THE AIRPORT BUS

Recently what happened to 55 passengers being transported by a shuttle bus from the boarding gate across the tarmac to their aircraft in Bengaluru Airport was both comic and tragic. When their flight started moving across the tarmac without taking them they were stumped! "Why aren't you on board?" messaged a passenger on the Delhi-bound aircraft to Neeraj Bhat, his friend on the bus, but there was nothing to be done. The aircraft had left the parking bay oblivious of the fact that 55 booked and checked in passengers had not boarded yet! The airline operating the flight, Go First, apologized profusely later, booked passengers on a following flight, stood down the staff responsible and offered a free flight on the airline's domestic network to affected passengers but the damage had been inflicted on the industry. How do you explain this callousness? These are passengers who have checked in and crossed the departure gates. Is the airline not expected to account for each and every passenger? How can they miss 55 of them and depart?

 

Why buses?

We have often had a flight that began with a bus ride to the plane. These buses were once diesel but are now becoming green and battery operated to avoid pollution. Not only in India but in several Asian and European airports shuttle buses between terminal and aircraft are common. While in many Indian airports passengers usually board their aircraft via an aerobridge, a short walk across the tarmac for rear-boarding on stairs is not uncommon. In Australia you can walk to the departure lounge after coming down the stairs if there is no aerobridge connection but excessive security and long distances from the terminal to the parked aircraft in our airports compels the use of shuttle buses. Airport buses keep everything organised. If the people were allowed to board flight on their own, few would be taking selfies, few would wander around and few would distract the ground operation vehicles. Furthermore, there might be some elderly/disabled people in the passenger's list, so arranging a separate bus for them wouldn't make sense. Thus, airlines use buses to pick all the passengers from the boarding gate in the absence of an aerobridge connection.

 

Speed is another reason. If you want to turn an aircraft around quickly, stairs and shuttle buses are the way to go, and turnaround time is money for a budget carrier. Loading and unloading via stairs means that aircraft don't have to wait for an aerobridge to connect before disembarking passengers. Otherwise it is not uncommon to wait for 10 minutes or more after the engines stopped for an aerobridge to be connected.

 

Another advantage of stairs – when passengers are on board and seated, aircraft can start moving under their own power without waiting for pushback from a tug. This is again a time saver. Even better option is if the aircraft can deploy its own stairs from the fuselage. One of the options on the Boeing 737 is internal staircases at front and rear, which can unfold without relying on ground-based services. Ryanair, with a fleet of almost 600 Boeing 737s, is a major customer for this option, and that's one reason Ryanair's turnaround times are as short as 25 minutes.

 

An airport can boom when a destination experiences a surge in popularity. That's happened in Istanbul, Iceland's Reykjavik and Bengaluru (Bangalore) in India. But while air traffic can increase overnight, adding facilities to handle the extra traffic is often a decade-long process. The ideal solution is a new airport, and with air traffic increasing exponentially many newer airports ar coming up all over India. Delhi is looking to build a second international airport, Jewar in Noida but smaller airports often do not have sufficient number of aerobridge. When an airport suddenly finds itself with too few gates and aerobridges, busing is a quick fix.

 

A different kind of bus

The shuttle buses or apron buses used are specialized vehicles unlike any other bus. Ground clearance is minimal since they're only negotiating flat surfaces, with just one small step onto the floor of the bus. There are few seats. It's a short ride and the priority is packing in as many bodies as possible, passenger comfort comes way down the list. For the same reason they're wider and longer than public transport buses, and capable of transporting as many as 160 passengers, about three times the number on a typical city bus. Usually there are doors on both sides, as many as three per side and they're wide. They can be of normal bus design, or due to not running on the public highway, can be extra long and wide to accommodate more passengers and cabin luggage. Sometimes a trailer bus is employed for the same reason.

 

Airlines tend to pack their shuttle buses tightly. While it's not something to look forward to after a long flight, for some travelers it's a fun ride. From ant level, you're looking up at the undersides of giant aircraft, enormous wheels and engines that inhale an inlet air mass flow of 1000 kgs per second. It's hard not to be awed.

 

Americans don’t like stairs

Buses between aircraft and terminal are uncommon in the US, used by only 21 airports in that country according to the Port of Seattle. That's despite US airports being the world's busiest measured by the number of aircraft movements. Some unkind social media posters have suggested the reason might be because Americans are so unfit that a staircase would present major problems for loading and unloading, but flyers would regard stairs as a service deficiency. Americans want an aerobridge every time.

Seattle-Tacoma International Airport (Sea-Tac) is one of the few that bus passengers between aircraft and terminal. The reason is the rapid expansion in visitor traffic as the port of Seattle has become a gateway for the Alaska cruise industry. In April 2022 Sea-Tac completed an expansion project that increased the number of international gates from 12 to 20 but despite the upgrade Sea-Tac is still bussing passengers to and from aircraft. Many Indian airports are witnessing similar rapid expansion but with limited number of aerobridges, hence the popular use of airport apron buses.

Interestingly, Washington Dulles airport uses mobile lounges with a liftable passenger cabin for airside transfer; they work as a combination of an airside bus and a jet bridge.

 

The German Scene

AeroGround, a 100% subsidiary of Munich Airport operator Flughafen München and the only suppler of a full range of handling services at the gateway, looks after the airport’s bussing operation. In  the last count, AeroGround transported 6,200,000 passengers and 580,000 crew members across Munich Airport’s apron annually. Their fleet has various models of Mercedes buses and a high degree of punctuality is demanded of them in order to avoid any delays.

 

The Japanese automation

 

 Japan’s All Nippon Airways (ANA) carried out trials for a self-driving electric bus at Haneda International Airport (HND) and are planning to put them in action. These buses travelled the same 1.9km (1.18 mile) segment of restricted area at Haneda Airport multiple times throughout the testing period. During the test, the buses were evaluated based on their ability to “perform the conditional automation with little human oversight”. Self driven vehicles made their debut in Las Vegas International Airport.

Advantages of an aerobridge

The use of an aerobridge has several major advantages over loading passengers from the ramp via portable staircases:

Boarding of handicapped passengers: Not all passengers can use stairs: a jet bridge allows passengers with limited mobility,  particularly those confined to wheelchairs, to board and disembark from the same level as the passenger deck.
Accommodating these passengers from the ramp would require some kind of lift mechanism to raise them to the passenger deck of the aircraft - this is typically accomplished elsewhere in the terminal when a jet bridge is used, e.g. via passenger elevators in the ticketing area, or via an elevator in each "mini-terminal".

Passenger shelter: Boarding from the ramp may work well on a beautiful spring day, but in less favorable conditions (rain, snow, and temperature extremes) most passengers would not find the experience to be enjoyable. The jet bridge provides an enclosed and relatively climate-controlled route from the terminal to the aircraft.

Passenger Safety: Airport ramps are inherently dangerous places: Aircraft are starting their engines, being pushed back for departure, etc. and ground support vehicles are moving at all times carrying luggage, cargo, catering supplies, etc. to and from the aircraft. In addition to the ongoing movement there is a great deal of noise from these operations. Bringing passengers into this environment represents an inherent liability risk: Someone could be struck by a support vehicle, or injured by jet blast. A jet bridge is an enclosed area away from these dangers, providing an improvement in passenger safety.

Airport Security: A great deal of effort goes into ensuring that unauthorized persons do not have access to the airside facilities at an airport. Bringing passengers into this area represents a security risk, as even a ticketed passenger could be intent on causing disruption or damage once airside.
A passenger wandering off on the ramp would represent both a safety hazard (as the passenger could be injured) and a security hazard (as the passenger could perform any number of malicious acts before they are located).

Tarmac less cluttered: If a shuttle bus is used to transport passengers then airports need to handle yet another set of vehicles. You have enough things going on between luggage, catering, maintenance etc. And now you add several buses, plus stairway-vehicles, plus vehicles needed to take the crew to the plane and you have a cluttered tarmac.

 

Airport buses are usually be equipped with larger luggage space, and incorporate special branding. They are also commonly (but not always) painted with bright colours to stand out among other airport vehicles and to be easily seen by the crews of taxiing aircraft when negotiating the aprons or tarmac. Though aerobridges are undoubtedly the best way to board an aircraft in many busy airports with fewer aerobridges airport apron buses remain a popular mode of shuttling passengers between terminals and aircraft.