Hello all!
I have a question to you all: is an commercial jet designed to break the sound barrier?
sound barrier
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Re: sound barrier
No.
Has mostly to do with the wing ( http://en.wikipedia.org/wiki/Swept_wing )
Lot's of info to be found about this on wiki etc...
Has mostly to do with the wing ( http://en.wikipedia.org/wiki/Swept_wing )
Lot's of info to be found about this on wiki etc...
Re: sound barrier
Indeed, the plane was not designed for it. Only the Concorde and its Russian counterpart TU-144 were so.
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As Willem states, the wingshape can't take the transsonic boom and the vibration that goes with it.
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Below short clip explains it v well from historical point of view.
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http://www.youtube.com/watch?v=XWymfiFFOHI
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Starts from 0:10
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As Willem states, the wingshape can't take the transsonic boom and the vibration that goes with it.
.
Below short clip explains it v well from historical point of view.
.
http://www.youtube.com/watch?v=XWymfiFFOHI
.
Starts from 0:10
Re: sound barrier
Don't forget about Mach Tuck either... Commercial airliners are not designed to cope with the shifting center of gravity.
Thomas
Re: sound barrier
Very interesting video Squelsh, thanks for sharing!
Re: sound barrier
Found this on the internet, interesting!
News Extra - A DC8.org Exclusive!
Wednesday, August 21, 1961
Douglas Passenger Jet Breaks Sound Barrier
DC8.org Newswire
Edwards Air Force Base, Calif. - The Douglas Aircraft Company has broken yet another record with its DC-8 aircraft. Earlier today, during a routine certification test flight, Douglas Chief Pilot Bill Magruder flew the aircraft faster than the speed of sound, making the DC-8 the first Commercial Jet Transport to break the sound barrier. After climbing to an altitude of 52,090 feet, the DC-8-42 series aircraft attained a maximum speed of Mach 1.012 or 660 mph while in a controlled dive through 41,088 feet. The purpose of the flight was to collect data on a new leading-edge design for the wing.
A Lockheed F-104 Starfighter and a North American F-100 Super Sabre accompanied the record setting flight to confirm the data.
Upon completion of flight testing, the record setting aircraft will be delivered to Canadian Pacific Air Lines for regular scheduled service.
In June, the DC-8 set 3 speed records while being operated by Delta Airlines.
Aircraft Info:
Type: Douglas DC-8-43
Production Line#: 130
Serial #: 45623
Customer: Canadian Pacific
Delivery Date: 11/15/1961
News Extra - A DC8.org Exclusive!
Wednesday, August 21, 1961
Douglas Passenger Jet Breaks Sound Barrier
DC8.org Newswire
Edwards Air Force Base, Calif. - The Douglas Aircraft Company has broken yet another record with its DC-8 aircraft. Earlier today, during a routine certification test flight, Douglas Chief Pilot Bill Magruder flew the aircraft faster than the speed of sound, making the DC-8 the first Commercial Jet Transport to break the sound barrier. After climbing to an altitude of 52,090 feet, the DC-8-42 series aircraft attained a maximum speed of Mach 1.012 or 660 mph while in a controlled dive through 41,088 feet. The purpose of the flight was to collect data on a new leading-edge design for the wing.
A Lockheed F-104 Starfighter and a North American F-100 Super Sabre accompanied the record setting flight to confirm the data.
Upon completion of flight testing, the record setting aircraft will be delivered to Canadian Pacific Air Lines for regular scheduled service.
In June, the DC-8 set 3 speed records while being operated by Delta Airlines.
Aircraft Info:
Type: Douglas DC-8-43
Production Line#: 130
Serial #: 45623
Customer: Canadian Pacific
Delivery Date: 11/15/1961
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andorra-airport
- Posts: 1193
- Joined: 19 Oct 2008, 16:21
Re: sound barrier
@ EBAW
Yes the DC8 is a famous example, but some others went through the sound barrier as well, when they were in a dive. I remember the 707, 727, and the 747. I read an interesting article about a Cessna Citation X, who went supersonic, forgot where it was on the net.
Yes the DC8 is a famous example, but some others went through the sound barrier as well, when they were in a dive. I remember the 707, 727, and the 747. I read an interesting article about a Cessna Citation X, who went supersonic, forgot where it was on the net.
Re: sound barrier
Cool, one learns every day 
Didn't know about that DC-8, but when I saw the ALT it was more logical 
Didn't know about that DC-8, but when I saw the ALT it was more logical Re: sound barrier
Was just watching this interesting docu 'Skygate' from pilots for 9/11 truth which has some good information and interesting footage on this subjectEBAW wrote:The purpose of the flight was to collect data on a new leading-edge design for the wing.
. The modified DC-8 story gets mentioned at 35:12, seems that leading-edge wing design did the trick.
http://www.youtube.com/watch?v=k3NyFX9ZJsQ&t=29m18s
29:18 till 33:40 has the beef :
Re: sound barrier
long time ago, I sat in a Swissair MD-11 ZUR-BKK and the old style overhead screen showed a speed > 1000 km/h 
I just checked Wiki and the max cruising speed of a MD-11 is 945 km/h. So with some good tailwind / jet stream it might have been possible that this figure was right.
But it is still not mach speed.
- thinking: would it be possible for an airplane, even a civilian airliner, while flying pretty fast and coming quite suddenly in a zone with very high jet stream of 200 knots, to break the sound barrier by accident?
"Scotty, beam me up"
I just checked Wiki and the max cruising speed of a MD-11 is 945 km/h. So with some good tailwind / jet stream it might have been possible that this figure was right.
But it is still not mach speed.
- thinking: would it be possible for an airplane, even a civilian airliner, while flying pretty fast and coming quite suddenly in a zone with very high jet stream of 200 knots, to break the sound barrier by accident?
"Scotty, beam me up"
Re: sound barrier
High groundspeeds with tailwind are not so uncommon.
Rember a Sabena flight from Boston to Brussels, think it must have been late nineties : I think we reached Brussels in less than 5 hours. Highest speed was close to 1200 km/h.
We took off in Boston at the moment hurricane Floyd was passing and the jetstream was very strong at that moment.
Please note that that does not mean the plane broke that sound barrier. Its relative airspeed was still probably around 900 km/h. You have to look at the airspeed, not the groundspeed.
Rember a Sabena flight from Boston to Brussels, think it must have been late nineties : I think we reached Brussels in less than 5 hours. Highest speed was close to 1200 km/h.
We took off in Boston at the moment hurricane Floyd was passing and the jetstream was very strong at that moment.
Please note that that does not mean the plane broke that sound barrier. Its relative airspeed was still probably around 900 km/h. You have to look at the airspeed, not the groundspeed.
Re: sound barrier
OK , ground speed.LUC1 wrote:High groundspeeds with tailwind are not so uncommon.
Rember a Sabena flight from Boston to Brussels, think it must have been late nineties : I think we reached Brussels in less than 5 hours. Highest speed was close to 1200 km/h.
We took off in Boston at the moment hurricane Floyd was passing and the jetstream was very strong at that moment.
Please note that that does not mean the plane broke that sound barrier. Its relative airspeed was still probably around 900 km/h. You have to look at the airspeed, not the groundspeed.
But 1200 km/h , that was really fast. Warp speed accros the Atlantic !
Re: sound barrier
Would it be possible? Sure, just floor the throttles and let her rip. Some airplanes would be more capable than others to do this.
HOWEVER, I wouldn't want to be the engineer doing the postflight inspections. That's of course assuming the plane lived through it.
HOWEVER, I wouldn't want to be the engineer doing the postflight inspections. That's of course assuming the plane lived through it.
Thomas