Quantifying B-25 Performance

[Widewing]

In keeping with my usual practice, I took the newest additions to the plane-set offline to quantify performance.

I did speed runs at MIL power and WEP at sea level (50 feet) and 5,000 feet.

I did max climb from sea level to 5,000 feet

I did minimum turn radius without flaps and with full flaps.

I also did max dive speed before failure, unloaded (no g applied to airframe).

All data was taken at 25% fuel at zero burn rate (about 28 minutes of gas in the MA) and no bombs.

Here's the data....

SPEED-

Sea level max speed, MIL power:
B-25C glass nose: 265 mph
B-25C solid nose: 264 mph
B-25H: 263 mph

Sea level max speed, WEP power:
B-25C glass nose: 277 mph
B-25C solid nose: 276 mph
B-25H: 274 mph

5,000 feet max speed, MIL power:
B-25C glass nose: 283 mph
B-25C solid nose: 282 mph
B-25H: 281 mph

5,000 feet max speed, WEP power:
B-25C glass nose: 293 mph
B-25C solid nose: 292 mph
B-25H: 291 mph

Max dive speed before structural failure (zero g loading): 450 mph
Max speed to induce structural failure at 4 g loading: 355 mph

Notes: Lighter weight means a slight increase in speed, but there is little to choose from as spread is typically just 3 mph from fastest to slowest. However, the B-25H has the slowest acceleration, typically taking 10 seconds longer from 200 to 250 mph. This is expected, because it is the heaviest of the three.

CLIMB-

Climb from sea level to 5,000 feet, beginning at 160 mph, using WEP power. Time in minutes:seconds.tenths of seconds to reach 5k.

B-25C glass nose: 2:04.70
B-25C solid nose: 2:13.59
B-25H: 2:29.81

TURN RADIUS-
B-25C glass nose not tested, but should be a bit better than B-25C solid nose.

Full flaps, three turns counter-clock wise, average time and speed. Three tests done, results averaged.

B-25C Solid nose: 705.7 feet @ 12.62 degrees/sec
B-25H: 772.1 feet @ 12.13 degrees/sec

No Flaps, B-25C solid nose tested: 837.0 feet @ 16.17 degrees/sec.

Max speed that allows you to begin lowering flaps is 185 mph IAS.

Note: Weight makes a big difference here. Considering the size of the aircraft, the turn radius is excellent. However, the turn rate is appallingly slow. Using flaps to maneuver with other aircraft, especially fighters is generally counter-productive. While you may gain an angle for a snap shot, you will find yourself hopelessly slow with little prospect of regaining E over the short term.

I suggest not using flaps while turning with other aircraft. Take note that the B-25C (solid nose) turns very well without flaps beginning from 260 mph. Be sure to trim manually, with elevator trim neutral (mid scale on the indicator). Starting at 260 mph, the B-25C can complete a 360 degree turn in 19.9 seconds, averaging just over 18 degrees a second. Since it bleeds E rapidly, the turn tightens dramatically. Clean and devoid of bombs, it turns tighter over one circle than a Fw 190D-9 or the A-8, and at a comparable rate of turn too. Of course, the B-25 bleeds E like crazy, and will not be able to sustain this much beyond a single circle, thus the 190s will quickly reverse the table on the Mitchell. Nonetheless, the B-25's excellent instantaneous turn rate and its tremendous gun package means that it is a major threat to many fighters during the first stages of a fight. You must make the first opportunity count as there is a strong possibility that there will not be a second chance, unless the enemy pilot is hopelessly inept (fortunately, there's plenty of those).

Speaking of manual trim, if attacking ground targets, be sure to trim at least neutral elevator to prevent augers. DO NOT load the aircraft beyond 4 g in the pull out. DO NOT trim so much up elevator that it induces more than 4 g. Reduce power to idle and attempt not to exceed 300 mph when diving on ground targets.

I forgot this myself and clipped a tree while carrying 2 fighter kills and 3 GV kills... Wasn't happy with my oversight.

My regards,

Widewing

[beau32]

Very Informative. I just printed this out so I could study it a little more. And to do some praticing myself to compair notes.

[Sweet2th]

Awesome job WideWing as usual.I have one bit of info to add on it.

The bomb loadout i feel that works the best is the 3-1,000's.When and if you do get to the enemy field you only have so much time to drop the bombs so this loadout works really well.


The pilot is most vulnerable spot on the aircraft.The B-25-H takes hits very well and the modeling is top notch here.I got hit by a flak panzer last nite and instead of loosing  a whole wing like normal i had minimal damage.





All in all the B-25-H is the most fun i have had in Aces High in a while.

If you could get 20 of these in a mission, with 20 people who know how to fly it, and some good fighter coverage, well lets just say reset points would come along alot easier.

[SunBat]

Originally posted by Widewing

TURN RADIUS-
B-25C glass nose not tested, but should be a bit better than B-25C solid nose.

Full flaps, three turns counter-clock wise, average time and speed. Three tests done, results averaged.

B-25C Solid nose: 705.7 feet @ 12.62 degrees/sec
B-25H: 772.1 feet @ 12.13 degrees/sec

No Flaps, B-25C solid nose tested: 837.0 feet @ 16.17 degrees/sec.

Very interesting.  Thanks for the info...

Out of curiosity, how are you able to take the turn radius measurements above?  I'd like to know how you do that, if it's not too much trouble to explain.  

Thanks.

[BiGBMAW]

lobbing pumpkins at  m16s and flaks from 1.5k out..is..well..very nice


And I agree with the 4g and 350 compress...Ouch..done that a few times now..

Did ton think about trim neutral..thnx widewing

[Krusty]

Hum....

Shouldn't the -H be considerably slower? It's got a much blunter, draggier, nose (not to mention a huge foot-wide hole for the cannon barrel! lotsa drag there!)

I seem to recall reading the -C was the fastest variant (and to me 1mph is too close to count)


EDIT: P.S. I think the B-25s are too strong in this game. I came across some at 20k in a mossie. I unloaded hundreds of 20mm rounds (4x hispanos!) and wasn't even firing MGs after the first pass. Saw hitsprites EVERYWHERE (small clusters, each one should have brought down the plane).


In the end I gave up and parked off the tail at d400 and just unloaded into the lead. He soaked up well over 200 rounds directly into the lower arse before finally just going *poof* and leaving me with 1 eng dead, 1 PW, and no oil in the other eng.

I made it home with 1 wheel off the runway and no engine left to taxi, but it pissed me off. No way should the B-25 be THAT damned strong!

[KTM520guy]

I gave a B25 heck with a niki. It soaked up everything that I had to shoot with before the tail feel off.

[crockett]

Thanks for the info.. you don't happen to have that info on other planes on a website somewhere do yea?

[bj229r]

i managed to plink b24's at 1.5k offline, if my stick wasnt so bad, might getem from 2k

[Saxman]

Krusty: And yet I took a single ping to the top turret from a P-38's Hispano and it killed my pilot.

[Widewing]

Originally posted by crockett
Thanks for the info.. you don't happen to have that info on other planes on a website somewhere do yea?

Try DokGonZo's website

You'll need java enabled in your browser.

My regards,

Widewing

[Krusty]

I like that website for speed and climb charts, but wish he'd include bombers as well (Hey, I ain't complaining! I realize it takes a lot of work and he gets no thanks, but "if" I had a wish, it would be to include bombers)

[edit: typo]

[BiGBMAW]

all these "claims" of super B-25 armor NEED FILM...

Otherwise its just weenies  crying about the spilt milk

[Krusty]

bgbmaw, some folks are getting them, some are not. I wonder if it's not specific to the B-25, but a "rubber bullet" syndrome across the board? There's a post in the training forum (wrong forum methinks) about rubber bullets, and now I think they may be related.

[Sweet2th]

Originally posted by BiGBMAW
all these "claims" of super B-25 armor NEED FILM...

Otherwise its just weenies  crying about the spilt milk

FILM viewer is corrupted so it doesn't matter anyway.