To avoid queues of over 30 aircraft waiting at the runway, the MIT team developed a queuing model that is able to predict how long a plane will be required to wait before taking off. The model considers various factors that can influence the waiting period, such as current weather conditions, runway traffic, and incoming and outgoing flight schedules. This way, air traffic controllers will be able to more efficiently plan departures, avoiding runway congestion as much as possible by holding planes at the gate until a departure slot becomes available and they are ready for takeoff.
The idea behind this formula is to save on fuel as the planes will not have to keep their motors running during the wait. Another important goal is to save on passenger time - why waste time sitting on board when you can stay inside the terminal, relax and enjoy the perks it offers?
In a press release, Hamsa Balakrishnan, an associate professor of aeronautics and astronautics at MIT, stated: "Sometimes, if there is a controller with a lot of experience or intuition, they might actually decide they'll hold aircraft back. Historically, though, they don't, they just let everybody go." Which is why, according to Balakrishnan, there are so many airplanes waiting on the runway to take off - something that needs to be avoided in the future. ""If you predict only 10 aircraft are likely to take off in the next 15 minutes, you probably don't have to release 25 aircraft from the gate."
Balakrishnan also commented on the testing period at the U. S. airports and noted that "holding planes at the gate cut taxiing time by about 20 percent and saved each plane about 16 to 20 gallons of fuel" and added that "what you need in order to do departure metering is a way to predict what's actually going to happen, and use that to meter." Hence, they're building the models to help them achieve just that.