P-51D speed check, version 2.1

I have felt for quite a time that the plane is kinda slow compared to what we are fighting. I have made few test flights in the 2.1 Normandy version.

Test settings:

Pressure: 760 mm Hg

Temperature: 15' C

Wind: 0 m/s

Altitude: Sea Level

Plane: P-51D

Weight: 4 427kg (9760lb)

--------------------------------

Referece Data:

- DCS YoYo's chart:

Military Power, 61' Hg: 364 mph

- Flight Tests on the North American P-51D Airplane, AAF No. 44-15342

Military Power, 61' Hg: 364 mph

War Emergency Power 67' Hg: 375 mph

http://www.wwiiaircraftperformance.org/mustang/P-51D_15342_Level.jpg

http://www.wwiiaircraftperformance.org/mustang/p51d-15342.html

Test 1:

Manifold Pressure 61' Hg; RPM 3000; Mixture setting: Run; Radiator setting: Automatic;

TAS achieved: 576 kph (357 mph)

Test 2:

Manifold Pressure 67' Hg; RPM 3000; Mixture setting: Run; Radiator setting: Automatic;

TAS achieved: 590 kph (366 mph)

Summary and conclusion:

The test begun with engine temperatures within limits and speed was achieved via level flight acceleration and not dive. Airplane was trimmed to keep the level flight and adjustments were done via elevator and aileron trim. The airplane did not meet the speeds provided by the referential data.

I hope someone can cross check my tests. I will provide more if needed.

Old test I made in version 1.5:

https://forums.eagle.ru/showpost.php?p=3062437&postcount=34

So basically 61" vs 67":

Real 'Stang: 364/ 375

Our 'Stang: 357/ 366?

That's a lot of difference, and can decide between life and death, considering it's the least maneuverable of all our warbirds. Thanks for your test, Solty! Hope it gets corrected.

Just fly above 34,000ft Solty, looks like the DCS model is better than reference up there. /j

Any by the way, that graph of airspeeds tracks pretty damned close to the reference line if you ask me... I've seen considerably more variation in other sims before (naming no titles specifically...).

Thirdly, how come there is only a single reference data line? I'd layer up three or four reference lines if they are available to see what the "range" is.

Just fly above 34,000ft Solty, looks like the DCS model is better than reference up there. /j

 

Any by the way, that graph of airspeeds tracks pretty damned close to the reference line if you ask me... I've seen considerably more variation in other sims before (naming no titles specifically...).

 

Thirdly, how come there is only a single reference data line? I'd layer up three or four reference lines if they are available to see what the "range" is.

That is a line provided by YoYo, the FM developer and it is the intended performance from older DCS versions, which as my tests have shown is not the same that we have currently.

There are not many P-51D performance tests, that is not data that can be easily acquired. The reference data was confirmed in the past as the standard on which the FM was built upon, that is why I am using it. Every plane in DCS is aiming for the best possible performance.

That is a line provided by YoYo, the FM developer and it is the intended performance from older DCS versions, which as my tests have shown is not the same that we have currently.

Ahh, I thought the yellow line was your test results, and the red line was the reference line.

Ahh, I thought the yellow line was your test results, and the red line was the reference line.

No it is YoYo's chart :).

I feel like the test pilot wouldn't have conducted the test 2m from the drink... Would you mind upping your altitude to say 50m? At least check it out and see what you get?

Do we have speed test results for the German planes and the Spitfire? I'd like to see those tests as well and see how they compare to what we should have. As I understand we have fairly "hotrod" versions of the German planes though so maybe getting info for our specific models of those would be more difficult to find?

Aright...

Same environment conditions as you I'm getting 596 (370.34MPH) at 35m (114'). 35m was maintained for a good 10 seconds after coming up gently from 34m. 34-36m was maintained for quite some time before that.

At 50m I'm getting 594 (369.1mph). 50m was held for a good 20 seconds.

Incidentally and slightly beside the point ...

I'm getting 599Kp/h in the TF51... so even that one isn't quite as fast as it should be.

A few more notes...

The test was conducted in Dayton Ohio. The lowest elevation in Ohio is 455' ASL. If they flew the plane up to Lake Erie they still wouldn't have been able to get under 569' as that's the surface elevation of Lake Erie.

Does this mean that the 375MPH data was extrapolated from the rest of the data?

Does it mean that the 375MPH data was "close to the ground somewhere" so we really don't know what elevation the test was conducted at?

Does it mean they flew the aircraft all the way out to the East Coast to fly the tests at 2m ASL? I doubt it...

Something isn't right here about both our tests and the "official" tests.

We need more info.

That data was confirmed in the past as benchmark which P-51 was based on and it was capable of those speeds in version 1.2 and most of 1.5 but has dropped in later versions of 1.5 and 2.0.

Be sure to remember that the Ohio test was using a Mustang with wing racks attached which shave off some speed.

...and can decide between life and death, considering it's the least maneuverable of all our warbirds.

Lol!

Lol!

:huh:?

:huh:?

He told himself a joke he had never heard before ;)

Anyway, I tested over Normandy yesterday, and I was having a hard time getting near 350 after a while due to the rads being open.

I don't understand why people attack these tests by questioning the original testing conditions. ED gave us a chart, saying "This is how our Mustang performs". It's clearly not the case. Period.

The claim that the Mustang is the worst turner of DCS: WWII atm is very opinionated.

It depends on three variables. Speed, weight, and pilot skill. I've seen some guys on Burning Skies that turn mind flipping and outrageous turns with the 51D. I can't even get close to the turns they pull off in It! Flaps, countering the stall of the turn and all, defueled before taking off, and when fighting alongside them they still pull away from me. I've only seen three guys that can pull it off in the 51 however. My guess is that they have high quality controls, and have flown more hours in the Mustang than me, tenfold!

I've seen them successfully out turn 109s at the deck. Occasionally that 109 will be me, and I only start to gain the better turning until about 250km/h or so, by which time they've realized and pulled away to gain altitude, and prepare to start again.

The claim that the Mustang is the worst turner of DCS: WWII atm is very opinionated.

It depends on three variables. Speed, weight, and pilot skill. I've seen some guys on Burning Skies that turn mind flipping and outrageous turns with the 51D. I can't even get close to the turns they pull off in It! Flaps, countering the stall of the turn and all, defueled before taking off, and when fighting alongside them they still pull away from me. I've only seen three guys that can pull it off in the 51 however. My guess is that they have high quality controls, and have flown more hours in the Mustang than me, tenfold!

I've seen them successfully out turn 109s at the deck. Occasionally that 109 will be me, and I only start to gain the better turning until about 250km/h or so, by which time they've realized and pulled away to gain altitude, and prepare to start again.

Please do not derail this topic anymore, speed diference has nothing to do with one's ability to dogfight.

Reflected is right though. There is a big difference between beeing faster and beeing slower than the enemy. If you are 5 mph faster than the enemy you can escape, if you are slower you can't. I think that is clear and self explanatory.

PS. Flying is not magic. You can't turn tighter than your airplane is capable of.

Flying is not magic. You can't turn tighter than your airplane is capable of.

Never said it was, ever. Just some people are really good at their aircraft.

As for the speed, yes, it does seem like there is some inaccuracy somewhere.

.... your speed and air density may vary....

That's why it's important to use ISA. And these tests are always done with the same temperature and pressure, at sea level.

That's why it's important to use ISA. And these tests are always done with the same temperature and pressure, at sea level.

it means 760 mm Hg and 15C at sea level.

Then, the speed is TAS (corrected) and the better way to get it - to use F2 view.

https://forums.eagle.ru/showpost.php?p=2696464&postcount=27

Manifold Pressure 61' Hg; RPM 3000; Mixture setting: Run; Radiator setting: Automatic;

I'm not sure of course, but don't you need to close radiators for maximum performance? It seemed to me that I managed to gain the desired 607 kph at sea level with radiators closed for minimizing drag.

I'm not sure of course, but don't you need to close radiators for maximum performance? It seemed to me that I managed to gain the desired 607 kph at sea level with radiators closed for minimizing drag.

The Ohio test claims 375mph with automatic radiator and wing racks. If you close the radiator you might loose the engine quickly and it is not a normal operation.

What was your way of getting that speed? Did you keep to the testing standard?

What was your way of getting that speed? Did you keep to the testing standard?

I dont think so. Just level flight several meters above the sea surface for reasonable time (accelerating from lower speed, without diving from above). Trimming also applied.

However, with shutters closed I could achieve 375 mph or very close to it. With 'automatic' shutters the result is ~15 mph lower.

I'm aware that with radiators closed I can overheat and break the engine, but at least this way I can surely outrun Bf.109K at low alt. The time before overheat is usually sufficient to gain significant distance when pursued by a Kurfurst.

Mustang turns better then a dora so pls check your facts.

Mustang turns better then a dora so pls check your facts.

Tell me how a plane with lower p/w ratio and CLmax can sustain a turn better. I'm waiting.

I'm going to use some fake words to describe this thread. I have never seen a deader horse beaten harder or more deader.

Guys this is thread # one million, six hundred trillion about the under powered Mustang. We all get it. we got it at thread number one thousand three. The rest were all just carbon copy dribble.

It is quite obvious that this issue isn't going to change. My god.............A dead horse is a dead horse.