by David Gagliardi, Civil Aviation Safety Inspector, Flight Operations, Civil Aviation, Transport Canada
Checklists often do not get the respect they deserve. When used well, they significantly contribute to flight safety, but when used poorly, they can actually reduce flight safety.
There are two kinds of checklists applicable to the operation of light aircraft:
- Do lists: These are written checks where the action is read and then done. For example, on the pre-start checklist “circuit breakers………..checked”
- Checklists: These are written checks where the actions are first done from memory and then “checked” against the written checklist. For example, on the prelanding checklist “mixture…………rich”
As a general rule, “do lists” are used when the aircraft is stopped or in cruise flight. “Checklists” are used when the aircraft is in motion reading, and doing a do list may result in an unacceptable distraction. The prelanding checklist is a good example where the checklist philosophy is usually employed. While the memory actions should still be checked against the written checklist, it is understood that there may be a delay or even that it is not practicable in some circumstances to go heads down, reading the checks, without reducing flight safety. Having a practiced flow will greatly improve the efficacy of these types of checks. By flow I mean you have practiced the physical actions enough that muscle memory helps you get all actions done quickly and completely without having to read each item. Flows should be organized in a consistent pattern, like down to up/left to right or a clockwise circle of the instrument panel.
Effective use of checklists requires checklist discipline. This means accomplishing checks in a deliberate and unhurried fashion without distractions. If you realize you have skipped an item on a check, the best practice is to start over. Finally, you should be sure you understand not only “what” you are checking but also “why.” If you have any questions on why a particular check is called for or what exactly you are looking for, talk to an instructor to clear up any confusion.
There are three different types of checklists:
- Normal checklists: As the name implies, these are used for the usual operations, like the pre-start checklist.
- Abnormal checklists: These are for issues with the airplane that need attention, but an urgent response is not required and have no memory recall actions. Examples are illumination of the low voltage light or landing with a flat tire.
- Emergency checklists: These are checklists which are for situations which require immediate actions. They will include actions which must be done from memory and follow-on actions which can be read from the checklist. Memory actions are commonly identified with the text with bold font (note that memory actions are sometimes referred to as “bolded actions”). Therefore, emergency checklists are used initially as a “checklist” with the first, vital actions, completed by memory and then checked on the checklist, followed by the remainder of the checks completed as a do list.
Every pilot should know and have committed to memory all the memory items on every check in the Pilot Operating Handbook (POH) emergency checklist, which, for light aircraft built after 1976, will always be in Section 3 of the POH or in the Aircraft Flight Manual (AFM). Abnormal checklists should never be completed from memory, and the expanded explanatory text in the last part of section 3 should be consulted when time and circumstances permit. In addition, it is worth reviewing the systems descriptions in the POH or in the AFM, as they will often contain information regarding abnormal procedures for some of the systems. For example, in the Cessna 172 POH, the description of the aircraft braking system has valuable information on how to recognize and handle an impending brake failure.
Checklist discipline and effective and efficient use of checklists increase flight safety and are an example of professionalism in a pilot, regardless of their experience level or license held.