More on FLOW + PRMs

So the other morning we were using RWY 16 PRM Approaches; due to wind and low cloud on the approach path. The landing rate was a cool 3 minutes between arrivals; or 40 Arrivals an hour. This is an efficient rate to allow optimum aerodrome capacity.

Effectively the tower needs a radar standard between the arrival and the departure; so 3 minute spacing allows for a departure between each arrival. If the arrivals are more tightly spaced; i.e. 5NM apart on final (the normal rate) in such conditions due to not being able to sight the arriving aircraft the tower can’t ‘fire’ the departure. So you can arrive two closer than 3 minutes even in PRMs; but not get a departure away too.

During PRM approaches the general concept is, due to the huge length of final it’s inefficient; this isn’t actually the case; yes, it’s not as efficient as visual conditions but it’s better than full dependent ILS approaches; see more below.

So the other morning we were on 40 arrivals and 40 departures an hour = maximum capacity (by law).

However, CTMS was at play and on ground delays which are strategic by nature didn’t equal the arrival rate; the CTMS rate was 34. So we are ‘expecting’ 6 slots not fully utilised. Why? Well when the CTMS program was run at 0500; it looked like the capacity would have been 34 Arrivals an hour; 17 on each runway; this configuration happens when we use 16 Dependent ILS Approaches.

PRM in Sydney is only staffed for in an adhoc at call manner; i.e. we only use it when people agree to come in on their day off. So at 0500 it wasn’t likely that enough people were going to say yes (2 of them). So rather than running CTMS rate of 40 and only achieving 34; and costing heaps of tactical fuel burns they ran it at 34. The PRM consoles are independent positions; when PRM is open all 12 consoles in Sydney are open and the room buzzes; but what do I know about such things, I’m based in Melbourne. CTMS was re-calculated around 0700; but the extra slots created were not fully utilised.

This is where effectively we use a radar standard between arrivals operating to different runways; in the SY case there is less than 1NM between centre lines; so to establish them in a dependent stream it requires spacing such as this.

Dependent Approaches

PRM Approaches


The advantage of PRMs is that if required you can have arrivals tighter than the ‘nominate acceptance rate’ on the same ILS; possibly swapping a departure slot for an extra arrivals slot etc; without effecting what’s happening on the other runway with dependent approaches; what ever you do on one ILS in terms of spacing has an effect on the other runways spacing too.

So back to what I do. The sequence here.... Just talking about the RWY16R sequence.

I’ve taken the liberty to include the savings in time (due to high speed and track shortening) into account across the averages. Things to note; between 2017 and 2054 the runways is at effective maximum capacity; then the CTMS rate of 34 left a few holes, basically 3 nine minute gaps. From 2127 until 2151 again its a maximum capacity.

Another thing to consider is we deal in whole minutes for the purposes of MAESTRO and flow; but the realities of the beast is is we have 150 seconds (2.5 minutes) between arrivals or a rate of 48 arrivals an hour; we actually use this rate (or tighter at times). So early or late at a fix does transpose into the real sequence spaces not the flowed spaces.

The nuts and bolts about how this one happened: QFA42 was slowed to follow EA2202; VOZ401, VOZ809 and QFA730 were given 250Kts and a vector to follow QFA42. HVN783 was given DCT to RIVET with high speed to follow QFA730; as was JST761.

VOZ811 and QFA408 were actually vectored to follow JST761 for separation, even though it appears there was no delay. VOZ619 was given DCT RIVET with high speed. QFA412 was untouched and QFA130 joined in from BN sectors (using my runway); QFA586 was untouched and RXA514 was shortened up on the non-jet STAR.

Then there were the gaps and all aircraft got high speed descents. CPA023, CAL051 and CES561 joined the sequence via BN sectors. QFA414 was given a crew managed delay time for RIVET; i.e. “adjust speed to cross RIVET at 13 at 250K.” Note it’s 23 minutes from RIVET at 250K (45NM SY) via the PRM approach to touch down.

SIA231 was vectored at cruise and given slow speed on descent (250K) to make RIVET at time 19; but later it became apparent that they wouldn’t make 19 (cause they got low); so they were brought back to profile speed; QFA740, VOZ821 were vectored to follow SIA231 and descended at 250K.

QFA564 (Canberra Sydney) was given a ‘strategic’ slot for departure to make good a landing of 2150; they got away early so were estimating the field at 2145; but the delay was need to make a landing of 2151; so they got a vector at 250K.

We came off PRM approaches at 2151 and the folks that came in on their day off got to go home after about 3 hours work.

Hello hello?

With the modern world a distinct advantage of technology is improved communications; various mediums are available to transfer data and voice communications. Here in India, there is a need for much improved systems; particularly relating to ATC system. It is laughable to many ATCs here that our communication phone lines to neighbouring centres are at best intermittent; when can then walk outside, use our mobile phones and get much better communications than through our official sources. I replicate the article that recently appeared in the Indian Express.

AAI joins hands with German specialists to replace obsolete air communication network with state-of-the-art messaging system

In a move that will catapult Mumbai-and India-in the league of aviation biggies, the Airports Authority of India (AAI) has roped in German Air Traffic Control (ATC) specialists COMSOFT to undertake the installation of an aeronautical message handling system (AMHS) at the Chhatrapati Shivaji International Airport.

The AMHS-used to relay flight plans, meteorological data, emergency messages, etc as a flight is transferred from one ATC centre to another-will be a dedicated data network connecting air traffic control centres across the globe. It is a new, refined and superior technology over the currently used aeronautical fixed telecommunication network (AFTN).

While the functionality of the AFTN-implemented in the '70s-is so limited that it can at the most carry text with a maximum of 1,800 characters, the AMHS can carry any kind of digital information including text, graphics, images, files, databases, audio and video.

The move to replace the obsolete AFTN has been underway since March 2005 when AMHS service was established between Japan and USA. While the AFTN is akin to a telex circuit, "the new system will have the same display as in an e-mail, though the underlying protocol will be different," explains Anil Kumar, GM (communication), Mumbai ATC.

Among the most pressing concerns will be the security of the network, "it cannot be compromised and has to be customised to ensure hacking is not possible," he added.

With the installation, India will become the fourth country in the Asia-Pacific region-after Philippines, Australia and Singapore-to make the switch. During the implementation, COMSOFT will install ATN (aeronautical telecommunications network) routers and terminals at the airport to establish the Mumbai node-which will act as the redistribution point or an end point for data transmissions-by December.

"The Mumbai node will be the backbone of the system here since it will act as the gateway to India by linking all stations within the country, apart from serving international stations like Nairobi, Karachi, Muscat and Colombo," said Kumar.

In the first phase, ground-to-ground messaging, that is controller-to-controller communication, will be realised. Later, the system would be enhanced to facilitate ground-to-air communication, which is dialogue between controllers and pilots.

"The contracting parties have agreed to a tight time schedule: the system is to be installed at Mumbai airport and taken into operational service by early 2008. Staff training will be held at COMSOFT facilities in Germany to prepare the technical and operational team for a swift transition to the new technology," COMFSOFT said in a statement.

Delhi, Kolkata and Chennai are next in queue for the switch, since these are the trunk routes.

Why Holding?

Callsign.....ETA_FF..........STA_FF..........Enroute Delay
QFA06.......1930................1945..........15
BAW015.....1937................1947..........10
SIA221.......1943................1949...........6
QFA32........1944................1951..........7
ETI450........1945................1954..........9
UAE412......1952................1956...........4
RBA193......1954................1958...........4
VOZ623......1954................2000..........6
QFA400......1955................2003..........8
JST601........1956................2005..........9
RXA453.......2001................2006..........5
EA2221.......2005................2008..........3
VOZ601......2012.................2012*........0
RXA774.......2013................2013*........0

So lets now explore this basic type of a sequence. QFA06 is number 1 but it’s the end of the curfew and the first arrival slot is 2000. In the above table the ETA_FF and STA_FF is for position RIVET for jets and WELSH for non jets; which is about 15 minutes flying time to the 16R threshold at 250K IAS. So QFA06 needs to cross RIVET at 1945 for a landing time of 2000. Also note at the end RXA453, EA2221 and RXA774 have less delay than looks necessary; this is because from the WELSH there is approximately 65NM still to go to touchdown which take a non jet an extra minute.

So what do we do to delay the aircraft?

All going well the ALOFT program has been calculated correctly and the enroute delay has been applied to the aircraft somewhere near 2 hours ago. ALOFT is a new system to achieve time based sequencing for the pre 0700 local time arrivals; this came about mostly due to the significantly more aircraft arriving at 0600 local time, than the aerodrome could handle; i.e. many aircraft want to get on the ground as close to 0600 as possible; this is an airline scheduling issue not an ATC one; but we have developed this tool to determine the landing order based on the estimates for Sydney calculated around 4am. Hopefully as a result of ALOFT pilots have made sufficient adjustments to absorb the majority of their delay prior to reaching the descent phase of flight.

But I’ll expand on this situation without ALOFT in use and the delays only ‘discovered’ with around 200NM to go.

The solution to absorb delay in the safest manner is through holding.


From the South West of Sydney we have 3 Jet holding patterns and 3 non jet holding patterns (with a red in-fill in the picture) for use to delay aircraft; all patterns are left hand patterns with the exception of TARAL which is a right hand hold; (to keep clear of the BIK holding pattern)

We treat CULIN and MAKKA as the same pattern and stack vertically within them, to feed the TARAL pattern; we do similar with KEDDY and NICKI, which are rarely used; but give us options when the BIK area is busy. Usually we stack aircraft vertically where number one in the sequence is at the lowest level; this doesn’t always happen because of the mix in cruising levels and aircraft types.

Normally at TARAL we stack jets at FL210, FL220, FL230 and use FL240 as a transition level, so this is used some times. Then we move back to fill CULIN and MAKKA. Treating those patterns as one, we stack at FL250, FL260 etc.

Normally the exit hold time at TARAL is 5 minutes before RIVET; so we manage the patterns at CULIN and MAKKA to fill the pattern at TARAL. The idea being that you hold in the outer patterns without it being time critical and are moved up to TARAL for more accurate delaying action. This usually only happens when delays exceed 15 minutes; but we do use both patterns at time with less delay than that due to not fitting enough aircraft in the TARAL pattern.

Now when to hold or not, is a very difficult decision. When the delays exceed 9 minutes, it’s a no brainer; holding is best and easiest to manage. Why 9 minutes, well 2 minutes for slow speed from TOD to the pattern, 6 minute holding pattern and another minute leaving the hold at reduced speed. Not totally accurate, but close enough for government work.

But look at the sequence above; 4 aircraft have at least 9 minutes to lose, but are mixing it with aircraft that don’t have that much. QFA06, BAW015 will hold, and perhaps JST601, but looking at the disposition of the others it looks like vectors and speed control to achieve the delays. (QFA400 is on the cusp, maybe a hold maybe a vector, but if holding not going slow into the pattern, which always seems to confuse the crews) If QFA400 and/or JST601 are held they will need positive vertical positioning to avoid the aircraft on vectors and speed control so the get into the pattern in an orderly manner and underneath the aircraft that will overfly them in the pattern.

We tend to manage exiting holding patterns through Stack Departure Times (SDTs) we want pilots to be very accurate with them, but there is a bit of give and take still in the sequence; as you’ve got the best part of 100NM to touch from TARAL, unless it’s RWY 07.

The pilot responsibility is to be anywhere between 30 seconds early and 1 minute late; it’s amazing how many times I see this buggered up. For example pilots approaching TARAL 2 minutes early and either saying good enough, or worse turning out for another pattern. Me being the vigilant bloke I am, I’m thinking a 2 minute orbit, not bloody likely unless you’ve only got boxes down the back; if you are too early ask for assistance, don’t manage it yourself. If you are late, no problem, depending on how late, expect higher speed or if too late expect a swap in slots.

Next time, vectoring and speed control; and how we ‘pick the order’; the old I was going to be number one but, *#%^& dumb controller...; scenario.

New ATC technology

Today we replicate the text of a speech delivered by Patrick Forrey, President of NATCA to a transportation industry meeting earlier this week.


Good morning ladies and gentlemen. Thank you for being a part of this important event and thank you for the invitation to be here with you to discuss three of my favorite subjects: The air traffic control system, safety, and modernization.

I am speaking to you today on behalf of the 14,000 air traffic controllers and 5,000 other dedicated safety professionals the National Air Traffic Controllers Association represents.

This summer, we are celebrating our 20th anniversary of service to the American flying public and our motto remains the same: Safety above all.

Nothing else matters to us as we work on the front lines of the daily challenge to keep our skies safe, secure and efficient as possible.

Air traffic controllers are highly-skilled, dedicated, supremely passionate about what they do, and eager to lend their expertise in planning for the future, and modernizing our air traffic control system.

Controllers love modernization and love the newest, most modern equipment, whether it’s the GPS in their cars, the iPhones strapped to their belts or the new STARS displays they have in their radar control rooms.

The title of this panel is "Next Generation Air Traffic Control," and air traffic controllers are excited about those five words. We are eager to be involved.  There is only one problem and it’s a biggie...

The Federal Aviation Administration does not WANT us... Why? Well, you’ll have to ask them. But it’s obvious to me that excluding controllers is part of their agenda to run the air traffic control system more like a business.

I mean, who wants those pesky controllers interfering with the development and implementation of equipment and procedures controllers will need to handle the increased capacity our airspace system demands?

After all, as safety watchdogs and systems experts we might see something that won’t work or won’t help us safely and efficiently handled the demands of tomorrow... and that could interfere with the bottom line.

First they sent home every one of our dozens of controllers that worked as technical experts on modernization programs, new equipment testing and rollout plans, airspace redesign initiatives, and new air traffic procedures.
Then, the FAA imposed work and pay rules on us Labor Day weekend last year, after completely destroying the fair collective bargaining process.

They gave their managers authoritative and aggressive free reign, to run roughshod over the workforce that is directly responsible for the FAA’s ability to call our system the world’s safest.

If it sounds like I’m angry, I am... Because, we see almost daily another example of how the FAA is jeopardizing the safety and success of new equipment and procedures, by failing to work with the air traffic controllers who will be using this equipment and these procedures.

Here in Texas, we are working to try and halt the FAA’s plan to consolidate Beaumont Terminal Radar Approach Control into the Houston TRACON, until there is a full and open process for all stake holders to exam the proposed move.

It is critical that we address safety, operational, and staffing issues associated with any consolidation effort.

Let me be clear, NATCA supports consolidations where they make sense. In the case of Beaumont, the FAA agreed to participate in a public meeting that took place on Tuesday. But the FAA has no intention of listening to the stakeholders...

You see, they had already scheduled training for Houston controllers to learn how to take over Beaumont’s airspace, and even had the audacity to move up that training to Monday, one day before the public meeting took place.

We have found one way to get around the FAA’s efforts to keep us away from modernization projects. And that is to work directly with the vendors that are manufacturing the air traffic control equipment of tomorrow.

One notable example is a ground radar system known as ASDE-X. We have been working with the Sensis Corporation to work out issues and potential problems at many airports around the country.

We are looking forward to the commissioning of two ASDE-X sites later this month; at Chicago O’Hare and Charlotte Douglas International Airport.

The updated system, which already provides enhanced runway safety measures, will provide controllers with information which may reduce departure delays off the airport, due to the departure transitions now being displayed to the controller on the radar.

This is an example of using new technology to assist air traffic controllers working in control towers, by providing more information without increasing workload.

There is a large and diverse chorus of supporters of NATCA’s position, that the best modernization efforts involve ALL stakeholders, including controllers.
For many years, the Government Accountability Office has consistently reported, that failing to involve air traffic controllers in the technology development process to resolve tricky human factors issues, has led to costly reworks and delays.

The Inspector General has noted that the need for focused "human factors" research has important safety implications.

As House Aviation Subcommittee Chairman Jerry Costello stated in a hearing on modernization issues in May, "common sense would suggest that the people that will be using and maintaining this new technology should be involved in its development."

Which brings us to NextGen, the Next Generation air traffic control system. NATCA has been shut out by the FAA on all efforts to work on NextGen.

But we are now working directly again with the Joint Planning Development Office, which is spearheading the efforts to develop NextGen. NATCA has also joined RTCA, and reinserted our participation with the NGATS Institute.

NATCA strongly supports participating in a collaborative process with the FAA in the development of NextGen, as well as the agency’s new modernization programs and initiatives.

Chairman Costello’s colleague across the aisle on the House Aviation Subcommittee, Republican Ranking Member Tom Petri of Wisconsin, wrote in the Roll Call newspaper last month that, "The manufacturers, airlines, operators, airline employees and FAA employees all share an interest in the success of the new system and will contribute immensely to its effective operation. As such, it is critical that the FAA include the aviation stakeholders in the development of the new system. Only with such collaboration will the FAA be able to deliver the best service to the flying public."

Well, we couldn’t agree more with Ranking Member Petri.

While we press for more collaboration on modernization, I must point out to you the importance of how the air traffic control system is being run right now... ..

Because like it or not, this is the system we have for the next several years, possibly another decade or more, until NextGen becomes a reality and ground infrastructure is expanded to accommodate more traffic.

And the system we have, ladies and gentlemen, is steadily eroding due to critically low staffing numbers within all work forces and in all segments of the FAA.

But there is something that can be done about it.

Currently, we are urging Congressional passage of an FAA Reauthorization bill that would send us back to the contract negotiating table with the FAA, to fix the unfair process that led to imposed work and pay rules on several NATCA bargaining units last year, and worsened an already critical controller staffing shortage.

This language is critical because it would provide an incentive for veteran controllers to stay on the job long enough, to keep the system running, and to train their replacements.

Right now, the massive exodus of controllers is eroding the safety foundation of the system, and delaying flights.

It has resulted in 1,100 fewer total controllers on the job since shortly after 9/11, and an alarming 1,300 fewer fully certified controllers in the same time frame, despite a huge increase in traffic, which according to the FAA and the airlines, has overwhelmed the system.

Here in Dallas for example, a worsening shortage of air traffic controllers at several facilities is a major concern to everyone except the FAA.

We are worried about the effects on our controllers’ ability to remain sharp, focused and well-rested, as they battle thunderstorms, congestion, and a summer travel season that has been marked by record delays thus far.

Does it not pique anyone’s interest that summer weather hasn’t changed, yet we are experiencing record delays...

Maybe the shortage of flight crews and controllers has something to do with that.

At Dallas TRACON, there are currently 68 fully certified controllers on staff. There should be over 100.

The understaffing has resulted in increased usage of overtime by FAA management officials, to desperately try and staff the positions. From January through this month, the FAA is slated to use $444,000 worth of overtime to cover for a lack of staffing.

Of the 68 controllers working today, 80 percent now are forced to work OT, resulting in longer periods on position, longer work weeks, and increased fatigue.
The situation is likely to get worse before it gets better.

While two trainees are scheduled to be fully certified this year, at least five fully certified controllers will retire, with approximately 10 more retirements in 2008. The other trainees have at least two years of training left.

At DFW Tower, there are 44 fully certified controllers on staff, along with seven trainees. The 51 total is eight short of what is needed to safely staff the facility.

And at Fort Worth En Route Center, there are currently 290 fully certified controllers on board, and 65 more in training, which is well short of safe staffing levels. The FAA must overcome this shortage by routinely combining sectors of airspace, resulting in controllers working more than one sector at a time.

The staffing numbers at Las Vegas approach, one of the country’s fastest growing airports is very disconcerting. Training is very sporadic and they can no longer staff the facility without using partially certified trainees.

In 2003, the staffing number for Las Vegas TRACON was 56. Today, the FAA staffing range for certified controllers is a maximum of 52. So while their traffic has increased by approximately 25%, the staffing has been decreased by the FAA. And the only explanation to this illogical activity is a bottom line business approach to ATC services.

The controller schedule beginning this October contains only 23 CPC's. The only way Vegas is able to staff the facility, is to use trainees that are partially certified, which stops their training. There are currently 18 trainees in the building. As of October, Las Vegas TRACON will have more trainees than instructors!

What better way to pull the wool over the eyes of the American public, than for the FAA to flood the media about NextGen. This is all designed to draw your attention away from the absolute travesty the ATC system has degraded to.
Here in Dallas is also where news was made last month in the form of a report issued by the Office of Special Counsel, that stated that FAA management officials covered up operational errors made by controllers who were diligent and honest in reporting them.

The special investigator in charge wrote in his summary that, quote, "these allegations expose a continuing pattern by FAA management of abuse of the basic measures of protection meant to insulate the flying public from disasters that very well may be preventable."

We agree with the OSC, that by manipulating data and events, so that operational errors and deviations are not accurately reported, FAA officials directly affect the statistical analysis of air traffic safety.

So before we as a nation turn our full attention to NextGen, and the future aviation system we hope to enjoy, we must work to ensure that the system we have to use today, to drive our economy and get us where we need to go, remains the safest in the world and one where no corners are cut in a foolish rush to institute business agendas over safety practices.

Thank you and I look forward to addressing the issues in this panel.


Well is he right? What do think? Does this apply to your ANSP; new technology essentially developed in isolation of the workforce; without proper concepts of operation? Well it certainly sounds like my employer should take note of this world wide phenomenon; give them a machine that goes ping, why, well that’s obvious it goes ping!

Flow Mysteries

There are 3 strategic methods used for Flow control, on ground delays, airborne time in trail sequences and airborne miles in trail sequences; the latter two are effectively the same thing, but it’s hard to put a PA31 miles in trail with a B747 at 100NM from touch down.

The primary function of a tactical FLOW controller is to ensure that all available landing slots are utilised. The amount of landing slots varies on many things including aerodrome layout, current weather conditions, forecast weather conditions, noise abatement, legislative requirements.

Where I work, the FLOW Controller uses a tool, to help calculate landing slots, called MAESTRO. The FLOW chooses the arrival mode, such as MODE 7 (Jets via RIVET get 34L everything else gets 34R unless operationally require 34L) or 16PRMs, or 07ILS etc. Then they landing rate is chosen, normally this is done via a number of arrivals per hour; which then translates back to a ‘time between arrivals’. For example on 07ILS the arrivals rate may be 28 per hour, which is about 128 seconds apart.

MAESTRO uses the original arrival time (provided to it by TAAATS or manually manipulated by controllers or the FLOW) of each aircraft and applies a delay to an aircraft to ensure it lands in the calculated arrival slot.

For example, Bigplane1 is estimating landing at 00 and is number 1, so no delay is given assuming fast and shortening isn’t an option, Bigplane2 is estimating landing at 00+30 seconds and is number 2, so a delay is given to ensure that Bigplane2 lands at time 02 and so on.

So lets assume single runway operations with that 128 second arrival rate. It is pretty easy to follow in chart form, where ETA_FF is the actual estimate and STA_FF is the adjusted estimate for the sequence to work; for ease of management, slots are allocated 2,2,2,2,3 minutes between arrivals; so the 1st 4 are tighter than the rate and the 5th on time.

Callsign... ETA_FF..... STA_FF
QFA006... 1945.......... 1945
BAW015... 1945.......... 1947
SIA221... 1946............ 1949
UAL863... 1946........... 1951
ETI450... 1947........... 1954
UAE412... 1950......... 1956
RBA193... 1953......... 1958
VOZ623... 1955......... 2000
QFA400... 2000......... 2003
JST601... 2000......... 2005
RXA453... 2001......... 2007
EA2221... 2001.......... 2009
VOZ601... 2012......... 2012*
RXA774... 2013......... 2015*

You can see from the table that ETI450, despite being only 2 minutes behind number 1 in the sequence has been given a 7 minute delay; and VOZ601 has been allocated the landing slot 12 based on it’s estimate, but there may be opportunity to track shorten to achieve a landing time of 11; this may also flow on to the rest of the sequence.

MAESTRO shares the delays required between approach (TMA), and enroute. The first 1 to 2 minutes of the delay will be absorbed within the TMA (210K from Welsh or 250K from RIVET), so to enroute it will appear that no delay is required for BAW015 in the above table; yet the airplanes are effectively on top of the other so some spacing is required by enroute; otherwise it’s a step descent and lots of work etc. Then by slowing/vectoring BAW15 it impacts on the next aircraft etc. This also assumes same track into the TMA.

Where I work we have one jet track and one non-jet track into the Sydney TMA. Jets via RIVET and non-jets via BIK and ODALE.



All the Jet routes converge at TARAL, about 4 minutes flying time prior to RIVET with 4 major routes joining at CULIN about 8 minutes prior to RIVET.

Often for the purposes of separation, it is not prudent to let converging jets manage their own sequence times; despite the advantages it may give re VNAV etc. With 4 routes converging at CULIN almost never works to have a two minute gap managed by the pilots, as a two minute gap at RIVET may be a zero minute GAP at CULIN.

For separation we may want you doing a different speed than what we actually need for the sequence; this is when we may change your speed for descent. Then there are the occasions when we expect the aircraft in front of you, turning at MAKKA and TARAL to gain speed or loose speed depending on the winds and they just don’t.

Lets also not forget the fly-over and fly-past way-points that boeing and airbus use; Airbuses via CB-CULIN, and MAKKA-TARAL cut the corner (sorry smooth the corner) and save a good three track miles or so.

When we adjust your speed, preferably upwards rather than down, we will do so because the sequence permits it; but sometimes it’s needed to slow you down too. Sometimes the flow just puts another aircraft in “your” slot, for whatever reason (WX, Operational Requirements, MED priority) if this happens and you are inside 200NM it will cost you another 2 minutes minimum; and usually the whole sequence gets vectored and slowed.

On ground delays (CTMS) are strategically used in Sydney too; these are for flights within 2 hours only. They effectively use flight-planned arrival times to allocate an ETA based upon ETD at departure. With the exception of ‘departure aerodromes’, CTMS times are not considered by the flow or MAESTRO. Departure aerodromes include Canberra, Bathurst, Orange, Williamtown etc. If you have an on ground delay and are early to depart you may be penalized and held for your CTMS arrival slot; if you get away late you forfeit your slot and join the regular sequence. Another big impact is arrangements with airlines re departures from West Coast USA and Africa, where the maximum delay applied shall not exceed 10 minutes.

In my next blog for EMC, I’ll be explaining some of the methods we use to achieve the delays.

So it begins.

Welcome to the inaugural edition of the blog “Every Minute Counts”.

This blog is a collaborative effort from many wide a varied sources. We have secured multiple authors from multiple countries and we are looking for additional contributors (particularly South American, Asian, and African based ATCs).

We hope to keep you updated from an ATCs perspective about hot topics, advancements in ATC systems, industrial relations news pertaining to ATC (in various countries), IFATCA news, incident/accident investigations, OH&S (including fatigue issues), airspace planning, collaborative decision making principles, slot allocation, CFMU, CANSO, ANSP news, legal issues, projects with global reach, local projects, aircraft advancements, etc.

So all you budding authors out there if you have a topic to discuss, jot down a hundred words or so and we’ll do our best to publish it here; no guarantees, but such is life. Join our contributory team and become a true member.

We encourage you to share this blog with your friends and colleagues. Please comment about our posts (all comments may be subjected to moderation) and will strive to address e-mails sent to us (see the address above); please use this e-mail address if you have any tips or rumours that need publication; all information (and sources thereof) will be kept strictly confidential; otherwise we understand that this blog will be compromised; and generally not worth reading.

So like most blogs consuming the information super highway, this is a relatively lame start and more about telling you our intent.

Now an extract from a letter from Us Congressman Bill Shuster to FAA administrator Marion Blakey on 23 July 2007, with thanks to John Carr at the “Main Bang” see it here http://themainbang.typepad.com/blog/



Dear Administrator Blakey:

I am writing to urge that you voluntarily return to the negotiating table and finish the contract discussions that unfortunately broke down last year with your air traffic control workforce. I believe that such action would remove a significant impediment to the successful passage of legislation to reauthorize the Federal Aviation Administration, set to expire this September.

Though I voted against the Costello amendment to H.R. 2881, the FAA Reauthorization Act of 2007, the bipartisan supermajority with which it passed is a clear indication of the level of support for reopening the imposed contract. Please do not mistake my opposition to the amendment as a signal that I unilaterally support the FAA's actions in this matter.

It is evident that without definitive action by your Agency to negotiate a fair agreement, Congress may attempt to void the contract imposed by the FAA last year, risking legislative stalemate.

Let me be clear that the main objective is to see that the FAA reauthorization reaches a successful conclusion. If the issue remains between FAA and its unions, the entire bill could be jeopardized and the National Airspace System will undoubtedly suffer.

With the summer travel season upon us and delays projected to reach record levels, it is safe to anticipate public animosity will continue to build toward the state of aviation in this country. Therefore, I believe that it is the best interest of all stakeholders, including the FAA, the air traffic controllers, the flying public and the Congress, that this matter be resolved so that I can focus my attention on preparing our skies for future increases in air traffic.

It is my hope that you will do so voluntarily and soon as to put this matter behind us and move on with the business of modernizing our air traffic control system.



Up next, The concepts of FLOW control, why must aircraft go slow, go fast, all the things in between and sometimes it happens twice or more.