Checklist Flows

Creating a pattern for procedures

June 1, 2004

The team of three pilots climbed into the cockpit of the simulator and went immediately to their assigned tasks. Hands glanced over the buttons, switches, and dials of the Boeing 747-100 as each worked through his section of the panel, preparing the simulated airplane for flight. Though the pilots focused their full attention on the procedure, they accomplished it as if reading by Braille.

No doubt about it, these guys know their cockpit.

Airlines have been using the flow concept for decades, accomplishing normal, abnormal, and emergency procedure checklist items through use of specific patterns. And whether you realize it or not, you use at least one flow whenever you prepare an airplane for flight. A flow is a good way to structure an important task so that every item is completed in a timely fashion and nothing is missed.

Why flow?

Even though the flow is used regularly in two- or three-pilot crews at the airlines, it actually makes just as much sense for a single pilot. Checklists — or more properly termed do-lists — are better suited for use by two people. As one pilot reads the checklist action item, the second pilot performs the action. When you perform a checklist solo, you can lose your place. Ask yourself: How many times has your sweaty thumb slipped while sliding down a laminated list, causing you to forget where you stopped, and to possibly miss an item?

Any flow you conduct should be backed up with the checklist (in an emergency, only if time permits). In airline practice, flows are typically backed up with "killer item only" checklists — which means just what it sounds like. You go back through the list to ensure that the items that, if left undone, could kill you are accomplished.

Other distractions creep in when you fly with another pilot. In the interest of speeding up the preflight, the two pilots may opt to share duties (keeping in mind that one is always the designated pilot in command). Omissions and uncertainty creep into these situations, especially when the two pilots are accustomed to flying single pilot. If you separate a flow into two sides of the airplane, meeting at the back or front of the airplane, you may each do your part of the flow uninterrupted, and then double-check each other's actions with a question or glance to hit the killer items. Did you put the oil cap back on? Are the fuel caps secured? Is the tail still tied down? (OK, so the last one won't kill you, but it might kill your ego.)

A flow also works well for the single pilot during emergencies such as a power loss, when items must be accomplished from memory because time is short and you're the only one there to do them.

You can design your own flows so that the items in a particular checklist, such as a before-takeoff or after-landing check, follow a pattern on the panel. Just remember, you more easily remember action items by grouping related equipment and instruments.

A flow of your own

One flow you already perform begins when you walk out to the airplane. Most preflight inspection checklists printed in airplane pilot's operating handbooks (POHs) follow a walkaround pattern — Cessna even draws it out for you. Piper does too, but then backs it up with a written checklist that jumps all over the airplane — at least in 1970s-vintage POHs. While you can purchase checklists that lay out a flow for you, another option is for you to design the pattern that works best (see " Out of the Pattern: Gear Up!" November 2002 Pilot).

A Flow to Remember

  • Arrange the flow in logical and spatial order.
  • Touch each item as you pass it in the flow.
  • Verbalize the items as they are accomplished.
  • Follow up with a run through a printed checklist, unless an emergency situation dictates otherwise.
  • Revert to the checklist if you fly infrequently, or are returning to the airplane after a hiatus.
  • Remember that the flow is not a substitute for a written checklist but an additional aid.

Find the airplane diagram from the preflight inspection page in the POH (if yours has one), and enlarge it on a copier to the point that you can fill in legibly each item from the preflight checklist. Take the results out to the airplane with you the next time you fly. As you conduct the preflight, walk around the airplane in a way that you would naturally, and number each item in the order you come to it on the airplane. Then construct a new checklist from this new order and print it in a size that fits your kneeboard or chart case. Now you can back up your flow with a printed checklist in the same order as your walkaround.

When you create a flow, look for places in the printed checklist where the specific layout of your cockpit and/or instrument panel, or the operational requirements of aftermarket equipment, makes the original checklist less workable or clumsy. For example, you may have a multifunction display (MFD) that requires significant warmup time before it's ready to go. Modifying the original checklist so that you turn on the electrical system, avionics master, and MFD soon after starting the engine allows the avionics to warm up while you attend to other tasks before taxi.

Another example is the before-takeoff checklist. For some aircraft, no good run-up checklist exists. Using the old standby mnemonic CIGARS (controls, instruments, gas, attitude, run-up, seat belts), you can create a flow pattern to double-check that everything's in the right place before you launch. In some aircraft, especially those with a single seat or tandem seating, you can start a flow procedure at your left elbow and move right across the panel to the right elbow (or vice versa). An aircraft with more complex avionics and other systems may not adapt as well to this procedure, and the standard checklist should always be used in case of any doubt.

Optimal flows move from left to right, and up to down, according to an AOPA Air Safety Foundation InstructoReport, "Paper Safety." Within this movement, you may be able to group items that flow logically together. For example, in a before-takeoff flow associated with engine runup, you can move from left to right and chunk together "magnetos, mixture, carb heat, engine instruments, suction gauge, and ammeter," depending on where the items are located in your airplane. Any jumps in the flow (exceptions to the spatial task sequence, e.g., moving from the panel to the floor and back) are caution areas, places where confusion and errors are more likely to be introduced.

Test flows

We picked a couple of flows to try out on an unsuspecting member of the AOPA staff. OK, she suspected all along that the offer of a free hour of dual would have strings attached — she was working on her private pilot certificate at the time, which she has since won.

Adrienne Rosone, associate art director for Pilot, already uses a flow during preflight of the Piper Archer she flies. So we looked at the other checklists to see which might hide useful flows for her to integrate for her upcoming flights.

One good example turned out to be the "restart after engine failure" checklist in the emergency section of the POH. Rosone was well versed in the "aviate" portion of coping with an engine failure (flying best-glide airspeed, picking a field), but she appreciated help with troubleshooting. A flow for correcting an engine failure, in most airplanes, begins with fuel, so we started at the fuel selector valve, located near the pilot's left knee. Grouping fuel items together in a spatial sequence, we moved across the panel to the fuel pump, then to the mixture lever on the throttle quadrant. Our fuel action items complete, we progressed down and left, back across the cockpit, turning on the carburetor heat, adjusting the throttle, checking that the primer was in and locked, and cycling the mags.

Another checklist easily adapted to a flow in the Archer was the after-landing checklist. There are a couple of additional reasons to use a flow upon exiting the runway. Typically, pilots let down their guard after coming to a stop. The flight is considered over, but in reality, accidents still happen when taxiing back to the hangar. The flow allows you to reset your mind mentally for postflight. Also, a good after-landing flow helps you to leave the airplane properly configured for taxi, and for the next takeoff — whether it's happening right away or during a subsequent flight. Finally, when you have items in the airplane like weather radar, ensuring they are shut down before taxiing to the ramp can help you avoid frying an innocent member of the line crew.

In the Archer, Rosone found that a simple flow worked: Starting from between the front seats, she retracted the flaps, then she moved up and roughly left to right, leaning the mixture for taxi, turning off the fuel pump and the strobes and/or landing light, and then setting the transponder to standby. Other action items on similar aircraft may include turning off the carburetor heat, turning off the air conditioner, resetting the trim to neutral, and turning any unneeded avionics to standby or off.

Flow control

Once you have a flow down solid, think about what happens if some event interrupts the flow. For example, you're walking around the airplane executing the preflight inspection, and a friend from a neighboring hangar comes up to ask you a question. Even if you tell him to stand by (well within your rights as pilot in command), your train of thought is necessarily interrupted, and you may be further distracted by the knowledge that your friend is now observing your preflight.

So, after telling your friend to get lost and bribing him with a postflight beer upon your return, you return to the task at hand. Since flows are quick and easy, it's less of a problem to start back at the beginning, or to go back one group (such as redoing the left wing during a preflight) if you're stopped.

Once you know the flow, you'll have greater confidence that nothing was missed and become a more efficient pilot.


E-mail the author at julie.boatman@aopa.org.