Oil Filter, Screen and Chip Detector Inspection for the A&P Practical

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

For the Airframe and Powerplant (A&P) oral and practical (O&P), our A&P practical oil filter inspection rehearsal follows the removed material through inspection and interpretation. Use the assigned engine’s instructions to prepare the work, judge the findings, and identify the required next action.

What does this O&P project evaluate?

Start this inspection rehearsal with the Federal Aviation Administration (FAA) Airman Certification Standards (ACS) skills below.

Each assigned practical project includes a skill plus two questions.

FAA Order 8900.1, Vol. 5, Ch. 5, Sec. 11, CHG 929, printed 16, PDF 16, 5-5-11-7C3)c)

Available and applicable references may support both the skill demonstration and its practical answers.

FAA Order 8900.1, Vol. 5, Ch. 5, Sec. 11, CHG 929, printed 16, PDF 16, 5-5-11-7C3)c)

The individual project has a pass/fail outcome.

FAA Order 8900.1, Vol. 5, Ch. 5, Sec. 11, CHG 929, printed 16, PDF 16, 5-5-11-7C3)f)

Successful completion on the first skill attempt and successful answers to the two associated questions are required to pass the project.

FAA Order 8900.1, Vol. 5, Ch. 5, Sec. 11, CHG 929, printed 16, PDF 16, 5-5-11-7C3)f)

The applicant must complete the project to the required performance standard to pass, and the examiner can find that standard in the downloaded test. The FAA Mechanic Test Generator (MTG) FAQ says each practical project is standalone; projects can no longer be combined during testing.

FAA Order 8900.1, Vol. 5, Ch. 5, Sec. 11, CHG 929, printed 16, PDF 16, 5-5-11-7C3)g) · FAA Mechanic Test Generator FAQs, updated May 22, 2023, unnumbered page, PDF 4

The FAA sample is a practice example, not an assigned test. Our study advice: follow the evidence from removal through inspection and the required maintenance decision.

FAA sample oral and practical test, unnumbered page, PDF 6

FAA-S-ACS-1, printed 51, PDF 56

Use the engine’s procedure and inspection limits

Always follow the manufacturer’s current instructions for maintenance. For engine-replacement decisions, the handbook makes the applicable manufacturer’s instructions the final authority in every case. Our preparation advice: locate the current filter, screen, and chip-detector instructions, the applicable limits and any required approved data before opening the oil system.

FAA-H-8083-32B, Powerplant, printed 6-18, PDF 264 · FAA-H-8083-32B, Powerplant, printed 8-1, PDF 328

Risk list before opening the oil system

The ACS safety appendix calls for current maintenance publications and procedures.

FAA-S-ACS-1, printed A-3, PDF 67

The ACS safety appendix lists observing safety precautions, such as wearing safety glasses, hearing protection, and any other required personal protective equipment (PPE).

FAA-S-ACS-1, printed A-3, PDF 67

Under the ACS, any disregard for safety is not tolerated and will result in a failure. The evaluator will ask for simulation where an actual project action would jeopardize safety.

FAA-S-ACS-1, printed A-3, PDF 67

• The lubrication-system ACS lists engine-oil use or mixing, departures from manufacturer lubricant recommendations, and handling, storage, and disposal of used oil as risks.
• When changing from straight mineral oil to ashless dispersant oil, the handbook says not to add ashless dispersant oil to straight mineral oil; for turbine oil, it notes that most engine manufacturers do not recommend the indiscriminate mixing of approved oil brands.
• Contact with turbine-oil liquid, vapor, and mist should be minimized.
• Breathing hydrocarbon vapor above prescribed limits for a prolonged time may cause lightheadedness, dizziness, and nausea.
• Protective clothing, gloves, and eye protection should be used for turbine oil.

FAA-S-ACS-1, printed 51, PDF 56, AM.III.G.R1–R3 · FAA-H-8083-32B, Powerplant, printed 6-17, PDF 263 · FAA-H-8083-32B, Powerplant, printed 6-19, PDF 265 · FAA-H-8083-32B, Powerplant, printed 6-19–6-20, PDF 265, 266 · FAA-H-8083-32B, Powerplant, printed 6-20, PDF 266

• If turbine oil is ingested, call a doctor immediately and identify the product and amount.
• Petroleum products should never be siphoned by mouth because of ingestion risk.
• Prolonged or repeated turbine-oil contact can irritate the skin and cause dermatitis.
• Wash skin thoroughly with soap and warm water after contact.
• Remove oil-soaked clothing promptly and wash.
• For turbine oil in the eyes, flush with fresh water until irritation subsides.
• Our preparation advice: review the oil and cleaning solvent Safety Data Sheets (SDSs), exposure response, spill controls, and used-oil disposal arrangements before starting.

FAA-H-8083-32B, Powerplant, printed 6-20, PDF 266

Oil subjected to very high operating temperatures can break down into a product of unknown toxicity. If that happens, the handbook’s printed wording is that “all precautions to avoid explosives should be taken.” Turbine-oil spills can blister, discolor, or remove paint. The handbook says painted surfaces should be wiped clean with petroleum solvent after a spill.

FAA-H-8083-32B, Powerplant, printed 6-20, PDF 266

Remove and inspect the filter or screen

The handbook says a suitable container should be provided to collect the oil that drains from the filter housing or cavity, and the container must be clean so the collected oil can be examined for foreign particles. Any contamination already present in the container gives a false indication of the engine condition, which could result in a premature engine removal.

FAA-H-8083-32B, Powerplant, printed 6-15, PDF 261

The handbook’s reciprocating-engine spin-on example removes safety wire and turns the filter counterclockwise using its rear wrench pad. Cut the spin-on can open with the special filter-cutting tool to remove the element for inspection. Carefully unfold the paper element and examine its trapped material. Also inspect the filter’s oil for signs of metal contamination.

FAA-H-8083-32B, Powerplant, printed 6-17, PDF 263 · FAA-H-8083-32B, Powerplant, printed 6-18, PDF 264

On an engine with a pressure-screen system, check that screen for metal particles. After draining the oil, remove the sump suction screen and check it for metal. In the handbook’s spin-on example, the opened filter is moved in a clean plastic bucket containing varsol to remove contaminants, and a clean magnet is used to check the filter or varsol for ferrous metal particles. The remaining varsol is poured through a clean filter or shop towel, and a bright light is used to inspect for any nonferrous metals.

FAA-H-8083-32B, Powerplant, printed 6-17, PDF 263 · FAA-H-8083-32B, Powerplant, printed 6-18, PDF 264

What do the metal findings mean?

Metal particles, shavings, or flakes in the element or screens indicate premature or excessive component wear. If abnormal metal content is found, additional service may be required to find its source and determine possible corrective maintenance. Metal particles in the engine oil screens or the magnetic chip detectors are generally an indication of partial internal failure of the engine. Carbon can break loose in rock-like pieces that resemble metal. Before removing an engine for suspected internal failure, the handbook says to place the particles close to a magnet to determine whether they are ferrous metal. Any ferrous metal in the oil screens is cause for concern. Very small nonferrous quantities can sometimes be normal, especially following major engine maintenance.

FAA-H-8083-32B, Powerplant, printed 6-17, PDF 263 · FAA-H-8083-32B, Powerplant, printed 8-2, PDF 329

If the particles are metal, the handbook says to determine the probable extent of internal damage. For example, if only small particles similar to filings are found, the handbook says to drain and refill the oil system, ground-run the engine, and reinspect the oil screens and magnetic chip detectors. If no further evidence of foreign material is found, the handbook says to continue the engine in service or follow the manufacturer’s instructions; however, engine performance should be closely observed for any indication of difficulty or internal failure.

FAA-H-8083-32B, Powerplant, printed 8-2, PDF 329

In the separate sudden-speed-reduction inspection, heavy metal in the oil indicates definite engine failure and the engine must be removed. Our decision check: preserve the finding’s context and use the manufacturer’s inspection and disposition instructions instead of treating a magnet result or an example as a universal release limit.

FAA-H-8083-32B, Powerplant, printed 8-2, PDF 329

Name metal types without guessing a failed part

The handbook’s spectrometric oil analysis section, which measures microscopic wear metals in parts per million (PPM), gives examples of wear metals associated with areas of the engine that could lead to their source. Our identification advice: distinguish the observed magnetic response from a confirmed material identification; the examples below do not identify an alloy by appearance.

FAA-H-8083-32B, Powerplant, printed 6-20, PDF 266

• Iron examples include rings, shafts, gears, the valve train, cylinder walls, and pistons in some engines.
• Chromium examples include chromed parts, such as rings and liners, and some coolant additives.
• Nickel is a secondary wear indicator for certain bearings, shafts, valves, and valve guides.
• Aluminum indicates wear of pistons, rod bearings, and certain types of bushings.
• The copper list includes bearings, rocker-arm and wrist-pin bushings, thrust washers, other bronze or brass parts, and oil additive or antiseize compound.
• Tin is listed for bearing wear.
• Lead is listed mostly as tetraethyl-lead contamination.
• Silver is associated with silver-bearing wear and, in some cases, is a secondary indication of oil-cooler problems.

FAA-H-8083-32B, Powerplant, printed 6-20, PDF 266

Remove and inspect the chip detector

Magnetic chip detectors catch ferrous, magnetic particles in the oil. During maintenance, the handbook describes removing the detector and inspecting it for metal. If no metal is found, that procedure cleans the detector, puts it back, and safety-wires it. If metal is found, an investigation should determine its source. Our inspection advice: use the assigned detector’s removal, seal, torque, installation, and safety provisions; a clean magnetic detector does not inspect the filter for you.

FAA-H-8083-32B, Powerplant, printed 6-28, PDF 274

Reassemble under the correct filter procedure

The screen must be cleaned before it is reinstalled in the engine. Follow the manufacturer’s procedures when disassembling or reassembling an oil-screen assembly.

FAA-H-8083-32B, Powerplant, printed 6-16, PDF 262

When reinstalling a filter or screen, use new O-rings and gaskets and the maintenance manual’s torque. Safety the filters as required. The handbook’s typical turbine-filter steps are to provide a container for the drained oil if needed, discard the old seals, immerse the screen or filter in an approved carbon remover, rinse it in a degreaser fluid or cleaning solvent, blow it dry with an air jet, install it with a new seal tightened to the torque prescribed in the manufacturer’s instructions, and secure it with lock wire. Our final check: complete the manufacturer’s servicing and operational checks, preserve the inspection findings, and follow the applicable disposition before returning the engine to service.

FAA-H-8083-32B, Powerplant, printed 6-16, PDF 262 · FAA-H-8083-32B, Powerplant, printed 6-31, PDF 277

Common mistakes in inspection practice

Our review list: inspect the element rather than just the can, include applicable screens, distinguish ferrous and nonferrous findings, retain manufacturer limits, and do not substitute oil-analysis examples for material identification.

Practice explaining the inspection findings

For spoken A&P preparation, DMEReady offers an artificial intelligence (AI) voice examiner in your phone or computer browser. The AI offers follow-up questions the way a Designated Mechanic Examiner (DME) would. The product rehearses oral discussion and does not train the physical inspection task. The first drill costs nothing and needs no sign-up. DMEReady is an AI examiner, not a human DME, and it is independent and not affiliated with or endorsed by the FAA.

Start your free drill

For examiner fees and planning, read the DME exam cost guide.

Related guides

• Engine lubrication oral questions
• Engine inspection oral questions
• A&P Practical Projects: What the DME Evaluates on the O&P
• FAA A&P Practical Test Changes 2026

Sources

Primary sources checked October 20, 2026.

• FAA-S-ACS-1
• FAA Mechanic Test Generator FAQs, updated May 22, 2023
• FAA 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