Measured Aircraft Acceleration

[artik]

I had measured the acceleration of several AH fighters at 500 feet altitude, with 50% fuel (with exception of P-51D that I did it with 25%), for different speed ranges: 150-200/200-250/250-300

The measurements is time (s) it takes to accelerate an aircraft in that range:

Aircraft	150-200mph	200-250mph	250-300mph
262	12.4	12.7	13.5
La 7	7.9	11.3	16.6
109K	7.9	11.1	17.1
Spit XIV	7.7	11.2	18.5
190D	8.6	12.3	19.0
Yak-3	8.6	12.2	20.8
Yak-9U	9.7	13.7	22.5
P-51D	10.0	14.1	22.6

I fly Yak-3 quite a lot, when before I flew Mustang and Dora, and I felt it accelerates very well and very maneuverable. Actually its acceleration is not as good as of Dora but quite close, on the other hand it is much more maneuverable than both Dora and Mustang, so it "feels" better in that case.

[Tank-Ace]

I still see the K4 dominating acceleration for most of the speed curve.

[morfiend]

I still see the K4 dominating acceleration for most of the speed curve.

  Really,


  I see the La7 and spit14 all being so close to the K4 and even abit quicker in some ranges.

    When you make a bias statement,it comes off as,well biased!


   

PS:  I pretty much only fly german planes but you don't see me making statements about how great they are all the time.

[Karnak]

I have some more that I have tested in those speed ranges as well, though my fuel target is always to get the plane to as close to 30 minutes endurance as I can.

Aircraft/Fuel	150-200mph	200-250mph	250-300mph	300-350mph
A-20G 50%	14.06	21.41	Not Done	N/A
Bf110C-4b 50%	13.53	23.59	N/A	N/A
Bf110G-2 75%	12.03	19.00	42.15	N/A
F4U-1D 100%	11.06	15.72	25.44	82.12
FM-2 100%	12.12	20.87	N/A	N/A
Fw190F-8 100%	10.43	14.91	25.28	109.06
Ki-84-I 75%	8.63	12.56	22.47	N/A
Mosquito Mk VI 50%	10.62	15.15	25.06	84.66
P-38L 75%	10.09	14.60	26.03	N/A
P-40N 75%	13.78	21.63	54.97	N/A
Spitfire Mk XVI 100%	7.97	11.91	21.59	N/A

[Tank-Ace]

  Really,


  I see the La7 and spit14 all being so close to the K4 and even abit quicker in some ranges.

    When you make a bias statement,it comes off as,well biased!


   

PS:  I pretty much only fly german planes but you don't see me making statements about how great they are all the time.

Mostly talking with regard to the Yak-3. Should have clarified, but I'm on my phone, and it's a pain in the butt to take only part of a quote, so I got lazy.

Just that everyone thought they would be all that. They pictured it climbing with a spit 14, accelerating with a K4, and nimble as a spixteen. Now we have a slightly peppier Yak -9U.

[Karnak]

Mostly talking with regard to the Yak-3. Should have clarified, but I'm on my phone, and it's a pain in the butt to take only part of a quote, so I got lazy.

Just that everyone thought they would be all that. They pictured it climbing with a spit 14, accelerating with a K4, and nimble as a spixteen. Now we have a slightly peppier Yak -9U.

Who is "everyone"?  The Yak-3 performs significantly better in AH than I thought it would and I know I am not the only one who thought like that.  All you have to do is go back to the thread when its image was posted and you can see a lot of us were expecting about a 3800fpm climb rate.

[bozon]

Who is "everyone"?  The Yak-3 performs significantly better in AH than I thought it would and I know I am not the only one who thought like that.  All you have to do is go back to the thread when its image was posted and you can see a lot of us were expecting about a 3800fpm climb rate.

It does climb at 3800 FPM - at 80 mph IAS! trimmed full right rudder and stall buzzer blowing. This plane simply has no power-on stall speed. Its limiting speed is the ability to counter the torque, not the lift on the wings. Most planes fall out of the sky at 80 mph, while this one still rockets upwards at rates that many planes can only come close to at their best climbing speed (usually 150-180 mph IAS).

[icepac]

You can loop a TA152 at astoundingly low speeds.

This has nothing to do with acceleration.

[artik]

Updated table with some new aircraft: Me-163, 109G-14, P-38L, Ta-152, Typhon

(Note each measurement is median of 3 independent measurements)

The measurements is time (s) it takes to accelerate an aircraft in each range:

Aircraft	150-200mph	200-250mph	250-300mph
Me 163	5.5	5.8	6.3
262	12.4	12.7	13.5
La 7	7.9	11.3	16.6
109K	7.9	11.1	17.1
Spit XIV	7.7	11.2	18.5
190D	8.6	12.3	19.0
109G-14	7.9	12.0	20.0
Yak-3	8.6	12.2	20.8
Typhoon	10.2	14.0	20.9
Yak-9U	9.7	13.7	22.5
P-51D	10.0	14.1	22.6
Ta 152	9.9	14.2	23.7
109G-14+gun-pods	9.2	13.3	24.0
P-38L	9.7	13.9	25.9

[hitech]

A very simple and very precise way to measure acceleration.

All you need to do is .speed  xxx and observe the climb rate at the speed you desire. To be extremely precises simply measure all planes as you cross a given alt, say 2000 or 3000 ft.


Climb rate and acceleration linear function of each other.


HiTech

 

[xJUGGOx]

Thanks hitech 

[xJUGGOx]

Looking for input here about how the F4U-4 "really" compares to the P38L and P51D. Only because everything I have been reading between here and other sources show the -4 to be a lot more dominant then the P51D.

http://www.classicfighters.org/content/chance-vought-f4u-4-corsair-history

This is one that I keep coming across from searches.

[Karnak]

That doesn't work at low altitude though, HiTech.  It takes too long for the climb to stabilize and, unlike you, we don't have a tool to set the entire AH atmosphere to sea level pressure.

[artik]

A very simple and very precise way to measure acceleration.

All you need to do is .speed  xxx and observe the climb rate at the speed you desire. To be extremely precises simply measure all planes as you cross a given alt, say 2000 or 3000 ft.


Climb rate and acceleration linear function of each other.


HiTech

Thanks!

Yes, indeed hadn't thought about it that way.

I want to estimate some other parameters as well:

1. Immediate turn ratio
2. Sustained turn ratio

The first one has actual direct relation to stall speed.

  turn g = 1g * (V_ias / V_stall) ^2

But it is not 100% correct because it does not take in account the engine force.

I've tried to measure stall speed by using Auto-Level trim and throttling to 0 to see what I get the stall "shake". But it is problematic because
the aircraft starts to loose the altitude before it starts to shake (it stalls before). What would be the best method to measure stall speed?
 

The second one is much harder besides trying to manually keep the speed/level and to see at what G I don't loose and gain the speed/altitude.

But it is quite challenging. Is there a better way to do it?


P.S.: Have you seed this thread (on wishlist forum) http://bbs.hitechcreations.com/smf/index.php/topic,352075.0.html ?