In theory ... Supersonic flight ... A320 ???
In theory ... Supersonic flight ... A320 ???
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Discussion

JVaughan

Original Poster:

6,025 posts

312 months

Tuesday 4th January 2011
quotequote all
Well, sat watching the speed at 39,000ft this morning, it was reading 650mph .. then I started to wonder ... could the A320 I was sitting in accelerate to Mach-1 ...

maybe in a shallow dive ?
would the airframe be up to it ?

Yes, I know Concorde has already been there, and performance / efficiency of the engines would be an issue .. but could one (if you were so inclined) make a passenger jet go supersonic? and would it still be flyable ?

Soovy

35,829 posts

300 months

Tuesday 4th January 2011
quotequote all
DC8 did it years ago (albeit in a dive)


http://www.dc-8jet.com/0-dc8-sst-flight.htm


yikes


Needed full takeoff thrust throughout the dive and recovery.

And titanium b0ll0 cks.


Edited by Soovy on Tuesday 4th January 15:15

Cyder

7,185 posts

249 months

Tuesday 4th January 2011
quotequote all
JVaughan said:
Well, sat watching the speed at 39,000ft this morning, it was reading 650mph .. then I started to wonder ... could the A320 I was sitting in accelerate to Mach-1 ...

maybe in a shallow dive ?
would the airframe be up to it ?

Yes, I know Concorde has already been there, and performance / efficiency of the engines would be an issue .. but could one (if you were so inclined) make a passenger jet go supersonic? and would it still be flyable ?
You could almost certainly get one supersonic if the computers allowed it.

I think it would put a huge strain on the airframe, and over any period of time could cause the aircraft to disintegrate.
It would also be extremely difficult to control.

I'm sure years ago they got a Victor to fly supersonic by accident (?) but it put so much strain on the airframe that they never did again.

Disclaimer: I am working from knowledge gained in the dim and distant past when I read Aerospace Engineering at uni. I now work with cars which rarely fly, and even more rarely travel supersonic, and as such have expunged almost all useful knowledge.

FourWheelDrift

92,231 posts

313 months

Tuesday 4th January 2011
quotequote all
JVaughan said:
Well, sat watching the speed at 39,000ft this morning, it was reading 650mph .. then I started to wonder ... could the A320 I was sitting in accelerate to Mach-1 ...
Please say you weren't the pilot.

roryfizz

143 posts

210 months

Tuesday 4th January 2011
quotequote all
I would have thought it possible, once.. with either massive damage to the aircraft or to the ground in the big hole it would make for itself. With my very limited knowledge I thought an all moving tailplane was required to have elevator control at speeds beyond Mach 1 and without one it would be nearly impossible to pull out of the dive, especially with the modern fly by wire aircraft? I await someone with far superior knowledge to prove me wrong!!

Rory

JVaughan

Original Poster:

6,025 posts

312 months

Tuesday 4th January 2011
quotequote all
FourWheelDrift said:
JVaughan said:
Well, sat watching the speed at 39,000ft this morning, it was reading 650mph .. then I started to wonder ... could the A320 I was sitting in accelerate to Mach-1 ...
Please say you weren't the pilot.
Now that would be funny
"Ladies and Gentlemen, Ive been sat here thinking .... I wonder if I can get this bugger supersonic into Vienna" .... hehe

No, I was the one snoring in seat 11A

I remember reading the storys about having a movable rear elevator.
I seem to remember seeing increments on the tail plain to alter the pitch of the elevator... are these factory set or can they be moved dynamically ?

Edited by JVaughan on Tuesday 4th January 15:29

Eric Mc

125,600 posts

294 months

Tuesday 4th January 2011
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PHer takes charge of Airbus -


Soovy

35,829 posts

300 months

Tuesday 4th January 2011
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Simpo Two

92,639 posts

294 months

Tuesday 4th January 2011
quotequote all
JVaughan said:
I remember reading the storys about having a movable rear elevator. I seem to remember seeing increments on the tail plain to alter the pitch of the elevator... are these factory set or can they be moved dynamically ?
You normally move the elevators with the control column... pretty much standard since 1903. Or do you mean moving the whole tailplane?



I reckon the A320 is too big and fat to go supersonic.

Edited by Simpo Two on Tuesday 4th January 16:48

Eric Mc

125,600 posts

294 months

Tuesday 4th January 2011
quotequote all
I would also think the structure was built to flimsily to withstand the buffetting etc. Planes like the DC-8 and Victor tended to be over engineered (except for the tailplane in the case of the Victor).

JVaughan

Original Poster:

6,025 posts

312 months

Wednesday 5th January 2011
quotequote all
Cheers Eric ... it just got me thinking that was all ... after all, supersonic is only really another 75 or so mph on top of its cruising speed ( I guess with the savings and tolerances in today's manufacturing, things arnt generally over engineered anymore ).

paprika

5,510 posts

196 months

Wednesday 5th January 2011
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To put it in very simple terms.....no it won't !

FourWheelDrift

92,231 posts

313 months

Wednesday 5th January 2011
quotequote all
JVaughan said:
I remember reading the storys about having a movable rear elevator.
I seem to remember seeing increments on the tail plain to alter the pitch of the elevator... are these factory set or can they be moved dynamically ?
Airbus will be adjustable for trim like all aircraft, trim tabs controlled by the pilot or automatically by the autopilot for stable flight without having to move the controls backwards or forwards to hold a specific pitch attitude. Not sure about complete movement.

Not quite as important as on the Trident when you had to alter the pitch of the tailplane to give it between 3-5 degrees of positive to assist in take off, those pilots who didn't do this usually got pretty close to the end of the runway before defying Newtons law.

thinfourth2

32,414 posts

233 months

Wednesday 5th January 2011
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paprika said:
To put it in very simple terms.....no it won't !
Well not more then once

Waynester

6,514 posts

279 months

Wednesday 5th January 2011
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I can't remember if it was something I had read or maybe just heard about but were there not stories of WW2 aircraft /warbirds exceeding Mach 1 in a dive?

Maybe just stories told down the years, if true recovery must have a total bh with locked elevators!

Then again if true I believe a way to recover the aircraft from it's date of terminal destiny was to use the trim
tabs.

Assuming the aircraft stayed together of
course.


Edit: coming back to me now. I remember a story about a Spitfire that pulled so many G's recovering that it literally broke it's back, and the stressed skin panels were all wrinkly!


Tango13

10,044 posts

205 months

Wednesday 5th January 2011
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Tony Martindale dived a Spitfire PR MK XI to beyond Mach 0.9

On one occasion he landed without the propeller, the gearbox and a few engine cowlings. Another time despite a fully coarse propeller the engine still oversped at Mach .92 then blew up and catch fire. He suffered a spinal injury in the subsequent crash but still managed to recover the recording camera.

Flanders.

6,435 posts

237 months

Wednesday 5th January 2011
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Didn't a China Airlines 747-SP hit Mach 1 when the Pilot lost control over the Pacific? They landed it but the thing was badly damaged.

mat from preston

186 posts

203 months

Wednesday 5th January 2011
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Wasn't the cessna citation taken to Mach 1 in testing?

Hooli

32,278 posts

229 months

Thursday 6th January 2011
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Waynester said:
Edit: coming back to me now. I remember a story about a Spitfire that pulled so many G's recovering that it literally broke it's back, and the stressed skin panels were all wrinkly!
Rings a bell. I think it was mentioned in P Closterman's book 'The Big Show' as done by a rival squadron when Closterman was flying Tempests and everyone was trying to down a Me262.

BigBen

12,155 posts

259 months

Friday 7th January 2011
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I have been on a 747 that was showing well over the speed of sound on the in flight moving map. This was due to a very strong tail wind so not in effect having to break the sound barrier to achieve this.