Author Topic: Thoughts on the Current Flight Model  (Read 6491 times)

Offline Stoney74

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Re: Re: Thoughts on the Current Flight Model
« Reply #15 on: February 24, 2007, 09:00:36 PM »
Quote
Originally posted by Benny Moore
American fighters did not have a special War Emergency Power control.  


Late model P-47D's (after the D-21 block) had a manual water injection control.  The pilot had to manually engage water injection above 52" of MP in order to achieve the higher WEP manifold pressures or risk detonation.  The throttle controlled the MP, but without engaging the water injection control, they could damage the engine at the higher MP.  The M and N models that water injection was automatically controlled by the throttle.  I don't know how the water injection was controlled on the D-11 through D-20 blocks.  I have no idea how the F4U or F6F's were setup.

Offline bozon

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Re: Thoughts on the Current Flight Model
« Reply #16 on: February 25, 2007, 05:04:52 AM »
Quote
Originally posted by Widewing
4. When the last change was made to the drag model, some aircraft suffered a loss of handling and maneuvering performance. Chief among that group was the P-51s. For example, at 25% fuel, without flaps, a P-51B has a lower wing loading than the P-47D-11. It also has a very similar coefficient of lift. It should out-turn the Jug. Yet, it does not. Once flaps are deployed it gets worse for the Mustang. I have detailed the issue in this thread.

6. Some aircraft demonstrate unusual stall behavior when flown into a power-off nose-high stall.

Please feel free to add to this list, but please make sure you can back up your points with primary source data or other credible sources (for example, the History Channel isn't a good source).

#4
From what I see in the game, P51B handily out turns the D11 when the speeds gets slow. I'm pretty sure that they were not historically tested flying circles at 100 mph with flaps full out. If there is something wrong with P51's flaps you will not find it in such comparative reports.

Also, that figure of turning circles you keep posting is out of scale misleading. The spitfire does not turn at a third of a P47/Tempest radius, and P51 does not turn in half a P47 radius. I'm also pretty sure that the tempest could turn tighter than a P47. It most definitly does in the game. That figure is symbolic "this is smaller than that", but not by how much.

#6
The mosquito is perhaps the most obvious problematics FM. The tail wiggleing (yaw instability), the sudden departures, the flat spins and deep stalls unique to it (maybe also the spit I) are clear indications of that. Couple that with the flamable damage model and the chosen version, the slower night version, to kill this most unique and cool WWII plane.

Quote
Originally posted by dtango
On the Mossie, I didn't realize it didn't have counter-rotating props and haven't thought through the dynamics of that situation. Post stall characteristics especially at extremely high angles of attack can be really tricky to analyze.
[/B]

It will have about twice the torque give or take secondary effects. But it is also a much heavier plane with large wingspan to control it. Some adverse effects are reduced (prop wash on the tail for instance).

What happens in a deep stall is that the plane turns into a rock. The airflow on the surfaces is in completly wrong direction, plus turbulant, and you can't use any simple "lift" or "drag" or thrust equations. It is the same as trying to calculate the airflow around a giraffe. I have absolutely no idea how AH handles this, but this is one area where hand corrections and guesses are legitimate. If anything, I think most planes are too easily controled near and past stalls.
« Last Edit: February 25, 2007, 05:09:10 AM by bozon »
Mosquito VI - twice the spitfire, four times the ENY.

Click!>> "So, you want to fly the wooden wonder" - <<click!
the almost incomplete and not entirely inaccurate guide to the AH Mosquito.
https://www.youtube.com/watch?v=RGOWswdzGQs

Offline mussie

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Re: Re: Thoughts on the Current Flight Model
« Reply #17 on: February 25, 2007, 05:13:42 AM »


Not being an expert, and not knowing what P-Factor is (Other Than Pucker Factor)

FARK THAT PIC IS COOL

Next time someone starts mouthing off over the Flight model I am gonna point them at this..

To the guys at HTC

NOTE: Dont bother explaining P-Factor... It will just cause a stack overflow.... :p

Offline kreighund

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Thoughts on the Current Flight Model
« Reply #18 on: February 25, 2007, 08:51:05 AM »
The dogs of war are awakened once again,,,,,,

I have another P-51 chart showing the -39 with WEP (56") up to 9000' but I can't seem to locate it but this is from my P-40E manual;

Ah nuts, I can't post the Specific Engine Flight Chart..............I'm behind this stupid firewall the Saudis have put up which prevents me from establishing a URL.

Someone give me your email   bitte


Ok I threw them a bone now they are going to sleep.

Offline dtango

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Thoughts on the Current Flight Model
« Reply #19 on: February 25, 2007, 10:01:12 AM »
Quote
Originally posted by kreighund
The dogs of war are awakened once again,,,,,,

I have another P-51 chart showing the -39 with WEP (56") up to 9000' but I can't seem to locate it but this is from my P-40E manual;

Ah nuts, I can't post the Specific Engine Flight Chart..............I'm behind this stupid firewall the Saudis have put up which prevents me from establishing a URL.

Someone give me your email   bitte


Ok I threw them a bone now they are going to sleep.


krieghund - you can send it to tango-p51@hotmail.com and I'll post it for you.

Tango, XO
412th FS Braunco Mustangs
Tango / Tango412 412th FS Braunco Mustangs
"At times it seems like people think they can chuck bunch of anecdotes into some converter which comes up with the flight model." (Wmaker)

Offline Widewing

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Thoughts on the Current Flight Model
« Reply #20 on: February 25, 2007, 10:23:00 AM »
Quote
Originally posted by kreighund
The dogs of war are awakened once again,,,,,,

I have another P-51 chart showing the -39 with WEP (56") up to 9000' but I can't seem to locate it but this is from my P-40E manual;

Ah nuts, I can't post the Specific Engine Flight Chart..............I'm behind this stupid firewall the Saudis have put up which prevents me from establishing a URL.


Up on Zeno's there is a .pdf version of the Flight Operational Instruction Chart for the P-40D/E. It shows 45.5 in/hg for takeoff and 44.6 in/hg for MIL power with the V-1710-39/F3R engine.

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline Widewing

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Re: Re: Thoughts on the Current Flight Model
« Reply #21 on: February 25, 2007, 11:00:03 AM »
Quote
Originally posted by bozon
#4
From what I see in the game, P51B handily out turns the D11 when the speeds gets slow. I'm pretty sure that they were not historically tested flying circles at 100 mph with flaps full out. If there is something wrong with P51's flaps you will not find it in such comparative reports.

Also, that figure of turning circles you keep posting is out of scale misleading. The spitfire does not turn at a third of a P47/Tempest radius, and P51 does not turn in half a P47 radius. I'm also pretty sure that the tempest could turn tighter than a P47. It most definitly does in the game. That figure is symbolic "this is smaller than that", but not by how much.


Several of us have tested both aircraft for minimum turn radius at full flaps w/WEP. The P-47D-11 turns a circle about 140 feet smaller (70 ft smaller radius) than the P-51B and maintains a faster rate of turn as well.

The P-51D does even worse.

Now, as to that chart that bothers you; it was never intended to show a precise measurement, but to provide a reference only. In every Brit test I've read, the P-51B/Mustang III out-turned every contemporary with the exception of the Mk.IX/XIV/XVI Spitfires. That chart shows this in a simplified manner. Here is the text that accompanies the chart in the document (found here).

"In circumstances where the ability to turn quickly or tightly are infinitely variable, and where two aircraft are nearly the same, such as the Tempest V and Thunderbolt II, a great deal depends on the ability of the pilots. Speed must be taken into account if the results are going to be of any real value.

For example, if a Tempest dives on a Thunderbolt with an overtaking speed of only 50 mph, the Thunderbolt will easily be able to avoid the attack by turning, although at the same speed in the hands of equally competent pilots, the Tempest will outmanoeuvre the Thunderbolt. This advantage, however, is no by any means so apparent at high altitudes, due to the greater engine efficiency of the Thunderbolt above 25,000ft.

Similarly, where low-altitude and high-altitude fighters are compared any advantage shown by the former will be reduced as the high-altitude fighter gets nearer to its best operational altitude. After taking all these considerations into account, the position of the aircraft relative to each other will be seen from the diagram.

Once again, the Spitfire maintains top place, followed by the Mustang, Meteor, Tempest and Thunderbolt. Too much regard to this order should not be paid, particularly by the individual who will angrily recall the occasion when he out-turned a Meteor when flying his Tempest. This sort of thing is inevitable, but we can only repeat that where the circumstances are common to both aircraft, these positions are not far wrong."

Finally, if we go back to older versions of Aces High, including AH1, the P-51B turned a slightly smaller circle than the P-47D-11. I have 3 different versions installed.

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline Benny Moore

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Re: Re: Re: Thoughts on the Current Flight Model
« Reply #22 on: February 25, 2007, 12:11:21 PM »
Quote
Originally posted by mussie
FARK THAT PIC IS COOL

Next time someone starts mouthing off over the Flight model I am gonna point them at this..

To the guys at HTC


I agree.  In fact, I delight in throwing that very picture at the IL-2 fanboys every time they start gushing about IL-2 being the paragon of flight model realism (it is far from that).  It usually shuts them up for a while.

Offline Fruda

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Thoughts on the Current Flight Model
« Reply #23 on: February 25, 2007, 12:13:32 PM »
Heh, I thought the P-51s seemed a bit too much like flying bricks these days...

...However, they're not my biggest complaint. It's the Il-2 Sturmovik's unbelievably flimsy nose armor. Every single time a get a hit anywhere near the nose, the radiator is killed. Having that happen somewhat often would lead me to believe that the Sturmovik just had insufficient nose armor, but since it happes every time, I've formulated the opinion that the armor model has a few bugs that need to be ironed out.

Other Sturmovik pilots will attest to this. Not that it's my main flight of choice (that would probably be the 109 series), but as far as Jabo work is concerned, it's the best there is. Save for that radiator.
« Last Edit: February 25, 2007, 12:16:12 PM by Fruda »

Offline Bronk

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Thoughts on the Current Flight Model
« Reply #24 on: February 25, 2007, 01:05:36 PM »
Quote
Originally posted by Fruda
Heh, I thought the P-51s seemed a bit too much like flying bricks these days...

...However, they're not my biggest complaint. It's the Il-2 Sturmovik's unbelievably flimsy nose armor. Every single time a get a hit anywhere near the nose, the radiator is killed. Having that happen somewhat often would lead me to believe that the Sturmovik just had insufficient nose armor, but since it happes every time, I've formulated the opinion that the armor model has a few bugs that need to be ironed out.

Other Sturmovik pilots will attest to this. Not that it's my main flight of choice (that would probably be the 109 series), but as far as Jabo work is concerned, it's the best there is. Save for that radiator.


Il2 was fixed. They were taking massive damage from tank rounds and flying away.
You have gotten use to the overmodel. No more hoing infinitly.

Bronk
See Rule #4

Offline Shuckins

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Thoughts on the Current Flight Model
« Reply #25 on: February 25, 2007, 01:48:12 PM »
Widewing,

I believe you are spot on about the F6F-5's top speed being undermodeled.

One of the F6F-3s that were pulled from the production line and experimented on to increase the Hellcat's top speed, included the following modifications:  a redesigned engine cowling yielding a more streamlined nose;  a water-injection system for increased horsepower;  a high-gloss dark sea blue paint that greatly decreased the drag of the non-specular paint used on the -3.

In January of 1944, one of these modified -3s hit 410mph at 20,000 feet.  It's some what unrealistic for some to state that production -5s were some 20 to 30 mphs slower than this.

Regards, Shuckins

Offline F4UDOA

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Thoughts on the Current Flight Model
« Reply #26 on: February 25, 2007, 04:53:11 PM »

Offline Widewing

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Thoughts on the Current Flight Model
« Reply #27 on: February 25, 2007, 05:51:36 PM »
Quote
Originally posted by F4UDOA
Naval Acceptance trials of F6F-5's


This shows that they acknowledged that the test aircraft was way down on power, yet still managed 391 mph at MIL power (not Combat power w/water injection).

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline F4UDOA

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Thoughts on the Current Flight Model
« Reply #28 on: February 25, 2007, 07:21:35 PM »
Much of that performance is based on condition of the Aircraft. The 1944 test that shows 391MPH at Mil power the F6F has one pylon attached. The 1945 test has a max speed of 379MPH at mil power with 6 rocket stubs attached. Both test show significant improvement over the F6F-3 even with combat power.

This graph shows a pretty good range of F6F performance both -3 and -5.




Offline Stoney74

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Roll Rate in the Hurri
« Reply #29 on: February 25, 2007, 08:31:38 PM »
Dave Southwood article that Wolfala sent me had some interesting observations in it.  One of the paragraphs talked about the basic roll characteristics of serveral aircraft and so one night we tested the Hurri to see if Southwoods observations and the aircraft in the game were the same.

Quote:  "However, the same [360 degree roll at 5,000 feet MSL] in the Hurricane at 200 KIAS takes 6 seconds to complete."

We tested the Hurri I and Hurri II in the game and using 220 MPH IAS, both aircraft completed both rudder assisted rolls (4 seconds) and unassisted rolls (4.5 seconds) faster than Southwood's article.  Rolls were made to the left, to take advantage of the torque effect.  Pretty big difference indeed, if the articles claims of the roll rate are correct.  I looked on WWII performance for some roll rate information and couldn't find it.  So, I have no idea if this is an issue or not.