MUMBAI: The city’s airspace is notorious for being congested. But that’s a half-truth. The reality is that even when it is not congested, flights into and out of Mumbai get delayed because of a shortage of air traffic control (ATC) officers in Mumbai.
“If the Mumbai ATC gets an additional 190 controllers, flight delays will go down by 50%,” said an airport official. Currently, the holding time for arrivals is a maximum of 35 minutes and an average of 15-20 minutes. For departures, during peak hours, it’s an average of 30 minutes, he said.
So, how does a shortage of ATC officers add to delays? The problem comes with communication. Pilots and controllers talk to each other by tuning in to a given radio frequency. For instance, 118.1 MHz is the frequency used by pilots of aircraft waiting for take-off clearance from the ‘tower controller’. They tune in to the given frequency by using a push-to-talk radiotelephony system, which, like a walkie-talkie, allows for only one person to speak at a time. If two people talk simultaneously, the sound becomes unintelligible.
“During peak hours in Mumbai, a ground controller would have 4-5 aircraft moving on ground, 4-5 that have pushed back getting ready for taxiing and 6-7 waiting for their turn to push back. Thus, there would be an aural queue of 14-17 pilots waiting for their turn to speak to the lone ground controller,” said an ATC official. Anyone who tunes into the frequency can hear all conversations taking place on it. “Pilots of domestic flights waiting for pushback clearance sometimes get into a squabble during morning peak hours as they want to depart at the soonest,” said a controller. “We have to request them to stop talking and not jam the only communication channel.”
An airline commander said, “At 11am on last week’s rainy Friday, 15 pilots of departing aircraft were in a queue, all waiting for pushback clearance from the lone ground controller. In airports that handle so many flights, there are at least two ground controllers. Even with the given ground infrastructure, if there is less workload on a controller, our delays would come down considerably.”
For pilots of aircraft arriving into Mumbai, the problem comes with trying to contact the en-route controller (who handles overflying aircraft; during peak hours, about 30 pilots of aircraft flying in his or her jurisdiction would be trying to establish contact). “Some would be seeking information like the runway in use at their destination airport, the weather at the destination, etc. Others seek a change in routing or a change in flight level due to weather or turbulence,” said a controller. The most common request though is for “direct routing”. Flight paths are generally zigzag and a direct routing helps save an average of 4-5 minutes of flying time, which would increase fuel savings and decrease carbon emissions. “Even when it’s possible to give a direct routing, we cannot, because we are too busy carrying out the primary job functions,” said a controller. A direct routing reduces flying time, saves fuel and cuts down carbon emission.
Then again, in India, no limit has been set on the maximum number of aircraft a controller can be allowed to handle at a time. Last month, when the volume of overflying aircraft in Mumbai’s airspace went up, during peak hours, the two en-route controllers on duty were forced to handle 45 overflying aircraft each at a time. In comparison, an en-route controller working anywhere in Europe is given a maximum of 25 overflying aircraft. Back home, a Chennai en-route controller handles not more than 15 aircraft at a time.
