While you're at the gate, an aircraft doesn't simply wait. It is being walked around, read, tested, fuelled, loaded, signed for and cross-checked. Nothing moves until every item on that list is complete.
The walkaround
One of us leaves the flight deck and walks a full circle around the aircraft, by hand and by eye. Tyres and brakes, engine intakes and fan blades, control surfaces, static ports and probes, panels, doors, lights, and the skin itself.
It is deliberately old-fashioned. Computers are superb at monitoring systems; a trained pair of eyes at two metres is still the best instrument we have for anything physical.
The technical log
Every aircraft carries a running logbook. Anything reported on a previous flight, however small, is written down, actioned by engineers, and signed off before the aircraft can fly again.
I read that log before every departure. If an item isn't cleared, or isn't permitted to be deferred under the rules, we do not go. That decision is mine, and no one may overrule it.
Fuel, weight and balance
We calculate fuel for the trip, plus enough to fly to an alternate airport, plus a further reserve on top, plus extra for expected weather or delay. We routinely carry more than the flight needs.
Every bag, passenger and cargo item is accounted for so the aircraft's weight and centre of gravity sit inside the certified envelope. The performance figures for the runway are calculated for today's exact temperature, wind, and runway state.
Weather and route briefing
Before we ever reach the aircraft we study the weather at departure, en route, at destination and at our alternates, together with forecast turbulence, jet stream winds, and anything unusual on the route.
That's how we already know, at the gate, roughly where today's bumpy stretch is likely to be — and often plan a level or a track that avoids it.
Cross-checks in the flight deck
Two pilots set the aircraft up independently and then compare. Navigation, performance figures, departure route, engine settings, emergency briefings for the runway we're using — all spoken aloud and confirmed by both.
Checklists are read by one and answered by the other. It is unhurried by design. If we're behind, we slow down rather than skip.
By the time the door closes, this flight has already been checked, calculated and agreed by people whose whole job is to say no if anything is wrong.