Aces High Bulletin Board

General Forums => Aircraft and Vehicles => Topic started by: Softail on January 01, 2015, 10:01:14 PM

Title: B-29 Superfortress Performance
Post by: Softail on January 01, 2015, 10:01:14 PM
So this is a bit strange.  I was chasing some B-29's in my 262 last month.....the proceeded to dive away from me....at over 530MPH....TWICE.  Once from 30K to 27K then again from 24K to 22K.

I thought parts fell off of this AC over 350mph?    Did HTC Beef up the wings on the B29???

Thanks.

Softail.
Title: Re: B-29 Superfortress Performance
Post by: FLS on January 01, 2015, 10:25:40 PM
Likely explanation is air density.
Title: Re: B-29 Superfortress Performance
Post by: xPoisonx on January 01, 2015, 11:56:23 PM
Likely explanation is air density.
Yup
Title: Re: B-29 Superfortress Performance
Post by: Serenity on January 02, 2015, 12:04:00 AM
Likely explanation is air density.

Which begs the question from Softail, 530 indicated? Or true? Because 530 indicated should have the exact same affect on the aircraft regardless of air density, right?
Title: Re: B-29 Superfortress Performance
Post by: xPoisonx on January 02, 2015, 12:10:13 AM
Which begs the question from Softail, 530 indicated? Or true? Because 530 indicated should have the exact same affect on the aircraft regardless of air density, right?

Pretty sure this falls under the exaggeration category... such as brewster diving 600mph etc etc...

It would not be 530 indicated at 30k
Title: Re: B-29 Superfortress Performance
Post by: FLS on January 03, 2015, 05:52:11 AM
Which begs the question from Softail, 530 indicated? Or true? Because 530 indicated should have the exact same affect on the aircraft regardless of air density, right?

What is TAS if IAS is 530 at 27k? 800 MPH? 
Title: Re: B-29 Superfortress Performance
Post by: Softail on January 03, 2015, 10:41:37 PM
Hmmmmm.....still think I am exaggerating?

Right there 535MPH....and no parts are falling off.   The REAL B29 had a max speed of 357 mph.   

I was compressing......but the B29's didn't seem to be having a problem.


(https://farm9.staticflickr.com/8611/16191232005_3f11343735_o.png)
Title: Re: B-29 Superfortress Performance
Post by: xPoisonx on January 04, 2015, 12:07:56 AM
Hmmmmm.....still think I am exaggerating?

Right there 535MPH....and no parts are falling off.   The REAL B29 had a max speed of 357 mph.   

I was compressing......but the B29's didn't seem to be having a problem.


(https://farm9.staticflickr.com/8611/16191232005_3f11343735_o.png)

That would be TRUE air speed, not indicated.
Title: Re: B-29 Superfortress Performance
Post by: kvuo75 on January 04, 2015, 12:15:07 AM
What is TAS if IAS is 530 at 27k? 800 MPH?  

816.200

http://www.csgnetwork.com/e6bcalc.html


(tas is at the bottom)
Title: Re: B-29 Superfortress Performance
Post by: lyric1 on January 04, 2015, 12:26:25 AM
They wrote these manuals for a reason. :aok

(http://i1002.photobucket.com/albums/af142/barneybolac/Boeing%20B29/300mphmax_zpsf11cf7df.jpg) (http://s1002.photobucket.com/user/barneybolac/media/Boeing%20B29/300mphmax_zpsf11cf7df.jpg.html)

http://www.avialogs.com/index.php/en/aircraft/usa/boeing/b-29superfortress/aaf-51-126-6-b-29-pilots-and-flight-engineers-training-manual-for-the-superfortress.html#download

Title: Re: B-29 Superfortress Performance
Post by: FLS on January 04, 2015, 12:40:20 AM
Hmmmmm.....still think I am exaggerating?

Right there 535MPH....and no parts are falling off.   The REAL B29 had a max speed of 357 mph.   

I was compressing......but the B29's didn't seem to be having a problem.


535 TAS at 28k is 343 IAS.  Seems reasonable.
Title: Re: B-29 Superfortress Performance
Post by: xPoisonx on January 04, 2015, 03:12:08 AM
They wrote these manuals for a reason. :aok

(http://i1002.photobucket.com/albums/af142/barneybolac/Boeing%20B29/300mphmax_zpsf11cf7df.jpg) (http://s1002.photobucket.com/user/barneybolac/media/Boeing%20B29/300mphmax_zpsf11cf7df.jpg.html)

http://www.avialogs.com/index.php/en/aircraft/usa/boeing/b-29superfortress/aaf-51-126-6-b-29-pilots-and-flight-engineers-training-manual-for-the-superfortress.html#download



Doesn't apply to this game since we don't worry about how a plane will do on its next sortie, since every one spawns in 100% perfect condition.
Title: Re: B-29 Superfortress Performance
Post by: lyric1 on January 04, 2015, 01:21:49 PM
Doesn't apply to this game since we don't worry about how a plane will do on its next sortie, since every one spawns in 100% perfect condition.

Max diving speed at 300 IAS at any altitude & at anytime should matter on the flight you are involved with at that moment.

Not sure what you are talking about for future flights. :headscratch:
Title: Re: B-29 Superfortress Performance
Post by: Masherbrum on January 04, 2015, 01:37:25 PM
Hmmmmm.....still think I am exaggerating?

Right there 535MPH....and no parts are falling off.   The REAL B29 had a max speed of 357 mph.   

I was compressing......but the B29's didn't seem to be having a problem.


(https://farm9.staticflickr.com/8611/16191232005_3f11343735_o.png)

Seems to me that he managed his altitude better that you did is all. 
Title: Re: B-29 Superfortress Performance
Post by: xPoisonx on January 04, 2015, 01:44:53 PM
Max diving speed at 300 IAS at any altitude & at anytime should matter on the flight you are involved with at that moment.

Not sure what you are talking about for future flights. :headscratch:

I'm saying the reason they had that restriction is not because the second you passed 300IAS the plane would rip apart, but it could cause structural damage that could affect it on future flights (weakening of the airframe). Every sortie in AH we get a new plane, so diving faster is not uncommon.
Title: Re: B-29 Superfortress Performance
Post by: Masherbrum on January 04, 2015, 02:00:06 PM
I'm saying the reason they had that restriction is not because the second you passed 300IAS the plane would rip apart, but it could cause structural damage that could affect it on future flights (weakening of the airframe). Every sortie in AH we get a new plane, so diving faster is not uncommon.


What did the B-29 player do wrong?    Nothing.     What did the OP/262 player do wrong?    A few things and that is all that needs to be said in this thread.    Current sorties/future sorties/past sorties come down to implementation and the 262 should learn how to use altitude to his advantage, instead of giving the opponent the leg up and this thread never gets posted.
Title: Re: B-29 Superfortress Performance
Post by: xPoisonx on January 04, 2015, 02:15:22 PM
What did the B-29 player do wrong?    Nothing.     What did the OP/262 player do wrong?    A few things and that is all that needs to be said in this thread.    Current sorties/future sorties/past sorties come down to implementation and the 262 should learn how to use altitude to his advantage, instead of giving the opponent the leg up and this thread never gets posted.

That statement was addressed to lyric not you.
Title: Re: B-29 Superfortress Performance
Post by: lyric1 on January 04, 2015, 02:29:35 PM
I'm saying the reason they had that restriction is not because the second you passed 300IAS the plane would rip apart, but it could cause structural damage that could affect it on future flights (weakening of the airframe). Every sortie in AH we get a new plane, so diving faster is not uncommon.


Why would they put the info in the flight manual that horizontal tail surfaces will peal off over 300 IAS then?

What would be the correct information if not the pilots handbook?

300 IAS would be relevant for the crew on every mission it was to keep the crew alive for the next mission.
Title: Re: B-29 Superfortress Performance
Post by: xPoisonx on January 04, 2015, 02:41:16 PM
Why would they put the info in the flight manual that horizontal tail surfaces will peal off over 300 IAS then?

What would be the correct information if not the pilots handbook?

300 IAS would be relevant for the crew on every mission it was to keep the crew alive for the next mission.

Once again you are confusing what I'm saying with real history. I am talking about the game whose forums we are on. Go to 30k and dive at 300 IAS and tell me how that is a set restriction.
Title: Re: B-29 Superfortress Performance
Post by: FLS on January 04, 2015, 10:27:25 PM
Why would they put the info in the flight manual that horizontal tail surfaces will peal off over 300 IAS then?

What would be the correct information if not the pilots handbook?

300 IAS would be relevant for the crew on every mission it was to keep the crew alive for the next mission.

300 IAS is the max speed for normal dives. This is for limiting the high g loads generated by maneuvering at 300 MPH. It doesn't mean you can't safely go over 300 IAS at 1g.
They probably didn't feel the need to say you could go a little faster if you were going to be shot at.
Title: Re: B-29 Superfortress Performance
Post by: bozon on January 04, 2015, 10:37:56 PM
300mph at 30K is already in the compressibility regime. TAS matters as well.
While the plane may not disintegrate at that speed, it may be unable to safely generate enough G to take it out of the dive without breaking important pieces. Having the drones dive with the lead in formation is just ridiculous.
Title: Re: B-29 Superfortress Performance
Post by: lyric1 on January 04, 2015, 10:49:15 PM
300 IAS is the max speed for normal dives. This is for limiting the high g loads generated by maneuvering at 300 MPH. It doesn't mean you can't safely go over 300 IAS at 1g.
They probably didn't feel the need to say you could go a little faster if you were going to be shot at.

Proof please.
Not your theory's.
Title: Re: B-29 Superfortress Performance
Post by: FLS on January 04, 2015, 11:37:05 PM
Airframe fatigue is cumulative. Every flight stresses the airframe. The airframe has an expected useful life based on the accumulation of normal stress. Limiting the normal max dive speed limits the stress accumulation so the airframe attains it's normal lifespan. You can increase the fatigue on a single flight and shorten the useful lifespan without breaking anything.

Getting shot down also limits airframe lifespans. Overstressing the airframe in a high speed dive may limit the lifespan less than getting shot down.
Title: Re: B-29 Superfortress Performance
Post by: Lusche on January 04, 2015, 11:58:57 PM
300mph at 30K is already in the compressibility regime. TAS matters as well.

Unfortunately only for fighters in AH ;)

The B-17 can shallow dive away in formation at speeds sending even the Me 163 can hardly match and is massively fighting compressibility.  :confused:
Title: Re: B-29 Superfortress Performance
Post by: Chalenge on January 05, 2015, 01:27:47 AM
Yet, the B-24 has a posted/known speed limitation of 358, which is also its limitation in the game. There is even a warning placard in the cockpit. That said, it is probably YAGC (yet another game concession) because of all the perks that are on the line.
Title: Re: B-29 Superfortress Performance
Post by: DaveBB on January 05, 2015, 04:46:35 AM
Limiting factor on B-24 dive speed is the rubber de-icing boots.  Wasn't one of the procedures to extinguish an engine fire in a B-17 to dive at 375mph?
Title: Re: B-29 Superfortress Performance
Post by: bozon on January 05, 2015, 09:23:44 AM
Limiting factor on B-24 dive speed is the rubber de-icing boots.  Wasn't one of the procedures to extinguish an engine fire in a B-17 to dive at 375mph?
TAS or IAS?
You realize that if this is IAS, the waist gunners are facing an open window with over 500 mph wind blowing through it?
Title: Re: B-29 Superfortress Performance
Post by: earl1937 on January 05, 2015, 10:39:27 AM
Limiting factor on B-24 dive speed is the rubber de-icing boots.  Wasn't one of the procedures to extinguish an engine fire in a B-17 to dive at 375mph?
:airplane: Not sure about safe diving speed of the 17, but in the B-29, if we had an engine fire, we didn't pay much attention to the 342VNE speed! You wouldn't either if you have 600 galleons of 115/145 fuel, which the flames were pouring back over and the FE is desperately transferring fuel overboard or somewhere else as fast as he can! Never had to confront that situation but twice and fire bottles took care of both of them in seconds. Best thing to do is keep CHT's as low in the green arc as you can, then you don't have to been so concerned, unless "Dame Fate" plays a hand you can't beat!
Title: Re: B-29 Superfortress Performance
Post by: vHACKv on January 05, 2015, 05:50:25 PM
262s are terrible at that alt, why did you take it so high? Worried about the perkies? 342 IAS at 30k is 547.2 KTAS by the way
Title: Re: B-29 Superfortress Performance
Post by: Zoney on January 05, 2015, 05:58:03 PM
262s are terrible at that alt, why did you take it so high? Worried about the perkies? 342 IAS at 30k is 547.2 KTAS by the way


I fly 262's at 30k a lot hunting high buffs.  She's a wonderful interceptor at that alt IF you also have speed which take a long time to build up at alt.  I've killed Mossie 16's at 34k in the 262.  So, no, I didn't fly it high because of the perk risks, I flew it high because my enemy was high, and with 4 30's, one pass and one dies.
Title: Re: B-29 Superfortress Performance
Post by: RonB29 on January 15, 2015, 03:00:17 PM
Does anyone have a reference to the B-29 drag polar; that is the Drag coefficient as a function of Lift coefficient.  Along with that the reference area for the coefficients is needed.  An alternative would be the lift and drag coefficients as functions of angle of attack.