whoever modelled the La7....

[funkedup]

Torque = Power / Angular Velocity
Not hard to calculate.  

[hazed-]

I have to say theres only one area id question the FM whilst playing AH and it does seem to happen most when fighting La7s or P51ds.

Basically, I cannot be sure I have the right perception of what 'my' aircraft should be capable of so I cannot really do anything about it in terms of providing data, but this is the situation i often find myself in:

in a high speed dive chasing a P51d and it pulling a very high G reversal,(edge of black out) just a simple shallow dive to hard vertical climb all the way over to inverted (and reversed), rolling 180 degrees and flying level in oppersite direction.

I have had his happen several times where i was chasing in a 190d9 and followed this very maneuvre only to find the P51d literally leaving my plane standing once the reversal is performed.
Now i may have the wrong idea here but i was of the opinion that the 190 had excellent e retention in the vertical and quite an excellent elevator authority which I assume would result in a good retention of speed in a high speed vertical reversal.Perhaps there is the high wing loading kicking in here and under high G it causes massive energy and or speed loss when the P51d with its laminar flow wing doesnt? I certainly would like someone to explain what is happening because its happening all to often lately and i am finding the maneuvre will pretty much always lose me if we start with similar energy states.

Now i DO NOT KNOW if this is the correct outcome but i certainly am constantly surprised by it.I have tried lag pursuit,lead pursuit and pure pursuit to try to keep some speed with the p51 but everytime it accelerates away at such a rate that im left almost standing still.What should i be looking into with this? wingloading,power to weight,high speed slip/e loss etc ? what should i look at to decide if its correct?

This is something that also seems to happen in a sustained high speed turn when fighting LA7s in 109s.if you try to follow in lead pursuit you will never pull enough lead and will lose lots more energy than the la7.If you lag or pure pursuit you also seem to lose lots of ground.Now i realise the 109 isnt the best turner in the world but at high speeds and pulling moderate G the 109 I would have thought would be able to maintain excellent speeds but obviously there must be a factor here that causes the 109 to lose speed quicker than the LA7? is it a high drag factor,high wingload, light weight that causes it to perform so much less in this manouver i wonder or a combination of all three?
I have looked at the various weights and HP of the planes and several other areas but as im no aeronautical engineer Im finding it incredibly hard to know what to factor in to the equation.Can somebody explain both of these situations? kweassa could you help?

btw great post kweassa, i agreed with most if not all of what you say there.

P.s unfortunately i have very little info on the la7 so its almost impossible to investigate it thoroughly, (not that i could anyhow!! my maths isnt great!) but as to hooligan saying about light planes with powerfull engines not accelerating well ( i assume he was being sarcastic? ) the La5 is empty 6,173lb with 1,650 hp and the 109g6 is 1,475hp at 5,952lb empty so which should in theory be quickest up to say 250-300mph?

[Hooligan]

Hazed:

Film an incident when the other plane does something difficult to understand.  Since you won't know beforehand when this will happen you will probably just have to film as a matter of course the until you capture an incident.   Then use the film viewer to see what is going on in the other cockpit.  i.e you will see how hard a turn they really took, how fast they were going, whether they unloaded etc...  Then you will understand why it happened or you will find a bug and have film to report it with.

Hooligan

[gatt]

Take a look at this nice site about the La5 and La7:

http://www.btinternet.com/~fulltilt/Lavochkin.html

[Wilbus]

Wilbus:

You seem to be asserting that there is something seriously wrong with AH's FM. Would you care to offer some proof, including perhaps some verifiable way to measure torque in AH?

Hey Hooligan, I'm not good at math so don't know what Funked mean with "Angular Velocity", maybe he can explain

However, I find it very odd that a plane such as the LA7, weighting 5840 lbs empty, with a big 1850 HP engine and a (comparable) large prop has LESS tourqe then a Piper Cherokee, weighting 1400 lbs, with 150 HP engine and a small 2 bladed prop.

La7 weights 4 times as much, it has 12 (!!!!!!) Times as many Horsepowers and a much bigger prop. Don't come and tell me this plane would barely be affected by tourqe when a Cherokee is.

Overall, all planes have too little tourqe in AH, actually all planes. 109 and 190 together with Spit 14 has most, most other planes are barely noticable.

[Spritle]

I think that it is MUCH easier to see the E retention problems of various aircraft if you turn the engine OFF.  Some of the aircraft (La-7 for example) exhibit the same performance as some of the best modern gliders.   Now that just aint right.  

Spritle

[Dowding (Work)]

Wilbus, first you say you don't know what angular velocity is, then you completely contradict yourself and talk with assumed authority on the subject of torque and how incorrectly AH models it.

So if you don't know what angular velocity is, which is a simple physical quantity, how could you possibly know anything about the relatively complex subject of torque?

[Spritle]

funkedup,

You better check your calculations.  Your formula is WRONG!

FORCE = Power / Angular Velocity

TORQUE = MOMENT OF INERTIA * ANGULAR ACCELERATION

Better hit the books if you want that A in Physics.

Spritle

[funkedup]

Originally posted by Spritle
funkedup,

You better check your calculations.  Your formula is WRONG!

FORCE = Power / Angular Velocity

TORQUE = MOMENT OF INERTIA * ANGULAR ACCELERATION

Better hit the books if you want that A in Physics.

Spritle

Spritle what degree(s) in engineering and physics do you hold and which university(ies) did you get them at?  I want to know this so I can be sure not to send my kids there.

Your first equation is just plain wrong.  The units don't even work.  You've got force units on the left side and work (or torque) units on the right side.

Your second equation is correct, but I am considering a steady state case where RPM is constant, therefore angular acceleration equals zero.  In that case the reaction torque on the airframe is equal to power absorbed by the prop divided by the angular velocity of the prop.

PLEASE!  

[dtango]

Hazed:

190D-9 vs. P-51D ===========
D9 and -51D have roughly similar max level speeds.  They are roughly the same weight as well.  Because of these similarities the difference in the wing-span / wing-loading comes to the forefront in performance differences.  The D9 has a shorter wingspan that results in higher induced drag.  Similar weight+shorter wingspan = higher AoA needed for lift = higher induced drag.  This is magnified even more with increasing AoA in maneuvers.

La-7 vs 109 ============
I've done some EM analysis of the La-7 (comparison of the La-7 vs. P-51D for that matter since the La-7 in my experience is the chief nemesis for the Pony and being a Pony driver…well...).

The La-7 has a noticeable advantage in instantaneous turn performance vs. other energy planesets in AH.  It also has an outstanding sustained turn advantage against other energy planesets in AH.  I'll post my La-7 v P-51D EM chart when I get home later and it will speak for itself.  Suffice it to say an outstanding sustained turn characteristic is demonstrative of the La-7's E retention advantage over other "energy" a/c in maneuver.   Why?  As already mentioned the La-7 profits from a great thrust/weight ratio (there's actually more to it than this but this is a good generalization to explain why the La-7 retains its E so well).  When you look at the aerodynamics the La-7 is a pretty dog-gone amazing plane.

Tango, XO
412th FS Braunco Mustangs

[Pongo]

What has always confused me is why is the La7 so much better then the la5fn. Same engine. near same weight.  Same wing.....
they are nearly the same plane how can one out perform the other so easily?

[Mathman]

There were some refinements made to the aerodynamics of the La5FN that resulted in the La7.  I would assume that there were also some other refinements made concerning any weight issues or what-not, but as I said that is just an assumption.

[Wilbus]

Go get the book "LA5/7 Fighters in Action" Explains all differences, too much for me to type here though.

[MrLars]

Cool, another La7 thread.

The more people complain about it the more people fly it...that's ok in my book...just means more of them to kill, and damn near every one of 'em is an easy kill....bring them on!!!

[dtango]

Pongo:

Difference in parasite drag.  The La-7 airframe is much cleaner aerodynamically.

Thus, the designers engaged in a program to further lighten the airframe by the substitution of aluminum structures for the main spar and other parts of the design wherever possible, as well as a general cleaning-up of the airframe.  The result was the La-7, which first appeared in prototype form in January, 1944.  With the airframe gaps sealed, a different propeller, and the engine oil cooler removed from the drag-producing position atop the engine cowling to a neat scoop under the fuselage, the wheel wells covered completely, and a different exhaust cover, maximum speed was increased to 407 m.p.h at 15,000 ft. - over 40 m.p.h. faster than the La-5FN - making the La-7 the fastest of all Soviet fighters to see service during the war.

Here's the link for the quote: La-7 link

Here's another link:
La-7 link 2  

Tango, XO
412th FS Braunco Mustangs