force generated by the wings. In level flight, this is 1G.

 

Then you have a lateral force (a force to the side), generated by sideslip, pulling the ball to the side.

 

If the lateral force is equal to the normal force, the ball will be 45 degrees from the bottom position (had the glass tube been curved enough - let us pretend it is for now).

 

Assume you are in level, 1G flight with enough slip to keep the ball at 45 degrees off the bottom. The lateral acceleration will equal the vertical acceleration, i e it will be 1G. 1G vertical, 1G lateral. With me so far?

 

Maintain the sideslip and the lateral 1G, but push the stick forward, reducing the vertical force to 0.5 G. Suddenly the lateral force is twice as large as the vertical force, for the same amount of sideslip! The ball will now (or would, had the glass tube been curved enough) deflect to almost 65 degrees from straight down - for the same amount of sideslip. To get it back to 45 degrees, you would have to reduce the sideslip in order to reduce the lateral force as well to 0.5 g.

 

In other words, the sensitivity of the libelle (the glass tube with the ball) increases with reduced G loading!

 

Another way to reduce vertical (normal) G load is to pitch up or down. In unaccelerated flight at a pitch attitude of plus/minus 60 degrees, the G load is 0.5G. The G load decreases towards zero as the pitch approaches vertical.

 

As the G load approaches zero, the sensitivity of the libelle (the ball) increases towards infinity. I e, any amount of sideslip/lateral force will have the ball at either end of the glass tube.

 

(Physics disinclined readers - start here ;))

That's the theory. Now, that may be incomprehensible to a lot of people. Let us try to put it into an everyday perspective. Take your curved glass tube containing a ball. Place it on the desk in front of you, with the ends pointing up just as when installed in the dash of your plane. Now, tilt the table. How much will the ball move for a given amount of tilt? This is level flight, with the tilt of the table representing your sideslip.

 

Now, put the tube flat on the table. This is the way it is oriented in a vertical dive. How much will you need to tilt the table to make the ball move to either end of the tube?

 

Similarly, the sensitivity decreases as you pull on the stick in a hard turn or pull-up.

 

Cheers,

/Fred

Edited July 4, 2012 by effte