Preparing to Launch: The Preflight Inspection 1
From the cockpit
Continuing our Preparing to Launch series, we’ll take another look at the duties airline pilots perform prior to takeoff. When you board an airliner, you’ve probably glanced into the cockpit and noticed the pilots intently engaged in some activity. If you’ve wondered what exactly they’re doing up there, we’ll demystify the process by highlighting some of these tasks.
The preflight inspection consists of two major parts: the internal preflight and the external walkaround. While both are vitally important parts of the pilots’ preparation, we’ll concentrate on the internal portion for this post. Prior to pushback, airline crews must complete several steps to ensure the aircraft is safe and legal for the upcoming flight.
Aircraft/Maintenance & Flight Logs
After reading through the Flight Release (see previous post), pilots will refer to the Aircraft Log (sometimes referred to as the Maintenance Log) and the Flight Log. In the Aircraft Log, the crew is checking to ensure that all required inspections are up-to-date and properly documented. Additionally, they’ll verify that any inoperative equipment complies with the Minimum Equipment List (MEL; details in previous post) and is properly placarded. If everything appears satisfactory, the captain will sign the Aircraft Log to accept the aircraft. If anything requires attention, (s)he’ll coordinate with the airline’s maintenance department to address the issue(s).
The Flight Log maintains a record of the aircraft’s utilization. In this document, the flight crewmembers record their names & positions, as well as the duration of all legs they fly. This log also keeps track of aircraft & engine cycles (number of engine starts and number of landings). On many modern aircraft, some of this information might be entered and stored electronically. As with the Aircraft Log, the captain will sign the Flight Log when accepting the aircraft.
Panel Scans and Checklists
If you’ve noticed pilots actively pushing buttons, flipping switches, and moving levers as you’ve boarded an airplane, you’ve seen them running their panel scans and checklists. Before each leg, both pilots complete a checklist to verify the position and operation of the plane’s systems. Each pilot has his own cockpit flow, a type of memorized checking procedure, he performs to review the systems he’s responsible for. For the first flight of the day and/or each crew’s first leg in a particular aircraft, the panel scans are especially thorough. For subsequent legs, certain items may be abbreviated.
When these scans/flows are complete, the crew will refer to a checklist to verify they’ve covered all necessary items. Any faulty equipment will be rechecked for proper operation. If maintenance is required, the crew will notify company mechanics. Occasionally, the flight will be delayed or a new plane will be assigned. For minor issues, it’s often possible to MEL the item and continue the flight.
Weather and Clearance
Shortly before pushback, the crew will obtain the departure airport’s latest weather observation. This info may be manually recorded or generated automatically, depending on the airport’s weather reporting system. Pilots use this data to supplement/update the weather information in the Flight Release and to verify the legality & performance parameters of the upcoming takeoff. When they contact Air Traffic Control (ATC) for taxi instructions, they’ll let the controller know they have the latest weather info by stating the phonetic identification (Alpha, Bravo, etc.) of the most recent broadcast.
After obtaining the latest weather report, crews will contact ATC to receive their clearance. The clearance is a game plan for the flight leg. It includes the initial altitude to climb to after takeoff, the subsequent altitude to expect, the route of flight/heading to fly, the radio frequency to use after takeoff, the transponder identification code, and any other pertinent information. The clearance is obtained before pushback to allow the crew to set up their radios and navigational equipment prior to departure. Doing so minimizes workload during taxi and takeoff, which helps enhance safety.
As you can see, airline pilots have a significant workload to prepare their aircraft for each flight. In a future post, we’ll examine additional crew responsibilities and how each contributes to the safety and comfort of the flight. We’ll also co