Final approach speeds
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Borat The Pilot
Quite right IceMan,No one is of the same calibre as me
Nor do they have the same self effacing modesty
Greetings from Khakstan
PS I once flew with a Big Airways trainer who pulled me up for decelerrating too quickly. You dont have to be that accurate about what they ask for he said.
Of course some of you might agree as it was at a Froggy Field, named after one of their big nosed politicians.
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Are there any types that can NOT fly gear down, land flap, 160kts at 4 miles and still not reduce back to approach speed by 1000 Rad Alt?
I find it hard to believe that with a headwind that this is so difficult to achieve.
I find it hard to believe that with a headwind that this is so difficult to achieve.
.4 seems to be more concerned now than in the past about the general "approximate" speed adherence going on. Either he is just getting old and crinkly
or, more likely, new procedures and tools mean speed adherence needs to be tighter. Surely the way ahead is therefore to find a speed profile that can be adhered to, meets the SOPs (or adjust the SOPs), and most importantly in this day and age, keeps the tree huggers happy 
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Just re-issued, Noise From Arriving Aircraft - An Industry Code of Practice might be of interest in this debate, especially para 29 
Per Ardua ad Astraeus
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I fully agree with your comments re 1000'AAL but AFAIK the 'flag' appears at 1000'RA. 1300+AMSL at the FNC VOR is more than 1000'aal and it DOES flag, I can assure you! Whether or not there is something which looks at the aal bit I know not, but raised terrain on the approach path will flag. ?
I am a 'monitoring fan', BTW. No shooting of the messenger, please?
I am a 'monitoring fan', BTW.
No shooting of the messenger, please?
Training everyone, as an SOP, to undertake noisier, more fuel consuming and Flap wearing approaches to fit in with ATC is not, IMHO, the way ahead
I'd be more than happy to let you fly your own speeds all the way in - just remember capacity will be halved, delays will be measured in hours not minutes and your airline will go bust.
Can we please get away from this "tail wagging the dog" attitude?
As an ATCO I cannot give a tailor made service to suit the needs of the individual when it compromises the most efficient system that gives benefits to all.
Plumbum Pendular
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BOAC,
Hopefully an enlightened management will realise that FNC is a complete
anomaly and let you off setting off warnings like that.
Nigel,
I fully agree with what you are saying however there is the short term issue here that if ATC ask you to do 160 to 4 there are very few circumstances in which you can not do it, and if you can not then you must tell ATC.
Then there is the long term issue about setting the correct procedures with ATC talking to operators to resolve this in the most efficient way possible.
Hopefully an enlightened management will realise that FNC is a complete
anomaly and let you off setting off warnings like that.
Nigel,
I fully agree with what you are saying however there is the short term issue here that if ATC ask you to do 160 to 4 there are very few circumstances in which you can not do it, and if you can not then you must tell ATC.
Then there is the long term issue about setting the correct procedures with ATC talking to operators to resolve this in the most efficient way possible.
Per Ardua ad Astraeus
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Whoa there! I am as guilty as others at allowing 'thread drift' here and suggest that for the benefit of ATC we re-focus on the ACTUAL range involved, which at LGW is just over 3 miles. It is all Cough's fault in post 107.
Hence it is the 'requirement' to go from 160kts to a 'stable' approach type configuration in less than 1 mile that occasionally causes the problem.
Suggest we leave RA's, LBA, JER etc out of it - I promise (and FNC ) The only time RA will be a problem is with raised ground on an approach which MAY require SOME airlines to be 'stable' earlier - not at LGW or LHR - how's that?
Hence it is the 'requirement' to go from 160kts to a 'stable' approach type configuration in less than 1 mile that occasionally causes the problem.
Suggest we leave RA's, LBA, JER etc out of it - I promise (and FNC
) The only time RA will be a problem is with raised ground on an approach which MAY require SOME airlines to be 'stable' earlier - not at LGW or LHR - how's that?
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Nigel
You may be right! I must be getting old and crinkly,... and cranky too: It appears that in my frustration I irritated the lady in the tower last night when I asked her to send around the aircraft which was 140kts at 6nm. I was most embarrassed at her complaint and gladly ate much humble pie.
I don't have so much of a problem with aircraft starting to slow from 160kts at 5nm, in fact I have taken to giving B75s and A319s 16kts to 5 so that the air crew feel comfortable. No, my issue is with the guy who is at 145kts at 6nm having accepted 160kts to 4nm. It caused another 'dirty dive' for the other side last night in less than good conditions. Paper work is done.
GL
Thanks for the very useful insight into Airbii "tools". If I understand correctly this means that where the wind gradient is steep there is a greater chance that the A/C will slow earlier as it drops out of the wind? Have I got that right? Last night there was about a 40+kt wind at 3000' but only about 20kts at 2000'. Would that degree of gradient encourage an Airbus to slow to 140kts at 6nm? The airline' Ops guy seemed to be suggesting it would.
If this is necessary then the difficulty for us is going to be how to know when to slow you down to take account of the different requirements. How do you judge 5nm gap efficiently when traffic is going to fly different speeds? I agree with DP, we would have to allow extra space for what we cannot control and that will reduce capacity.
.4
You may be right! I must be getting old and crinkly,... and cranky too: It appears that in my frustration I irritated the lady in the tower last night when I asked her to send around the aircraft which was 140kts at 6nm. I was most embarrassed at her complaint and gladly ate much humble pie.
I don't have so much of a problem with aircraft starting to slow from 160kts at 5nm, in fact I have taken to giving B75s and A319s 16kts to 5 so that the air crew feel comfortable. No, my issue is with the guy who is at 145kts at 6nm having accepted 160kts to 4nm. It caused another 'dirty dive' for the other side last night in less than good conditions. Paper work is done.
GL
Thanks for the very useful insight into Airbii "tools". If I understand correctly this means that where the wind gradient is steep there is a greater chance that the A/C will slow earlier as it drops out of the wind? Have I got that right? Last night there was about a 40+kt wind at 3000' but only about 20kts at 2000'. Would that degree of gradient encourage an Airbus to slow to 140kts at 6nm? The airline' Ops guy seemed to be suggesting it would.
If this is necessary then the difficulty for us is going to be how to know when to slow you down to take account of the different requirements. How do you judge 5nm gap efficiently when traffic is going to fly different speeds? I agree with DP, we would have to allow extra space for what we cannot control and that will reduce capacity.
.4
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The airbus ground speed mini does not work that way, all that it means is that if there is a strong headwind that it will slow down LATER not earlier, it will gradulally reduce to Vapp at touchdown.
It is bascially to protect you from windshear by maintaining a higher IAS and so buffer from the stall, incase there is a sudden lull in the wind.
There is nothing to stop apilot from overriding the ground speed mini (managed speed) by manually selecting a speed.
It is bascially to protect you from windshear by maintaining a higher IAS and so buffer from the stall, incase there is a sudden lull in the wind.
There is nothing to stop apilot from overriding the ground speed mini (managed speed) by manually selecting a speed.
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From our FCOM
GROUND SPEED MINI FUNCTION PRINCIPLE
The purpose of the ground speed mini function is to take advantage of the aircraft inertia, when the wind conditions vary during the approach. It does so by providing the crew with an adequate indicated speed target. When the aircraft flies this indicated speed target, the energy of the aircraft is maintained above a minimum level ensuring standard aerodynamic margins versus stall.
If the A/THR is active in SPEED mode, it will automatically follow the IAS target, ensuring an efficient thrust management during the approach.
The minimum energy level is the energy level the aircraft will have at touchdown, if it lands at VAPP speed with the tower reported wind as inserted in the PERF APPR page.
The minimum energy level is represented by the Ground Speed the aircraft will have at touchdown. This Ground Speed is called "GROUND SPD MINI".
During the approach, the FMGS continuously computes the speed target, using the wind experienced by the aircraft, in order to keep the ground speed at or above the "Ground Speed Mini".
The lowest speed target is limited to VAPP and its upper limit is VFE of next configuration in CONF 1, 2, 3 and VFE - 5 in CONF FULL.
The speed target is displayed on the PFD speed scale in magenta, when approach phase and managed speed are active. It is independent of the AP/FD and/or ATHR engagements. Wind is a key factor in the ground speed mini function
The purpose of the ground speed mini function is to take advantage of the aircraft inertia, when the wind conditions vary during the approach. It does so by providing the crew with an adequate indicated speed target. When the aircraft flies this indicated speed target, the energy of the aircraft is maintained above a minimum level ensuring standard aerodynamic margins versus stall.
If the A/THR is active in SPEED mode, it will automatically follow the IAS target, ensuring an efficient thrust management during the approach.
The minimum energy level is the energy level the aircraft will have at touchdown, if it lands at VAPP speed with the tower reported wind as inserted in the PERF APPR page.
The minimum energy level is represented by the Ground Speed the aircraft will have at touchdown. This Ground Speed is called "GROUND SPD MINI".
During the approach, the FMGS continuously computes the speed target, using the wind experienced by the aircraft, in order to keep the ground speed at or above the "Ground Speed Mini".
The lowest speed target is limited to VAPP and its upper limit is VFE of next configuration in CONF 1, 2, 3 and VFE - 5 in CONF FULL.
The speed target is displayed on the PFD speed scale in magenta, when approach phase and managed speed are active. It is independent of the AP/FD and/or ATHR engagements. Wind is a key factor in the ground speed mini function
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All this talk about Ground Speed Mini is irrelevant, except in extremely strong winds when ATC will not be using 2.5 mile spacing anyway. (Yes I fly the Airbus and do know what GS mini is).
If ATC ask for 160 to 4 then select 160 and fly it, as you are instructed! Not being able to get stable by 1000' is rubbish - it just requires a bit of thought.
If ATC ask for 160 to 4 then select 160 and fly it, as you are instructed! Not being able to get stable by 1000' is rubbish - it just requires a bit of thought.
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All this talk about Ground Speed Mini is irrelevant
If ATC ask for 160 to 4 then select 160 and fly it, as you are instructed!
Are there any types that can NOT fly gear down, land flap, 160kts at 4 miles and still not reduce back to approach speed by 1000 Rad Alt?
I find it hard to believe that with a headwind that this is so difficult to achieve.
I find it hard to believe that with a headwind that this is so difficult to achieve.
I'll stick my neck out here and say that I've been operating into LHR for over a decade in large and small aircraft and have never really had a problem with this requirement. Sometimes I've had to use the gear, flap and (horror!) the speedbrakes but it wasn't what I would term "rocket science".
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Borat The Pilot
Yes Mr Wings, but I suspect that you use your Brain in addition to SOPs.It would appear to me that Thinking is becoming a crime.
I have been aviating for a long time and am inclined to agree with you.
Incidentally I have done 3 go arounds from CDG in the last17 years and two of those were due to British ( the country, not the callsign) aircraft that were apparently not flying the assigned speed.
Love from Khakstan
Todays Tip; dont order the Pollonium at your local sushi bar
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Hopefully GS mini is cleared up now, it shouldn't be an issue inside outside 4 dme since selected speed should be flown.
120.4, I've noticed your frustrations frequently refer to a slow down at 6 miles. I think this is because many operators select the gear down at 6/2000. Pilots flying manual thrust will anticipate the extra drag of the gear and add a handful of power to maintain the speed. Autothrust however will not add power until it seesa reduction in speed, and will after spool up give an unnecesarily large boot of power to return to the target speed. This may take 10 seconds or so, but if your mode S updates during this period, you will see less than 160kts at 6 miles. The distance lost in this scenario could be measured in metres, I would suggest.
Bare in mind that BA Airbus pilots are forbidden to use manual thrust because of the deranged musings of a discredited shed fur brains, and so you will often see this 'gear dip' on a Speedbus approach.
120.4, I've noticed your frustrations frequently refer to a slow down at 6 miles. I think this is because many operators select the gear down at 6/2000. Pilots flying manual thrust will anticipate the extra drag of the gear and add a handful of power to maintain the speed. Autothrust however will not add power until it seesa reduction in speed, and will after spool up give an unnecesarily large boot of power to return to the target speed. This may take 10 seconds or so, but if your mode S updates during this period, you will see less than 160kts at 6 miles. The distance lost in this scenario could be measured in metres, I would suggest.
Bare in mind that BA Airbus pilots are forbidden to use manual thrust because of the deranged musings of a discredited shed fur brains, and so you will often see this 'gear dip' on a Speedbus approach.
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How much fuel can one save landing in Conf 3? Given that flap full is selected at about 4-5 miles and the engines are close to idle down the glideslope? (-600 and -300) Fuel useage is minimal so fuel saving must be microscopic.
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Fuel savings?
I stumbled across this website (again) while searching for 777 Vref approach speeds (which do not exist ANYWHERE online)...
While searching for the same thing last night I ran across this very interesting Boeing article about delayed flap retraction and the associated fuel savings. Press page down 4 times to get to the table with the fuel savings figures.
AERO - Conservation Strategies: Descent and Approach
While searching for the same thing last night I ran across this very interesting Boeing article about delayed flap retraction and the associated fuel savings. Press page down 4 times to get to the table with the fuel savings figures.
AERO - Conservation Strategies: Descent and Approach