Propeller Track and Blade Inspection for the A&P Practical

October 20, 2026 · Primary sources checked October 20, 2026

Use this Airframe and Powerplant (A&P) practical propeller tracking guide to rehearse a static track check and blade inspection for the oral and practical (O&P) exam.

The propeller manufacturer specifies the permitted difference in track at corresponding points.

FAA-H-8083-32B, Powerplant — printed 7-22; PDF 308

What the evaluator can assign on the O&P

The Airman Certification Standards (ACS) distinguish checking track, inspecting condition, and making a minor metal-blade repair:

FAA-S-ACS-1 — printed 59; PDF 64

• AM.III.M.S2: “Check blade static tracking.”
• AM.III.M.S3: “Inspect a propeller for condition and airworthiness.”
• AM.III.M.S5: “Perform a minor repair to a metal propeller blade.”

FAA-S-ACS-1 — printed 59; PDF 64

Propeller maintenance and inspection hazards are risk element AM.III.M.R2.

FAA-S-ACS-1 — printed 59; PDF 64

Order 8900.1 requires the project’s performance standard to be met. To pass that project, the applicant must accomplish the skill demonstration successfully on the first attempt and successfully answer the two associated practical questions.

Order 8900.1, Vol. 5, Ch. 5, Sec. 11, CHG 929 — 5-5-11-7C3)f) and g), printed 16; PDF 16

The Mechanic Test Generator (MTG) FAQ puts the two project questions at a safe and appropriate time during the applicant’s work.

FAA Mechanic Test Generator FAQs, May 22, 2023 — unnumbered page, PDF 4

The Federal Aviation Administration (FAA) practice sample labels its project pages as being for practice purposes only. Use the sample to recognize the project’s given materials and performance standard, not to infer that a particular propeller task is guaranteed.

FAA sample oral and practical test — unnumbered page, PDF 7

Treat the propeller as live before touching it

Whenever touching a propeller, assume the ignition is on. A faulty ignition switch can allow the engine to start even with the switch off. Never allow any part of your body into the propeller’s path, even when the engine is not being cranked.

FAA-H-8083-30B, General — printed 1-13; PDF 34

An open magneto ground lead, or P lead, leaves one or more magnetos operating despite an OFF ignition-switch position, and the trouble must be corrected. Turning the propeller in that condition can cause personnel injury or death because the engine can start with someone in the propeller arc. Our study advice: rehearse the applicable engine and aircraft precautions with your instructor before attempting the static check.

FAA-H-8083-32B, Powerplant — printed 4-31; PDF 190

Perform the handbook’s static blade track check

Tracking compares the positions of blade tips relative to one another; it does not establish their actual path.

FAA-H-8083-32B, Powerplant — printed 7-22; PDF 308

Chock the aircraft to prevent movement. The handbook’s general method removes one spark plug from every cylinder to make the propeller easier and safer to turn.

FAA-H-8083-32B, Powerplant — printed 7-22; PDF 308

Position one blade pointing down. Use a solid block beside the tip so it just touches, or attach a pointer to the cowling. The handbook’s example of a block is a heavy wooden block at least a couple of inches taller than the distance between the propeller tip and the ground.

FAA-H-8083-32B, Powerplant — printed 7-22; PDF 308

Slowly rotate the propeller to compare the next blade at the same block or pointer. Judge the track difference against the propeller manufacturer’s tolerance, not a universal number from an illustration.

FAA-H-8083-32B, Powerplant — printed 7-22; PDF 308

An out-of-track propeller may have a bent blade, bent flange, or over- or undertorqued mounting bolts. Out-of-track operation causes vibration and stresses the airframe and engine, and may cause premature propeller failure.

FAA-H-8083-32B, Powerplant — printed 7-23; PDF 309

Our rehearsal suggestion: record the observed track difference and its comparison with the specified tolerance; investigate a failed check through the applicable maintenance procedure.

Inspect the blade material you actually have

If a propeller has had a ground strike or sudden stoppage, or was in an accident that may have caused internal damage, follow the engine and propeller manufacturers’ maintenance manual recommendations; the handbook says the propeller should be disassembled and inspected.

FAA-H-8083-32B, Powerplant — printed 7-20; PDF 306

Metal blades

Sharp nicks, cuts, and scratches concentrate stresses and make metal blades susceptible to fatigue failure. Examine the full length of the leading edge (especially near the tip) and of the trailing edge, shank grooves and shoulders, and dents and scars with magnification to distinguish scratches from cracks.

FAA-H-8083-32B, Powerplant — printed 7-21; PDF 307

For aluminum blades, a transverse crack or flaw of any size is cause for rejection. Do not repair the roots or hub ends of aluminum-alloy adjustable-pitch blades. Multiple deep nicks and gouges on the leading edge and face are also rejection conditions. Confirm suspected cracks with dye penetrant or fluorescent dye penetrant and refer unusual findings to the manufacturer.

FAA-H-8083-32B, Powerplant — printed 7-21; PDF 307

Wood and composite blades

Inspect wood blades for defects such as cracks, dents, warpage, glue failure, finish delamination, and charring between the propeller and flange. Also inspect the metal cap, leading-edge strip, and surrounding areas for defects such as looseness or slipping, loose rivets, cracks, corrosion, and separation between the metal leading edge and the cap. Keep moisture holes open and inspect trailing edges for bonding, separation, or damage.

FAA-H-8083-32B, Powerplant — printed 7-21; PDF 307

Composite-blade visual inspection includes nicks, gouges, loose material, erosion, cracks, debonds, and lightning-strike damage. With the described coin-tap method, a hollow or dead change in sound makes a debond or delamination likely. Tap a composite cuff and its transition separately from the blade area because the cuff has a different tone.

FAA-H-8083-32B, Powerplant — printed 7-21; PDF 307

Keep nick dressing within the permitted repair

Advisory Circular (AC) 43.13-1B addresses inspection and repair of nonpressurized civil-aircraft areas only when manufacturer repair or maintenance instructions are absent. The AC says its data generally pertains to minor repairs.

AC 43.13-1B, Change 1 — printed unnumbered title page; PDF 1

The AC says to follow the propeller manufacturer’s recommendations in all cases and to reject damaged blades whose model numbers are on the manufacturer’s list of blades that cannot be repaired. An A&P mechanic may not perform major propeller repairs; steel-blade repairs require the manufacturer’s instructions.

AC 43.13-1B, Change 1 — printed 8-29; PDF 408

For an eligible aluminum blade, removing or treating damage must not materially affect strength, weight, or performance. A reasonable number of repairs on one blade need not create a dangerous condition, unless their locations form a continuous line of repairs that would materially weaken the blade.

AC 43.13-1B, Change 1 — printed 8-29; PDF 408

The AC describes fine-cut files or suitable sandpaper, a smooth finish, rounded edge repairs, and shallow saucer-shaped face repairs that remove the deepest injury and raised metal. Avoid abrupt contour changes and preserve the contour substantially as it was.

AC 43.13-1B, Change 1 — printed 8-29; PDF 408

Figure 8-25 calls for maintaining the original radius and, if possible, preserving the section’s maximum thickness.

AC 43.13-1B, Change 1 — printed 8-30; PDF 409

A blade with appreciable metal removal must be properly balanced before use. Etch repairs, use local etching during suspected-scratch removal to avoid excessive material loss, and inspect the entire blade afterward by etching or anodizing. Remove the effects of etching with fine emery paper.

AC 43.13-1B, Change 1 — printed 8-29; PDF 408

Cold-worked blades may need peening after repair under manufacturer instructions, but never peen an injury’s edges so metal laps over the damage.

AC 43.13-1B, Change 1 — printed 8-29; PDF 408

Never straighten a damaged propeller, even partly for shipment, because hidden damage may then go undetected. Shortening propeller blades is a major repair. Reject blades reduced below the applicable repair limits. The AC also says blades that have been heated for any repair must be rejected, and all blades showing evidence of unapproved repairs should be rejected.

AC 43.13-1B, Change 1 — printed 8-31; PDF 410 · AC 43.13-1B, Change 1 — printed 8-39; PDF 417

Common mistakes in study

• Our study check: explain why an OFF switch does not prove that a magneto cannot fire.
• Our study check: keep static tracking separate from blade-angle measurement and balancing.
• Our study check: decide whether damage is eligible for a minor repair before rehearsing a dressing method; do not treat a crack as a nick.

FAQ

Is the blade track tolerance always 1/16 inch?

No; the allowable difference comes from the propeller manufacturer. The Powerplant handbook’s tracking method shows each blade within 1/16 inch (plus or minus) of the opposite blade’s track, but the handbook says the figures and sizes in its propeller inspection and maintenance section are solely for illustration and do not have specific application.

FAA-H-8083-32B, Powerplant — printed 7-22–7-23; PDF 308–309 · FAA-H-8083-32B, Powerplant — printed 7-20; PDF 306

Why is an open P lead hazardous with the switch off?

An open P lead can leave a magneto active, so turning the propeller can start the engine and injure or kill personnel.

FAA-H-8083-32B, Powerplant — printed 4-31; PDF 190

May I straighten a bent blade before shipping it?

No; even partial straightening can hide damage and allow an unairworthy propeller to be returned to service.

AC 43.13-1B, Change 1 — printed 8-31; PDF 410

Can I dress a crack out of an aluminum blade?

No. The Powerplant handbook says a transverse crack or flaw of any size in an aluminum blade is cause for rejection. The aluminum-blade repairs in AC 43.13-1B cover damage such as dents, cuts, scars, scratches, nicks, and leading-edge pitting.

FAA-H-8083-32B, Powerplant — printed 7-21; PDF 307 · AC 43.13-1B, Change 1 — printed 8-29; PDF 408

Prepare the explanation out loud

Our suggestion: describe the ignition hazard, measurement reference, tolerance source, and inspection decision aloud before a supervised shop rehearsal. DMEReady is an AI examiner for practicing the A&P oral by voice. Your first drill costs nothing and needs no sign-up. DMEReady rehearses the oral; it does not train hands-on practical skills. DMEReady operates independently without FAA affiliation or endorsement.

Try the free oral drill

Related guides

• Propeller oral questions
• Understanding practical projects
• Magneto Timing on the A&P Practical: Internal and External Timing
• FAA A&P Practical Test Changes 2026: What's New
• Planning exam costs

Sources

Primary sources checked October 20, 2026.

• AC 43.13-1B, Change 1
• FAA-S-ACS-1
• FAA-H-8083-30B, General
• FAA Mechanic Test Generator FAQs, May 22, 2023
• Order 8900.1, Vol. 5, Ch. 5, Sec. 11, CHG 929
• FAA-H-8083-32B, Powerplant
• FAA sample oral and practical test

About this guide: drafted with AI from the FAA sources listed on this page and checked claim by claim against them. Not reviewed by an A&P mechanic or DME. How we make our guides