Slow 767's
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Slow 767's
Rather than posting on the old thread bulldog I thought I'd start it up here.
For those not familiar with the issue here is bulldogs orignal post.
Thank you Keg,sorry to side track the thread,maybe should start a new:"Why are QF 767s so slow inside 30nm".ATC and other pilots would be fascinated(ATC states that if you tell a QF 767 to do a high speed descent a few minutes are lost!Explains Binoculars poor skills).
Witnessed an AIRNZ 767 pilot beautifully manage a high speed descent(340kts to 20 track miles),no speed brake,very deft energy management.AN 767 same.
Unless your piloting skills are below average there sould be no concerns for pax safety/comfort on a well managed high speed descent.
Oh yeah,have a QF interview soon,appreciate the snippets.
Yes you can take gear out of sequence but it is very noisy, and then only below 270 kts. If you were at 20 miles at 340 kts on profile (say 5000') I havn't tried it but I doubt you would get it in, even taking gear at 270 kts. Brisbane often require 340 till 20 DME, which for runway 01 means around 20 track miles, and believe me you need ALL the speedbrake. Once again the CTA steps are an issue in BNE.
As to your other question, within 30 miles, everyone must be doing 250 kts, and with the requirement to be 8000'/9000'or below I dont see how the speeds can be all that different. If you are happy to take flap and gear on the limits well then yeah, you can probably push it a bit, but who does that?
So how did this AirNZ bloke do it without speedbrake?
For those not familiar with the issue here is bulldogs orignal post.
Thank you Keg,sorry to side track the thread,maybe should start a new:"Why are QF 767s so slow inside 30nm".ATC and other pilots would be fascinated(ATC states that if you tell a QF 767 to do a high speed descent a few minutes are lost!Explains Binoculars poor skills).
Witnessed an AIRNZ 767 pilot beautifully manage a high speed descent(340kts to 20 track miles),no speed brake,very deft energy management.AN 767 same.
Unless your piloting skills are below average there sould be no concerns for pax safety/comfort on a well managed high speed descent.
Oh yeah,have a QF interview soon,appreciate the snippets.
Yes you can take gear out of sequence but it is very noisy, and then only below 270 kts. If you were at 20 miles at 340 kts on profile (say 5000') I havn't tried it but I doubt you would get it in, even taking gear at 270 kts. Brisbane often require 340 till 20 DME, which for runway 01 means around 20 track miles, and believe me you need ALL the speedbrake. Once again the CTA steps are an issue in BNE.
As to your other question, within 30 miles, everyone must be doing 250 kts, and with the requirement to be 8000'/9000'or below I dont see how the speeds can be all that different. If you are happy to take flap and gear on the limits well then yeah, you can probably push it a bit, but who does that?
So how did this AirNZ bloke do it without speedbrake?
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Depends on the engine variant.
As I recall a study was done into Perth about 5 years ago. This study was to ascertain why QF 767's had a flatter descent gradient and had trouble in speed reduction.
As it turned out there was in fact a difference within the QF fleet. The GE powered, by memory, had a higher ground idle thrust. Until flap was deployed the gradient was very flat.
The PW had slower flap limit speeds so close to the final approach slowing could be a problem.
If other model 767's had the same flap limits as the GE powered 767, with a lower ground idle thrust, the aircraft would be a lot more flexible.
This is by memory as I haven't been on the 767 for a while.
As I recall a study was done into Perth about 5 years ago. This study was to ascertain why QF 767's had a flatter descent gradient and had trouble in speed reduction.
As it turned out there was in fact a difference within the QF fleet. The GE powered, by memory, had a higher ground idle thrust. Until flap was deployed the gradient was very flat.
The PW had slower flap limit speeds so close to the final approach slowing could be a problem.
If other model 767's had the same flap limits as the GE powered 767, with a lower ground idle thrust, the aircraft would be a lot more flexible.
This is by memory as I haven't been on the 767 for a while.
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The Reason that QF fly so slow is not because of the engines but it because they do not fly their aircraft correctly!
Buts thats forgiven because they ARE the lords of the australian airways!
Ask John Anderson!
Buts thats forgiven because they ARE the lords of the australian airways!
Ask John Anderson!
Oliva
The P&W engines are the ones with the high Flight Idle thrust which gives a flatter descent profile that the GE powered aircraft flown at the same IAS. This is why the standard descent speed for the P&W B767 (in Aus) is 320 knots vs 300 knots for the GE B767.
I almost agree with Toecutter in that I do not believe the correct techniques are used when flying at 340 knots until 20 miles. QF training section states that standard procedure during descent is to use VNAV despite several shortcomings with the B767's VNAV programming. If FLCH is used and the aircraft is flown to be slightly low on profile at 20 miles then there is no major drama in slowing the aircraft up and having a stable approach.
The rest of Toecutters post does not deserve a response.
The P&W engines are the ones with the high Flight Idle thrust which gives a flatter descent profile that the GE powered aircraft flown at the same IAS. This is why the standard descent speed for the P&W B767 (in Aus) is 320 knots vs 300 knots for the GE B767.
I almost agree with Toecutter in that I do not believe the correct techniques are used when flying at 340 knots until 20 miles. QF training section states that standard procedure during descent is to use VNAV despite several shortcomings with the B767's VNAV programming. If FLCH is used and the aircraft is flown to be slightly low on profile at 20 miles then there is no major drama in slowing the aircraft up and having a stable approach.
The rest of Toecutters post does not deserve a response.
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Going Boeing well stated. We tend to fly VNAV to say FL100, then FLCH form there for a little more fine tuning of the profile whilst remaining in flight idle. You are correct about VNAV being a little twitchy, I guess it may depend somewhat on what FMC you are using as well.I also agree on the idea of being slightly low on profile to allow time to slow down at a reduced descent rate. Lets remember though that level flight is a waste of energy, try just reducing V/S.
Personal preference is encouraged (if efficient and safe within Co. guidelines) and interesting to watch. Never a dull day.
Personal preference is encouraged (if efficient and safe within Co. guidelines) and interesting to watch. Never a dull day.
2XL,
"Lets remember though that level flight is a waste of energy, try just reducing V/S."
Sorry but level change can be a very efficient mode if used correctly. I see so many people chase VNAV profile, it's sad. Thrust and speedbrake on the one descent several times or level change, adjusting your speed or using manual thrust, makes for a smoother descent.
Whilst talking about the 767 it's probably true for other types that a flat speed bleed in preference to even 500fpm is far more inefficient and helps lose energy on a fast approach - no boards required.
For those not in the know, the QF 767 is the junior aircraft in the QF fleet, you need far more seniority to get a 737 F/O slot than 767. Many newer 767 F/O's have little or no real experience. Please excuse their tardy speed control whist they learn.!
For those QF767 operators who do the right thing, don't take offence please, just trying to explain why our SOP's are as they are.
[ 08 November 2001: Message edited by: Mud Skipper ]
"Lets remember though that level flight is a waste of energy, try just reducing V/S."
Sorry but level change can be a very efficient mode if used correctly. I see so many people chase VNAV profile, it's sad. Thrust and speedbrake on the one descent several times or level change, adjusting your speed or using manual thrust, makes for a smoother descent.
Whilst talking about the 767 it's probably true for other types that a flat speed bleed in preference to even 500fpm is far more inefficient and helps lose energy on a fast approach - no boards required.
For those not in the know, the QF 767 is the junior aircraft in the QF fleet, you need far more seniority to get a 737 F/O slot than 767. Many newer 767 F/O's have little or no real experience. Please excuse their tardy speed control whist they learn.!
For those QF767 operators who do the right thing, don't take offence please, just trying to explain why our SOP's are as they are.
[ 08 November 2001: Message edited by: Mud Skipper ]
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Back to the original question though; who can put their hand on their heart and say that from 20 track miles out at 5000'and 340 kts that they were stable by 1000'and correctly configured, without using the speedbrake? That is after all what we are trying to achieve. If you pushed it a bit too far then ok, I will accept 500' and stable. Anyone.......anyone...........Bueller?
Hey Brutus, another question that needs to be asked is why were Ansett B767's flown so fast within 20 miles when they were flown so god-damned slow in the cruise?
I always thought that they flew slow to increase their pay packets.
I always thought that they flew slow to increase their pay packets.
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Lets look at this from a cost benefit/analysis point of view. Firstly, what is the benefit of doing 340 kts vs 250 kts inside 20nm?
Now what is the cost?
So I would suggest that on a cost/benefit analysis a professional airline pilot would probably choose not to fly at 340kts in the terminal area.
- Saves about one minute
- Strokes pilots ego
Now what is the cost?
- Increased passenger discomfort through increased noise and a harder ride
- Increased risk of crew/passenger injury from turbulence (clear air, wake)
- Increased risk of Overspeed from wind shear
- Decreased manouvreability from higher TAS
- Increased risk of noise complaints
So I would suggest that on a cost/benefit analysis a professional airline pilot would probably choose not to fly at 340kts in the terminal area.
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I'm with you cutie-borg, one would need a pumping HWC to get it in. But Bulldog has witnessed an AirNZ 767 perform such a feat of aviation prowess using the tried and true "deft energy management". I am still awaiting a reply on how it is done. I must, I confess, have "below average" flying ability, because I could not even get it close to the ballpark, let alone in, without using speed brake.
Maybe there is a secret override function for inflight deployment of reverse thrust. I dunno, there must be a trick I am missing.
Maybe there is a secret override function for inflight deployment of reverse thrust. I dunno, there must be a trick I am missing.
You QF boys and girls are going to love the managed descent profile of the A330-200 when it comes. Start practicing your 4* tables, and go around techniques if you try to fly it like a 767.
Nunc est bibendum
I'm with Brutus and Borgette. I defy anyone on a 767 to be doing 340 knots with 20 to run at 5000' and get in without the boards.
I suppose they might if they could bomb it all the way in to 500' and then slow down from there!
i'll admit that I've questioned some of the blokes I've flown with on why they are slowign down to 220knots when the book says 250 on downwind etc. Having said that, I have come across a bit of a 'mindset' in some guys about not using the boards when in the latter part of the approaches.
I wouldn't have said that QF training were particularly 'biased' toward VNAV either. Certainly for crossing restrictions and speed control (250 below 10'000 for example) but other than that I've only ever come across a feeling of whatever works for you and some suggestions on ways that may keep you from stuffing up restrictions etc.
What I have definately seen is guys being chipped for using VNAV inappropriately (ID incorrect programming and following it or even just blind following it and not understanding what the VNAV is trying to achieve which may not be what we want to achieve)
I'm with McGoo a little on this one though. Flying the aircraft that 'assertively' should have some beneficial trade off. On time arrival, gain an advantage over another carrier, fit in with ATC etc. I certainly give it away if pax comfort starts to become an issue.
Just some thoughts on the matter...
I suppose they might if they could bomb it all the way in to 500' and then slow down from there!
i'll admit that I've questioned some of the blokes I've flown with on why they are slowign down to 220knots when the book says 250 on downwind etc. Having said that, I have come across a bit of a 'mindset' in some guys about not using the boards when in the latter part of the approaches.
I wouldn't have said that QF training were particularly 'biased' toward VNAV either. Certainly for crossing restrictions and speed control (250 below 10'000 for example) but other than that I've only ever come across a feeling of whatever works for you and some suggestions on ways that may keep you from stuffing up restrictions etc.
What I have definately seen is guys being chipped for using VNAV inappropriately (ID incorrect programming and following it or even just blind following it and not understanding what the VNAV is trying to achieve which may not be what we want to achieve)
I'm with McGoo a little on this one though. Flying the aircraft that 'assertively' should have some beneficial trade off. On time arrival, gain an advantage over another carrier, fit in with ATC etc. I certainly give it away if pax comfort starts to become an issue.
Just some thoughts on the matter...
Nunc est bibendum
Oh what the hell then. My wife has always wanted me to go to the jumbo so I'd get more time off (and she would probably like it if my wallet came home with an extra allowance in it too!!)
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Fascinating responses.
Clearer picture now as to why QF767s are so slow inside 30nm.Seems a fallout of long-haul culture and inexperience.
As previously mentioned,the disparity is significant,noticed by ATC and other airlines.I thought that any self respecting pilot would be terribly embarrassed by such.
Good onya fellas,pride your descents and energy management like your landings;don`t tell me you bang it on the markers at all costs(one of your finest cadets,TJ,advocates that).
To the QF767 virtuosos,whatever your percentage,must be as frustrating to sit next to these guys as it is to be stuck behind them!
Clearer picture now as to why QF767s are so slow inside 30nm.Seems a fallout of long-haul culture and inexperience.
As previously mentioned,the disparity is significant,noticed by ATC and other airlines.I thought that any self respecting pilot would be terribly embarrassed by such.
Good onya fellas,pride your descents and energy management like your landings;don`t tell me you bang it on the markers at all costs(one of your finest cadets,TJ,advocates that).
To the QF767 virtuosos,whatever your percentage,must be as frustrating to sit next to these guys as it is to be stuck behind them!
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I must confess that two of the most frustrating things of recent times has been either following a QF 767 into a terminal area or any AN aircraft (any type) enroute. In both cases you will be vectored and slowed all over the place.
Why AN used to go slow enroute (to make $$$$) and yet were seemingly very efficient in the terminal area and QF 767’s are the complete opposite just goes to show there are many ways to skin a cat.
But seriously, 340 knots to 20NM in BN would not and DOES NOT require speed brake. The CTA steps from the south allow you down to 4000 at JCW (that’s 26NM from touch) therefore you would be well and truly level at 4000 by 20DME (almost exactly 20NM to touch given the location of the BN DME) therefore maintaining altitude and bleeding off speed, take gear at about 240kts, take the first couple of stages of flap on schedule as you start descending at about 500fpm, take the rest of the flaps as required, increasing the ROD as the flaps start coming out. If flown correctly you will drift a little above the desired 3 degree slope initially but will be right back on track by about 2000 feet, and easily stable by 1000.
There are two things about this that QF 767 pilots would be horrified about:
1) Taking gear before flaps!!! Shock OH Horror!!!
2) Bleeding off speed whilst level – Not efficient they say! Well, It means about an extra 2 to 3 miles at cruising altitude (i.e. later descent) BIG DEAL, but if you rely so heavily on VNAV you will still descend at the same point and it will be more inefficient. Besides ATC didn’t ask for efficiency they asked for a HIGH SPEED DESCENT.
Now I’m not recommending to fly every approach like this, but if a company aircraft behind you doesn’t have to get vectored all over the shop, then from a BIG PICTURE perspective (and longhaul love talking about this large picture, but rarely actually look at it) it is an efficient way to fly. Remember ATC don’t give you a high speed descent for fun they are asking you to help following traffic, and these days, more often than not, it will be company aircraft.
And whilst high speed descents don't seem to make a big diffence to you (maybe a minute or two) going just a little faster for just a little longer in the lower levels makes a VERY BIG diffence to the distance between you and someone behind who is flying a profile descent.
Why AN used to go slow enroute (to make $$$$) and yet were seemingly very efficient in the terminal area and QF 767’s are the complete opposite just goes to show there are many ways to skin a cat.
But seriously, 340 knots to 20NM in BN would not and DOES NOT require speed brake. The CTA steps from the south allow you down to 4000 at JCW (that’s 26NM from touch) therefore you would be well and truly level at 4000 by 20DME (almost exactly 20NM to touch given the location of the BN DME) therefore maintaining altitude and bleeding off speed, take gear at about 240kts, take the first couple of stages of flap on schedule as you start descending at about 500fpm, take the rest of the flaps as required, increasing the ROD as the flaps start coming out. If flown correctly you will drift a little above the desired 3 degree slope initially but will be right back on track by about 2000 feet, and easily stable by 1000.
There are two things about this that QF 767 pilots would be horrified about:
1) Taking gear before flaps!!! Shock OH Horror!!!
2) Bleeding off speed whilst level – Not efficient they say! Well, It means about an extra 2 to 3 miles at cruising altitude (i.e. later descent) BIG DEAL, but if you rely so heavily on VNAV you will still descend at the same point and it will be more inefficient. Besides ATC didn’t ask for efficiency they asked for a HIGH SPEED DESCENT.
Now I’m not recommending to fly every approach like this, but if a company aircraft behind you doesn’t have to get vectored all over the shop, then from a BIG PICTURE perspective (and longhaul love talking about this large picture, but rarely actually look at it) it is an efficient way to fly. Remember ATC don’t give you a high speed descent for fun they are asking you to help following traffic, and these days, more often than not, it will be company aircraft.
And whilst high speed descents don't seem to make a big diffence to you (maybe a minute or two) going just a little faster for just a little longer in the lower levels makes a VERY BIG diffence to the distance between you and someone behind who is flying a profile descent.