The REAL capacity of Bengaluru International Airport

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.