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73GIAP_Milan
10-26-2005, 12:23 PM
Today i found a few things from one of my many books. Regarding the P-51 Mustang this time.

From the book "The Great Planes"
A few quotes; "The 'Fifty-one' is'nt stable, you can trim it all the way you want, all the time, but you will never be able to fly it with your hands off the stick. Push the nose only a tad down and in less then no time the speedometer climbs to 850KM/H and the plane races down like a bomb. Pull the stick back and gravity will push you flat against your chute. It is easy to bring the 'Fifty-one' in the compressability region, the fuselage is shaped so well. You know when you are at that point as the controls will start to feel heavy and the plane will start to vibrate, sway and pitch in an almost uncontrolable manner. If you enter a vertical dive with 400KM/H on 5000M, you have to start to pull out before you reach 3000M. And no-one has ever brought the Mustang horizontal from a dive just by pulling out, no, you do that with a vertical roll or an immelman. The Mustang simply asks for stuntwork, but dare not to be scared and halfway try to get out of a slow roll; you must have quite alot of altituded for that and not be afraid of gravitational forces and high speeds."

Half a page further something interesting on stall behaviour and torque.
"The Mustang was not a hard plane to fly, you just had to know the pilot's manual very well and have a little feeling for flying. It had only 1 vice; the torque from the 1400HP merlin could turn you upside down on low airspeeds. At a certain point during flight trainingschool you got ordered to take the 'Fifty-one' to considerable altitude, lower the flaps and undercarriage and slow down to 210KM/H and then suddenly apply full power. Only 1 of these demonstrations was enough: even with everything full in the right corner of the cockpit, you fell out of control to the left."

I tried to recreate this slowdown procedure described above ingame multiple times but i failed, even at lower and higher speeds i did not even stall. This learns that both the torque and stalls in the current game probably are undermodelled.

Sources used for this book:
Green, William, Famous Fighters of the Second World War. New York, Doubleday, 1967

Gruenhagen, Robert W, Mustang. New York, Arco, 1969

Morgan, Len, The P-51 Mustang. New York, Arco, 1963

Toliver, Raymond F and Constable, Trevor, Fighter Aces. New York, Macmillan, 1965

danjama
10-26-2005, 01:24 PM
I agree torque is undermodelled on high powered planes such as the mustang, but i wont complain! Although it would be funny to see Noobs jamming the throttle to 110% on spawn and flipping their plane over wondering what the hell is wrong! http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Bearcat99
10-26-2005, 01:42 PM
I dont think the 51s speedo was set to metric..... was it? http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

Of course this guy could have done the math in his head for artistic sake....

73GIAP_Milan
10-26-2005, 01:56 PM
Originally posted by Bearcat99:
I dont think the 51s speedo was set to metric..... was it? http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

Of course this guy could have done the math in his head for artistic sake....

I forgot to note that this book i have is translated from English to Dutch. So did the author probably on the speeds. That is why i added the sources used in the book, for reference.

And feel free to try it ingame, all i got was a slight wobble at speeds even far below the mentioned 210KM/H, i slowed down to 150KM/H even.
Just for all; i am not the author, i just felt like sharing this, it could be interesting.

http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

MEGILE
10-26-2005, 02:02 PM
The Mustang is far from being the only plane which should suffer from this.

Gibbage1
10-26-2005, 02:14 PM
Originally posted by danjama:
I agree torque is undermodelled on high powered planes such as the mustang, but i wont complain! Although it would be funny to see Noobs jamming the throttle to 110% on spawn and flipping their plane over wondering what the hell is wrong! http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

How about torque on a 2000HP and 1/2 the weight of the Mustang? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Hetzer_II
10-26-2005, 02:42 PM
How about believing an aircraft with 2000 Ps and half the weight aof 51 should easily outfly, outclimb and outturn 51´s? http://forums.ubi.com/images/smilies/59.gif

lrrp22
10-26-2005, 02:51 PM
Originally posted by Hetzer_II:
How about believing an aircraft with 2000 Ps and half the weight aof 51 should easily outfly, outclimb and outturn 51´s? http://forums.ubi.com/images/smilies/59.gif

Half the wing size, too.

Not really half though. 70-80% of the weight on 74% of the wing area.

Out climb? Yes. Outfly and outturn? Probably not.



.

.

faustnik
10-26-2005, 03:53 PM
I didn't get that the torque question was only about the P-51. It would apply to almost every single engined a/c we have in the sim, right?

Chuck_Older
10-26-2005, 04:14 PM
My F-51 D manual (also covers non-gyro sight equipped D model P-51s, the USAF just renamed the plane) has all instrumentation in commonly used American terminology. Zero use of metrics


Never heard the P-51 was un-trimmable before. I very much doubt this was the case with the vast majority of the P-51/F-51 family, as they were used for extremely long range flights. I have two books by Mustang aces, one flew the D model, one flew the B, and neither of them, even on flights to Berlin from England, or to Poltava (in the USSR) from Italy, mention the plane needing constant stick pressure because of an untrimmable state. That is very surprising to me to read that statement. I've never heard Yeager or Anderson mention the P-51 being un-trimmable or in any way unstable, nor can I recall the report of any P-51 pilot anywhere stating this

I can only conclude that the P-51, in any variant, was no more or less stable or un-trimmable than it's contemporaries from the US. the lack of mention of this trait, which would be fatiguing in the extreme on long flights, tells me that it's stability and trim-state behavior was considered normal for the time and for the type of aircraft it was

Slickun
10-26-2005, 07:24 PM
I have no problem believing it picked up speed and retained it in a massive fashion.

My Dad said you had to always trim the P-51, but it certainly was trimmable. You just got used to constantly trimming it.

Hetzer_II
10-27-2005, 05:43 AM
Half the wing size, too.

Not really half though. 70-80% of the weight on 74% of the wing area.

Out climb? Yes. Outfly and outturn? Probably not.


Hehe and what about the laminar wing-profile? Thats the standard reason why many people say the 51 was so superior at high-speeds and this reason is also used here.. whatch the naca-reports/profile tests.. laminar isnt good for lift.. so its not good for 1)climb 2)turn 3)energy rentation so maybe the 51 was faster.. maybe... because in the power settings we currently have its has plenty less power than K4 for example... if i remember correctly ...

If you realy want to hear my opinion... yes the 109 is moddeled to strong in il2 but i see no reason why the 51 should be so much superior exspecially in the low level quake-dogfightserer most people play..

DangerForward
10-27-2005, 06:12 AM
The "flip you on your back" torque was always one of things I was looking for when 4.0 came out. I did it once landing the P51(and died), but didn't really notice it on many other planes. I always thought it was going to be a big feature of planes like the P51, Spitfire and ME109, but only noticed it that one time.

73GIAP_Milan
10-27-2005, 11:17 AM
My Dad said you had to always trim the P-51, but it certainly was trimmable. You just got used to constantly trimming it.

My guess is that the author of my book is referring to this then. Possibly under combat conditions - i.e. during fights, taking in account what Chuck Older said above.

But even though that the quotes i stated may have become a little murky due to the massive amount of sources on the P-51 (and other warbirds) still i find that both the stall and torque ingame are really not enough.

Not even the P-51 should suffer from serious torque but as was mentioned, most of the planes from that era.

I did succeed on recreating the stall-out effect as was mentioned in my 1st post here last night.
I dropped my speed below the stated 210KM/H down to 140KM/H with full flaps and gear down. Only then this effect occurs. At speeds above 150KM/H the plane remains (fairly) stable.

LilHorse
10-27-2005, 12:01 PM
Originally posted by faustnik:
I didn't get that the torque question was only about the P-51. It would apply to almost every single engined a/c we have in the sim, right?

Yes. This is one of the few things that CFS seemed to model better or at least more consistantly than IL2/FB et.al.

On takeoff when the prop swings right (clockwise) from the pilots perspective the plane should want to swing left and you need right rudder or lots or right rudder trim or, in some cases, right rudder and lots of right rudder trim to prevent veering off to the left.

This doesn't seem to be the case in this sim. It always seems strange to me that when I throttle up in any plane in this sim who's prop spins as described above that the plane wants to veer right.

danjama
10-27-2005, 12:45 PM
Originally posted by LilHorse:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by faustnik:
I didn't get that the torque question was only about the P-51. It would apply to almost every single engined a/c we have in the sim, right?

Yes. This is one of the few things that CFS seemed to model better or at least more consistantly than IL2/FB et.al.

On takeoff when the prop swings right (clockwise) from the pilots perspective the plane should want to swing left and you need right rudder or lots or right rudder trim or, in some cases, right rudder and lots of right rudder trim to prevent veering off to the left.

This doesn't seem to be the case in this sim. It always seems strange to me that when I throttle up in any plane in this sim who's prop spins as described above that the plane wants to veer right. </div></BLOCKQUOTE>

Have you ever taken off a focke wolfe? Go try it and then delete that post, or at least the last few lines. That plane has the most left torque in the game. I have to give full right rudder when taking off in it.

Joilet_Xray
10-27-2005, 10:37 PM
~S! Gentlemen, the same trait is shared by many, if not most high powered high performance single engine aircraft.

Example, when checking out in a V-35 Beech Bonanza years ago, could roll it up with the torgue when slow (in pre-stall buffet) in landing config, by just opening the throttle..... recovery was immediate on reducing power. Fly it alittle faster (i.e lower angle attack)adding power would be entirely controllable.

73GIAP_Milan
10-28-2005, 02:37 AM
Should the torque and stall factors be adjusted to more historical/realistic levels?

I wonder..
If this would make the game nearly unplayable for newbie pilots - my guess is that the devteam chose it the current way to keep the game playable.

Playability in favour over more Historical factors..