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CASA threw one heck of a hand grenade at General Aviation when it issued directives that restricted aircraft movements at GAAP airports and sounded the death knell for this unique Australian airspace category.

Released only two weeks after the tabling of the long-awaited GAAP Utility Report, the directives instructed Airservices Australia to put an immediate cap of six aircraft per circuit, banned pilots from taxiing down inactive runways without a clearance, and required GAAP to be replaced with Class D control zones from April 2010.

CASA also directed Airservices to expand the tower hours to cover all daylight operations without sacrificing the existing coverage after last light and reinstated ground controllers.

According to CASA’s Director of Air Safety, John McCormick, the directives were, “an appropriate, measured and justifiable response” to safety issues identified in the Utility Report by consultant company Ambidji.

With only one week for the industry to mull over the changes before the directives leapt from draft to reality, no one really knew what the ramifications would be.

But in the ensuing weeks it became clear there were many consequences that CASA hadn’t considered, or if they had, had chosen to ignore.

GAAPs in our history

The concept of GAAP was born in the halcyon era of general aviation in Australia: the mid-1970s.

Traffic movement was increasing rapidly and the capital city GA airports were flat out coping under the Secondary Aerodrome Procedures (SAPs).

In 1978, SAP became GAAP – General Aviation Aerodrome Procedures.

The new system was basically a copy of the US’s Class D airspace with some modifications; the biggest being the requirement to track via an Inbound Reporting Point (IRP).

This funneled aircraft into conger lines that ATC could easily find through the binoculars and sequence into the circuit.

Parafield was the beta version of GAAP, and once proven viable the system was rolled-out across Bankstown, Camden, Moorabbin, Jandakot and finally Archerfield.

GAAP wasn’t perfect, but it did the job for 20 years without Cessnas and Pipers raining on the surrounding houses.

Then came an indescribable decade. From 2000 to 2009, 22 people lost their lives in accidents with aircraft operating from, or near, a GAAP airport.

The previous 20 years had seen only seven fatalities.

Not all the accidents can be blamed on GAAP procedures – some might argue none – but it is a statistic that must have shaken the rule-makers.

Subsequently, CASA commissioned two reports, both of which were presented earlier this year.

The July directives are the fall-out from the reports’ conclusions.

Report day

Justification for the changes hangs on the recommendations of two reports: CASA’s own review of GAAP training and Ambidji’s GAAP Utility Report.

Both reports returned findings that amounted to fine-tuning of procedures, not a major overhaul.

The document causing the most fuss is the Ambidji report, as it targeted the effectiveness of GAAP itself. Again, drastic corrective action is absent from the recommendations.

Instead, the consultants concluded that, “the existing Class D GAAP model contains the most appropriate classification for the six aerodromes reviewed.

This position is based on the model’s high traffic processing capacity for the diverse range of traffic categories that utilise the GAAP product.”

In all, the Ambidji recommendations actually contain some pretty sensible stuff.

See for yourself - it is on the CASA website.

However, reconciling the CASA approach with the recommendations can be confusing as the two are not obviously compatible.

“The recommendations that Ambidji presented were based upon reducing risk at the six GAAP aerodromes,” intoned one response from CASA.

“Additional action taken by CASA supports Ambidji’s findings and allows for an immediate reduction of collision risk through the circuit cap.

"It is anticipated that further implementation of the Ambidji recommendations, where agreed, will further reduce the collision risk.

"Many options were considered ranging from suspending operations at GAAP aerodromes to implementing recommendations and improvements on a long term plan.

"The final decision was based on evidence that was presented from a number of sources.

"This evidence showed that immediate action was required.”

It may yet prove that CASA’s actions were the correct ones, but for certain they have provoked emotional responses from the GA industry.

Capping the circuits

Easily the most blood-boiling issue is the directive to limit each circuit/controller combination to six aircraft, plus one extra departure.

Just about everyone who has operated from a GAAP will have, at one time or another, encountered a circuit busier than Bourke Street.

CASA’s move to de-clutter the circuit was probably then a natural one.

Considered to be severe by most operators at all airports but Moorabbin, the issue was defended by CASA in their response to queries.

“The figures were calculated on the average speed and rate of climb of typical training aircraft normally operating in the circuit at these six aerodromes.

"In general, the effect of the cap will be to reduce the peak density of traffic, rather than to reduce the total possible number of movements.

"The cap itself is considered a temporary measure while other initiatives to manage the identified risks are developed, assessed and implemented.”

Sounds all good, until you examine the consequences.

Aminta Hennessy is CFI and Chief Pilot of Clamback and Hennessy at Bankstown.

She and her students have found themselves on the dark side of the circuit cap.

“The implementation has affected our operations enormously because they are only allowing six aircraft in the training circuit, and if the two frequencies are hooked up, only six in the zone!” she said.

“The scheduling of our students has become chaotic, which can only mean people will not wish to learn to fly here because of the uncertainties associated with their lessons.

“At Hoxton Park [a CTAF] we would often have eight to 10 in the circuit without too many problems.”

It’s when students are at an inbound point and get turned away that is giving CFIs the most grey hairs.

"As the IRPs are not within the GAAP zone, students’ actions on being refused entry are solely up to them; they’re in G airspace.

"The general response in the weeks after the directives went live was to turn through 180° and head back where they came from - straight at other inbound traffic.

Problems were amplified at Bankstown and Jandakot, both of which have effectively only one IRP for students to get home from the training area.

For Bankstown, that’s 2RN, site of last year’s tragic mid-air collision.

The system has no friend in Aminta Hennessy.

“At the moment aircraft are denied entry to the airspace and the students have to fend for themselves - the whole thing is chaotic, costly, negative, not user-friendly and for no reason!” she decried.

Airservices anticipated hassles at the IRPs, stating that ATC would give priority to inbounds and would make space by directing an aircraft doing circuits to full-stop.

It was acknowledgment that CASA’s directive had had the effect of shifting potential conflict from the circuits to the IRPs.

At Camden, it had another effect.

Students doing solo flights have to return to the airport from which they departed, but dual flights don’t have to, and so many Bankstown aircraft opted to depart for the circuit at Camden rather than wait on the ground at home.

With the ‘inbound priority’ in their pockets, they quickly took the place of local aircraft in the Camden circuit.

Procedures at Camden – an airport with only one main runway – were further modified to restrict the circuit to four aircraft, making room for two possible inbounds.

Four aircraft in a controlled circuit! Please, no one tell the Americans … we’ll be laughed out of the next ICAO meeting.

Way out west at Jandakot things aren’t much better.

Student pilots are regularly being turned away from the critical Six South inbound point, turning the area into a melee of aeroplanes.

Royal Aero Club of WA CEO Alan Hoffman is a worried man.

“The direction of 21 July addresses a notional safety hazard, but has caused a real and imminent threat of an accident at the entry points, particularly Six South and Boatyards,” Hoffman said.

“We are very concerned that we face a potential fatal outcome of a collision at the entry points and we suggest that action be taken forthwith to restore the status quo.”

Concerns over this issue run very deep at RACWA, deep enough for them to be looking closely at their Murrayfield satellite air strip near Mandurah, south of Perth.

“We are investigating our options here,” Hoffman revealed.

“It is not a preferred solution as, whilst our facilities are good at Murrayfield, there are time factors to be taken into account for students travelling to and from Murrayfield.

"However, if the GAAP changes are not corrected quickly, we may have little alternative than to transfer some of our training activity to Murrayfield.”

Similar tales of woe are coming from Archerfield and Parafield.

The only airport that seems to have shrugged-off the circuit cap is Moorabbin; however, the Great Southern GAAP has worries all of its own.

Using the inactives

Almost alone, Moorabbin has borne the brunt of the directive that all aircraft must get a clearance to taxi on or cross an inactive runway.

With two sets of parallel runways intersecting mid-length and a single crossing runway, the surface movement pattern at Moorabbin has been described as being like, “a spilt bowl of spaghetti”.

When compared with other GAAPs, it is certainly more complex.

In the weeks immediately after July 21, operators at Moorabbin were inundated with Electronic Safety Incident Reports (ESIRs) for their students failing to request clearance to use the inactive runways.

It is thought that MB tower was writing up to 30 per day.

It brings forth images of ATC issuing a full-stop clearance with the left hand and simultaneously starting work on the impending ESIR with the right hand.

The tide of ESIRs was stemmed after about eight weeks.

The problem was that only one week’s warning was given before the July directives became enforceable.

If CASA had given GAAPs a probationary period, a lot of paperwork could have been avoided.

The complexity of the taxiways at Moorabbin has translated directly into the radio calls and increased chatter significantly.

For example, if you are headed for the holding point of runway 31R, you will need to request clearances to cross 17R/35L, 17L/35R and 04/22 at least.

Unlike the circuit cap, which is timed to expire on July 20 2010, needing a clearance to cross an inactive runway will stay; at other controlled airports, all runways are considered active.

That includes Class D towers.

The move to Class D

CASA’s directive to replace GAAP with Class D airspace caught many operators off guard, and caused division within the aviation community.

There are three clear factions in the argument: ICAO Class D, USA Class D and keeping GAAP.

As of the time of writing, there has been much sabre-rattling and finger-pointing, and the word ‘safety’ has been bandied around that much that it is losing its value.

The cause of the ruckus is the original statements that

CASA and Airservices made, and the subsequent comments from John McCormick.

CASA did not make it clear which system was to be implemented.

The July directive said that Airservices must provide services appropriate for Class D, the CASA press release stated that the move would better harmonise Australia with, “the current International Civil Aviation Organization (ICAO) airspace classification system,” and AIC H09/09, released by Airservices on July 24 was emphatic that they had been directed by CASA to install ICAO procedures.

When CASA was asked which brand of Class D was to be adopted, the answer told a different story.

“The Director has stated that his preference is to follow the FAA system,” the spokesperson said.

“The statement of ‘ICAO Class D’ is a working definition and does not override the implementation plan being developed by Airservices.

"CASA will ensure that the specifics of the Class D introduced into Australia best reflect the Australian operating environment.”

The best thing that can happen is that, by the time this story is published, the issue has been resolved in favour of one system or the other, and we can all go back to flying.

ICAO Vs USA

Australia already has 10 ICAO Class D towers. Without going into every single procedure that distinguishes them from GAAP, the main ones relate to tracking over inbound points, getting airways clearances, ATC staffing requirements and IFR separation services, minimum distances between parallel

runways and vertical distance from cloud.

In truth, they are not a whole lot different from GAAP now, and as such may not generate the quantum leap in safety that CASA is looking for.

If so, why go to Class D at all?

“Class D simplifies the teaching and learning of regulations,” the CASA response stated.

“Depending upon the implementation plan provided by Airservices, it can deliver fewer radio calls and will reduce congestion.

“The [Ambidji] report stated that GAAP was suitable in the ‘short to medium term’.

"CASA is looking at the longer term such that any changes to the current GAAP procedures are carried out one time only.”

The US has the largest total area of Class D airspace in the world, and the proponents naturally maintain their system would therefore be the best.

What makes it most different from ICAO is that there are no inbound reporting points; aircraft can approach the zone boundary from any direction and are sequenced into the circuit.

Under some circumstances, an aircraft can enter the zone having made contact with the tower, but not have been given a specific clearance.

Aminta Hennessy is adamant in her support for the FAA Class D, and believes it may cure some serious ills at Bankstown.

“The positive change would only be if the US-style ‘D’ were brought in, as the aircraft would arrive from any direction and not be funneled through two points [Prospect Reservoir and 2RN], which is dangerous.

You would be issued with a clearance to land when you call inbound. You have to be prepared to go around, and if it is really thick and heavy they will tell you to go around.

“If we don’t get FAA Class D, keeping GAAP would be a better option, because if they implement ICAO Australians will require an airways clearance.”

Approaching from every compass point “wagon wheel” style stands to eliminate bottlenecks at the inbound reporting points, although some GAAP CFIs have stated they would likely tell their students to track home from the training area via specific highly-visible landmarks anyway.

That would probably have the effect of reinstating the bottlenecks.

Changing to the American system will, CASA has confirmed, result in all Class D towers switching over, not just the ex-GAAPs.

Suddenly we are talking about overhauling procedures at 16 towers around the country.

For many of those, the change will do nothing as safety is not as much of an issue and the traffic volumes aren’t a patch on the GAAPs.

They will be the ‘collateral damage’ of the drive for FAA Class D.

The ‘do nothing’ strategy

RACWA strongly recommends that Class D airspace is not introduced at Jandakot.

It is RACWA’s opinion that the introduction of Class D airspace would have an even greater detrimental effect on operations with no safety gains.

The GAAP procedures until recently in place at Jandakot have proven to be a safe and reliable model of operation – a model that has been refined over a number of years resulting in an extremely safe method of operation.”

Alan Hoffman could not make RACWA’s position clearer than that: they want GAAP to stay. Other operators at Moorabbin and Camden have echoed RACWA’s sentiments.

The bedrock of this position must lie in the presumption that there is nothing amiss with GAAP now.

CASA seems to think otherwise. For sure, the last decade has been a shocker safety-wise for GAAPs, but the previous two have a much better record.

Of the 34 incidents investigated at GAAP aerodromes, only six occurred between 1978 and 2000.

Three high-profile fatal collisions have occurred since 2000, with two of them still at the preliminary stage of the investigation at the time of writing.

Perhaps it is these that CASA is reacting to more than anything else; the regulator has a mandate to protect the general public.

What GAAP operators are questioning more than anything is whether or not going to Class D, ICAO or FAA, will bring the desired result.

CASA is sticking to its guns though: “It is difficult to estimate the value of simplifying regulations; however, nearly every stakeholder has agreed that it is a desirable outcome and that is what Class D achieves.

"Experience in the US is that [FAA] Class D is demonstrably safer than GAAP.”

A conclusion, of sorts

Whether or not GAAP must go is an open debate that is apparently remarkably similar to the one that dogged the moves to GAAP in the first place.

If safety is a problem, then change must come. ICAO Class D does not, at face value, appear to be different enough from GAAP for the aviation industry to have confidence that it will bring about a marked increase in safety.

FAA Class D does have the potential to do that, presuming the level of risk assessed by CASA is real.

As the guardians of the airspace, CASA is holding all the power, and can impose their solutions out of hand.

That’s not what operators need; a co-operative solution is possibly the only track to real change.

The contradictions between Airservices and CASA have created the impression within the industry that there is some conflict between the two.

This is about as welcome as water in the avgas.

These six airports are too important to aviation for their masters to use them as political footballs.

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