Process-Driven Checklists for General Aviation

In spite of all the advancements in managing aircraft maintenance information and behavior, we all benefit when the playbook is simplified. Safety begins with how we see things on the hangar floor. It’s easier when the tools we use help us exercise more control over our work environment. Process-driven actions on the hangar floor of general aviation facilities do not have to be cumbersome or complex.

Let’s begin with a discussion of a tool everyone knows: the checklist. Do you use one for annual inspections? When the checklist was written what thought was given to what it should contain or what use could be made of it? What was its purpose when it was developed and how is it used?

The checklist is the basic production and control tool. It starts as a “to-do” list. In fact, Appendix D of 14 CFR 43 contains the FAA’s “to-do” list that defines the basic annual and 100-hour inspections.

We can incorporate these tasks into a checklist format. Looking at Figure 1 we see that this checklist is not so different from a grocery list. In fact we could just roll along with a check mark in each row as we accomplish work on the aircraft.

Computers have managed to morph the checklist into a powerful device that can be so much more than a “to-do” list. By adding a heading and additional columns (Figure 2) we have a better record of our performance and the performance of others. We can track progress of personnel to whom we assign work as well as create a record of current status to remind ourselves of where we are in the inspection process. (That’s good if we are working by ourselves.) From a project management perspective we have an idea of where we are, who has done what and what’s left.

Checklists are adaptable and can serve many purposes:

Production tool:

It can be the basis for establishing an estimate of the work – write man-hours or job time in the mechanic block as a work sheet. Add it all up and see if you have enough hours in the day to do the work. When you are juggling multiple customers and deliveries, knowledge like that is useful. Being stretched too thin creates the temptation to cut corners.

Inspection diary/turnover record:

It can be a task reminder of where we are and what is going with the aircraft. A work turnover is a diary of the day’s activities. Entries are safety related as well as information of concerning incomplete work.

Some examples include: Rig pin or lock pin installations, circuit breakers status – safety prohibitions to actuation of a system, safety issues related to explosive actuated systems such as parachute/rocket combinations, wet paint, and operational checks requirements.

Yes, you can make a turnover if you are the only one on the job or if there is only one shift. Having a tool that reminds us of what we already know and keeps us from making embarrassing omissions.

It’s important that personnel record the last step accomplished in an interrupted procedure to assure that work doesn’t begin at the wrong place.

A section on the reverse side of a page can be designed to record key things that you may want to note as the inspection progresses. See Figure 3.

Record of material history and component control

Material issues can be recorded in the checklist to show component changes. Component removal and installations are important items to include with any work order. A separate section of the checklist format can be created for attachment or printed on the reverse side of the checklist. Once completed, they create a history of parts information related to the work order. A diary of component histories comes in handy for future work when the aircraft returns for repeat business. See Figure 4.

Safety checks

In general aviation maintenance operations the mechanic simply signs for his work with his A&P in the log or on a work order format. Checklists can and are often used with no inspection column – in a small shop with a few mechanics a person may do much of the work alone. A buy-back process such as a safety check has to be developed from the floor in cooperation with the folks who will be subject to the process. Mechanics may resent having their work “judged” for correctness.

From a human factors point of view, the act of inspecting another’s work needs to come with mutual acknowledgment by both parties that errors found are not a personal reflection of a mechanic’s technical competency. In fact, there is a tendency for the most egregious errors to be caused by the most experienced technicians since they are often the ones who are called on to perform the most challenging tasks. Though they are rare, the outcome of a slip or misjudgment on their part may result in more severe consequences.

If a little effort is applied, key elements of an inspection process similar to the required inspection processes in air carriers can be designed into any checklist in nearly any operation. By definition, a required inspection item (RII) is a maintenance item that, if improperly done, creates an immediate hazard to the flight. In this discussion I am going to refer to “RII-like” items as safety check items.

These items can be found on any aircraft of any type. The point here is to assure that there are no quality escapes in the work. It may seem that we are calling artillery on ourselves, but asking for a second set of eyes as a matter of practice will capture errors that, while embarrassing if found, are dangerous if not. Use of an “RII-like” process may never reveal an error. But it only has to do it once to make its use worthwhile.

In review of the aircraft systems and the inspection checklist, you can make some decisions on what to designate as a safety check item on the RII definition. For example, in performing a propeller installation, a key part of the installation would be the mounting bolt torques and their subsequent “safetying” with the right wire. The checklist could be formatted to show a verification of the torque and safeties by a second person. One mechanic does the work and another is tasked with witnessing the torque. Prior arrangement for this kind of activity is necessary. Also this is a safety check and not a return to service action. See Figure 5.

A search on the internet reveals that there are lots of checklists out there for the use of the general aviation mechanic. Some are very detailed. In addition, certain general aviation manufacturers publish annual inspection checklists that are configured to the aircraft and type. Use of these versions is recommended rather than using internally generated documents for inspection activities.

General aviation has been the source of much of the industry’s talent and innovation over the last century – from flying kites on a North Carolina beach to privatization of space travel. In spite of the individualistic and family like environments that persist and are the mainstay of general aviation, real skill sets are evolving that are highly effective and professional; not “mom and pop.” As we focus on industrial level maintenance activities associated with modern air transportation we can lose sight of that.

The lowly checklist can be used as the vehicle to connect all kinds of information together that paints a picture of effective processes and control on a scale that many in GA can relate to. By using a standardized method for performing aircraft maintenance, we create repeatability in our efforts to maintain and promote the highest level of safety in our operations.

Vern Berry began his aviation career as an A&P mechanic in 1979. His experience within the aviation industry includes key management roles in quality and safety for both MRO and air carrier operations. He currently resides in upper state New York where he writes and manages a consultant firm at www.blowntireaviation.com.

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