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Mixed mode increases capacity by 25%
Yes, it can squeeze in more movements, but will it address the congestion and delays, both on the ground and in the air?
Last edited by Fairdealfrank; 28th Jun 2012 at 21:43.
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Well, there needs to be a combo of flight and ground ops.
Currently, when one brings in a group of heavies, it kills the ground ops. That is why mixed mode is only so successful.
A gate is a gate, it is full with 120 pass ac or 450 pass ac.
Blended ops bring in heavies and lights, so ground ops isnt hit with a large number of high occupancy aircraft at one time or a large number of smaller occ aircraft at the same time...that is where the real capacity enhancement can be realized.
The airspace is not optimized when you have a group in hold, while another group queues. A light should not be in a hold pattern while 10 heavies approach.
We need to move past the light/medium/heavy/et al, designations and blend the aircraft to optimize the airspace and ground ops, and not use, the 'worst case' as a foundation for aircraft operations.
Currently, when one brings in a group of heavies, it kills the ground ops. That is why mixed mode is only so successful.
A gate is a gate, it is full with 120 pass ac or 450 pass ac.
Blended ops bring in heavies and lights, so ground ops isnt hit with a large number of high occupancy aircraft at one time or a large number of smaller occ aircraft at the same time...that is where the real capacity enhancement can be realized.
The airspace is not optimized when you have a group in hold, while another group queues. A light should not be in a hold pattern while 10 heavies approach.
We need to move past the light/medium/heavy/et al, designations and blend the aircraft to optimize the airspace and ground ops, and not use, the 'worst case' as a foundation for aircraft operations.
Last edited by FlightPathOBN; 28th Jun 2012 at 22:15.
So the arrival of a group of aircraft together is absolutely standard and to be expected. Excuses by the likes of the UK Border Agency or absent gate personnel that "several aircraft arrived together and we can't handle that easily" are a nonsense. All aspects of the airport should have got used to this long ago.
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FlightpathOBN,
What do you mean by a blended queue?
What do you mean by ground ops? How could that increase capacity?
I assume you're aware of the work ongoing around Europe of time based arrival spacing and thence pair wise separation, but that's a long term initiative, it's not going to happen overnight.
If you look at the queue with wake separation, a blended queue could easily give you 25% more capacity, especially when coupled with ground ops...
What do you mean by ground ops? How could that increase capacity?
I assume you're aware of the work ongoing around Europe of time based arrival spacing and thence pair wise separation, but that's a long term initiative, it's not going to happen overnight.
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My company has a real time wake turbulence measurement system. The measurements are about every 3 seconds, and the measurements are taken at 500m, 1500m, and 2500m from threshold. The system measures a grid up to 300m high at each location. When the ac passes over the array, it begins measuring the wake turbulence.
Since this is real time measurement, you can bring in the aircraft without guessing where the wake is, you know exactly where it is and the velocity, and when it is clear...(or where it has gone)
The ac is descending on the flightpath, and the wake is descending as well. This system is used in combination with a wind profiler, which is located at 3000, from threshold, and measures the wind column, real time as well, up 1000m. The profiler shows wind velocity and direction every 5m in altitude. It very distinctly shows wind direction changes, shear zones, and advection layers as they rise or fall. The great thing about this information is it provides winds right on final, and at real time. You will see the exact shear zone, the direction and velocity change, and be able to adjust. The system will also pick up microburst, downdraft/updrafts, and will broadcast on the windshear ADSB system.
Okay, so this system will show the approach path, when it is clear, when the conditions start to degrade and ATC needs to have greater separation distances, and when conditions improve, tighten the spacing up.
Should a gust or something else happen, an immediate warning is given to ATC with sufficient time to have the following aircraft do a go-around, and/or broadcast to the ac warning system for avoidance measures.
In short, after the system is up and operational for a period of time, ATC will be able to balance and blend the queue with the actual types of aircraft, and the associated loading, that are common for that runway.
Using this system fits within the ICAO framework of the RECAT, which allows for greater freedom of wake separation when monitored real-time.
ICAO Block upgrades support this, Global Initiatives, ACE, and the RECAT programs, and fits within many automated MET and ATM systems.
In reality, the wake turbulence currently is based on weight, with RECAT movement towards finite weight classes from the 3x3 matrix to 6x6 or 8x8, to the ultimate 64x64 matrix?!?! I really cannot see how anyone could track a 64x64 matrix and stay sane.....
After looking at thousands of flight datasets, it isnt about weight. A while back, there was a different system testing the Airbus ac with real time measurements, and the results were so unexpected, that they did not believe the LIDAR system worked. The system did work, what doesnt work is the mathematical approximations of the wake turbulence models.
As I noted before, 3 identical 737-8 in a row, all made very different vortex, simply because of the difference between flaps 20/30/40 with inboard flaps. A 737-4 makes a much different vortex as well, because that ac has outboard flaps as well.
The beauty of it is, the system is stand alone at this point, nothing is required to be added to the aircraft. For ATC, the system show the various locations as red, yellow and green for the clearance, so minimal training with situational awareness of the system is required.
We also have a similar system for single runway, cross runway and parallel runway departures.
Since this is real time measurement, you can bring in the aircraft without guessing where the wake is, you know exactly where it is and the velocity, and when it is clear...(or where it has gone)
The ac is descending on the flightpath, and the wake is descending as well. This system is used in combination with a wind profiler, which is located at 3000, from threshold, and measures the wind column, real time as well, up 1000m. The profiler shows wind velocity and direction every 5m in altitude. It very distinctly shows wind direction changes, shear zones, and advection layers as they rise or fall. The great thing about this information is it provides winds right on final, and at real time. You will see the exact shear zone, the direction and velocity change, and be able to adjust. The system will also pick up microburst, downdraft/updrafts, and will broadcast on the windshear ADSB system.
Okay, so this system will show the approach path, when it is clear, when the conditions start to degrade and ATC needs to have greater separation distances, and when conditions improve, tighten the spacing up.
Should a gust or something else happen, an immediate warning is given to ATC with sufficient time to have the following aircraft do a go-around, and/or broadcast to the ac warning system for avoidance measures.
In short, after the system is up and operational for a period of time, ATC will be able to balance and blend the queue with the actual types of aircraft, and the associated loading, that are common for that runway.
Using this system fits within the ICAO framework of the RECAT, which allows for greater freedom of wake separation when monitored real-time.
ICAO Block upgrades support this, Global Initiatives, ACE, and the RECAT programs, and fits within many automated MET and ATM systems.
In reality, the wake turbulence currently is based on weight, with RECAT movement towards finite weight classes from the 3x3 matrix to 6x6 or 8x8, to the ultimate 64x64 matrix?!?! I really cannot see how anyone could track a 64x64 matrix and stay sane.....
After looking at thousands of flight datasets, it isnt about weight. A while back, there was a different system testing the Airbus ac with real time measurements, and the results were so unexpected, that they did not believe the LIDAR system worked. The system did work, what doesnt work is the mathematical approximations of the wake turbulence models.
As I noted before, 3 identical 737-8 in a row, all made very different vortex, simply because of the difference between flaps 20/30/40 with inboard flaps. A 737-4 makes a much different vortex as well, because that ac has outboard flaps as well.
The beauty of it is, the system is stand alone at this point, nothing is required to be added to the aircraft. For ATC, the system show the various locations as red, yellow and green for the clearance, so minimal training with situational awareness of the system is required.
We also have a similar system for single runway, cross runway and parallel runway departures.
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Well, a great solution would be to implement GBAS. With that, you can get the mins down and open up the ops window a bit.
This would allow for the displaced threshold and variable glidepath, keep the aircraft that work better with 2.8GPA on threshold, and the 3.1 GPA on the displaced, this , if the speed gates are in the right place, could reduce ROT a bit as well.
This would allow for the displaced threshold and variable glidepath, keep the aircraft that work better with 2.8GPA on threshold, and the 3.1 GPA on the displaced, this , if the speed gates are in the right place, could reduce ROT a bit as well.
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FPOBN,
You need to have three installations under the approach for each runway, is that correct? (Or four, including the 'wind profiler at 3000' (metres?) from the runway')
So the furthest out you can monitor in real time is about 2nm? Not sure this will help, as the UK only provides wake turbulence separation to 4nm out, and it is accepted that there is catch up inside of that as spacing compresses due to the speed reduction to landing stabilisation speed.
Again, I'm not really sure what you're proposing here. What is 'balancing and blending the queue'?
Can you expand on that please? are you talking about the minimum visibility/decision height in CAT III ops? It's not the landing minima that is the capacity issue with CAT III, it's the spacing required to protect the integrity of the ILS/MLS.
My company has a real time wake turbulence measurement system. The measurements are about every 3 seconds, and the measurements are taken at 500m, 1500m, and 2500m from threshold. The system measures a grid up to 300m high at each location. When the ac passes over the array, it begins measuring the wake turbulence.
So the furthest out you can monitor in real time is about 2nm? Not sure this will help, as the UK only provides wake turbulence separation to 4nm out, and it is accepted that there is catch up inside of that as spacing compresses due to the speed reduction to landing stabilisation speed.
In short, after the system is up and operational for a period of time, ATC will be able to balance and blend the queue with the actual types of aircraft, and the associated loading, that are common for that runway.
Well, a great solution would be to implement GBAS. With that, you can get the mins down and open up the ops window a bit.
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The basic decision on those distances was the studies showed that the most critical phase of flight for a wake vortex encounter was about 300 feet above threshold or a wingspan.... This is where the ac is in final config, near stall, and a Wake vortex encounter would have disastrous effect.
Wake encounters further out are not fun, but there is much better chance of recovery.
The wind profiler going up to 1000m gives a better idea of the conditions of winds aloft, looking specifically for wind shear levels and inversion or marine layers. These layers can cause a vortex to hang or even bounce. The winds aloft is real time, and this system, to me has quite a bit ov value, with winds at 5m, really defining winds for that runway end, and a very good definition of wind shear levels, and direction for config settings...
For the queue there are really 3 variables that set the separation distances, ROT, radar Sep, and wake sep.
The real time measurements show how long it takes for the flightpath to clear of the wake. This allows for other variables to be the controlling factor for the spacing, such as radar sep. So depending on the local conditions, you may be able to have a 320 follow a 744 at radar sep.
Balancing and blending the queue, not specifically for LHR, but others as well,
again, LTH with the 2 runways, bring the mediums in pretty fast on final, and the larger ac slower on a different runway, so the benefit of the system would be when you have the inversion and marine layers, or even a tailwind, that hang the vortex on final. This is an issue even when following a similar aircraft at radar sep, and the system will warn of this, as well as windshear, updrafts, downdraft, and microbursts.
(looking at LHR, with the mediums coming on final at average of 170kts, flaps are probably what around 20/25? This will generate a large core and a small core vortex on a 738, small core disapate very quickly, and large core tend to stay around longer, so the MET conditions with this approach speed and radar sep, would appear to be critical to look for a marine layer rising at night that would hang the vortex, of an inversion layer that would hang or bounce it as well...)
The transition times between reduced/increased operations can be much more finite, knowing exactly when the front has moved into or cleared the approach path, providing the data for informed decision making, and taking the guesswork out of the situation.
Yes, the spacing required to maintain the integrity of the ILS is not an issue with GBAS, so the spacing can be reduced. A runway end can be used for arrival and departure, but that's lemming talk in many ways...
I jumped the gun a bit there, I meant to say if you are using GPS, ie RNP transitions to a GBAS final, you break the 250HAT for RNP, and get the minima down to CAT III autoland. This transition is seemless.
Wake encounters further out are not fun, but there is much better chance of recovery.
The wind profiler going up to 1000m gives a better idea of the conditions of winds aloft, looking specifically for wind shear levels and inversion or marine layers. These layers can cause a vortex to hang or even bounce. The winds aloft is real time, and this system, to me has quite a bit ov value, with winds at 5m, really defining winds for that runway end, and a very good definition of wind shear levels, and direction for config settings...
For the queue there are really 3 variables that set the separation distances, ROT, radar Sep, and wake sep.
The real time measurements show how long it takes for the flightpath to clear of the wake. This allows for other variables to be the controlling factor for the spacing, such as radar sep. So depending on the local conditions, you may be able to have a 320 follow a 744 at radar sep.
Balancing and blending the queue, not specifically for LHR, but others as well,
again, LTH with the 2 runways, bring the mediums in pretty fast on final, and the larger ac slower on a different runway, so the benefit of the system would be when you have the inversion and marine layers, or even a tailwind, that hang the vortex on final. This is an issue even when following a similar aircraft at radar sep, and the system will warn of this, as well as windshear, updrafts, downdraft, and microbursts.
(looking at LHR, with the mediums coming on final at average of 170kts, flaps are probably what around 20/25? This will generate a large core and a small core vortex on a 738, small core disapate very quickly, and large core tend to stay around longer, so the MET conditions with this approach speed and radar sep, would appear to be critical to look for a marine layer rising at night that would hang the vortex, of an inversion layer that would hang or bounce it as well...)
The transition times between reduced/increased operations can be much more finite, knowing exactly when the front has moved into or cleared the approach path, providing the data for informed decision making, and taking the guesswork out of the situation.
Yes, the spacing required to maintain the integrity of the ILS is not an issue with GBAS, so the spacing can be reduced. A runway end can be used for arrival and departure, but that's lemming talk in many ways...
I jumped the gun a bit there, I meant to say if you are using GPS, ie RNP transitions to a GBAS final, you break the 250HAT for RNP, and get the minima down to CAT III autoland. This transition is seemless.
Last edited by FlightPathOBN; 3rd Jul 2012 at 20:50.
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Quote: "LHR needs to be a 24 hour airport.
Isn't it ridiculous, in the modern world, that the UK's main hub is closed for 7 hours a day?
Anybody brave (or stupid) enough to put forward ideas for bringing LHR into the 21st Century.
I'm sure there is a contingent who don't want any significant development.
Is that a good option?
Should the country's hub airport be determined by the few who live under the flight path?
For those who think LHR needs serious development but are unconvinced by
Boris's island, are there any 'outside the box' ideas that might just work?
Or are we destined to never ending public enquiries and squabbling."
Quite right, Contacted, it probably should be a 24 hour airport, but that is a long way off. A few more landings between 0500 and 0600 would need to be the first stage, as increased long haul flights would result in more overnight arrivals at this time.
LHR needs a third and a fourth rwy, parallel to the existing ones, to allow alternation to be kept. North-south rwys present too many problems.
Terminal capacity will need to be addressed. LHR5 was already too small for all of BA even before it was opened. A larger area north of the A4 trunk road than currently envisaged may be needed in the medium term.
Better rail access is essential, it was lunacy for airport junction not to have a facility to join LHR to the west, especially with the future crosrail and the massive rail hub at Reading some 20 miles west.
It was also lunacy that the original rail link to Feltham (first mooted in 1966) was never built! That would have linked the massive rail hub at Clapham Junction some 20 miles east. Had that link been built, LHR4 would have had a ready made railway underneath it.
Isn't it ridiculous, in the modern world, that the UK's main hub is closed for 7 hours a day?
Anybody brave (or stupid) enough to put forward ideas for bringing LHR into the 21st Century.
- 3rd (or even 4th) runway. Maybe North/South
- Proper integrated national rail hub. More than the expensive paddington express.
- Special nighttime approaches, using new technology. RNAV, GPS,etc.
- Steeper approaches
- Displaced landing threshold
- Ban noisiest aircraft
- Proper airfield winter ops and facilities.
I'm sure there is a contingent who don't want any significant development.
Is that a good option?
Should the country's hub airport be determined by the few who live under the flight path?
For those who think LHR needs serious development but are unconvinced by
Boris's island, are there any 'outside the box' ideas that might just work?
Or are we destined to never ending public enquiries and squabbling."
Quite right, Contacted, it probably should be a 24 hour airport, but that is a long way off. A few more landings between 0500 and 0600 would need to be the first stage, as increased long haul flights would result in more overnight arrivals at this time.
LHR needs a third and a fourth rwy, parallel to the existing ones, to allow alternation to be kept. North-south rwys present too many problems.
Terminal capacity will need to be addressed. LHR5 was already too small for all of BA even before it was opened. A larger area north of the A4 trunk road than currently envisaged may be needed in the medium term.
Better rail access is essential, it was lunacy for airport junction not to have a facility to join LHR to the west, especially with the future crosrail and the massive rail hub at Reading some 20 miles west.
It was also lunacy that the original rail link to Feltham (first mooted in 1966) was never built! That would have linked the massive rail hub at Clapham Junction some 20 miles east. Had that link been built, LHR4 would have had a ready made railway underneath it.
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Now whereas Sipson is physically in the way for runway three, Terminal 4 would be in the way of runway four surely? Not impossible, however if they do stay with LHR, the LAX/CDG model of two pairs of parallel runways would be an option. Which makes runway three, too far North.
Last edited by Skipness One Echo; 4th Jul 2012 at 23:47.
Perhaps the residents of Stanwell and East Bedfont could all be persuaded to sell their homes to BAA and allow for R4 to be build there instead ? All you need is to just reiterate the message that the needs of Heathrow come before all others...
Terminal 4 would be in the way of runway four surely?
A parallel southern runway with the same separation as between the two existing runways would run just to the north of the Esso fuel farm and then neatly bisect Stanwell and the northern of the two Staines Reservoirs.
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Unfortunately, we are likely all dreaming. The chances of a new runway virtually anywhere in Europe, USA, or AUS, is virtually none.
We can even get new procedures approved, let alone a new runway....this is why you dont see EO procedures, we have these for private RNP, but in the public realm, we tried this before, but as soon as the public needs to see is an EO procedure, with a "aircraft on fire with one engine" over their house...same for the missed, which is why they are mostly straight ahead to a certain alt...
The people moved in on the flightpaths, and all of a sudden, they hear jet noise, and they get to complain.
The airport facilities are like almost everything in aviation, by the time it is approved, it is out of date. If they had a good interconnecting rail system, and the airports were all owned by the same owner, then you could shift operations around between them to optimize air traffic in general....
Good luck with that...
We can even get new procedures approved, let alone a new runway....this is why you dont see EO procedures, we have these for private RNP, but in the public realm, we tried this before, but as soon as the public needs to see is an EO procedure, with a "aircraft on fire with one engine" over their house...same for the missed, which is why they are mostly straight ahead to a certain alt...
The people moved in on the flightpaths, and all of a sudden, they hear jet noise, and they get to complain.
The airport facilities are like almost everything in aviation, by the time it is approved, it is out of date. If they had a good interconnecting rail system, and the airports were all owned by the same owner, then you could shift operations around between them to optimize air traffic in general....
Good luck with that...
Last edited by FlightPathOBN; 5th Jul 2012 at 16:02.
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Quote: "I'd have thought that a runway going through the T4 site would be too close to 09R/27L to allow sufficient separation for independent operations."
So what is the exact minimum physical separation required for 2 parallel rwys for simultaneous operations? At Heathrow the 2 existing rwys are a little under 1 mi. apart, is this a lot more than required?
But these rwys pre-date any civil aviation regulations, the modern airport started as RAF Heathrow, and was built to military requirements. It is pure co-incidence that there was space for mid-field terminals.
So what is the exact minimum physical separation required for 2 parallel rwys for simultaneous operations? At Heathrow the 2 existing rwys are a little under 1 mi. apart, is this a lot more than required?
But these rwys pre-date any civil aviation regulations, the modern airport started as RAF Heathrow, and was built to military requirements. It is pure co-incidence that there was space for mid-field terminals.
Last edited by Fairdealfrank; 5th Jul 2012 at 21:51.
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Under FAA guidelines, there are a few conditions.
For Visual and VMC, simultaneous operations are allowed if runways are at least 700 feet apart, with MVA +500 ceiling and 3nm vis.
Under IMC and IFR, the runways have to be at least 2500 feet apart for simultaneous ops. One of the approach paths will have a 3 degree offset.
They could always do this! Yahooo!
The dream....
I just want the contract for the signage.....
For Visual and VMC, simultaneous operations are allowed if runways are at least 700 feet apart, with MVA +500 ceiling and 3nm vis.
Under IMC and IFR, the runways have to be at least 2500 feet apart for simultaneous ops. One of the approach paths will have a 3 degree offset.
They could always do this! Yahooo!
The dream....
I just want the contract for the signage.....
Last edited by FlightPathOBN; 5th Jul 2012 at 23:03.
So what is the exact minimum physical separation required for 2 parallel rwys for simultaneous operations? At Heathrow the 2 existing rwys are a little under 1 mi. apart, is this a lot more than required?
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Again...
For Visual and VMC, simultaneous operations are allowed if runways are at least 700 feet apart, with MVA +500 ceiling and 3nm vis.
Under IMC and IFR, the runways have to be at least 2500 feet apart for simultaneous ops. One of the approach paths will have a 3 degree offset.
For Visual and VMC, simultaneous operations are allowed if runways are at least 700 feet apart, with MVA +500 ceiling and 3nm vis.
Under IMC and IFR, the runways have to be at least 2500 feet apart for simultaneous ops. One of the approach paths will have a 3 degree offset.
Under IMC and IFR, the runways have to be at least 2500 feet apart for simultaneous ops. One of the approach paths will have a 3 degree offset.
