The moment a Boeing 737 touches the gate, 14 different processes start simultaneously. Not sequentially. Not in phases. All at once. The airline has 45 minutes to empty the aircraft, refuel it, restock it, clean it, and push it back with a full load of passengers.
Every minute over schedule costs money. The aircraft doesn't.
A narrow-body on a low-cost carrier's schedule flies six to eight sectors per day. At an average lease rate of $340,000 per month, every minute on the ground represents roughly $7.80 of idle capital. A 10-minute delay across six rotations costs $470 per day per aircraft. Multiply that across a fleet of 300 and the number becomes airline-altering.
The choreography starts before the wheels stop.
Ground power connects in under 90 seconds. The jet bridge extends. Forward and aft doors open simultaneously — passengers deplane through the front while catering trucks dock at the rear. Baggage handlers open the lower holds before the last passenger has left their seat.
Fuelling begins immediately. A narrow-body takes 15,000 to 20,000 litres of Jet A-1 for a full domestic load. The fueller connects a single-point pressure fitting under the wing and pumps at roughly 1,000 litres per minute. Fuelling alone takes 15 to 20 minutes — the longest single task in the turnaround.
That's why everything else runs in parallel.
Cabin crew flip the interior in under 12 minutes. Seat pockets cleared, tray tables wiped, lavatories serviced, overhead bins checked. A team of three to four cleaners works bow to stern. They don't deep clean. They reset.
Water trucks replenish the potable tanks. Waste trucks drain the lavatory system. Both connect to the same underside panel — separated by less than a metre. The margin for error in connecting the wrong hose is architectural, not procedural.
Boarding begins 20 minutes before departure. The gate agent needs every one of those minutes. A 189-seat 737 boarding at an average rate of 9 passengers per minute takes exactly 21 minutes in a perfect world.
The world is never perfect. That's why the buffer doesn't exist.
Forty-five minutes. Fourteen parallel processes. One aircraft that earns nothing on the ground.