Pilots go through many checklists before a flight

Editor’s note: Following the incident this month in which a Horizon Airlines ground worker commandeered and crashed a commercial airplane from Seattle-Tacoma International Airport, we asked former airline pilot John Cox to outline the regular procedure by which a flight crew takes control of an airplane and prepares for takeoff:

An hour (two for international) before your flight leaves, your crew is at the airport. They go through security (usually in an area reserved for employees). Once in the crew lounge, they begin the process of reading the latest information from the airline and checking the weather forecast.

Next step is a walk to the gate, where the gate agents have the flight release ready. The flight release is the formal document from the flight dispatcher that tells the pilots which airplane they will fly, the exact routing that has been filed, the fuel calculations (the predicted fuel burn, plus fuel to the alternate, plus 45 minutes fuel, plus any contingency fuel) and the altitude filed. Pilots then proceed to the airplane, where introductions are completed with the flight attendants.

We begin the flight deck setup, verifying each switch and lever is in the proper position. One pilot then goes outside to visually inspect the airplane. The walk-around is done before each flight looking for leaks, bird strikes or anything else unusual. Passengers are boarding as the walkaround ends. It’s then back into the flight deck to continue with the preparations.

The flight management computer is where all the flight plan information is stored and executed. A computer link from Air Traffic Control provides the route we are cleared to fly, the initial altitude, expected cruising altitude and a unique code for the transponder that will identify us on the radar.

Pilots use checklists for many

tasks. Using checklists reduces errors and ensures that the right task is done at the right time. The before-start checklist is read aloud, each pilot verbally responding to their specific tasks. A departure briefing follows, with the pilot that will fly the flight (pilots rotate flying and monitoring duties) verbally briefing the other pilot on the exact intended departure flight path, nearby obstacles, flight path if an engine fails and rejected-takeoff procedures.

The fueler brings the fuel slip, which must match the dispatch release fuel and the actual fuel onboard. Just before the door is closed, a customer service agent arrives with the actual passenger count and notice to the captain of any unusual cargo (e.g. dry ice) onboard. We are now ready to close the door and push back. The flight attendants verify that the cabin is ready for flight.

Most jets use air from the auxiliary power unit to turn the starter that turns the engine. Turbine engines are different than an automobile engine. They must turn a specific number of RPMs to stabilize the airflow within the engine before the fuel is introduced (on some airplanes this is automatic, for others it is a manual process). Once the fuel is introduced, “light off” occurs and the RPMs begin to rise quickly.

Now the after-start checklist is accomplished and switches are reconfigured for taxi. Ground control answers the call for taxi instruction, providing the specific route to the runway. On the taxiway, the taxi checklist is performed again, with switches and levers repositioned this time for flight. The checklist is read aloud, and the responses verbalized. With the flaps/slats in takeoff position, the trims set, the departure briefing complete, the FMC rechecked for the proper runway, weight of the airplane and initial departure, and the initial altitude in the altitude selector, we are ready to fly.