11-30-2011, 03:15 PM
Article from Business times
Published November 30, 2011
COMMENTARY
Crowded skies over Changi
Serious thought needs to be given now to this matter of congestion, both in the interest of safety and in ensuring that Changi remains an attractive airport for airlines
By PRITHPAL SINGH
CONGESTION in Singapore is no longer just on our roads and trains. It has now spread to the skies above Singapore and to the parking aprons at Changi International Airport, as well.
Airline pilots have commented that in the past few months they have been noticing a deterioration in the traffic handling ability at Changi airport by the controllers.
And as Changi Airport continues to experience significant growth in air traffic, both arrival and departure delays are likely to increase as a result.
The situation has become so bad that the rule of thumb for airlines and pilots seems to be if departing between 8am and 10am, take more fuel, because there will be a long line of aircraft waiting to take off. And there can be as many as 10 aircraft holding and waiting for takeoff.
Allowing for a minimum of two minutes per aircraft for takeoff, this is already a 20-minute delay, not counting taxi time. That is easily 800kg of fuel lost for a Boeing 777. In doing a short flight, 700kg is the entire contingency fuel for the sector for a B777 jet!
Pilots arriving between 3pm and 7pm are also taking more fuel. The number of arrivals during this period, especially on weekdays, is so high that air traffic control just cannot cope.
Aircraft are being typically vectored for long finals for landing with minimum 20 nautical miles (nm) final, sometimes 30nm + final, with lots of zigzagging if the weather is bad. This is inefficient.
Airlines are burning fuel unnecessarily and adding to their operating costs. Pilots have to take on more fuel than necessary in anticipation of these long taxi times before takeoff and delays on approaching Singapore. And passengers are grumbling too.
In fact, on Nov 18, the captain of SQ flight 953 from Jakarta to Singapore announced that due to 'congestion' at Changi Airport, he was flying to Kuala Lumpur International Airport (KLIA) to refuel.
The aircraft overflew Singapore, landed at Kuala Lumpur at 6.30 pm, refuelled, and eventually landed in Singapore at 8.30 pm - three hours late! This is not the first time this has happened and it is likely to happen again.
While the situation is not yet dire, serious thought needs to be given now to this matter of congestion, both in the interest of safety and in ensuring that Changi remains an attractive airport for airlines.
To be fair, the Civil Aviation Authority of Singapore (CAAS) is aware of the problem and is implementing new measures to more efficiently utilise the airspace, runways, and taxiways available in order to keep delays to a minimum.
For example, CAAS has advanced weather radar systems on the ground and they can vector aircraft typically to avoid weather which reduces pilot workload.
Problems and delays
Singapore's standard arrival procedures are also well organised and thought out. In the initial stages of the arrival, traffic is still manageable and the airport can cope.
However, once traffic from all directions meets in the terminal area, that's when problems arise. Add bad weather and it's a minimum 20-minute delay before an aircraft can even land.
CAAS has also recently done away with the requirement for pre-departure clearances for some routes, reducing takeoff and landing separation criteria.
It is also currently conducting a trial run on a continuous descent operation which allows the pilot to execute an optimised arrival descent, and is also looking at reducing the current eight-mile separation between two arrivals to six miles eventually. Other air traffic control measures are also being considered.
Notwithstanding all the efforts being made, these new measures have their limitations. The continuous descent operation is complicated. Feedback during the trials shows it is not working as well as expected.
A date has also not yet been fixed for the implementation of the six-mile separation target. Technology can only do so much when human performance and limitations come into play. Changi Airport Group (CAG) and CAAS therefore need to look at other ways to reduce congestion.
One has to ask if CAG, the commercial and revenue-driven arm of the airport, is accepting too many airlines and flights and allocating too many takeoff/ landing slots at peak periods when the infrastructure obviously cannot cope. Is there sufficient communication and consultation between CAG and CAAS to ensure that this gridlock being seen now at Changi is avoided?
In many respects, the situation we are seeing today with our skies is similar to our public transport system which has basically remained unchanged even when our population exploded over the last few years. Is CAG targeting breakneck unsustainable growth at any cost?
If so, it may be time now to review key performance indicators for CAG and modify them to reward growth which matches the airport's capability to handle this additional traffic.
Growth is good and necessary but this has to be in tandem with the ability of the infrastructure to handle this growth. A re-examination of this policy now is vital.
CAAS should also open up Singapore's little-known third runway to civilian commercial traffic. This runway built on more recently reclaimed land, called 02R/20L, is now used just once every two years for the Asian Aerospace Exhibition and occasionally by military aircraft.
Third runway
I suggest that the Budget Terminal be relocated to this third runway as a standalone budget terminal and runway facility. It will reduce departing traffic congestion and provide relief for arriving flights.
Slow flying turboprop aircraft such as those operated by Firefly and Berjaya Air should also be banned from Changi Airport until this third runway becomes operational.
Many international airports have this policy - including our neighbour KLIA which directs turboprop aircraft to the secondary Subang Airport. Similarly in Singapore, turboprop aircraft should use Seletar Airport instead.
Changi needs to implement 'intersection takeoffs' for smaller jets. Most smaller jets need only half the 4,000-metre-long runway for takeoff, yet are required to taxi right to the end of the runway, lining up behind widebody aircraft which need much longer runways, wasting time, fuel, and creating congestion.
Granted, this may not fit the present policy of first-come- first-served, but would not intersection takeoffs applied intelligently reduce congestion?
Changi's present policy forbids intersection takeoffs, an odd anomaly considering it is a common practice at major airports worldwide.
Changi Airport opened in 1981 with just one passenger terminal, one runway, and served 34 airlines, and eight million passengers. Today, it has four passenger terminals, two runways, serves nearly 100 airlines, and handles over 42 million passengers annually.
While on the 'land side', CAG and CAAS have constantly upgraded the infrastructure to cater to this growth with new terminals and other passenger facilities and winning many awards in the process, the 'air side' of this equation is lagging behind.
The air side being hidden away from the public eye is more mundane and less glamorous and therefore receives little publicity. However, it is the air side of the airport which is the lifeblood of any airport and needs to be managed well.
Now with pilots, airlines, and even air traffic control personnel feeling the strain, it's time that this lesser known aspect of the airport gets an airing and much needed additional attention.
Some congestion at major aviation hubs like Singapore is acceptable. However, CAG and CAAS need to pause and take stock. Are we taking more than we can handle in the race for the numbers game? Are the infrastructure and manpower numbers and quality of personnel on the air side matching this rapid growth? Will we jeopardise our reputation as a leading aviation hub if the congestion levels reach intolerable, even dangerous levels?
Congestion in the skies is a serious matter for airports and a lot more and immediate attention and action is needed by CAAS and CAG.
The writer is a pilot and an aviation consultant. The observations and opinions here are his own
Published November 30, 2011
COMMENTARY
Crowded skies over Changi
Serious thought needs to be given now to this matter of congestion, both in the interest of safety and in ensuring that Changi remains an attractive airport for airlines
By PRITHPAL SINGH
CONGESTION in Singapore is no longer just on our roads and trains. It has now spread to the skies above Singapore and to the parking aprons at Changi International Airport, as well.
Airline pilots have commented that in the past few months they have been noticing a deterioration in the traffic handling ability at Changi airport by the controllers.
And as Changi Airport continues to experience significant growth in air traffic, both arrival and departure delays are likely to increase as a result.
The situation has become so bad that the rule of thumb for airlines and pilots seems to be if departing between 8am and 10am, take more fuel, because there will be a long line of aircraft waiting to take off. And there can be as many as 10 aircraft holding and waiting for takeoff.
Allowing for a minimum of two minutes per aircraft for takeoff, this is already a 20-minute delay, not counting taxi time. That is easily 800kg of fuel lost for a Boeing 777. In doing a short flight, 700kg is the entire contingency fuel for the sector for a B777 jet!
Pilots arriving between 3pm and 7pm are also taking more fuel. The number of arrivals during this period, especially on weekdays, is so high that air traffic control just cannot cope.
Aircraft are being typically vectored for long finals for landing with minimum 20 nautical miles (nm) final, sometimes 30nm + final, with lots of zigzagging if the weather is bad. This is inefficient.
Airlines are burning fuel unnecessarily and adding to their operating costs. Pilots have to take on more fuel than necessary in anticipation of these long taxi times before takeoff and delays on approaching Singapore. And passengers are grumbling too.
In fact, on Nov 18, the captain of SQ flight 953 from Jakarta to Singapore announced that due to 'congestion' at Changi Airport, he was flying to Kuala Lumpur International Airport (KLIA) to refuel.
The aircraft overflew Singapore, landed at Kuala Lumpur at 6.30 pm, refuelled, and eventually landed in Singapore at 8.30 pm - three hours late! This is not the first time this has happened and it is likely to happen again.
While the situation is not yet dire, serious thought needs to be given now to this matter of congestion, both in the interest of safety and in ensuring that Changi remains an attractive airport for airlines.
To be fair, the Civil Aviation Authority of Singapore (CAAS) is aware of the problem and is implementing new measures to more efficiently utilise the airspace, runways, and taxiways available in order to keep delays to a minimum.
For example, CAAS has advanced weather radar systems on the ground and they can vector aircraft typically to avoid weather which reduces pilot workload.
Problems and delays
Singapore's standard arrival procedures are also well organised and thought out. In the initial stages of the arrival, traffic is still manageable and the airport can cope.
However, once traffic from all directions meets in the terminal area, that's when problems arise. Add bad weather and it's a minimum 20-minute delay before an aircraft can even land.
CAAS has also recently done away with the requirement for pre-departure clearances for some routes, reducing takeoff and landing separation criteria.
It is also currently conducting a trial run on a continuous descent operation which allows the pilot to execute an optimised arrival descent, and is also looking at reducing the current eight-mile separation between two arrivals to six miles eventually. Other air traffic control measures are also being considered.
Notwithstanding all the efforts being made, these new measures have their limitations. The continuous descent operation is complicated. Feedback during the trials shows it is not working as well as expected.
A date has also not yet been fixed for the implementation of the six-mile separation target. Technology can only do so much when human performance and limitations come into play. Changi Airport Group (CAG) and CAAS therefore need to look at other ways to reduce congestion.
One has to ask if CAG, the commercial and revenue-driven arm of the airport, is accepting too many airlines and flights and allocating too many takeoff/ landing slots at peak periods when the infrastructure obviously cannot cope. Is there sufficient communication and consultation between CAG and CAAS to ensure that this gridlock being seen now at Changi is avoided?
In many respects, the situation we are seeing today with our skies is similar to our public transport system which has basically remained unchanged even when our population exploded over the last few years. Is CAG targeting breakneck unsustainable growth at any cost?
If so, it may be time now to review key performance indicators for CAG and modify them to reward growth which matches the airport's capability to handle this additional traffic.
Growth is good and necessary but this has to be in tandem with the ability of the infrastructure to handle this growth. A re-examination of this policy now is vital.
CAAS should also open up Singapore's little-known third runway to civilian commercial traffic. This runway built on more recently reclaimed land, called 02R/20L, is now used just once every two years for the Asian Aerospace Exhibition and occasionally by military aircraft.
Third runway
I suggest that the Budget Terminal be relocated to this third runway as a standalone budget terminal and runway facility. It will reduce departing traffic congestion and provide relief for arriving flights.
Slow flying turboprop aircraft such as those operated by Firefly and Berjaya Air should also be banned from Changi Airport until this third runway becomes operational.
Many international airports have this policy - including our neighbour KLIA which directs turboprop aircraft to the secondary Subang Airport. Similarly in Singapore, turboprop aircraft should use Seletar Airport instead.
Changi needs to implement 'intersection takeoffs' for smaller jets. Most smaller jets need only half the 4,000-metre-long runway for takeoff, yet are required to taxi right to the end of the runway, lining up behind widebody aircraft which need much longer runways, wasting time, fuel, and creating congestion.
Granted, this may not fit the present policy of first-come- first-served, but would not intersection takeoffs applied intelligently reduce congestion?
Changi's present policy forbids intersection takeoffs, an odd anomaly considering it is a common practice at major airports worldwide.
Changi Airport opened in 1981 with just one passenger terminal, one runway, and served 34 airlines, and eight million passengers. Today, it has four passenger terminals, two runways, serves nearly 100 airlines, and handles over 42 million passengers annually.
While on the 'land side', CAG and CAAS have constantly upgraded the infrastructure to cater to this growth with new terminals and other passenger facilities and winning many awards in the process, the 'air side' of this equation is lagging behind.
The air side being hidden away from the public eye is more mundane and less glamorous and therefore receives little publicity. However, it is the air side of the airport which is the lifeblood of any airport and needs to be managed well.
Now with pilots, airlines, and even air traffic control personnel feeling the strain, it's time that this lesser known aspect of the airport gets an airing and much needed additional attention.
Some congestion at major aviation hubs like Singapore is acceptable. However, CAG and CAAS need to pause and take stock. Are we taking more than we can handle in the race for the numbers game? Are the infrastructure and manpower numbers and quality of personnel on the air side matching this rapid growth? Will we jeopardise our reputation as a leading aviation hub if the congestion levels reach intolerable, even dangerous levels?
Congestion in the skies is a serious matter for airports and a lot more and immediate attention and action is needed by CAAS and CAG.
The writer is a pilot and an aviation consultant. The observations and opinions here are his own
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