Procedures, Techniques, and Checklists

December 31, 2015

Unlike general aviation operations and many military operations, most air carrier operations use checklists to check that important procedures have been completed, but accomplish cockpit preparations by memory. In other words, they are check lists, not do lists.

Instead, cockpit preparation activities are performed by way of memorized procedures, sometimes called flows. Typically, the cockpit crew members will start their procedures in one portion of their cockpit Area of Responsibility (AOR) and proceed in an orderly fashion through the rest of the AOR. The AOR is clearly detailed in the airplane flight manual. The flow will cover every control, indicator and switch in the AOR, and the crew member will position the switch in the proper position as it is scanned in the flow.

A procedure specifies what is to be accomplished. A technique details how to accomplish this procedure. For example, in flight, a procedure may call for the speed to be reduced by 20 knots as the flaps are extended from position 5 to 15. The technique may be to activate the trim switch in the nose-up position for 2 seconds, since the trim reference speed changes by 10 knots for every second of activation (in this example).

After the flow is completed, the crew will then accomplish the appropriate checklist. Not all airlines adhere to this technique, but it works really well in ensuring that nothing is omitted: perform the procedure, then complete the checklist, then get the appropriate clearance. Procedure, checklist, clearance. For example, Preflight procedure, followed by Preflight checklist, followed by ATC clearance. Before Start procedure, followed by the Before Start checklist, followed by Ground Control clearance to start. Before Taxi procedure, followed by Before Taxi checklist, followed by taxi clearance from Ground Control. You get the idea.

Naturally, you need to operate in accordance with your flight manual and the procedures specified by the operator (your boss), but this discussion should improve your awareness of the difference between procedure and technique, and the role of the checklist.