Aces High Bulletin Board

General Forums => Aircraft and Vehicles => Topic started by: Widewing on November 16, 2006, 11:58:35 AM

Title: New F4U performance tests
Post by: Widewing on November 16, 2006, 11:58:35 AM
I have tested all new F4Us (not the F4U-1C) for sea level speed. Fuel was 25%, no burn. WEP engaged.

F4U-1: 359 mph
F4U-1A: 366 mph
F4U-1D: 358 mph
F4U-4: 376 mph

Speed at 10K for F4U-1A: 392 mph (2 mph faster than F4U-1, 2 mph slower than La-7, 4 mph slower than Tempest).

Acceleration test for the F4U-1A, from 150 mph to 250 mph: 23.37 seconds, about 1 second faster than the F4U-1D.

F4U-1A time to climb to 10k from sea level beginning at 300 mph TAS, using WEP: 2:27.75, which is 7.7 seconds slower than F4U-1D (2:20.03)

I will test the F4Us for turn radius and turn rate later today...

Note that there is a bug in the airspeed indicators for the new F4Us. There is a large difference between IAS and TAS at sea level and TAS never agrees with E6B.

My regards,

Widewing
Title: New F4U performance tests
Post by: Widewing on November 16, 2006, 12:26:15 PM
Preliminary turn radius and turn rate testing for the F4U-1A has been done.

Fuel 25%, zero burn. Standard test method, 3 timed circles, recording speed each circle. Two tests done and averaged.

Time: 54.84 seconds
Speed TAS: 99 mph
Turn radius: 422.6 feet
Turn rate: 19.71 degrees/second

Using Mosq's data for previous F4Us; turn radius comparison from smallest to largest.

F4U-1A: 422.6 feet
F4U-1: 425.3 feet
F4U-1D: 427.3 feet
F4U-4: 428.1 feet
F4U-1C: 443.4 feet

My regards,

Widewing
Title: New F4U performance tests
Post by: Lye-El on November 16, 2006, 12:50:16 PM
Sounds like a fun bird!
Title: New F4U performance tests
Post by: viper215 on November 16, 2006, 01:12:59 PM
Screen shots!!
Title: New F4U performance tests
Post by: Krusty on November 16, 2006, 01:25:58 PM
It's got horrible views, especially anywhere back or back-up. Anybody that flies it has a "pick me" sign on them :P

Views to the side are good, and left-back and right-back are decent, but there's this huge metal shroud literally over the back of your head that impedes vision. I'm not too crazy about "busy" feeling of this cockpit. Feels too busy. That's my opinion, mind you.

Flight wise, I couldn't say. I'm testing out rudder pedals and they're screwing with my abilities.
Title: New F4U performance tests
Post by: Balsy on November 16, 2006, 01:29:52 PM
Quote
Originally posted by Krusty
It's got horrible views, especially anywhere back or back-up. Anybody that flies it has a "pick me" sign on them :P

Views to the side are good, and left-back and right-back are decent, but there's this huge metal shroud literally over the back of your head that impedes vision. I'm not too crazy about "busy" feeling of this cockpit. Feels too busy. That's my opinion, mind you.

Flight wise, I couldn't say. I'm testing out rudder pedals and they're screwing with my abilities.


If you were flying that thing in REAL combat, you'd kiss that fine piece of metal protecting your grape.

Its all perspective I guess :).

Balsy
Title: New F4U performance tests
Post by: stantond on November 16, 2006, 02:05:05 PM
Hmm,

Looks like I may now be a F4U-1A combat pilot instead of the birdcage F4U-1.  I need to check out fuel distribution and range first, but I'll enjoy the heck out of it either way.  Thanks, and a belated thanks, Widewing for doing all these tests!


Regards,

Malta
Title: New F4U performance tests
Post by: Widewing on November 16, 2006, 02:37:15 PM
Another thing to note about the F4U-1A.

If you take an external fuel tank or a bomb, after it is dropped the pylon/shackles remain.

This results in a speed reduction of 6 mph, or 360 mph at sea level.

Having had an opportunity to fly this plane in the TA against the P-38J and P-51B, I can say that Co-E, Co-alt, they're both in deep trouble, especially the Mustang.

Apparently, HTC has adjusted the F4U flight model a bit to increase torque. At low speeds, full flaps, they resist rolling to the right. To get them rolling to the right, power must be reduced substantially until it rolls to where you wish, then you can power back up.

My regards,

Widewing
Title: New F4U performance tests
Post by: Krusty on November 16, 2006, 03:06:32 PM
Quote
Originally posted by Balsy
If you were flying that thing in REAL combat, you'd kiss that fine piece of metal protecting your grape.

Its all perspective I guess :).

Balsy


Oh, to be sure!

However, in AH2 (not RL) most of my PWs come from HOs or top-down (I don't think the armor will cover me from that angle). Then again I've "gotten used to" the 109s so I can "get used to" the 1A hog. :)
Title: New F4U performance tests
Post by: Widewing on November 16, 2006, 04:31:43 PM
F4U-1A speed at altitude tests. 25% fuel, WEP engaged.

406 mph @ 18,000 feet
411 mph @ 19,000 feet
419 mph @ 20,000 feet
416 mph @ 21,000 feet
414 mph @ 22,000 feet
407 mph @ 24,000 feet

My regards,

Widewing
Title: New F4U performance tests
Post by: Saxman on November 16, 2006, 09:27:29 PM
I'm trying to figure out if this is a glitch or intentional:

In the old F4U-1, when setting your fuel load it filled the main tank first, THEN filled the wing tanks. So at 50% internal fuel, the F4U-1 carried roughly 75% in the main tank, with the wing tanks dry. 75% fuel had full main, ~25% in each wing tank.

However when I upped the 1A, whatever I set for fuel load was the % loaded in ALL tanks. So at 50% I had 50% in the main, left and right tanks. 75% gave me 75% in all three, etc.

Is this right? Doesn't that end up working out to MORE than 50% or 75% fuel load.
Title: New F4U performance tests
Post by: SkyRock on November 16, 2006, 09:43:07 PM
Quote
Originally posted by Krusty
It's got horrible views, especially anywhere back or back-up. Anybody that flies it has a "pick me" sign on them :P

Views to the side are good, and left-back and right-back are decent, but there's this huge metal shroud literally over the back of your head that impedes vision. I'm not too crazy about "busy" feeling of this cockpit. Feels too busy. That's my opinion, mind you.

Flight wise, I couldn't say. I'm testing out rudder pedals and they're screwing with my abilities.
View schmiew!
Title: New F4U performance tests
Post by: Saxman on November 16, 2006, 11:07:30 PM
Views aren't so bad once you move them a little.
Title: New F4U performance tests
Post by: Creton on November 16, 2006, 11:44:07 PM
WOOT!!1 more hogs to kill in my K4.

Havent noticed it has any real advantage against a k4, in any type of fight.

Corsairs typically dont give me bother anyway,only thing Ive noticed about it is
the initial turn rate seems better.Can still catch it at alt or on the deck.

Has the initial turn rate increased?WW
Title: New F4U performance tests
Post by: Saxman on November 17, 2006, 11:59:29 PM
Did they increase the dive acceleration on the F4Us? The 1A SERIOUSLY hauls bellybutton in full power dives. I've been out-accelerating La-7s and Spixteens with the nose down, which in the old 1D didn't happen unless I had a big lead to start with.

Don't know about the turn rate, Creton, (although considering you've got a -1 turn radius with the engine power of the 1D...) but SERIOUSLY watch out for her in the zoom. Last night I went full vertical at about 450mph and jumped from the deck to right around 10k in somewhere about 2 minutes (best guesstimate).
Title: New F4U performance tests
Post by: Optiker on November 18, 2006, 12:31:10 AM
Widewing,
      I'm curious as to how the test for turn radius and rate is performed. Is there a writeup on how you measure these parameters? I can see how you might perform turn rate by recording compass readings and timing them, but turnradius has me stumped. How is the turn radius measured? And during the testing of the new models, were flaps engaged? How much and when to engage flaps still has me puzzled.

      Any place you can send me to study how flight performance envelopes are measured would be appreciated.

Thanks,

Bill "Optiker" Brady
Title: New F4U performance tests
Post by: Widewing on November 18, 2006, 12:49:08 AM
I don't know if initial turn rate has changed, it's a difficult metric to measure.
What I do know is that the F4Us seem to retain E better than before. Turn radius for the F4U-1A is the best of the Corsairs and about 20% better than the 109K-4. Climb is about the same as the -1D, but acceleration is slightly better. Zoom climb is excellent. Dive acceleration seems much faster. Saxman noted this too. Unlike previous tests of the F4U-1D done last spring, the F4U-1A really winds it up in a dive. I haven't tested the others beyond the F4U-4, but it appears to have gained as well.

I believe that the torque modeling has been changed. When slow with flaps fully out, the Hogs now resist rolling to the right. I'm sure you've experienced this with the 109s. To induce a roll to the right just above stall speed, you must pull back power first. I find that the 109s have the same problem.

My regards,

Widewing
Title: New F4U performance tests
Post by: Rocket on November 18, 2006, 07:13:56 PM
WW,

      I have noticed a feeling of better E retention.  The zoom seems longer now and getting slowed down once you get a head of steam on in the -1A seems harder.  The roll rate seems different, faster, lighter touch on the controls.  May be just a feel but I like it.  I have been waiting for this hawg for a looong time.  I came back at the right time.  :D


S!
Rocket
Title: New F4U performance tests
Post by: Saxman on November 18, 2006, 08:16:37 PM
Lol! Yeah, Rocket. I'm having a hard time slowing down enough to turn after an initial dive, even with gear out and throttle zero. She just holds onto E so well in the zoom and replaces it so well in a dive.

I had a Spit VIII earlier think he was gonna catch me in a dive, and when he broke off even after I had to immelmann to reverse still thought he'd be able to out-zoom me.

Now if only HTC could fix the glass engine, wings and tails...
Title: New F4U performance tests
Post by: MOSQ on November 19, 2006, 06:44:22 PM
I retested the 1 and 1D, along with the new 1A for turn radius and acceleration.

A few notes first:

1) Widewing typically outturns me in most planes by a little bit. So it's tough to add/compare any of WW's tests to mine and make a definative conclusion. They will be within the ballpark and are good for generalities, but don't go the bank thinking 10 ft difference in turn radius is going to make a hill of beans difference in a fight.

2) Either the flight models have changed for the F4U's or the IAS-TAS bug has made acceleration testing and turn testing inaccurate. The reason I say this is all the F4U's are a LOT faster from 300 mph to 350 mph than they were before. Acceleration times under 300 mph haven't changed much, but over 300 they have...a lot. Which leads me to believe that HTC changed the drag equations for the F4U's, or the airspeed is not being correctly reported on the E6B. Both of these possibilities would account for the faster dive speeds reported by WW and Saxman above. The problem for turn radius testing is that speed is a critical factor and if the E6B is incorrect for the F4Us, then the turn testing will be inaccurate as compared to the rest of the plane set.

So here's my old data compared to the new 3.09:

F4U-1
3.08: 150 to 350: 128 secs, 300 to 350: 76.1 secs
3.09: 150 to 350: 119 secs, 300 to 350: 67.4 secs

3.08: Full Flaps TR: 422 ft, DPS: 19.6
3.09: Full Flaps TR: 419 ft, DPS: 19.6

The turn radius probably didn't change, this is well within experimental error. However the high speed accel is 9 secs faster.

F4U-1D
3.08: 150 to 350: 137 secs, 300 to 350: 89.7
3.09: 150 to 350: 121 secs. 300 to 350: 74.6

3.08: Full Flaps TR: 430 ft
3.09: Full Flaps TR: 434 ft

Same comments as the -1. The TR is probably experimental error. But 15 seconds faster from 300 to 350 mph is significant.

I also tested the No Flaps Intial Turn radius, they are slightly different but again within experimental error and/or the E6B speed bug.

3.09 F4U-1A
150 to 350: 99.8 secs, 300 to 350: 54.1
Full Flaps TR: 425 ft. DPS: 19.3

I haven't tested the F4U-1C but I'd bet it's 300 to 350 time is faster too.

The conclusion: the F4U-1A is significantly faster than the others in high speed acceleration. It just outurns the -1D but a plain -1 will be an even match in a flat turning contest. Like I said above any two planes that are within about 20 ft in turn radius are too close to call in a flat turning contest.

I hope Pyro reads this thread and checks out the true speeds and indicated speeds of the F4U's soon.
Title: New F4U performance tests
Post by: Widewing on November 19, 2006, 07:03:24 PM
Quote
Originally posted by MOSQ

Widewing typically outturns me in most planes by a little bit. So it's tough to add/compare any of WW's tests to mine and make a definative conclusion. They will be within the ballpark and are good for generalities, but don't go the bank thinking 10 ft difference in turn radius is going to make a hill of beans difference in a fight.


You recorded 425 feet for the F4U-1A, I got 422 feet. Considering that we have different computers and probably different flight hardware, as well as our own personal stick settings, I'd say that this is as close as is feasible. Seriously, if I were testing a piece of hardware at a test lab, I'd consider this correlation to be extraordinary.

As to acceleration rates, perhaps the drag model was tweeked again. I'd suggest testing other types and compare that data with previous data to see if it spans the whole of the plane set or is unique to the F4Us.

My regards,

Widewing
Title: New F4U performance tests
Post by: Saxman on November 19, 2006, 07:50:10 PM
Incidentally, I wasn't judging dive acceleration by the E6B, as at the time I was trying to get the @%$& out of dodge with a full-power WEP dive, but rather by the airspeed indicator on the dash itself.
Title: New F4U performance tests
Post by: MOSQ on November 19, 2006, 09:25:50 PM
WW you're correct. They have changed the drag for all planes again. The difference is mostly apparent in the planes capable of 350 mph. And it's different depending on the plane.

The Typhoon, P-51D, P-47N, LA-7 only gained 2-3 seconds on their 150 to 350 times.

The FW-190 D9 gained 5 seconds. Ditto the 109-K4.

The FW-190 A8 gained 9 seconds.

So far the biggest winner is the F4U1C, it gained 19 seconds.

I'm not looking forward to retesting all the planes again!!
:mad: :mad:
Title: New F4U performance tests
Post by: Bodhi on November 21, 2006, 05:44:01 PM
Quote
Originally posted by Balsy
If you were flying that thing in REAL combat, you'd kiss that fine piece of metal protecting your grape.

Its all perspective I guess :).

Balsy


The piece of metal above you in the canopy is not armor. It is a piece of sheetmetal extended off the frame.  It was there to allow a cut out in the canopy so it could flex easier at the back so it did not crack when sliding it back on to the fuselage.
Title: New F4U performance tests
Post by: Oldman731 on November 21, 2006, 08:43:21 PM
Quote
Originally posted by Bodhi
The piece of metal above you in the canopy is not armor. It is a piece of sheetmetal extended off the frame.  It was there to allow a cut out in the canopy so it could flex easier at the back so it did not crack when sliding it back on to the fuselage.

My father-in-law was actually one of the folks who came up with this fix.

- oldman
Title: New F4U performance tests
Post by: Widewing on November 21, 2006, 10:29:52 PM
Quote
Originally posted by Bodhi
The piece of metal above you in the canopy is not armor. It is a piece of sheetmetal extended off the frame.  It was there to allow a cut out in the canopy so it could flex easier at the back so it did not crack when sliding it back on to the fuselage.


I was surprised to see it on the new F4U-4 as most production -4s had the later canopy with full plexiglass. Many ofthe F4U-1Ds also had the later glass...

Image below shows the current F4U-4 canopy...

(http://home.att.net/~c.c.jordan/4Canopy.jpg)

This next image shows what canopy was fitted to the typical F4U-4...

(http://home.att.net/~c.c.jordan/4Canopy2.jpg)

My regards,

Widewing
Title: New F4U performance tests
Post by: Bodhi on November 22, 2006, 12:46:47 AM
Quote
Originally posted by Widewing
I was surprised to see it on the new F4U-4 as most production -4s had the later canopy with full plexiglass. Many ofthe F4U-1Ds also had the later glass...

Image below shows the current F4U-4 canopy...

(http://home.att.net/~c.c.jordan/4Canopy.jpg)

This next image shows what canopy was fitted to the typical F4U-4...

(http://home.att.net/~c.c.jordan/4Canopy2.jpg)

My regards,

Widewing


even funnier Widewing is that most production F4u-4's had a flat windscreen (early production still had the rounded front as depicted), including most of  those produced and in service in WW2.  Either way, it does not matter, the views are not a hindrance, know where the nme is, and it is not an issue.

I also think the rear canopy extension is too big.
Title: New F4U performance tests
Post by: Widewing on November 29, 2006, 11:32:01 PM
Quote
Originally posted by Optiker
Widewing,
      I'm curious as to how the test for turn radius and rate is performed. Is there a writeup on how you measure these parameters? I can see how you might perform turn rate by recording compass readings and timing them, but turnradius has me stumped. How is the turn radius measured? And during the testing of the new models, were flaps engaged? How much and when to engage flaps still has me puzzled.

      Any place you can send me to study how flight performance envelopes are measured would be appreciated.

Thanks,

Bill "Optiker" Brady


Testing for turn rate and radius is relatively simple in concept, but not so easy in practice. The aircraft must be flown with great precision right at the edge of the flight envelope. This takes some practice.

The method is as follows:

Set up a reference point to use as the beginning and end of each 360 degree turn. Most of us use the .target command set at some reasonable distance. I use 1,000 yards. Get into a turn, adding flaps as you need them. Engage WEP. You must maintain altitude, not letting the nose drop or wander up. You should have E6B enabled with the clipboard stowed.

When you are flying at the limit, time 3 full 360 degree turns. Check speed each turn. Average the 3 speed readings.

Let's say your average speed was 99 mph. Divide 99 by 60 to obtain Miles Per Minute, or 1.65. Multiply that by 5,280 feet, or 8,712 Feet Per Minute. Divide by 60 seconds, and get 145.2 Feet Per Second. Multiply 145.2 by the total time of the 3 turns. In this case, 54.84 seconds. This will produce 7,962.768 (total distance flown). Divide 7,962.768 by 3 to obtain the circumference of the average circle, or 2,654.256 feet. Divide this by Pi (3.14 will do) to obtain the diameter of the circle, or 845.304 feet. Divide by 2 to obtain the turn radius, or 422.65 feet for the F4U-1A

To calculate average turn rate, multiply 360x3/time, or 19.694 degrees/sec.

My regards,

Widewing
Title: Flight Envelope
Post by: Optiker on November 30, 2006, 08:02:27 AM
Widewing,
     Thanks for the procedure - now that you've explained it, the radius calculation makes perfect sense. I can also see that flying a precise circle, without allowing the nose to drift is difficult.
      The statement "Get into a turn, adding flaps as you need them." is more difficult for me to comprehend. I assume during the 3 rotations being averaged, the flap setting is constant, correct? How do you know when and how many notches of flaps to add? Do you perform the test with no flaps, add a notch and re-test, and compare results? Or is there some metric (G loading, speed, instinct) that indicates "Gee, I need to add a notch here".
      Sorry for being a pain, but I started in spits and never used flaps and seemed to do OK. I'm still trying to learn F6F and with correct flap application I think it's going to be an awesome ride.

Thanks again for the writeup and in advance for any assistance you can lend.

"Optiker"
Title: Re: Flight Envelope
Post by: Widewing on December 01, 2006, 11:29:20 AM
Quote
Originally posted by Optiker
Widewing,
     Thanks for the procedure - now that you've explained it, the radius calculation makes perfect sense. I can also see that flying a precise circle, without allowing the nose to drift is difficult.
      The statement "Get into a turn, adding flaps as you need them." is more difficult for me to comprehend. I assume during the 3 rotations being averaged, the flap setting is constant, correct? How do you know when and how many notches of flaps to add? Do you perform the test with no flaps, add a notch and re-test, and compare results? Or is there some metric (G loading, speed, instinct) that indicates "Gee, I need to add a notch here".
      Sorry for being a pain, but I started in spits and never used flaps and seemed to do OK. I'm still trying to learn F6F and with correct flap application I think it's going to be an awesome ride.

Thanks again for the writeup and in advance for any assistance you can lend.

"Optiker"


Generally speaking, you will develop a feel for when flaps are needed. Many players will use flaps, but often use more than needed and keep them deployed longer than they should. It's really about balancing flap use with the need. You will learn this with practice.

My regards,

Widewing
Title: New F4U performance tests
Post by: TequilaChaser on January 13, 2008, 02:10:27 PM
Quote
Originally posted by Widewing
I was surprised to see it on the new F4U-4 as most production -4s had the later canopy with full plexiglass. Many ofthe F4U-1Ds also had the later glass...

Image below shows the current F4U-4 canopy...

(http://home.att.net/~c.c.jordan/4Canopy.jpg)

This next image shows what canopy was fitted to the typical F4U-4...

(http://home.att.net/~c.c.jordan/4Canopy2.jpg)

My regards,

Widewing


BUMPED FOR SERIOUS NEED OF FIXING on the F4U-1D & F4U-4  models, at least....

it is WAY TO BIG..........

PLEASE HTC, please take a look at this issue, and see if it can be remedied or at least made smaller....
Title: New F4U performance tests
Post by: Saxman on January 13, 2008, 02:43:09 PM
And while you're at it:

Tiny Tims!

Centerline pylon in the 1D with a max up to the 2000lb + 2x1000lb + 8xHVAR option.

Land-based option for the 1A without the wing-folding and arrestor gear

And PLEASE for the love of $Deity double the size of the gunsight in the Hogs! Don't make me link my thread on that. :p
Title: New F4U performance tests
Post by: TequilaChaser on January 13, 2008, 05:07:41 PM
Quote
Originally posted by Saxman


And PLEASE for the love of $Deity double the size of the gunsight in the Hogs! Don't make me link my thread on that. :p


not sure if you want to tackle it or not,

but I went in and redrawed a few gunsights for my personal use (both regular and alpha channels)...one of them was for the F4U.....reason for redrawing them  was to make them larger, as you have noted above....


but yes the F4U gunsights all seem to be considerably small in comparison to the rest of them for some reason....
Title: New F4U performance tests
Post by: Saxman on January 13, 2008, 05:41:35 PM
Problem is I've already got a Mk.8 sight that's as big as I can make it, (256x256) and it's STILL half the size it should be. The dimensions of the BMP file don't make much of a difference. The max size the gunsight displays is controlled entirely in some manner by the aircraft model itself.

Did some pretty thorough tests a while back on this, too. The gist is:

Mk.8 had the outer ring at 100mils, middle at 50, inner "pipper" at 25. The sight was calibrated so that an aircraft with a 30ft wingspan would have its wingtips touching the 25mil ring at 400yds, 50mil ring at 200yds, and the 100mil ring at 100yds, which would be pretty helpful for giving the pilot a quick-glance estimate of range if he knew the wingspan of the target (and since my guns are centered at 200yds, would give me a nicer indicator of when to shoot rather than the range counter which is much less specific).

Through a combination of using the target and the Dora offline (which has a wingspan of 34ft, close enough for the test) I confirmed that at default head position using the full Mk.8 sight (the one with the extended crosshair, not the version that just has the rings) the Dora's wingtips touched the 50mil ring at 400yds and the 100mil ring at 200 yds, precisely double the distance it should.

Moving the pilot's head position forward to correct it is too impractical with the way the fields of view are modeled. You'd have to move TOO far forward. Additionally, while it's not how the game is CURRENTLY modeled, the gunsight SHOULD stay the same size no matter how close/far you position your view

Doubling the size of the sight would do three things:

1) Most importantly, it would make the sight picture in the F4Us a LOT clearer. As it is, the gunsight is so small it can make the target very difficult to see unless you're using a very high transparency level.

2) It would make the size of the Mk.8 historically accurate.

3) It would place the bottom hash line on the lower crosshair of the Mk.8 at the top of the F4U's engine cowl. This is significant because the hashed crosshair was used as reference for aiming ordinance, and the F4U's typical aim point with ordinance is between the pipper of the gunsight and the top of the cowling depending on dive-angle, altitude and airspeed.