A380 will not make London QC2 for takeoff
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747Focal "We can get small reductions here and there"
"the last few dB or tenths of dB that are extremely hard to get"
A research program showed that initial approach noise (flaps down but gear still up) can be reduced by 75% if the flap end ribs are closed by simple foam blocks glued in and by small vortex generators at the outer end of the flap.
Some facts can be readhere (scroll down to ´Joint project Quiet Traffic´) but I´m still searching the web for the full report in english. A short summary in german can be read here.
"the last few dB or tenths of dB that are extremely hard to get"
A research program showed that initial approach noise (flaps down but gear still up) can be reduced by 75% if the flap end ribs are closed by simple foam blocks glued in and by small vortex generators at the outer end of the flap.
Some facts can be readhere (scroll down to ´Joint project Quiet Traffic´) but I´m still searching the web for the full report in english. A short summary in german can be read here.
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Mordien, in my limited knowledge the QC scale is a rating based on dB of aircraft on approach or departure. A lot of airports use the QC as a way of limiting night noise. For instance there is a QC4 ban at night for LGW so aircraft QC4 and over (with a couple of exemptions) are not allowed to be scheduled into the night period. Think the numbers are QC0.5, 1, 2, 4, 8 & 16.
Roughly speaking, 757/320/737 etc range anywhere from QC0.5 to QC2. DC-10s in general are QC4, 742s might be QC4 on arrival but QC8/16 on departure. Concorde was a QC16 and so is the An-124.
Roughly speaking, 757/320/737 etc range anywhere from QC0.5 to QC2. DC-10s in general are QC4, 742s might be QC4 on arrival but QC8/16 on departure. Concorde was a QC16 and so is the An-124.
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Come on 747Focal. I tend to read a lot of posts by you (you appear to post alot), and some of the time I find them really quite interesting, but let' say, 80% of the time all you do is appear to jump at any opportunity to knock an Airbus aircraft! That's when your posts become a little less interesting.
Not wanting to insult you (I assure you that is not my intention), but could you just drop the Airbus bashing and inciting AvB wars. I think most of us are getting a bit fed up with it!
Actually, since I started redaing these forums (not just pprune) and there are soooo many Americans who seem to get some sort of kick out of knocking Airbus (simply and clearly because it's not from the U S A), I've actually started finding myself thinking "oh, come Airbus, get another order for your 380 or whatever", I read about an order for the 7E7 and I think "darn, not an order for Boeing"... Then I have to very quickly say to myslef "what a load of rubbish".
I've always loved airplanes, be it Airbus, Boeing, whatever... so STOP creating these silly prejudices.
Not wanting to insult you (I assure you that is not my intention), but could you just drop the Airbus bashing and inciting AvB wars. I think most of us are getting a bit fed up with it!
Actually, since I started redaing these forums (not just pprune) and there are soooo many Americans who seem to get some sort of kick out of knocking Airbus (simply and clearly because it's not from the U S A), I've actually started finding myself thinking "oh, come Airbus, get another order for your 380 or whatever", I read about an order for the 7E7 and I think "darn, not an order for Boeing"... Then I have to very quickly say to myslef "what a load of rubbish".
I've always loved airplanes, be it Airbus, Boeing, whatever... so STOP creating these silly prejudices.
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Volume,
I know a lot about aircraft noise reduction and certification. I see all that stuff on a regular basis. Yes, some of it works, but a lot is impractical in the commercial aviation environment.
Also, aircraft noise certification is done gear down for approach and that gear makes a LOT of noise.
Come now Toulouse, if you truly read all my posts you know I bash Boeing every bit as much. There are plenty of A vs B threads around here. I never want thread to turn into A vs B, but since your countrymen like to turn it that way it always seems to end up that way.
I know a lot about aircraft noise reduction and certification. I see all that stuff on a regular basis. Yes, some of it works, but a lot is impractical in the commercial aviation environment.
Also, aircraft noise certification is done gear down for approach and that gear makes a LOT of noise.
Come now Toulouse, if you truly read all my posts you know I bash Boeing every bit as much. There are plenty of A vs B threads around here. I never want thread to turn into A vs B, but since your countrymen like to turn it that way it always seems to end up that way.
Mach 3
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Flip Flop Flyer
To me Fig 12 of the document answers your question for the T/O and APP phases of flight.
The responsbility is dual as the major contributors to "noise" change depending on which phase of flight you're in...
I can't quite figure out Fig 13 tho. I don't understand why the top of the blue column on the London departure doesn't coincide with the black "Objective" line because surely the blue represents the objective?
FWIW.
Isn't the noise problem, if true, an issue for engine makers RR and PW/GE?
The responsbility is dual as the major contributors to "noise" change depending on which phase of flight you're in...
I can't quite figure out Fig 13 tho. I don't understand why the top of the blue column on the London departure doesn't coincide with the black "Objective" line because surely the blue represents the objective?
FWIW.
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SR71,
Generally the final guarantee on the noise levels is the responsibility of the airframe manufacturer. The engine manufacturer is responsible to the airframe manufacturer. Too many variables can effect final noise levels for the engine manufacturer to be totally resposible for any phase of flight. Now that does not say if their is a problem after certification that the engine manufacturer will not work hard to help reduce noise levels coming from the engine to help over all noise levels. Just ask Rolls about the 744 and the 767.
Generally the final guarantee on the noise levels is the responsibility of the airframe manufacturer. The engine manufacturer is responsible to the airframe manufacturer. Too many variables can effect final noise levels for the engine manufacturer to be totally resposible for any phase of flight. Now that does not say if their is a problem after certification that the engine manufacturer will not work hard to help reduce noise levels coming from the engine to help over all noise levels. Just ask Rolls about the 744 and the 767.
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Air France delivery delay
WRT to AF A380 delivery delay. This maybe connected to CDG terminal collapse. This terminal was to be used for A380. Apparently there has consideration by ADP of total demolition and rebuild of the entire terminal, which would make A380 operations somewhat problematic for AF at their home base.
Was the AF delay announced pre or post terminal collapse, which was on May 23?
Was the AF delay announced pre or post terminal collapse, which was on May 23?
Last edited by canuck slf; 17th Jul 2004 at 18:29.
Bear Behind
Hmm. Noise - I hate all this noise stuff. Far too complex for my tiny brain to cope with.
Sorry I haven't posted. It's taken me this long to come round. I fainted after FOCAL said something that was a) nice and b) not related to emergency escape as regards the A380.
Sorry, old chap, but you really do only ever seem to attack the A380 and I can't recall you attacking Boeing products with such vigour.
Product A have developed a chevron nozzle for their '21s, as I recall. Do they have similar on the A380 for noise reduction?
Sorry I haven't posted. It's taken me this long to come round. I fainted after FOCAL said something that was a) nice and b) not related to emergency escape as regards the A380.
Sorry, old chap, but you really do only ever seem to attack the A380 and I can't recall you attacking Boeing products with such vigour.
Product A have developed a chevron nozzle for their '21s, as I recall. Do they have similar on the A380 for noise reduction?
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I think you might see chevrons on the primary, but not the secondary. The secondary ones tend to drive fuel burn rate up an unnaceptable amount. All chevrons cause some performance loss. It's the gift that keeps on giving, or in this case taking.
and I am neither a) old and b) have said plenty of nice things around here.
and I am neither a) old and b) have said plenty of nice things around here.
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Hopefully I get to fly first class on her someday. That looks really nice from the pics I have seen. The only bad thing about the bar is if you happen to pick somebody up you got nowhere to go but the biffy..........
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747 FOCAL,
You didn't say anything nice about me but you have my condolences to-day as Airbus just sold a bunch more including four 380s.
P.S. If you're on a Virgin 380 you can always rent one of their roomettes down in the hold.
You didn't say anything nice about me but you have my condolences to-day as Airbus just sold a bunch more including four 380s.
P.S. If you're on a Virgin 380 you can always rent one of their roomettes down in the hold.
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I find it amazing in this day and age that it would be legal to rent somebody a room on a passenger aircraft where they could lock the door and go in there and be doing anything. And I am not talking about joining the mile high club.
They could take something and bash a window out. Undo a panel and jab something through the skin. I mean, they could literally build the bomb in complete privacy over the 18 hours of flight.
They could take something and bash a window out. Undo a panel and jab something through the skin. I mean, they could literally build the bomb in complete privacy over the 18 hours of flight.
Last edited by 747FOCAL; 21st Jul 2004 at 18:51.
