LHR mixed mode proposal
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Hi Bug
Just missed your post.
No, you're right - that won't work for Mixed-mode. This was an area we gave close attention during the Concept of Operations development. There are a number of solutions including altering taxiways to get around the GP critical area on 27L. It is possible all traffic from the south would have to cross at the old Block 85.
.4
Just missed your post.
No, you're right - that won't work for Mixed-mode. This was an area we gave close attention during the Concept of Operations development. There are a number of solutions including altering taxiways to get around the GP critical area on 27L. It is possible all traffic from the south would have to cross at the old Block 85.
.4
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OK, 4% of our traffic will be in T4 as of Switch 1 (end March 2008), but once T4 is modified for multiple airline use (and some of the "Open Skies" boys will be starting their services in T4) its usage will start to grow, presumably back near to current levels.
Ground movements at Heathrow only just work at the best of times. Increasing the landing rate (two Gatwicks side by side) and moving inbounds and outbounds to/from two runways will very likely cause gridlock.
IIRC, the largest airport in the world (KKIA, Riyadh) is 50 sq miles, Denver is 35 sq miles. Heathrow, the "Busiest International Airport in the World", is 4.5 sq miles.
A bit before my time, but I am sure HD was correct in 1965, and it will cause big problems on the ground if it is tried in 2008.
SM
Ground movements at Heathrow only just work at the best of times. Increasing the landing rate (two Gatwicks side by side) and moving inbounds and outbounds to/from two runways will very likely cause gridlock.
IIRC, the largest airport in the world (KKIA, Riyadh) is 50 sq miles, Denver is 35 sq miles. Heathrow, the "Busiest International Airport in the World", is 4.5 sq miles.
A bit before my time, but I am sure HD was correct in 1965, and it will cause big problems on the ground if it is tried in 2008.
SM
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It won't be happening in 2008! It will take about 4 years for the technical work, airspace change process, etc.etc. but staffing could take longer than that. My guess is we are unlikely to see full mixed-mode before about 2013.
.4
.4
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Can I get a ticket to watch GMC? It should be hysterical! I don't think that those who formulate such schemes spend much time at the sharp end. As has been mentioned, Heathrow is a tiny place and traffic and concrete are infinitely more complex than when I wrote the article in the 60s.
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We join ours a vertical levels too. But we join with all 'domestics' independently in VMC; i.e. they get a traffic statement and thus are responsible for not going through the centreline due to traffic on the other side. It's fun watching two domestics pointing at each other; they have traffic of course on/before base.
Directors rarely talk to each other, it's look and go stuff.
Directors rarely talk to each other, it's look and go stuff.
Surely mixed mode ops will provide a higher overall movement rate for Heathrow? What about all the wasted runway occupancy with wake turb on departures?
And a question about non-PRM 'monitoring' controller ... is this in addition to DIR? DIR is the only requirement for IVAs and PRM ... max 52 (?) mile radar range.
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Just read the document linked in at the start of this thread which answers my monitor question above. Staffing this position doesn't need to be by director endorsed controllers. It could be by ab initio, tower, area, departures, etc. Quick training, 100% pass rate.
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Geffen.
The full original Concept of Operations is in my view the only practical option. I know, I would say that wouldn't I. The fact is I studied the options for 2 years and the quick solution (TWASS) is not practicable on safety grounds.
TWASS is not an option because... The current final director works his but off doing 44 per hour and the slightest distraction can lead to difficulties. There is ample evidence to suggest that, in fact, we need to take work load off him because the incident rate through ATC error is unacceptable. Picture this then, that instead of taking workload away from him, we add 10-15% and introduce more complexity too. That is what TWASS means, and it also means traffic turning in towards each other without a vertical safeguard on a frequency that is saturated and with a high number of foreign aircrew.
I wouldn't like to say it is impossible - that would be tempting fate but I think the only way the full ConOps could be delivered in two years would be if the Government intervened in the normal process of airspace change etc. NATS has quoted 4 years because on average that is the time it takes to complete an Airspace change (involving SIDS etc,) on the scale necessary.
I am also sure that using departure radar would enable some enhancement of departure capacity, which would then enable TEAM (6 arrivals per hour on the departure runway) to be used on a permanent basis without getting the airport out of balance. It is possible that this could be introduced in a relatively short period but that is not full mixed-mode and wouldn't deliver anything like the capacity - maybe 90 an hour with the right mix. Well, we sometimes do more than that now. It would make us a little more robust in strong winds though.
.4
The full original Concept of Operations is in my view the only practical option. I know, I would say that wouldn't I. The fact is I studied the options for 2 years and the quick solution (TWASS) is not practicable on safety grounds.
TWASS is not an option because... The current final director works his but off doing 44 per hour and the slightest distraction can lead to difficulties. There is ample evidence to suggest that, in fact, we need to take work load off him because the incident rate through ATC error is unacceptable. Picture this then, that instead of taking workload away from him, we add 10-15% and introduce more complexity too. That is what TWASS means, and it also means traffic turning in towards each other without a vertical safeguard on a frequency that is saturated and with a high number of foreign aircrew.
I wouldn't like to say it is impossible - that would be tempting fate but I think the only way the full ConOps could be delivered in two years would be if the Government intervened in the normal process of airspace change etc. NATS has quoted 4 years because on average that is the time it takes to complete an Airspace change (involving SIDS etc,) on the scale necessary.
I am also sure that using departure radar would enable some enhancement of departure capacity, which would then enable TEAM (6 arrivals per hour on the departure runway) to be used on a permanent basis without getting the airport out of balance. It is possible that this could be introduced in a relatively short period but that is not full mixed-mode and wouldn't deliver anything like the capacity - maybe 90 an hour with the right mix. Well, we sometimes do more than that now. It would make us a little more robust in strong winds though.
.4
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I am very disappointed indeed to read that the use of simultaneous approaches into Heathrow with a monitoring controller is being considered.
I will be perfectly honest and admit that I have never done a PRM approach (effectively the same thing from a flight crew perspective) for real, though I have had the mandatory simulator and CBT training, as the fleet I fly on has diversion aerodromes that use the procedure.
Having read, watched and "flown" various breakout manoeuvres, I find it simply baffling that any regulator could approve such a scheme. For anyone reading this who is not familiar with the technique, it involves aircraft flying parallel (or in the case of SOIA, converging) approaches under IFR, whilst using both radios. One radio is tuned to the normal ATC frequency, the other is used to listen to a "monitoring controller". In the event that an aircraft on one approach "blunders" (FAA word, not mine!) towards towards the aircraft on the parallel approach, the monitoring conroller issues a "breakout manoeuvre" on this special frequency.
In effect a pilot is one minute flying a nice, stable ILS approach when suddenly he is faced with an awful lot of conflicting signals: the ILS beam bar/GP indicator/flight director says fly one way, the monitoring controller says fly another way, the TCAS may be warning "traffic" or providing an RA, the autopilot disconnect wailer will be sounding and the autothrottle disconnect beeper may be sounding.
Even now I can imagine people reaching for their keyboards wanting to type about how "if I really was a professional pilot I would be able to cope" and I "would know how to silence various distracting warnings quickly" and "hasn't the standard of airmanship declined since the introduction of the glass cockpit". However, I believe they would be missing the point. The point is, we should be designing safety in to aviation, not devising procedures which require a backstop as flimsy as the monitoring controller.
I used to regard UK ATC as the best in world, but I have to say that recently I am struggling to defend some of the procedures. Heathrow, once a model for how to operate an airfield from an ATC perspective, is becoming indefensible. The ridiculousness of a DCL system which requires the same information to be transmitted by voice and the use of a LLZ only approach during TEAM when the ILS could be made available are but 2 examples of how the ATC procedures are frankly lacking.
To return to the discussion on approaches using a monitoring controller: SAFE? Not inherently or there would be no need for the monitoring controller. ORDERLY? Not if every operator is required to train every flight crew on another difference from every other airport in Europe and including a breakout which is anything but orderly. EXPEDITIOUS? It had better be. I'd hate to think you were planning to further reduce safety margins for no benefit.
G W-H
I will be perfectly honest and admit that I have never done a PRM approach (effectively the same thing from a flight crew perspective) for real, though I have had the mandatory simulator and CBT training, as the fleet I fly on has diversion aerodromes that use the procedure.
Having read, watched and "flown" various breakout manoeuvres, I find it simply baffling that any regulator could approve such a scheme. For anyone reading this who is not familiar with the technique, it involves aircraft flying parallel (or in the case of SOIA, converging) approaches under IFR, whilst using both radios. One radio is tuned to the normal ATC frequency, the other is used to listen to a "monitoring controller". In the event that an aircraft on one approach "blunders" (FAA word, not mine!) towards towards the aircraft on the parallel approach, the monitoring conroller issues a "breakout manoeuvre" on this special frequency.
In effect a pilot is one minute flying a nice, stable ILS approach when suddenly he is faced with an awful lot of conflicting signals: the ILS beam bar/GP indicator/flight director says fly one way, the monitoring controller says fly another way, the TCAS may be warning "traffic" or providing an RA, the autopilot disconnect wailer will be sounding and the autothrottle disconnect beeper may be sounding.
Even now I can imagine people reaching for their keyboards wanting to type about how "if I really was a professional pilot I would be able to cope" and I "would know how to silence various distracting warnings quickly" and "hasn't the standard of airmanship declined since the introduction of the glass cockpit". However, I believe they would be missing the point. The point is, we should be designing safety in to aviation, not devising procedures which require a backstop as flimsy as the monitoring controller.
I used to regard UK ATC as the best in world, but I have to say that recently I am struggling to defend some of the procedures. Heathrow, once a model for how to operate an airfield from an ATC perspective, is becoming indefensible. The ridiculousness of a DCL system which requires the same information to be transmitted by voice and the use of a LLZ only approach during TEAM when the ILS could be made available are but 2 examples of how the ATC procedures are frankly lacking.
To return to the discussion on approaches using a monitoring controller: SAFE? Not inherently or there would be no need for the monitoring controller. ORDERLY? Not if every operator is required to train every flight crew on another difference from every other airport in Europe and including a breakout which is anything but orderly. EXPEDITIOUS? It had better be. I'd hate to think you were planning to further reduce safety margins for no benefit.
G W-H
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GWH, I think we've covered the DCL before, so I won't go there, but are you aware the limitations that protecting the 27L GP has on the departure rate and GMC complexity when 27L TEAMing? We have to protect it out to 15 miles, so really we can't have anyone going past SB1 when an inbound is 20 or more miles from touchdown. With 6 an hour, that doesn't give us a lot of time to get anyone away from the south side.
And believe me, we hate it as much as you!
And believe me, we hate it as much as you!
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120.4,
I certainly would rather see mixed mode with all the bells and whistles, opposed to something cobbled together. How much pressure is going to be piled on NATS from the airlines and central government IF it gets approved? Hopefully the most robust system will be the one selected.
Gonzo,
Can't believe you haven't mentioned ground yet!
G-W-H,
One statement says it all. Commercial pressure. Money should be spent to shift the G/P and touchdown point so that we can line up, OR, HAL should build a new runway entrance.
I certainly would rather see mixed mode with all the bells and whistles, opposed to something cobbled together. How much pressure is going to be piled on NATS from the airlines and central government IF it gets approved? Hopefully the most robust system will be the one selected.
Gonzo,
Can't believe you haven't mentioned ground yet!
G-W-H,
One statement says it all. Commercial pressure. Money should be spent to shift the G/P and touchdown point so that we can line up, OR, HAL should build a new runway entrance.
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Gonzo
I know how awkward TEAMing can be for you, but there are better solutions than the LLZ only approach. One solution would be for Radar could clear the inbounds to 27L to 2000' then to follow the glide. You would only have to provide GP protection from 6dme then. Surely the added safety benefits would make this worthwhile?
If that solution doesn't float your boat, how about specifying no autocoupled approaches to 27L? I seem to remeber flying somewhere in Europe recently where this was being promulgated on the ATIS. I'd rather hand fly an ILS approach which is not too different from the one we have briefed for the arrival runway, than have to rebrief as we leave the hold for a npa for a landing on the departure runway.
If there is a bit of spare cash floating around, how aboat a fillet of concrete at S3 to allow traffic to make a right turn here for departure or crossing, and use this as the position for departures from the southside?
Returning to potential problems with the use of a monitoring controller. The system is currently used in the USA, but over there the controllers do not tend to use such tight arrival spacing. In my experience it would be rare to have 3 aircraft on approach within 5/6 miles (unless they are doing visual approaches). So, imagine a day when the inbounds from the north outnumber those from the south. 2.5dme spacing is used and a run of 3 aircraft are packed at 160kts on 27R. Meanwhile on 27L there are few arrivals, and the (about to become) villain of the piece is slowing (slowly) from 210kts to 160kts. If this aircraft blunders towards the north, 2 or perhaps extremely 3 aircraft may need to fly a breakout. I do not believe that when the system was devised multiple breakouts were envisaged. To remove this possiblity, the minimum spacing on final would have to be increased to 5/6 miles, in which case we may as well continue to operate dependant approaches.
Having said all that, the incredibly poor quality of transmissions from all TC sectors at the moment makes the whole system impossible. The levels of distortion are too great to guarantee safety for something as safety critical as the use of a monitoring controller.
All in my humble opinion of course.
G W-H
I know how awkward TEAMing can be for you, but there are better solutions than the LLZ only approach. One solution would be for Radar could clear the inbounds to 27L to 2000' then to follow the glide. You would only have to provide GP protection from 6dme then. Surely the added safety benefits would make this worthwhile?
If that solution doesn't float your boat, how about specifying no autocoupled approaches to 27L? I seem to remeber flying somewhere in Europe recently where this was being promulgated on the ATIS. I'd rather hand fly an ILS approach which is not too different from the one we have briefed for the arrival runway, than have to rebrief as we leave the hold for a npa for a landing on the departure runway.
If there is a bit of spare cash floating around, how aboat a fillet of concrete at S3 to allow traffic to make a right turn here for departure or crossing, and use this as the position for departures from the southside?
Returning to potential problems with the use of a monitoring controller. The system is currently used in the USA, but over there the controllers do not tend to use such tight arrival spacing. In my experience it would be rare to have 3 aircraft on approach within 5/6 miles (unless they are doing visual approaches). So, imagine a day when the inbounds from the north outnumber those from the south. 2.5dme spacing is used and a run of 3 aircraft are packed at 160kts on 27R. Meanwhile on 27L there are few arrivals, and the (about to become) villain of the piece is slowing (slowly) from 210kts to 160kts. If this aircraft blunders towards the north, 2 or perhaps extremely 3 aircraft may need to fly a breakout. I do not believe that when the system was devised multiple breakouts were envisaged. To remove this possiblity, the minimum spacing on final would have to be increased to 5/6 miles, in which case we may as well continue to operate dependant approaches.
Having said all that, the incredibly poor quality of transmissions from all TC sectors at the moment makes the whole system impossible. The levels of distortion are too great to guarantee safety for something as safety critical as the use of a monitoring controller.
All in my humble opinion of course.
G W-H
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From a purely tower point of view, to us a LLZ/DME, or a platform height of 2000ft would be great.
Unfortunately, this increases workload for Director, and also means some of the 'deemed separations' below the GS over London wouldn't be available.
Not sure the regulator would go for this at all. There was enough hassle from them with us doing LLZ/DME approaches to a runway where full GP was available. I've also been told by crews that if there is an a/c moving in front of the GP on 27L, it can show up as a full 'fly down' indication.
BAA having spare cash to spend on airport infrastructure?
When BA moved into T4, I believe a condition was that all departures would be able to depart from S3. When we have had WIP that precluded a full length departure from SB1, lots and lots said that they needed full length.
I'm sure I don't need to tell you also that with the number of flights out of T4 at the moment, it would completely screw GMC2 (121.7) up if S3 was the departure holding point. One a/c waiting there and the whole south side would very quickly come to a grinding halt.
Unfortunately, this increases workload for Director, and also means some of the 'deemed separations' below the GS over London wouldn't be available.
If that solution doesn't float your boat, how about specifying no autocoupled approaches to 27L? I seem to remeber flying somewhere in Europe recently where this was being promulgated on the ATIS. I'd rather hand fly an ILS approach which is not too different from the one we have briefed for the arrival runway, than have to rebrief as we leave the hold for a npa for a landing on the departure runway.
If there is a bit of spare cash floating around, how aboat a fillet of concrete at S3 to allow traffic to make a right turn here for departure or crossing, and use this as the position for departures from the southside?
When BA moved into T4, I believe a condition was that all departures would be able to depart from S3. When we have had WIP that precluded a full length departure from SB1, lots and lots said that they needed full length.
I'm sure I don't need to tell you also that with the number of flights out of T4 at the moment, it would completely screw GMC2 (121.7) up if S3 was the departure holding point. One a/c waiting there and the whole south side would very quickly come to a grinding halt.
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According to the AIP (chart AD 2-EGLL-8-10) the LLZ/DME procedure starts from 2500'. Since this is the case, you guys in the Tower would only have to guard the glidepath from 7.5dme if we used 2500' as the platform altitude for the 27L ILS when TEAMing. This won't cause a problem with deemed separations as clearly 2500' is OK for the LLZ/DME so it must be OK for the ILS.
As to adding workload to FIN. I wouldn't like to comment on whether it was better to increase the workload of someone who has spent the night in his own bed or taken a long sleep in the bunk room/vacant office, or whether it would be better to give more work to 2 guys who are arriving after spending a night out of bed, coming from a timezone 6 hours away, perhaps snatching an hour of sleep in the seat, then staring at the rising sun for 3 hours. (More seriously, the GS could act as coordinator to keep FIN's workload manageable).
G W-H
As to adding workload to FIN. I wouldn't like to comment on whether it was better to increase the workload of someone who has spent the night in his own bed or taken a long sleep in the bunk room/vacant office, or whether it would be better to give more work to 2 guys who are arriving after spending a night out of bed, coming from a timezone 6 hours away, perhaps snatching an hour of sleep in the seat, then staring at the rising sun for 3 hours. (More seriously, the GS could act as coordinator to keep FIN's workload manageable).
G W-H
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So, imagine a day when the inbounds from the north outnumber those from the south. 2.5dme spacing is used and a run of 3 aircraft are packed at 160kts on 27R. Meanwhile on 27L there are few arrivals, and the (about to become) villain of the piece is slowing (slowly) from 210kts to 160kts. If this aircraft blunders towards the north, 2 or perhaps extremely 3 aircraft may need to fly a breakout.
.4
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<<whether it would be better to give more work to 2 guys who are arriving after spending a night out of bed, coming from a timezone 6 hours away, perhaps snatching an hour of sleep in the seat, then staring at the rising sun for 3 hours. >>
Dear Lord... I've bitten my tongue on thousands of occasions through loyalty to my pilot friends but I now have to say it - if I hear ONE more thing about pilots' workloads I'm going to be very seriously sick.
<<(More seriously, the GS could act as coordinator to keep FIN's workload manageable).>>
Written by someone with little knoiwledge of how the system works. For one thing, the GS may not have a validation for the sector. How would you like an unqualified person leaning over your shoulder telling you how to fly your aeroplane? And just how could a second person make the Final Director's workload manageable without getting in his way?
Dear Lord... I've bitten my tongue on thousands of occasions through loyalty to my pilot friends but I now have to say it - if I hear ONE more thing about pilots' workloads I'm going to be very seriously sick.
<<(More seriously, the GS could act as coordinator to keep FIN's workload manageable).>>
Written by someone with little knoiwledge of how the system works. For one thing, the GS may not have a validation for the sector. How would you like an unqualified person leaning over your shoulder telling you how to fly your aeroplane? And just how could a second person make the Final Director's workload manageable without getting in his way?