11.3 Practical Projects, Tools, Equipment, and Safety Discipline

How the Practical Test Is Structured

Under the Mechanic ACS, the practical test is built from standalone projects — discrete tasks the DME selects from the ACS for your rating. The published project counts are 9 projects for the General rating and 11 projects each for the Airframe and Powerplant ratings. A key change the ACS brought is that projects can no longer be combined during testing; each is performed and graded on its own, so you cannot rely on one demonstration to satisfy two requirements.

For every project, the DME must, at a safe and appropriate time during your performance, ask two practical questions (sometimes called research questions) that are relevant to that project. Crucially, reference material is permitted during the practical — unlike the oral. This mirrors the real flight line: a professional mechanic looks up torque values, tolerances, and procedures in the approved data rather than trusting memory. The research questions specifically test whether you can find and apply the correct data, which is itself a core skill element of the ACS.

Because the General must be passed before either rating is issued, candidates typically complete all three orals and practicals in one testing event arranged with the DME, though scheduling varies. A full Airframe-and-Powerplant event combining three orals and 31 total practical projects is a long day — often running the better part of a working shift — which is one reason fatigue and time pressure (both Dirty Dozen factors covered in 11.4) are real test-day risks, not just textbook concepts.

Safe Work Starts Before the First Tool Moves

A practical project is not merely proof you can turn a wrench; the DME is grading a mechanic process. The expected sequence is: understand the task, gather the approved data, identify the hazards, select and verify the right tools and equipment, perform the work methodically, inspect the result, and clean up. Skipping the front end — diving in before consulting data or considering hazards — is a common reason candidates lose points even when the final result looks correct.

Elements the DME is specifically watching include:

• Tool selection and condition — using the correct tool for the fastener or measurement, and confirming that precision tools (torque wrenches, micrometers, calipers) are within calibration.
• Personal protective equipment (PPE) — eye protection, gloves, and hearing protection appropriate to the task.
• Foreign object debris (FOD) control — accounting for hardware, lockwire clippings, rags, and tools so nothing is left in a structure or engine.
• Energy control / communication — never energizing, pressurizing, or moving a system without verifying the area is clear and announcing the action.
• Cleanup and tool accountability — returning the work area and aircraft to a safe condition and confirming all tools are accounted for.

These are not bonus behaviors; they are scored performance items. A technically correct repair completed with an uncalibrated torque wrench, missing eye protection, or an unaccounted-for tool is an unsafe outcome in the DME's eyes.

Brief the Task, Then Execute Methodically

The most effective way to show process quality is to brief the project aloud before touching the aircraft, engine, or component: state what the task is, what reference you will use, what hazards are present, and what tools you need. Then work in the order the data specifies, verifying each step. When you reach a point where the DME's two research questions fit naturally — for example, the torque value for a fitting or the inspection criteria for a part — you demonstrate the lookup, which is exactly what the research questions reward.

Finish by inspecting your own work and verifying the result against the standard before declaring the project complete. A worked example: on a fluid-line fitting project, you would identify the fitting type, look up the manufacturer's torque and any lockwire requirement, apply the correct torque with a calibrated wrench, safety the fitting per AC 43.13-1B acceptable methods, then inspect for proper engagement and leaks before signing off mentally. Claiming completion before inspecting is a frequent error.

Think of each project as a miniature real-world maintenance task with a witness. The DME is watching whether you would be safe and methodical when no examiner is present — because that is the behavior the certificate authorizes for the rest of your career.

Finally, do not improvise around missing resources. If the correct tool, part, or data is not at hand, the professional response is to say so and stop, not to substitute an incorrect tool or guess at a value. The DME would far rather hear "I can't complete this safely without the calibrated torque wrench and the manufacturer's value" than watch a candidate force a fastener to a remembered number. Lack of resources is one of the recognized human-factors traps, and recognizing it on a practical project is scored as good judgment, not as failure to perform.