Spit 16

[Widewing]

Originally posted by Kweassa
(contd.)

 Bf109F-4 (1.0/1.2/1.2)
- 16 seconds (162mph), 184.5m
- 18 seconds (146mph), 187.1m
- 18 seconds (138mph), 175.5m


 Out of 53 plane types, 20 planes are recorded as having a better turn rate at full flaps. However the differences in turn times are hardly more than 1~2 seconds apart in each ase. The majority of the planes either have a worse off turn rate, or basically an unchanged turn rate when turning with full flaps. Some of them can't even fly a turn tight/slow enough to use full flaps in a full 360d turn in the first place.

 The list of the planes that have a better turn rate at full flaps is as follows;

Bf110C-4
Bf110G-2
C.202
F4F-4
F4U-1C
F4U-4
F6F-5
Ki-84-I-Ko
La-5FN
La-7
Mosquito Mk.VI
N1K2-J
P-38G
P-38J
P-38L
P-47D-11
P-47D-40
P-51D
Spitfire Mk.V
Yak-9T

 Some of them are strange, but other are as expected.

 For instance, the Ki-84 has an even more efficient Fowler flap layout than the P-38s. The N1K2 is a very well handlong plane equipped with an automatically engaged combat flap system. The Soviet Lavochkin fighters are among the best accelerating planes in the game, and all your precious P-38s have also made it in the list.

 On the contrary, all the Spitfires have a one-stage flap that deploys fully at a very extreme angle. As you can see only the Spit5 made it into the list, and all the rest of the Spits show a worse off turn rate at full flaps.

 The 110s or Macchi fighters are quite a surprise, but what's even more surprising is the number of US fighters on the list. Almost all of them have show a better turn rate with full flaps engaged.



 In conclusion, aside from a few unexpected anomalies (and extremely suspicious situation concerning US fighters using highly deflected flap settings), most of the fighters do have a worse turn rate with full flaps. Knegel's comment, at least from my point of view, is either a clear exaggeration of what's really going, or a misinformation from questionable test data, or maybe even both. [/B]

Kweassa, That is old data taken well before the major changes in the drag model.

In many if not all instances, things have changed. I suggest you re-test the aircraft some day and compare the old data to the current flight model.

My regards,

Widewing

[Kweassa]

Kweassa, That is old data taken well before the major changes in the drag model.

In many if not all instances, things have changed. I suggest you re-test the aircraft some day and compare the old data to the current flight model.

 I am aware of that WW, I was just trying to make a point that some planes were always showing a slightly better turn rate at full flaps, and it wasn't such a strange thing to see.

 The recent drag model change is said to have penalized planes even more severely when at high flap deflection (according to HT), so if any new testing is done on my part I'd expect the turn rate at full flaps getting even worse.

[Knegel]

Hi  Kweassa,

i had exact your datas in mind when i started this discussion!!

What you write regarding the roll instability and the need to flaps to stabilize the plane, with the knowledge that the turnrate dont increase is how it was!!

At that time(your tests show that) only some planes had the "magical flaps"(i found the P51D, F4U and P38 took most and unbelievable benifit by full flaps, but i also found the 190A flaps much to good, while the 190 had many problems otherwise, so this benefit didnt show up that much)

Now also the 109´s turnmuch better with full flaps!!

The turnrate remain rather the same, but the radius decrease extreme, similar to the F4U and P38!!

Take a 109K, 100% fuel, then seak for the slowest speed in a level flight without altitude lost(full flaps), thats around 95-100mph. At this speed its of course impossible to bank the plane without altlost, cause we need 100% lift to keep alt.

But already at 105-110mph we can make the most tight turn with a 45° bank.

So we gain 100% lift within 5-15mph!!

Isnt that magic??

At least we dont need to complain the US flaps anymore. lol

Normal flaps dont increase the lift in general!!

In most planes flaps decrease the max lift!!

Flaps shift the speed of best lift to a slower speed and they specialy lower the nose of the plane while that, but at same time the max AoA get decreased as well and this have in many cases a smaler lift as result.

You need to understand why this is so:

Most planes can fly below landing speed without flaps, , the problem is that the angle of attack in this flightposition would let touch the tailwheel at 1st and of course the pilot would have problems to see the runway.

Full flaps now change the airfoil, its somewhat like the whole wing turned around, to have a more big angle in relation to the flightdirection.

As result the wing get a higher AoA  when the flaps get extracted, without to move the elevator,  but the airfoil dont allow a that high max AoA anymore.

The changed airfoil would explain the upmoving nose for some time, on the other had the full extended flaps cause a asymetrical drag below the plane, somewhat a leverage and as faster the plane fly this leverage will push the nose down.
The rather bad formed extreme slowspeed airfoil(wing + full flaps) will lose its lift at higher speeds rather fast, cause the airflow will break, so the drag leverage of the flaps will move the nose down.

Flaps only change the Airfoil from a highspeed to a slow speed airfoil, while the wingarea DECREASE.  
So we have at one stage a very smooth airfoil with a bigger wingarea and on the other had a pretty squary airfoil with a smaler wingarea.

Real flaps rarely will increase the turnradius in a sustained turn, neighter the turn ratio!!

The high drag of the full extended flaps in combination with the smaler max lift make a turn radius gain while a sustained turn, like we have it now in AH, almost impossible.

Greetings,

Knegel

[Krusty]

Knegel, you're saying you need 100% more lift to bank 45 degrees. You don't. You can bank 45 degrees without flaps and not fall from the sky.

[squealer]

turns inside a zero
speed of a tempest

You talk bollocks, on both accounts...

[Benny Moore]

Kweassa, I am certain that what you describe is impossible with conventional flaps.  If that were the case, it would be advantageous to take off with full flaps.  In reality, if two conventional flap ships take off simulataneously and one uses flaps and the other does not, the airplane using flaps will take off first.  However, a minute later, the airplane that did not use flaps will be higher and faster, even if the ship that used flaps raised them soon after takeoff.

That is not the case in reality.  Aircraft handbooks universally recommend taking off without flaps unless the runway is short or an obstacle must be cleared.  This is because conventional flaps are much less efficient than not using flaps.  For the same reason, using conventional flaps to turn should decrease the turn radius but increase the turn time.  Fowler flaps are another story because they increase wing area, thus lowering wingloading.

[Knegel]

Originally posted by Krusty
Knegel, you're saying you need 100% more lift to bank 45 degrees. You don't. You can bank 45 degrees without flaps and not fall from the sky.

Hi,

of course yopu dont need 100% more lift to bank your plane, but to keep altitude.

At higher speed it might be that the fuselage provide extra lift (siderudder oposide to the bank direction), but in gegeral you need to pull the stick if the plane got banked by 45° to increase the lift, otherwise the plane will sink down rather fast.

If a plane get banked to 90° the wing related upward lift get minimized to 0 %, with 45° it 50% , in level flight 100% point upward.

You can try it in AH, fly a plane, bank it to 45° and dont pull the stick.


Greetings,

Knegel

[WpnX]

Originally posted by loony1
something needs to be done about the spit 16 it is totally over modeled

...., so i don't need any flames on my flying skills. ...

Sounds like you need to work on your flying skills:)

[dtango]

Here are a few points that I thought were worth discussing in this thread that I hope illuminates the subject a bit more:

Don't assume that in sustained maneuvering between dissimilar aircraft that the bogey is bleeding energy in a turn even if the bogey is turning tighter than you.  This catches some people by surprise.  Sustained turn performance is primarily determined by the specific energy (Ps) of an aircraft.  Specific energy (Ps) is fundamentally an aircraft's ratio of excess power to it's weight which varies with lift and velocity.   In a sustained turn the plane with the higher relative excess-power to weight ratio will out-turn the other aircraft.

Here's an Energy-Maneuverability chart Badboy posted in another thread (you can find that thread here: http://forums.hitechcreations.com/forums/showthread.php?threadid=194195&referrerid=3699)  that displays some relative Ps data between two aircraft (NOTE: the chart is based on a previous AH FM version but it serves to illustrate the point).



We have an F6F-5 compared to a Ki-84 in the chart.  Both planes are similar in terms of instantaneous turn performance.  There's a difference in sustained turn performance however.  The Ps=0 curve represents the envelope where excess power is equal to zero.  Essentially this is where thrust exactly offsets the total drag of the aircraft produced in a turn.  At the Ps=0 envelope a plane could sustain this turn without losing or gaining any energy.  Above this curve, in a sustained turn the aircraft would bleed E.  Below this curve, the aircraft would gain E in a turn.

Let's assume both aircraft are in a sustained turn with each other at 200 mph with no energy bleed.  You can see that the Ki-84 (point A) is turning both tighter (20 dps, 3.3 g's) and at a smaller radius (850 ft) vs. that of the F6F-5 (point B - 18 dps, 3 g's, 950 ft)….and the Ki-84 is able to do this WITHOUT bleeding any energy!  

I think this type of relative difference in specific energy is one reason of why people are amazed by planes like the Spit XVI.  They expect the other plane (Spit XVI, N1K2-J, you name the plane, etc.) to be bleeding E in a turn when in fact it might be gaining angles on them without even losing any energy at all.  Planes with greater relative excess-power accomplish this because they have greater horsepower/thrust available which offsets the drag in a turn more than another aircraft.  Nothing magical about this.

A plane that is turning at a higher rate and smaller turn radius does not guarantee you an angles advantage.  This is yet another source of  the "how did they do that???!!!" exclamation.  How can my plane that is turning faster and at a smaller radius not win a turn fight?  Here's an example:



Plane A and Plane B start abeam each other and let's assume that plane A is known as the "better turning plane" relative to Plane B.  Plane A has a higher velocity, better rate of turn and smaller turn radius vs. Plane B.  I've overlaid in light red and blue the turn radius' of both planes to demonstrate that there is a difference in turn circles.  At time 1 they turn into each other.  At time 2 Plane A reverses the turn to attempt a lead turn because of the angular advantage it has gained thinking "I'm the better turning plane!" while Plane B responds in kind in the classic nose-to-nose turn contest.  But Plane B even though it has a larger turn radius and slower turn rate compared to Plane A somehow ends up with angles on Plane A instead at time 4.  How did that happen?  In this situation the relative difference in speeds with Plane B being slower is the deciding factor, not the plane with the better turn radius or the turn rate.

This is one way "better turning planes" are defeated by planes with poorer turn performance and I believe another one of those things that surprises the heck out of people who don't see it coming.

I have a few more things to post but I'll save them for later when I can put them together.

Tango, XO
412th FS Braunco Mustangs

[Benny Moore]

And that is exactly why American ships do so much more poorly in the game than their real counterparts; the real fighters had much more horsepower to call upon with no weight increase.  Bring on the real ratings, I say!

[Knegel]

Hi,

i hope noone mix up excess-power with engine power!!

Excess power in a sustained turn is "thrust power" minus "drag power".


In the example  above plane B dont outturn plane A, what happen is that plane B simply let overshoot plane A.

The pilot in plane A must be a absolut rooki to do the shown manouver.

With two normal skilled pilots plane B never wil outmanouver plane A in a close combat, cause plane A always keep enough enegry to disengage upward in a loop to find himself on the tail of the oponent, while the already slower A cant follow this loop.

Benny, the US planes dont had much more power in real life, the US planes in most cases was rather underpowered, but thats not a disadvantage!!

The late P38J(and L) for example had 2 x 1600HP, on WEP but only a initial climb of 3750ft/min with this setting.

In real life weight/inerta in combination with a rather low drag + a high power engine was more worth than a light nimble but sow plane.

Nothing turned to be more important that the ability to disengage in a smooth dive, to be able to follow other diving planes and to have the initial advantage of a very good upzoom due to a high inertia.

Unfortuately the inertia/weight and weight/drag relation get undervalues in AH, or better sayed, the wingload and powerload factor get overvalued, specialy at high speed. As result planes like the A6M5 and HurriII can follow the dive of a P51 or FW190 rather good and even with 2k distance and a good speedadvanatge this nimble planes will follow the upzoom(due to a incredible lift without the related e-bleed) to get into gunrange again(what is often deadly in AH).

The US planes, same like the FW190, simply wasnt slowspeed turnfighters, they was made to make B&Z war.  The pilots in disadvantage easily could disengage vs the better turning planes, while the better turning planes couldnt, if they was in disadvantage.
As result in real life the faster and higher climbing plane was the better plane to let the pilot survive(if the pilot did know to use the advantage).

Greetings,

Knegel

[Benny Moore]

Originally posted by Knegel
Benny, the US planes dont had much more power in real life, the US planes in most cases was rather underpowered, but thats not a disadvantage!!

The late P38J(and L) for example had 2 x 1600HP, on WEP but only a initial climb of 3750ft/min with this setting.

Nope, that's not at all true.  The P-38L had two Allison V-1710F-30s, each one of which could put out 2,000 hp, giving it a climb rate of nearly 5,000 feet per minute.  Usually they were rated for about 1850 hp. each.  I'm not exactly sure about the horsepower values for the P-47 and P-51, but I do know that their manifold pressures were a lot higher than in game (and that's what determines the horsepower.  P-51D was usually at least 72" Hg. MAP (as opposed to 67" in Aces High II), and the P-47D usually ran about 70" Hg. MAP (as opposed to 64" in the game).

The rest of your claim is fairly true.  However, the early FW-190 was considerably better in a dogfight in reality than it is in the game.  The British captured one and tested it extensively.  The result was that they determined that the early FW-190A was more maneveuverable than the Spitfire Mark V in every way except for turning circle.  That means it out-climbed, out-accelerated, and out-rolled the Spitfire, as well as being faster and having superior dive.  The FW-190 pilot should not be afraid to dogfight Spitfires (until later FW-190s when the power to weight ratio went down).

[dtango]

I wanted to help clarify a few things for folks that have been reading this thread specifically as they relate to turn radius.

Some folks are familiar with the following aircraft turn radius equation:



This is worth exploring a little.  If a smaller turn radius is an important factor in dogfights what are the ways to minimize turn radius?  Looking at the equation an obvious answer is reduce velocity.  The slower you go the smaller the turn radius right?  Here's another EM chart posted by Badboy (older AH FM but illustrates the point):



In the diagram why then does the turn radius get larger vs. smaller the slower below corner velocity each plane gets?  



The answer is that g's / bank-angle of the aircraft also changes with velocity at as well.  Infact the slower below corner velocity you go the lower the bank-angle achievable therefore the larger the turn radius.  So what is going on here?



Basically in a level turn there is a vertical and horizontal component to lift since the plane is banked at an angle to the horizon.  The vertical component still supports the weight. The horizontal lift is what produces the angular acceleration that causes the flight path to curve.  The horizontal lift is opposed by centrifugal (g-force) force due to the turn.  Fundamentally in a turn the aircraft must produce more lift than in level flight due to the additional g-force acting on the plane. The minimun required lift in a turn must equal both the weight and the g-force on the aircraft.  Infact the higher the bank angle, the higher the g-load which means the more lift needed.





So how do we increase lift?  By increasing the angle of attack (lift coefficient - Cl) and/or increasing airspeed since lift is a function of both of these variables.  At lower airspeeds to produce an equivalent amount of lift equal to that at a higher velocity we must increase Cl.  Of course there is a maximum angle of attack (Clmax) for an aircraft and exceeding Clmax results in a stall.  Therefore the envenlope of maximum lift producible by an airplane is at Clmax at that given velocity.  This is referred to as the lift limit which is the left-hand side of the EM plots.

Knowing this envelope also tells us the maximum bank-angle / g-force a plane can support for a given velocity at Clmax.  So we can see how bank-angle / g-force of a plane is limited by the amount of lift an aircraft can produce.  If we fix angle of attack at Clmax then we see that lift varies in proportion with velocity (velocity squared to be exact), therefore the slower you go (below corner velocity) the lower the maximum lift obtainable, the lower the bank angle supported, the greater the turn radius.

Which bring us to the issue of the impact of flaps on turn performance.  Flaps increase lift by either changing the camber of the wing, increasing surface area, or both.  Changing the camber of the wing increases the Clmax of the aircraft.  So what happens when we increase the maximum lift producible by the wing?  Here's yet another EM chart from Badboy that illustrates (note: again older AH FM but it illustrates the point):



Notice the 1-g stall speeds of the P-38 without flaps and at 5 notches of flaps and how it's much lower with 5 notches vs. not.  Also notice the lift-limit of the P-38 with and without flaps.  With 5 notches we can go slower and yet produce the same amount of lift needed to support the g-load / bank-angle at a higher speed without flaps.  Therefore the we can achieve a smaller turn radius, and also a higher turn rate (at least momentarily) compared to that of the P-38 without flaps.

Tango, XO
412th FS Braunco Mustangs

[Squire]

The P-38L did not have a wartime rating of 2000hp for its engines, not a typical example anyways!

No reliable source gives them more than 1725 hp at max WEP (which is pretty damn good), for a typical wartime fighter, which was beyond the 1600 hp rating they were actually "advertised as" by Lockheed and Allison, and were the "official" ratings.

I could see asking for the 1725hp rating in the game for the L (@70" Hg) beyond that is getting into pretty iffy territory for a wartime, operational example, of that fighter.

The trouble with many posters, is that you all want the absolute best example of any given fighter, while expecting the "average" ratings for your opposition. Almost ALL the WW2 fighters had examples of tweaked or higher hp models, from any # of causes (fuels, over boosted engines, ect), but its not practical to expect HTC to chase these rarer, souped up versions.

The RAF, USAAF, LW, Soviets, all ran fighters at higher ratings sometimes, but if you do it for one...then you have to do it for all, then it becomes an endless game to chase down the absolute highest examples irregardless of how many really saw action (and the fan-boys dont really care), with the usual endless debates that follow...

They model the average, rated hp's which is really the only sane thing to do. Its "Aces High" not "Reno Air Races High".

[Widewing]

Originally posted by Squire
The P-38L did not have a wartime rating of 2000hp for its engines, not a typical example anyways!

No reliable source gives them more than 1725 hp at max WEP (which is pretty damn good), for a typical wartime fighter, which was beyond the 1600 hp rating they were actually "advertised as" by Lockheed and Allison, and were the "official" ratings.

The 2,000 hp rating comes from data related to the use of 150 octane fuel by 8th AF Fighter Command.



Few P-38s were operating with the 8th AF when 150 octane came into general use, and it was not used by the 9th AF or any other unit outside of the ETO.

My regards,

Widewing