PROP

Disruption what-if simulator

One late departure rarely stays one late departure. Inject a delay into a six-aircraft flying day and see how turn buffers, a standby aircraft and crew duty limits change where it ends up.

6 aircraft, 36 sectorsMinimum turn 25 min186 seats, 92% load

Scenario

Every change re-runs the day instantly

Initial delay

Aircraft hit

Departure hit

Turn buffer above minimum Scheduled turn = 25 min minimum + buffer

Crew duty limit From report (60 min before first departure) to last on-blocks

Standby aircraft takes over a line running over 90 min late Everyday variation (small random delays)

The flying day

Thin line: schedule. Bar: what actually happened (↩ marks the flight back to base). Hover or tab to a sector for detail.

Departed within 15 min16 to 60 min lateOver 60 min lateCancelled (crew out of hours)

Scroll sideways to see the whole day.

What a bigger buffer buys

For this disruption: reactionary delay against minutes of buffer written into the schedule across all 30 turns

Reactionary delayBuffer in the schedule

How to read it

Each turn can absorb delay up to its buffer. Anything beyond that carries into the next sector as reactionary delay, which is why a single morning delay can still be visible at night.

Buffers are not free: every minute is aircraft time that could have flown. The crossing point of the two lines is a rough guide to where extra buffer stops paying for itself for this kind of disruption.

Crew limits create a cliff edge. Once a crew's projected duty exceeds the limit, the rotation is cancelled to protect the rest of the day, trading delay minutes for disrupted passengers.