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HAL airport has shown us that terminal capacity is far more flexible than runway capacity. After all, we Bangaloreans, who use the terminal, are temperate accommodating people, and as frugal Indians, it is in our nature to always try and extract the maximum from any precious resource, especially infrastructure. Runway capacity on the other hand, is dictated by the hard, cold, and unbending rules of international aviation safety.

As per IATA (International Air Transport Association) recommendations, a single runway can serve a maximum of about 550 air traffic movements (ATMs) per day or 200,000 ATMs per year. An ATM is defined as either a landing or a take-off.

Statistics of Mumbai airport for the calendar year 2007 corroborate the above. The main runway (27-09) handled approximately 550 ATMs per day and the subsidiary runway (14-32) handled 170 ATMs per day (mainly departures) for a total of 720 ATMs per day. The main runway has reached saturation at 550 ATMs. It is also important to appreciate that an airport handles both passenger and cargo traffic. Mumbai’s Air Traffic Control is staffed by the best and most experienced ATC controllers of AAI. By contrast, BIA will be staffed by comparatively less experienced controllers. Also, Mumbai, is the premiere international airport in India, has a significantly higher percentage of international ATMs when compared to Bangalore. International ATMs use much larger aircraft, when compared to domestic, and therefore the average passengers per flight increase i.e. more passengers with fewer ATMs. Despite these advantages, with 720 ATMs per day i.e. 262,800 ATMs per year, Mumbai, handled only 20 million passengers per annum.

Applying the Mumbai figures to Bangalore, at 200,000 ATMs per year, and even eliminating the high percentage of international traffic that Mumbai enjoys, and the efficiencies of its experienced ATC, the maximum capacity at BIA will be 15.22mn (200,000/262,800 x 20mn) per runway.

The website of the BIAL consortium will lead you to believe that the new Bengaluru International Airport (BIA) will be able to handle a capacity of 50 million passengers per annum (MPPA).

Sorry, but that is just not possible, at least not in Bangalore.

We have extremely diverse air traffic. We have and will continue to have a much higher proportion of domestic traffic than Mumbai. Boeing 747s and may be Kingfisher's Airbus A380 Super Jumbos will be mixing it up with the small regional "puddle jumper" ATRs of Deccan and Jet, and all the other aircraft in between.

If this logic and Mumbai, do not prove the point, one more small example -- there is only ONE airport in the world today, that serves more than 50 MPPA with two runways -- London Heathrow; consistently voted as the WORST major airport by air travelers, and they do this with FIVE terminals, not two as planned by BIAL.

So we know that BIA will have a capacity of about 15.22 MPPA. Given the tremendous growth rates of recent years, BIAL has projected to IATA, 15.6 MPPA by 2009-2010. The one runway will be saturated 18~24 months after opening. BIA says it will expand terminal capacity, and build a second runway.

BIAL is a world class company, and can build another terminal quickly, but a second runway will take at least 2 years. However, we do not even know, if a 2nd runway at BIAL will be permitted. The Indian Air Force has a major air base at Yelahanka, and has refused permission for the second runway.

Yelahanka air force base runway is only 4 nautical miles (nm) away (towards the south) from current runway of BIA i.e. horizontal separation. International safety regulations mandate a minimum 1 nm horizontal separation between two runways. BIA master plan shows plans for a second runway, 1nm south (towards Yelahanka). At this point of time, clearance and approvals for the second runway have not yet been accorded to BIA. IF the second runway at BIA is constructed it will be at most 3nm separation from Yelahanka runway. This proximity of Yelahanka air force base runway, will mandate precision flying by pilots using the two airports. Seasoned commercial pilots who will use BIA can be expected to maintain their position with reasonable precision, however, Yelahanka is a national level training academy for the Indian Air Force, and trainee pilots cannot be expected to be as precise.

BIA Air Traffic Control (ATC) has been allocated control of only 40% of the airspace over Bangalore. This imposes operational constrictions on BIAL.

Traffic considerations dictate arrival and departure procedures (refer to above map) that impose a penalty on maximum capacity realization from each runway. This restriction gets further compounded in a mixed environment of slow moving aircraft like ATR turbo-props combined with fast moving Boeing 737 or Airbus A320 jets.

Major chunks of airspace immediately around BIA are not under its control due to the existence of ‘local flying areas’ (LFAs) of Yelahanka and HAL airports, within which these airports carry out their respective flying tasks. Please also note the altitude control areas, keeping in mind the altitude of Bangalore is almost 3000 feet above main sea level (AMSL). The various Flight levels (FL) indicated on the map are taken with reference to MSL. If an FL is indicated in 3 digits, then another 00 is added for the actual altitude i.e. FL100 = 10,000ft AMSL or approximately 7000ft above ground level (AGL).

Indian DGCA safety norms dictate that all aircraft maintain a vertical separation of 1000 ft and a horizontal separation of 5nm (2 minutes) in an airport vicinity. Area C and D in the enclosed map, are directly to the east and west of BIA and in the runway path. In these areas, BIA ATC has jurisdiction only between 12,000ft (FL120) and 7,000ft (FL070) Above Main Sea Level (AMSL) i.e. only 5,000ft of airspace vertically. This places enormous constraints on BIA ATC and very little maneuvering room should any difficult situation arise.

A plain reading of the map shows how all aircraft departing from BIA will have to follow a straight path all the way till 7000ft i.e. more than 4000ft climb from the runway, before making a left or right turn towards a designated air corridor routes like W101, W56 S, W70, W47 S etc. Similarly, aircraft arriving in to BIA, especially from Southern side and Northwest of Bangalore, will have to come in at a high altitude, and cross the Yelahanka LFA, only then make a descent. Normally, jet aircraft climb at about 1500ft per minute, and turbo-props climb at 1000ft per minute. Therefore a climb of 4000ft will take a jet about 2min45secs, and turbo-prop about 4mins, against a desired 2mins for optimal ATC operations to achieve the 550 ATMs per day.

Currently at HAL, during peak hours aircraft climb to 5000ft (about 2000ft above runway) before making the turn.

As an aircraft flies, it generates a physical phenomena called “wake turbulence”. This is very similar to the turbulence seen at the back of a ship as it travels in water. Also, during take-off the engines are at maximum power, and any aircraft directly behind will experience severe turbulence. Therefore global aviation safety practices mandate, that, aircraft should not follow too closely behind. Since wake turbulence is aircraft specific, a minimum separation is maintained depending on the type of aircraft in the front as well as the aircraft behind i.e. if a Jumbo Jet is in the front, and a small ATR is at the back, the separation requirement will be very high at about 5 minutes when compared to 2 minutes for two similar sized aircraft like Boeing 737 or Airbus A320.

To ensure reduction of wake turbulence, ATC controllers turn aircraft away from the runway heading as soon as possible after take-off. At very congested airports in the United States and Western Europe, like Chicago O’Hare, Boston Logan, New York La Guardia, Frankfurt Main, it is common practice to turn an aircraft immediately after takeoff. This reduces the wake turbulence towards the runway, directly behind the aircraft, and enables another aircraft to use the runway more quickly.

This narrow corridor at BIA, will impose significant airspace constraints will result in heavy airspace congestion and consequent delays. Maximum capacity realization per runway at BIA will be significantly less than the maximum permitted 550 ATMs per day. Some experienced ATC controllers estimate it at 450~500 ATMs per day which translates to about 13.84 MPPA (Million Passengers Per Annum).

Quoting the Hindu Business Line of Feb 22, "BIAL would handle 440 peak season movements a day by August (2008)"

For all those who want an exclusive Bengaluru International Airport, this is just a thought to ponder.

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5 comments

N S Parthasarathy said... @ March 15, 2008 at 5:40 PM

Devesh,

A well written, technical article. While you have given some points to ponder based on the technical specifications, I am sure there are other equally compelling factors both for and against keeping the HAL airport open.

From a aam aadmi (an aam admi who uses the airport !), point of view, I see the following as points to keep the HAP airport open:
a) the road connectivity is a huge concern for frequent travellers
b) high usage fees
c) resulting in some of the LCC reducing their flights to Bengaluru
d) in a country where we are building infrastructure to take care of mostly the needs of the past ( as opposed to taking care of the needs of the future), closing an existing working infrastructure like an airport sound counter-intuitive to me.

The points against keeping the HAL airport open are:
a) the agreement signed by the Govt, which we need to either honour or renegotiate in good faith
b) issue of congestion of airspace around Bengaluru
c) Two airports will cause a nightmare for flight operators and people who take connecting flights by using Bengaluru as a hub

If you put all these together along the point that Devesh is making on the possibility of getting approval for a second runway for BIAL, I feel we should keep the HAL airport open for some limited time, during which we solve some of the issues and for some others we will have more realistic data to decide on the course of action.

Anonymous said... @ March 15, 2008 at 9:27 PM

Why were these issues not thought off before creating a world class facility. The old airport must go. Change is always a challenge!

Pankaj said... @ March 16, 2008 at 9:46 AM

Devesh, keep up the good work ! a blogspot is the current method to keep people informed of current status and expectations. It however does not serve to normally influence political and administration decisions.

While contracts should be honored, they are not usually cast in stone. The BIAL contract can be renegotiated but this can be done only by the GoK or GoI and both of them seem to have abdicated - considering their role as over once the contract was signed and BIAL has delivered !?

Even the PIL route does not give timely solace to affected citizens and these technical arguments are powerful, they may not have impact in a court besides the time delays in issuing any interim decision.

I am in agreement about the profit seeking attitude of BIAL but personal attacks on the current MD does not serve any purpose. An effort to have the GoI thru' the Civil Aviation Ministry directed at renegotiation rather than indirect pressure thru' AAI ( which has delayed the opening - a temporary reprieve at best !).

Pankaj Patel

Pankaj said... @ March 16, 2008 at 9:54 AM

Devesh,

Since the HAL airport is going to kept active but not for commercial operations - maybe executive aircrafts can be permitted !? If the GoI can permit this, then a concept of shared executive jets - a practice which is now gaining acceptance in India can be used at least by top company execs; it does hurt the BIAL in its user fee area - besides the already planned Chennai/Kochi for international flights linking to surface transport. Your idea of another new airport is also covered under the existing BIAL agreement so it may be a non-starter since if it were possible, it is surely better to just have the HAL airport itself as the second airport.

Anonymous said... @ May 29, 2008 at 9:34 PM

Good article. I completely agree with you on the BIAL capacity constraints which I had pointed out in forums. London Heathrow which is the busiest international airport is indeed not a very good airport as per my experience this May but it still runs and remains the busiest internation airport & functional thanks to the efficiency that you would find in most advanced countries. After seeing London airport T3 i realized where the inefficiencies in airport design have come from and creeped over to BIAL. I am not sure if single level (checkins & arrival) cramped airports are the norm in Europe but it doesn't work for us. The same Heathrow airport can become less crowded on the terminal and serve the same number of flights with lesser number of terminals and footprint with a well thought out dual level design.

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