Nois abatment for business jets
From personal experience
NO Derate, Hawker, Falcon 900
De rate available: BBJ we had 26K engines and always used 24k or 22k options.
In the Hawker we regularly used a standard departure with climb pwr @ 400ft because we simply would out climb or exceed the speed limit if we did not. TEB is the classic.
NO Derate, Hawker, Falcon 900
De rate available: BBJ we had 26K engines and always used 24k or 22k options.
In the Hawker we regularly used a standard departure with climb pwr @ 400ft because we simply would out climb or exceed the speed limit if we did not. TEB is the classic.
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Not sure you allways can
I've read with attention all posts, and i do not think that NAPD I or II can be done in all types of Bizzjets without trouble.
In my short experience with bizzjets (so far i have only flown one, the Lear 60),i am inclined to say that you can't fly V2+20 or whatever you want to stablish as a speed whitout having problems with too high nose attitude, excessive ROC, etc etc, this aircraft is a rocket, there is no derated procedure and the thing will climb at way over 8000 fpm while doing 250 kts at low levels, if not taken care of, altitude busts are an issue with this ROC (A/P isn't fast enough and a good reduction of thrust in advance will help avoiding the bust), imagine how it will go if you try to maintain V2+20
.
I would say that trying to perform NAPD's with this type is unnnecessary, the aircraft will be way over 5000' AGL only 1 minute after lift off, it just does not make sense to try to do it
.
LEVC
In my short experience with bizzjets (so far i have only flown one, the Lear 60),i am inclined to say that you can't fly V2+20 or whatever you want to stablish as a speed whitout having problems with too high nose attitude, excessive ROC, etc etc, this aircraft is a rocket, there is no derated procedure and the thing will climb at way over 8000 fpm while doing 250 kts at low levels, if not taken care of, altitude busts are an issue with this ROC (A/P isn't fast enough and a good reduction of thrust in advance will help avoiding the bust), imagine how it will go if you try to maintain V2+20
.I would say that trying to perform NAPD's with this type is unnnecessary, the aircraft will be way over 5000' AGL only 1 minute after lift off, it just does not make sense to try to do it
.LEVC
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Empty Cruise, airmen
I have not done the calculation but regardless of the fact the aircraft performance, stating high climb rates to justify the non compliance, is in most cases, not good enough.
Indeed 6000 fpm, 8000 fpm are achievable climb rates in all aircrafts (decent ones and not just bizjets) but as mentioned, with the correct rotation rate (2 to 3 degres per sec up to initial climb pitch angle - prob 15 to 20 degres as per the manufacturer's books-), to reach 8000 fpm by 800' (EU OPS), you will probably need to pull some Gs or feel the horizontal acceleration most civilan jets are not commonly expected to do during what is essentially..... A most ordinary take off.
Sure if people talk about an ALT Cap (Step climb) by 1 or 2000's, it is a different ball game and basic airmanship and aircraft control should be maintained.
If in some cases, which I m sure, represents a minority, NADP really doesn't work then so be it... But dismissing it on the basis that because we fly Bizjets is not the best solution either. We ought to really study it and try it until all efforts are confirmed fruitless.
Remember, the environmentalist will get us if we don't do our best. They will because there are in greater number than us which makes it in the interest of our very own self preservation to keep these people the happiest possible. Who knows ? If we do a good job we might even be able to prove that we are not as bad as people think and that a few more slots here or there should not be denied to us. My way of thinking anyway.
For those mentioning high body angles (37) and no maximum published in the part B, there is another restriction.... Which is the one defining unusual attitudes. So perhaps as a personal limit if nothing is published then such limit could be used. Sorry no number in mind without checking but it is just like banking to 60 degres.... Aircraft can do it but not a normal way of flying.
CL300 I guess it is all that noise where you live which made you tired
Final point... 1500' is the old procedure as explained (yet shown in your jepps, Text, page 251 etc). Not valid anymore although some airport will still would like you to follow it (think Bologna is one of them as an example clearly stated in the Jepps notes).
Good night all and thanks for keeping the debate so civilised.
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NADP can be flown in ANY aircraft, having around 14 bizjet type ratings from the wonderful slowtation to the GLEX through LR 20 and 30 series and the whole falcon family, and after circa 10K hours, It is easily doable even with an early level off ie KTEB or LFMD.
What is lacking is training. How often do you train at your various training providers to NADP ? I know the answer.
And then, since we are highly trained to fly at V2 at n-1, we have big trouble doing it on all operating.
The fundamentals are very easy, you have to reduce your noise footprint, on take off, for close-in engime matters, for distance, configuration is as important.
As an example, Cannes Airport LFMD, is actively into 'green effect', with noise, flight track monitoring, wed designed mandatory briefing, and hefty fines for non compliant flights up to ban specific planes/operators/pilots.
Just to say, you may not like it, nor think this is doable or achievable, but the noise foot prints are modelized , and if you mak too much noise, you will have to pay, and when you will be banned, you will lose your job...
Ready for thrust reduction ? and clean configuration on downwind ?
I bet you will be, after all, when going to KSMO or EGLC you are doing it , so...
Off to the beach...
What is lacking is training. How often do you train at your various training providers to NADP ? I know the answer.
And then, since we are highly trained to fly at V2 at n-1, we have big trouble doing it on all operating.
The fundamentals are very easy, you have to reduce your noise footprint, on take off, for close-in engime matters, for distance, configuration is as important.
As an example, Cannes Airport LFMD, is actively into 'green effect', with noise, flight track monitoring, wed designed mandatory briefing, and hefty fines for non compliant flights up to ban specific planes/operators/pilots.
Just to say, you may not like it, nor think this is doable or achievable, but the noise foot prints are modelized , and if you mak too much noise, you will have to pay, and when you will be banned, you will lose your job...
Ready for thrust reduction ? and clean configuration on downwind ?
I bet you will be, after all, when going to KSMO or EGLC you are doing it , so...
Off to the beach...
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Our SOP for the LJ45 is 15deg pitch & T/O pwr to 1000'AAL (or later if necessary) then max continuous for climb pwr or less. No complaints from LCY yet. 
Had noise complaints when flying the Citation V (with JT 15D-5 engines) out of LCY in around '98, so we had to reduce pwr early after T/O. These engines are on the Beechjet 400, which make the ramp at LCY extremely noisy at times (Sorry I can't call it a Hawker 400. I have flown a HS125-400 - is that not a called a Hawker-400 now?
). I believe the fans on these are not geared down unlike the Garrett (now Honeywell) engines in Lears and Hawkers. They spin at the same speed as the rest of the LP spool. That's why they windmill so well! 
D
Had noise complaints when flying the Citation V (with JT 15D-5 engines) out of LCY in around '98, so we had to reduce pwr early after T/O. These engines are on the Beechjet 400, which make the ramp at LCY extremely noisy at times (Sorry I can't call it a Hawker 400. I have flown a HS125-400 - is that not a called a Hawker-400 now?
). I believe the fans on these are not geared down unlike the Garrett (now Honeywell) engines in Lears and Hawkers. They spin at the same speed as the rest of the LP spool. That's why they windmill so well! D
Last edited by Dumbledor; 9th Apr 2009 at 15:54.
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I agree with CL300 about the clean config downwind within reason. It depends on what speed you're given (Cannes). At least no more than take off flap is req'd. It's quite easy to use the Gear and/or App flap as an airbrake to slow from your downwind speed to the target speed for base leg, start the descent with a semi circular turn onto final without level off. The power can normally remain constant from DW until the final spool up for full flap on final. This works on at least 3 types of Bizjet. This is the best way to cut down on noise in the circuit. Power against Gear or Appr flap in level flight is bad energy management.
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As the agent provocateur in the 37* NU saga, which appears to have ruffled some goats/ feathers, I now own up to using "flex" or derated power on most of our take-offs; first because it's easy on my type to select on the FMS, and secondly because I'd like the engines to remember I was kind to them, and third because it makes almost silent BR700's even more neighbourhood friendly!
As plenty of subsequent posters commented, many a/c when empty and over powered are capable of extreme deck angles and rates of climb, so the AFM published procedures need to be treated with some caution, such as a limiting deck-angle if one is not published elsewhere in the manual.
As plenty of subsequent posters commented, many a/c when empty and over powered are capable of extreme deck angles and rates of climb, so the AFM published procedures need to be treated with some caution, such as a limiting deck-angle if one is not published elsewhere in the manual.
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PL, I'm all for cutting down noise when we can but I don't like the idea of graduated take off power unless it was forced on me by the company. (We can only set T/O pwr on our machines like most bizjets anyway.)
What would bother me is that that V1 would come up closer to the end of the RW, giving less margin for stopping before V1. Also with an engine failure after T/O you would be lower or slower or both (ie less energy) than if you had full T/O pwr up till then.
Most modern bizjets (JT15D-5 powered less so) are pretty quiet nowadays, rotate early compared with the airliners, climb better and therefore are high enough not to trigger the noise monitors.
I can't see what is wrong with the pitching to 15deg (our SOP) or 20deg or whatever is comfortable with T/O pwr and reduce at say 1000' or 1500'AAL to climb pwr after that. Then at least you have put the maximum energy into the a/c untill then. Also you have cleared the bird strike risk level quickly and cleared the noise monitors with a good margin.
What would bother me is that that V1 would come up closer to the end of the RW, giving less margin for stopping before V1. Also with an engine failure after T/O you would be lower or slower or both (ie less energy) than if you had full T/O pwr up till then.
Most modern bizjets (JT15D-5 powered less so) are pretty quiet nowadays, rotate early compared with the airliners, climb better and therefore are high enough not to trigger the noise monitors.
I can't see what is wrong with the pitching to 15deg (our SOP) or 20deg or whatever is comfortable with T/O pwr and reduce at say 1000' or 1500'AAL to climb pwr after that. Then at least you have put the maximum energy into the a/c untill then. Also you have cleared the bird strike risk level quickly and cleared the noise monitors with a good margin.
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Unless you are derating according to the approved procedure, you are invalidating all T/O performances worked out. It is a dangerous thing to do if it is done without backed up data, charts or officially approved criteria.
Also the idea of preserving the engine (unless following the above mentioned procedure) is what people flying Sencecas think and for a good reason. Piston engines are nowhere near as reliable as jet engines and a lot more prone to mishandling (cooling, oil level etc...). Jet engines are revolutionary in many ways and in no way comparable to pistons. They are built to be used at T/O power for 10 mins minimum (check the manufacturer's book) and they are usually (if not always) derated by the manufacturer so you get the maximum lenght (hours) before you have to bin it.
I am with Dumbledor and CL300 and the myth noise abatment departure cannot be flown with a biz jet is just that. A myth. On the other hand it is easy to see that people who cannot/do not want to follow a simple procedure, will come up with all sorts of homemade solutions. Not very good.
My philosophy is the following. You should always try to do the right thing because even when we try, we can fcuk it up. If you, deliberately deviate from the right way of doing things then you are getting yourself closer to the edge... Added to that the "fcuk up" factor and the road to recovery is going to be a tricky one for you (but that s ok because you decided to put yourself there) and for your colleague and PAX, which is not ok because they probably were not given the choice.
Also the idea of preserving the engine (unless following the above mentioned procedure) is what people flying Sencecas think and for a good reason. Piston engines are nowhere near as reliable as jet engines and a lot more prone to mishandling (cooling, oil level etc...). Jet engines are revolutionary in many ways and in no way comparable to pistons. They are built to be used at T/O power for 10 mins minimum (check the manufacturer's book) and they are usually (if not always) derated by the manufacturer so you get the maximum lenght (hours) before you have to bin it.
I am with Dumbledor and CL300 and the myth noise abatment departure cannot be flown with a biz jet is just that. A myth. On the other hand it is easy to see that people who cannot/do not want to follow a simple procedure, will come up with all sorts of homemade solutions. Not very good.
My philosophy is the following. You should always try to do the right thing because even when we try, we can fcuk it up. If you, deliberately deviate from the right way of doing things then you are getting yourself closer to the edge... Added to that the "fcuk up" factor and the road to recovery is going to be a tricky one for you (but that s ok because you decided to put yourself there) and for your colleague and PAX, which is not ok because they probably were not given the choice.
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Use of Flex T/O Setting
DD and AMEX, there was a clue in my previous post (BR710's) as to which type I am operating.....actually could be a G550 or a GLEX, but in both cases the Flex take-off option gives you all the revised performance data automatically, and by the way, restores full power on the good engine automatically in the event of an engine failure or on both in the event of windshear.
I would therefore suggest that it is not "a dangerous thing to do", but the correct way to operate those types where the derated power is an option for the reasons in my earlier post. If the type you operate does not support a derated power setting, then obviously don't derate!
I would therefore suggest that it is not "a dangerous thing to do", but the correct way to operate those types where the derated power is an option for the reasons in my earlier post. If the type you operate does not support a derated power setting, then obviously don't derate!
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Replying after your post doesn't necessarily means the finger is pointed at you Paradise Lost 
As for the engine type you fly, I am not familiar with it (I am P&W, RB211, CFM kind of guy... so far) but if you say, there is an approved method for derating at T/O then (and assuming you still want play Cluedo), here is another clue in what I said too
"Unless you are derating according to the approved procedure, ". My very first words in fact in that post below yours.
So now we agree that nobdoy should come up with their very own derating method simply because they have trouble flying a noise abatement departure procedure. Bearing in mind that in the GA World, operating standards remain unchecked for many (yeah ok, the odd OPC/LPC if under an AOC), bad habits due to a lack of knowledge or understanding tend to develop easily. That was my point I guess, hence my comment about "dangerous thing to do".
Peace ?
As for the engine type you fly, I am not familiar with it (I am P&W, RB211, CFM kind of guy... so far) but if you say, there is an approved method for derating at T/O then (and assuming you still want play Cluedo), here is another clue in what I said too
"Unless you are derating according to the approved procedure, ". My very first words in fact in that post below yours.
So now we agree that nobdoy should come up with their very own derating method simply because they have trouble flying a noise abatement departure procedure. Bearing in mind that in the GA World, operating standards remain unchecked for many (yeah ok, the odd OPC/LPC if under an AOC), bad habits due to a lack of knowledge or understanding tend to develop easily. That was my point I guess, hence my comment about "dangerous thing to do".
Peace ?
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Its all very well quoting rules and regs and following them to the letter, in reality none of us are bothered about how much noise we make on departure we are bothered about getting caught and fined.
Now before I get leapt on Im not on about Cannes or London City, invariably we are not coming out of these places very heavy.
Consider the monitoring points, also consider that the vast majority of airports who apply monitoring have huge runways and what do we realistically use 1/3 maybe 1/2 so we have maybe 1-1.5 kms head start on heavies, so going for it on t/o (unless im empty and in the mood) is a no go for me, Im a handful off power as soon as I get the clean wing call kind of man never had any problems yet.
I recall in the Excel 65% would give me 230knts and 2000fpm, you're not going to get found out in an excel at 65% N1 or any other bizjet I can think off.
Focusing on this V2 + X on a busy departure with no autothrottle is not a good demonstration of airmanship better to dump all the noise on the runway and be passing the upwind numbers with a clean wing and a sensible N1 and reduced climb rate after all its the N1 thats making all the noise not the physical position of the aircraft!
Off course terrain/conditions considered before I get pounced on by the H&S police
Now before I get leapt on Im not on about Cannes or London City, invariably we are not coming out of these places very heavy.
Consider the monitoring points, also consider that the vast majority of airports who apply monitoring have huge runways and what do we realistically use 1/3 maybe 1/2 so we have maybe 1-1.5 kms head start on heavies, so going for it on t/o (unless im empty and in the mood) is a no go for me, Im a handful off power as soon as I get the clean wing call kind of man never had any problems yet.
I recall in the Excel 65% would give me 230knts and 2000fpm, you're not going to get found out in an excel at 65% N1 or any other bizjet I can think off.
Focusing on this V2 + X on a busy departure with no autothrottle is not a good demonstration of airmanship better to dump all the noise on the runway and be passing the upwind numbers with a clean wing and a sensible N1 and reduced climb rate after all its the N1 thats making all the noise not the physical position of the aircraft!
Off course terrain/conditions considered before I get pounced on by the H&S police
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OK, we have now moved from "not bovvered" with noise abatement (something I at least can understand the rationale behind, although I just happen to find not bovvered = lazy) to experimental derates to keep our beloved 10 degree deck angle and still keep the noise police happy.
Now, this is where my understanding starts going a bit out the window... apart from the proper kit (derate via FMS or TMC), where exactly do you set this derated N1? On the runway??? After gear up??? When you have enough altitude that you're happy with having someone play with the TLs?
Please enlighten me as to who has validated these numbers, the performance involved, the SOPs, the ETPs...
Common sense - just as full whack and 37 deg. ANU to keep +10 sure ain't the answer, just as surely the exerimental derate route ain't the answer either. None of these aircraft are the space shuttle, ladies and gents - they are simple pieces of equipment to fly, and they generally agree with simple procedures. In Empty's little book, if any actions apart from G/U are required below 1500 ft. AAL, then summat ain't right
KISS - works every time
Now, this is where my understanding starts going a bit out the window... apart from the proper kit (derate via FMS or TMC), where exactly do you set this derated N1? On the runway??? After gear up??? When you have enough altitude that you're happy with having someone play with the TLs?
Please enlighten me as to who has validated these numbers, the performance involved, the SOPs, the ETPs...
Common sense - just as full whack and 37 deg. ANU to keep +10 sure ain't the answer, just as surely the exerimental derate route ain't the answer either. None of these aircraft are the space shuttle, ladies and gents - they are simple pieces of equipment to fly, and they generally agree with simple procedures. In Empty's little book, if any actions apart from G/U are required below 1500 ft. AAL, then summat ain't right
KISS - works every time
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ICAO doc 8168 ( ATC pages of your beloved Jepp Book 1 pages 251 and beyond for a summary) plus the AFM for the respective aircraft is giving the indication on how to fly a NADP.
Let's take the falcons, and due to my age, just the last type flown for me ( F2ESy) This aircraft meets stage 3 requirements at take off, with a thrust cut back of 12 per cent (afm) and stage 4 with a cut back of 13 per cent.
This aircraft flight director does not know the pitch he knows only the path (relative to the ground, therefore airborne). AFM recommends a path of 12 deg after airborne to meet noise abatment profile ( along with the thrust reduction) limited to 20deg pitch. The wing though cannot care less about your path, this is a by-product, the wing cares about speed AND AoA , that you command with your pitch, The Falcon 2000 EASy, has a pitch attitude on take off at 11 deg, attitude to be inceased to around 20 deg, in order to get the 12 deg of path... where is your speed at that point ? somewhere between v2+10 and Vft, What is your Rate of climb ? Around 2500 ft/mn. Do you need autothrottles ? no... You just fly...Speed decay? pitch down.. Speed increase ? pitch up to 20 max or reduce furthermore.
Engine failure ? firewall everything, and keep your speed !
Dassault had develloped for the F7X at LCY a 20 per cent thrust reduction at 400 ft procedure, why? Because the bird was too noisy, and it is well below 100000 Lbs...
This is not a derated take Off, a derated take off, is luring the Engine computers by telling them a virtual temperature, in order to have a lower N1 and lower maintenance costs, flying a derated take off does not withdraw the NADP.
Anyway, for AOC holders, get to Part B, for the others RTFM..
Let's take the falcons, and due to my age, just the last type flown for me ( F2ESy) This aircraft meets stage 3 requirements at take off, with a thrust cut back of 12 per cent (afm) and stage 4 with a cut back of 13 per cent.
This aircraft flight director does not know the pitch he knows only the path (relative to the ground, therefore airborne). AFM recommends a path of 12 deg after airborne to meet noise abatment profile ( along with the thrust reduction) limited to 20deg pitch. The wing though cannot care less about your path, this is a by-product, the wing cares about speed AND AoA , that you command with your pitch, The Falcon 2000 EASy, has a pitch attitude on take off at 11 deg, attitude to be inceased to around 20 deg, in order to get the 12 deg of path... where is your speed at that point ? somewhere between v2+10 and Vft, What is your Rate of climb ? Around 2500 ft/mn. Do you need autothrottles ? no... You just fly...Speed decay? pitch down.. Speed increase ? pitch up to 20 max or reduce furthermore.
Engine failure ? firewall everything, and keep your speed !
Dassault had develloped for the F7X at LCY a 20 per cent thrust reduction at 400 ft procedure, why? Because the bird was too noisy, and it is well below 100000 Lbs...
This is not a derated take Off, a derated take off, is luring the Engine computers by telling them a virtual temperature, in order to have a lower N1 and lower maintenance costs, flying a derated take off does not withdraw the NADP.
Anyway, for AOC holders, get to Part B, for the others RTFM..
Last edited by CL300; 12th Apr 2009 at 09:37.
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CL300,
Agre 100% If there is a local procedure, of course you follow it. We know the places where special procedures are required (LCY, TEB etc etc) and stick wih how the OEMs tell us how to fly their product.
Anything outside that and we're into space shuttle teritory My 1500 ft AAL-remark was obviously not aimed at you or other LCY/TEB/ARN-operators.
Empty
Agre 100%
If there is a local procedure, of course you follow it. We know the places where special procedures are required (LCY, TEB etc etc) and stick wih how the OEMs tell us how to fly their product.Anything outside that and we're into space shuttle teritory
My 1500 ft AAL-remark was obviously not aimed at you or other LCY/TEB/ARN-operators.Empty
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GSPOTs Lost wrote: ''after all its the N1 thats making all the noise not the physical position of the aircraft!'' 
Isn't the whole reasoning behind a steep initial climb as advocated by ICAO to do with getting the noise away from the ground as fast as possible to contain the highest decebels with a small radius of the apt. A 146 flown 100ft over your head at T/O pwr (as heard from the LCY Jet centre ramp) is deafening but from the west end of Victoria dock (by the cracking Thai restaurant!) the noise is much reduced, and probably without a reduction in pwr by then. The noise reduces by inverse square law I believe. If the 146 flew a shallow initial climb it would increase the noise recorded by the monitors below.
I agree with GSPOT about the fact that most bizjets (not converted airliners) get airborne quicker but this allows them to get well above the noise monitors. The engines in theory produce less noise than a bigger engine of similar bypass ratio. (however Falcon 2000s (CFE 738), Beech 400 and Citation V/ultra (both with JT15 -5's) could be quieter!)
It sounds like PL is doing things by the book when derating the BR700's, but it is not something I would chose to do with the same kit unless it was an SOP. This is done for engine life not noise anyway. The MSP contract takes care of the engine wear I thought. Does the MSP company charge less if derated pwr is used? (new ground for me..)
The LJ45 according to the QRH is rotated to betwwen 9 to 14 deg depending on performance, but our SOP is to go for 15deg and T/O pwr to 1000' before setting climb pwr. The 15deg is for terrain clearance, noise, and to reduce the risk of the bird strike. At 1000' power is reduced to Max continuous, or less for an early level off. No consideration is given to reduce below Max continuous for noise purposes. These are no like Viper engines! At a modest 3500 to 4000fpm at 250kt we are reducing the ground noise at a fair rate. . (Not like the ROC of a -31/35 or -60 though
) We don't try to adher to the ICAO or sid noise profiles, just the level restrictions.
D
Isn't the whole reasoning behind a steep initial climb as advocated by ICAO to do with getting the noise away from the ground as fast as possible to contain the highest decebels with a small radius of the apt. A 146 flown 100ft over your head at T/O pwr (as heard from the LCY Jet centre ramp) is deafening but from the west end of Victoria dock (by the cracking Thai restaurant!) the noise is much reduced, and probably without a reduction in pwr by then. The noise reduces by inverse square law I believe. If the 146 flew a shallow initial climb it would increase the noise recorded by the monitors below.
I agree with GSPOT about the fact that most bizjets (not converted airliners) get airborne quicker but this allows them to get well above the noise monitors. The engines in theory produce less noise than a bigger engine of similar bypass ratio. (however Falcon 2000s (CFE 738), Beech 400 and Citation V/ultra (both with JT15 -5's) could be quieter!)
It sounds like PL is doing things by the book when derating the BR700's, but it is not something I would chose to do with the same kit unless it was an SOP. This is done for engine life not noise anyway. The MSP contract takes care of the engine wear I thought. Does the MSP company charge less if derated pwr is used? (new ground for me..)
The LJ45 according to the QRH is rotated to betwwen 9 to 14 deg depending on performance, but our SOP is to go for 15deg and T/O pwr to 1000' before setting climb pwr. The 15deg is for terrain clearance, noise, and to reduce the risk of the bird strike. At 1000' power is reduced to Max continuous, or less for an early level off. No consideration is given to reduce below Max continuous for noise purposes. These are no like Viper engines! At a modest 3500 to 4000fpm at 250kt we are reducing the ground noise at a fair rate. . (Not like the ROC of a -31/35 or -60 though
) We don't try to adher to the ICAO or sid noise profiles, just the level restrictions.D
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Dumbledor
When I refer to the aicraft position, I probably didn't explain myself properly, a properly perfectly flown NADP flown form a runway intersection will be louder than that from the numbers. Taken to the extreme an aircraft with a double engine failure will not cause the airport any noise complaints.
We are fortunate that we are overpowered, Noise abatement with the exception of LCY/F7X/JT15 et all is not a major factor in our thought process unlike the very heavily monitored airline crews who have to give it great consideration. They do not need to ensure the favourite newspapers are available for their passengers or indeed load the bags - horses for courses
I fully agree and incidentally Im with empty cruise when he refers to KISS, one has to really appreciate the scale of the problem when deciding upon an appropiate response.
Im at MCO right now on a 680 recurrent and have just had my windows rattled last night by a very heavy Virgin 747 which probably was only clearing 800-1200 fpm having used all 3500m of runway! If he brought his TL's back by a couple of inches in much the same way the VAST majority of bizjet crews do he would have been parked next to my car at the hilton
In the vast majority of cases (typical bizjet payloads), in the vast majority of bizjets (notwithstanding the noisy types) at the vast majority of airports there really isnt a problem so if it aint broke and all that....
If you fly a 7X to LCY most days then worry about it, if you fly a CJ2 out of 10000ft r/w's then dont, if you fly a heavy Ultra then worry about it sometimes....KISS
The ICAO documentation will be there to encompass the loudest legacy aircraft at the most stringent airports. Like all aviation legislation they always need to account for the lowest common denominator.
As this is a Bizjet forum can we forget about derated takeoffs - if you are lucky enough to fly a BBJ then you're only now allowed on these forums by the good grace of the lowly slowtation/similar others drivers anyway so stop rubbing it in with your airliner derived bizjets
When I refer to the aicraft position, I probably didn't explain myself properly, a properly perfectly flown NADP flown form a runway intersection will be louder than that from the numbers. Taken to the extreme an aircraft with a double engine failure will not cause the airport any noise complaints.
We are fortunate that we are overpowered, Noise abatement with the exception of LCY/F7X/JT15 et all is not a major factor in our thought process unlike the very heavily monitored airline crews who have to give it great consideration. They do not need to ensure the favourite newspapers are available for their passengers or indeed load the bags - horses for courses
I fully agree and incidentally Im with empty cruise when he refers to KISS, one has to really appreciate the scale of the problem when deciding upon an appropiate response.
Im at MCO right now on a 680 recurrent and have just had my windows rattled last night by a very heavy Virgin 747 which probably was only clearing 800-1200 fpm having used all 3500m of runway! If he brought his TL's back by a couple of inches in much the same way the VAST majority of bizjet crews do he would have been parked next to my car at the hilton
In the vast majority of cases (typical bizjet payloads), in the vast majority of bizjets (notwithstanding the noisy types) at the vast majority of airports there really isnt a problem so if it aint broke and all that....
If you fly a 7X to LCY most days then worry about it, if you fly a CJ2 out of 10000ft r/w's then dont, if you fly a heavy Ultra then worry about it sometimes....KISS
The ICAO documentation will be there to encompass the loudest legacy aircraft at the most stringent airports. Like all aviation legislation they always need to account for the lowest common denominator.
As this is a Bizjet forum can we forget about derated takeoffs - if you are lucky enough to fly a BBJ then you're only now allowed on these forums by the good grace of the lowly slowtation/similar others drivers anyway so stop rubbing it in with your airliner derived bizjets
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GSL,
All agreed. Most of us here have the luxury of flying quiet, light, good performing a/c. Noise abatement is not really an issue for us. Around a 15deg initial pitch att allowing the a/c to accelerate and pwr reduction at a safe ht/speed is enough . KISS as you say.
As for those exec BBJ, 727 and 318 drivers, by invitation only please....
All agreed. Most of us here have the luxury of flying quiet, light, good performing a/c. Noise abatement is not really an issue for us. Around a 15deg initial pitch att allowing the a/c to accelerate and pwr reduction at a safe ht/speed is enough . KISS as you say.
As for those exec BBJ, 727 and 318 drivers, by invitation only please....
