Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: HawkerMKII on March 07, 2011, 08:06:32 AM
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Look at speed..............yes it was in a dive :salute
(http://img820.imageshack.us/img820/10/ahss8.png)
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Your clipboard just so happens to cover up your main bomber...
How convenient... :noid
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Well, considering that you didn't give us your alt, and judging from the pic, you were prolly above 25k, so yeah you could prolly get away with -4500 fpm descent rate UP THAT HIGH, do it around 15k and you wont keep those wings attached for very long!
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Your clipboard just so happens to cover up your main bomber...
How convenient... :noid
That and your code is showing in your sig... :o
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yeah those clouds are at 15K
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You do realize you can calculate his alt based on the difference been true and indicated airspeeds, right?
Well, considering that you didn't give us your alt, and judging from the pic, you were prolly above 25k, so yeah you could prolly get away with -4500 fpm descent rate UP THAT HIGH, do it around 15k and you wont keep those wings attached for very long!
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You do realize you can calculate his alt based on the difference been true and indicated airspeeds, right?
Yeah, but that's too much math, and not enough coffee yet, this time of day!
The point is, up there where he's at, you could probably get away with that kind of descent rate, and bomber crews were trained to do extreme dives to extinguish engine fires that couldn't be put out by the fire suppression system, but those were EXTREME circumstances, NOT the norm, and NORMALLY, you wouldn't be doing a 4500 fpm descent rate in anything but a fighter!
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QFT.... :D Lucky for us though that we do not have to worry about many of the main variables such as air temp/density and wind speed/direction.
Yeah, but that's too much math, and not enough coffee yet, this time of day!
If you were ever interested in reading up on RL problems with doing that math, NASA has a nice 312 page publication regarding it......
http://www.spaceagecontrol.com/pm/uploads/Main.Freepubs/nasa-rp-1046.pdf
:salute
Your guess is a little low btw, without doing any math, I'm thinking he is about 34k at the time of the screenie. Pretty sure 29k is about 100kph above indicated..... err, we don't use knots here, mph make it.
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QFT.... :D Lucky for us though that we do not have to worry about many of the main variables such as air temp/density and wind speed/direction.
If you were ever interested in reading up on RL problems with doing that math, NASA has a nice 312 page publication regarding it......
http://www.spaceagecontrol.com/pm/uploads/Main.Freepubs/nasa-rp-1046.pdf
:salute
Your guess is a little low btw, without doing any math, I'm thinking he is about 34k at the time of the screenie. Pretty sure 29k is about 100kph above indicated..... err, we don't use knots here, mph make it.
Like I said, too much math, not enough coffee, wrong time of day! Point being, he's up high enough (I did say he was above 25k, not what alt he was at, so I wasn't wrong either, lol.) that he can get away with that kind of descent rate, if he were down around 20k or less, he would likely lost his wings before he could get a 4500 fpm descent rate!
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New plane on the block. The SBD-29
impressive
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New plane on the block. The SBD-29
impressive
Nah, you wont be doin teh "Lanc Stuka" with B-29's, cost tooo many perkies, to waste em like that! :aok
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4500 FPM isn't all that high of a descent rate. In the Cessna jump plane I'd average around 3800fpm and still had MP up in the green to keep the engine warm.
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thats no cessna there. . .
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Not sure how high it was to tell you the truth, but could a real 29 go this fast without damage at any alt?? :salute
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Comes down to air density really. Below 12k, heck no, all the way up at 30k, it is plausible. IMHO
Not sure how high it was to tell you the truth, but could a real 29 go this fast without damage at any alt?? :salute
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Not sure how high it was to tell you the truth, but could a real 29 go this fast without damage at any alt?? :salute
It's only 350mph. No big deal.
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You aren't looking in the right place sir.
It's only 350mph. No big deal.
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It's only 350mph. No big deal.
And right there is the truth of it. Indicated airspeed is measuring the pressure of the air molecules pushing on the aircraft (essentially speaking). At higher altitudes, there are fewer of those molecules per measure of volume, so a higher true speed is possible.
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You aren't looking in the right place sir.
Actually he is. From a structural standpoint, the 350 number is the one that matters.
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You ahhhhhhhhhhh..... Sure about that my brother?
Actually he is. From a structural standpoint, the 350 number is the one that matters.
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(http://i717.photobucket.com/albums/ww173/prestonjjrtr/Smileys/Coaster.gif)
(http://i666.photobucket.com/albums/vv23/Jayhawk1/B-29-1.jpg)
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(http://i717.photobucket.com/albums/ww173/prestonjjrtr/Smileys/Coaster.gif)
(http://i666.photobucket.com/albums/vv23/Jayhawk1/B-29-1.jpg)
Gordon Bennett Robertson was a B-29 pilot during the war and on his first mission over Tokyo flying a little over 5,000ft, thermal from the fires raging below caused his B-29 to flip inverted and the only way to recover was by doing a Split-S and at the bottom of the maneuver was going over 400mph and had to pull into a vertical zoom climb to bleed off the excess speed.
ack-ack
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Actually he is. From a structural standpoint, the 350 number is the one that matters.
Yep. For the most part, as long as you are away from compressibility, indicated airspeed is what is the better indication of forces on the aircraft.
A B-24 can do about 325 mph indicated before you start having to worry about the structure. So 350 mph for a B-29 doesn't seem surprising.
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Descending from FL370 the other day I decided to see what she would do. At High alt passing through FL330 she started buffeting or shock stalling right around mach .79 at about 300 indicated, I don't remember the true airspeed...if you have one of those fancy cx-2 flight computers and know ISA temperature for FL330 i suppose you could figure it out...off the top of my head i think its...around -50C. Remember if you begin to buffet, throttles to idle and use nose up trim to recover from tuck under/buffet so as to not overload your airframe with too many g's upon recovery. I've noticed that right around 360mph down low you tend to lose your elevators first and then your ailerons next without any high speed buffeting. Approximately 15 - 18 k and below....
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When they first encountered the jet stream that write that they were doing 450 at 30K or so with the tail wind.
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I got a B29 to 510 mph at 54k in a 29. Im gonna upload it to youtube
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Gordon Bennett Robertson was a B-29 pilot during the war and on his first mission over Tokyo flying a little over 5,000ft, thermal from the fires raging below caused his B-29 to flip inverted and the only way to recover was by doing a Split-S and at the bottom of the maneuver was going over 400mph and had to pull into a vertical zoom climb to bleed off the excess speed.
ack-ack
I would love to read the AAR on that. Wonder what everyone else thought when they saw it happen.