22 Engine Inspection & Fire Protection Practice Questions & Answers

1. 1. Under 14 CFR 91.409, how often must a standard-category airplane that is not operated for hire be given an annual inspection?

   • A.Within the preceding 24 calendar months, or 12 months if the airplane flies for hire
   • B.Within the preceding 12 months counted from the day the last one was signed off
   • C.Within the preceding 100 hours of time in service since the last annual inspection
   • D.Within the preceding 12 calendar months, ending on the last day of that month✓ Answer

   The rule is written in calendar months, not in days or in hours of operation: the inspection remains valid through the last day of the twelfth calendar month after the month in which it was signed off, which is why an aircraft inspected on March 3 is due by March 31 of the following year. Hours in service do not affect the annual, and only an appropriately rated mechanic holding an inspection authorization may approve the aircraft for return to service after one.

   Source: 14 CFR 91.409(a)(1)Report a problem with this question

2. 2. An airplane used to give flight instruction for hire is 3 hours past its 100-hour inspection time and is en route to a base where the inspection will be performed. Under 14 CFR 91.409(b), how is this handled?

   • A.The 100-hour limit may not be exceeded for any reason, so the flight was not authorized under any circumstance
   • B.The 100-hour limit may be exceeded by up to 10 hours en route, and the 3 hours must be subtracted from the next interval✓ Answer
   • C.The 100-hour limit may be exceeded only under a special flight permit, and the next interval begins at the inspection
   • D.The 100-hour limit may be exceeded by up to 10 hours en route, and the next interval begins at the new inspection time

   The regulation allows the 100-hour limit to be exceeded by not more than 10 hours, and only while en route to a place where the inspection can be done. The relief is a ferry allowance, not extra inspection interval, so the excess time is included in computing the next 100 hours: after a 3-hour overrun the following inspection comes due at 97 hours of time in service.

   Source: 14 CFR 91.409(b)Report a problem with this question

3. 3. A mechanic who holds only a powerplant rating has worked on a reciprocating engine. Under 14 CFR 65.87, which task may this mechanic perform and then approve for return to service?

   • A.A major repair to the crankcase, after performing it using approved data
   • B.A major alteration of the engine, after recording it on FAA Form 337
   • C.A 100-hour inspection of the powerplant and propeller, after performing it✓ Answer
   • D.An annual inspection of the powerplant and propeller, after performing it

   A powerplant-rated mechanic may approve a powerplant or propeller, or any related part or appliance, for return to service after maintenance or alteration, and may perform and approve the part 91 100-hour inspection. Two limits define the rating: major repairs and major alterations are excluded, and an annual inspection may be approved only by a mechanic who also holds an inspection authorization.

   Source: 14 CFR 65.87 and 14 CFR 43.7Report a problem with this question

4. 4. An owner discontinues an approved progressive inspection program. Under 14 CFR 91.409(d), when is the next annual inspection due?

   • A.Within 100 hours of time in service after the last routine inspection performed
   • B.Within 24 calendar months after the last complete inspection under the program
   • C.Within 12 calendar months after the last complete inspection made under the program✓ Answer
   • D.Within 12 calendar months after the date the program was formally discontinued

   A progressive program breaks the inspection into routine and detailed segments, so the reference point when the program ends is the last time a complete inspection of the airframe and its systems was finished, not the date of the paperwork ending the program. From that complete inspection the annual is due within 12 calendar months and the 100-hour within 100 hours of time in service.

   Source: 14 CFR 91.409(d)Report a problem with this question

5. 5. Which item must appear in the maintenance record entry for a 100-hour inspection but is not required in the entry for a routine engine repair?

   • A.The kind of certificate held by the person approving return to service
   • B.The signature and certificate number of the person approving the work
   • C.The total time in service of the aircraft on the date the inspection ends✓ Answer
   • D.The description of the work performed or a reference to acceptable data

   Inspection entries and maintenance entries are governed by two different sections. An inspection entry must show the type and extent of the inspection, the date and the aircraft total time in service, and the signature, certificate number and kind of certificate held, plus the airworthiness statement. A maintenance entry needs the description of work, the date, and the signature, certificate number and kind of certificate, but not total time in service.

   Source: 14 CFR 43.11(a) and 14 CFR 43.9(a)Report a problem with this question

6. 6. An aircraft is sold. Under 14 CFR 91.417, which record must be transferred with the aircraft to the new owner?

   • A.The current status of life-limited engine parts and of applicable ADs✓ Answer
   • B.The mechanic's own copy of the checklist used for the last inspection
   • C.The record of the spark plug rotation performed in the preceding month
   • D.The work order describing a cylinder repair completed nine months ago

   The regulation splits records into two groups with different lives. Records of individual maintenance work are kept only until that work is repeated or superseded, or for one year. The permanent group, which includes total time in service, the status of life-limited parts, time since overhaul, inspection status and airworthiness directive compliance, must be kept and transferred with the aircraft when it is sold.

   Source: 14 CFR 91.417(a)(2) and 91.417(b)(2)Report a problem with this question

7. 7. Under 14 CFR 43.15, what governs the checklist a mechanic uses when performing a 100-hour inspection?

   • A.It must be issued by the responsible Flight Standards office before the work
   • B.It may be any checklist the mechanic prefers, since no content is prescribed
   • C.It must be the checklist published by the airframe or engine manufacturer
   • D.It may be of the mechanic's own design if it covers the scope of Appendix D✓ Answer

   The rule regulates content rather than authorship: a checklist must be used, it may be the mechanic's own, the manufacturer's, or one from another source, and it must include the scope and detail of Appendix D. For the engine and nacelle group that scope covers items such as fluid leaks and their source, studs and nuts, internal engine condition, engine mounts, controls, lines and hoses, exhaust stacks, accessories and cowling.

   Source: 14 CFR 43.15(c)(1) and part 43 Appendix DReport a problem with this question

8. 8. Before approving a reciprocating-engine airplane for return to service after an annual inspection, 14 CFR 43.15 requires the mechanic to run the engine and check which items?

   • A.Power output, magnetos, fuel and oil pressure, and cylinder and oil temperature✓ Answer
   • B.Compression of each cylinder, oil consumption, and exhaust gas temperature spread
   • C.Starting characteristics, idle mixture, throttle response, and shutdown time
   • D.Manifold pressure, carburetor heat rise, mixture response, and fuel flow at idle

   For reciprocating engines the regulation names the run-up checks explicitly: power output measured as static and idle rpm, the magnetos, fuel and oil pressure, and cylinder and oil temperature. Turbine-powered aircraft are treated differently, with the engine run in accordance with the manufacturer's recommendations, so the two lists should not be interchanged.

   Source: 14 CFR 43.15(c)(2) and 43.15(c)(3)Report a problem with this question

9. 9. Which statement about a life-limited engine part is correct under 14 CFR 43.10?

   • A.Its mandatory replacement limit is set by the mechanic performing the last overhaul
   • B.Its life status must be recomputed by a repair station each time the engine is run
   • C.Its mandatory replacement limit comes from the type design, the maintenance manual, or the ICA✓ Answer
   • D.Its removal is required whenever the engine reaches the recommended overhaul time

   A part is life limited because the type design, the instructions for continued airworthiness, or the maintenance manual states a mandatory replacement limit for it, usually in cycles for turbine rotating parts and in hours for others; no one in the field may extend that limit. Once removed permanently the part must be controlled by a recordkeeping system, by a tag showing part number, serial number and current life status, by segregation, or by mutilation, and the record travels with the part if it is sold.

   Source: 14 CFR 43.10(a) and 91.417(a)(2)(ii)Report a problem with this question

10. 10. A cracked welded steel-tube engine mount will be repaired by welding, and the repair is a major repair. Which of the following is FAA-approved data for that repair?

    • A.The illustrated parts catalog entry that shows the mount assembly and its hardware
    • B.A repair method the FAA has approved for that mount, such as an STC or a field approval✓ Answer
    • C.A written procedure the mechanic signs and enters in the aircraft maintenance record
    • D.The maintenance manual chapter that covers removal and installation of the mount

    Approved data is data the FAA has itself approved for the product and the repair, such as a supplemental type certificate, a field approval recorded on FAA Form 337, or data approved through a designated engineering representative. Acceptable data, including much of a maintenance manual and general advisory material, tells a mechanic how to do a job properly but does not by itself provide the approval a major repair requires.

    Source: 14 CFR 43.13, 43.9(d), and part 43 Appendix BReport a problem with this question

11. 11. An engine manufacturer issues a service bulletin recommending replacement of a fuel line at a stated interval, and no airworthiness directive references it. For an aircraft operated under part 91, which statement is correct?

    • A.The bulletin is mandatory, because manufacturer data carries the force of regulation
    • B.The bulletin is advisory, and an AD is also advisory until the owner accepts it
    • C.The bulletin is mandatory as soon as the mechanic reads it and records its number
    • D.The bulletin is not mandatory, while an AD is a rule and compliance is required✓ Answer

    Airworthiness directives are issued as regulations, so complying with them is a legal duty and the record must show the method of compliance, the directive number and revision date, and the next due time for a recurring one. A service bulletin or service letter is manufacturer data that becomes compulsory only when an airworthiness directive adopts it, when an operator's approved program requires it, or when it forms part of an approved instruction for continued airworthiness.

    Source: 14 CFR part 39 and 14 CFR 43.16Report a problem with this question

12. 12. A propeller on a reciprocating engine strikes an object and the engine stops suddenly. What does this event require of the mechanic?

    • A.Perform the sudden stoppage inspection called for in the manufacturer's instructions✓ Answer
    • B.Check the crankshaft flange runout and return the engine to service if it is within limits
    • C.Inspect the engine mount and vibration isolators, then perform a differential compression check
    • D.Replace the propeller and return the engine to service after a satisfactory ground run

    A sudden stoppage or propeller strike is a special inspection because the shock loads travel back through the crankshaft and gear train, where damage such as a bent crankshaft, sheared counterweight bushings, or a cracked accessory drive cannot be seen from outside. The manufacturer's instructions for continued airworthiness define the required inspection, which may include internal examination or engine removal, and a ground run, a runout check or a compression check alone does not establish internal condition.

    Source: 14 CFR 43.13 and 43.16; FAA Aviation Maintenance Technician Handbook — Powerplant, special inspectionsReport a problem with this question

13. 13. During a 100-hour inspection, part 43 Appendix D requires the engine mount to be inspected for which conditions?

    • A.Bolt torque values as listed in the current type certificate data sheet
    • B.Cracks, looseness of the mounting, and looseness of the engine to the mount✓ Answer
    • C.Electrical bonding resistance across each mount leg and its attaching hardware
    • D.Alignment of the engine thrust line within the tolerance set for the airframe

    Appendix D lists the mount inspection as cracks, looseness of the mounting, and looseness of the engine to the mount, and separately calls for flexible vibration dampeners to be checked for poor condition and deterioration. A crack in a welded tube mount or a collapsed isolator lets the engine shift under torque and vibration, which loads controls, lines and exhaust components that were never meant to carry it.

    Source: 14 CFR part 43 Appendix D(d)(4) and (d)(5)Report a problem with this question

14. 14. Leaking fuel and hydraulic fluid ignite inside an engine nacelle. How is this fire classified?

    • A.Class D, because the burning material is a combustible metal such as magnesium
    • B.Class A, because the burning material is an ordinary solid combustible
    • C.Class C, because the burning material is energized electrical equipment
    • D.Class B, because the burning material is a flammable or combustible liquid✓ Answer

    Fires are classed by what is burning: ordinary solids are Class A, flammable and combustible liquids such as fuel, oil and hydraulic fluid are Class B, energized electrical equipment is Class C, and combustible metals such as magnesium are Class D. The class drives the agent, which is why nacelle systems use a halogenated agent or carbon dioxide that smothers the fire and interrupts combustion instead of water, which would spread a liquid fire.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, fire classificationsReport a problem with this question

15. 15. Which area is a designated powerplant fire zone requiring fire detection coverage?

    • A.The cabin area next to the nacelle, which carries no flammable fluid lines
    • B.The wheel well behind the nacelle, which vents overboard in flight
    • C.The engine accessory section, which is isolated from the power section✓ Answer
    • D.The wing leading edge duct that carries bleed air from the engine compressor

    A designated fire zone is an area where flammable fluid or gas sources and ignition sources exist together, so it is given detection and, where required, extinguishing coverage. The designated powerplant zones are the engine power section, the engine accessory section, any complete powerplant compartment with no isolation between those sections other than on reciprocating engines, an auxiliary power unit compartment, a fuel-burning heater installation, and the compressor, accessory, combustor, turbine and tailpipe sections of a turbine installation that contain flammable fluid lines.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, designated powerplant fire zonesReport a problem with this question

16. 16. In a thermal switch fire detection system, how are the heat-sensitive switches and the warning light connected?

    • A.The switches are wired in parallel with each other and in parallel with the light
    • B.The switches are wired in parallel with each other and in series with the light✓ Answer
    • C.The switches each drive their own light through one common return circuit
    • D.The switches are wired in series with each other and in parallel with the light

    Any single switch closing must be able to light the warning lamp, so the switches are paralleled with one another and that parallel group is placed in series with the light. Because each switch closes at a fixed temperature, the system is an overheat detector rather than a rate-of-rise detector, and a test relay is normally provided that puts the switches and the bulb in series so the wiring and the lamp can be checked from the flight deck.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, thermal switch fire detection systemsReport a problem with this question

17. 17. A thermocouple fire detection system gives no warning while a nacelle heats slowly to a high temperature. What explains this?

    • A.It responds only after the reference junction reaches its calibrated set point
    • B.It responds to a fall in element resistance, which slow heating does not cause
    • C.It responds to a rapid rate of temperature rise, not to absolute temperature✓ Answer
    • D.It responds to absolute temperature but needs both junctions to be heated

    The circuit compares a hot junction exposed to the zone with a reference junction shielded by an insulating block, and voltage appears only when the two differ in temperature. A slow rise warms both nearly equally, so almost no current flows and the sensitive relay, which closes at a few milliamperes, never picks up; a fire produces a sharp rise at the hot junction alone and trips the system. Slow overheating is therefore covered by a separate overheat detector.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, thermocouple fire warning systemsReport a problem with this question

18. 18. A continuous-loop detection element has a thermistor core between an inner conductor and an outer tube. What happens as the element is heated?

    • A.The resistance from the conductor to the tube drops until an alarm occurs✓ Answer
    • B.The core produces a voltage proportional to the rate at which it is heated
    • C.The core expands and closes a mechanical switch at the end of the sensing element
    • D.The resistance from the conductor to the tube rises until the unit alarms

    Thermistor material loses resistance as its temperature rises, so the control unit, which measures resistance from the inner conductor to the grounded tube, sees a falling value and annunciates overheat at one threshold and fire at a lower one. The element acts like a great many thermistors in parallel, so it reports a weighted average along its whole length and can be routed past a harmless hot spot without a false alarm; the rate at which resistance changes is what lets the unit tell an electrical short from a fire.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, continuous-loop fire detection systemsReport a problem with this question

19. 19. A continuous-loop sensing element has a dent that falls within the manufacturer's acceptable limits. What should the mechanic do?

    • A.Straighten the dent, then check the element with an ohmmeter for a short
    • B.Straighten the dent by hand so the element returns to its original contour
    • C.Leave the dent as found, because straightening it can induce stress and failure✓ Answer
    • D.Replace the dented section of the element before the aircraft is next flown

    Dents and kinks are judged against the manufacturer's limits, and one that is inside those limits is left alone: working the thin tubing to straighten it induces stress that can crack the sheath later and cause the element to fail in service. What the mechanic does inspect for is crushing between cowl panels, abrasion where the element rubs structure, hardened or oil-soaked grommets, loose end nuts, and frayed shielded leads.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, continuous-loop element inspection and maintenanceReport a problem with this question

20. 20. A preflight check finds the red disc missing from the fuselage skin at the extinguisher container's relief fitting. What does this indicate?

    • A.The container was drained by maintenance during a scheduled servicing check
    • B.The container discharged into the engine zone when the detection system tripped
    • C.The container was discharged normally by the flight crew using the fire switch
    • D.The container discharged overboard because excessive heat raised its pressure✓ Answer

    Two indicator discs report two different events. The red thermal discharge indicator is connected to the container relief fitting and is blown out when a rising temperature raises internal pressure enough to rupture the safety relief diaphragm and dump the agent overboard, so a missing red disc also points to an overheat condition that must be investigated. A missing yellow disc means the crew fired the system normally. In either case the container must be replaced before the next flight.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, extinguisher discharge indicatorsReport a problem with this question

21. 21. What determines the remaining service life of a fire extinguisher container discharge cartridge?

    • A.The date the container was last weighed, with life expressed in total flight hours
    • B.The manufacturer's date stamp on the cartridge, with life expressed in years✓ Answer
    • C.The date of the container's last hydrostatic test, with life given in years
    • D.The number of flight deck system tests run, with life expressed in cycles

    Cartridge life is counted from the manufacturer's date stamp, usually marked on the face of the cartridge, and is stated in years; reading it normally means disconnecting the electrical leads and the discharge line and removing the plug body from the container, which is why the squib circuit is de-energized first. A cartridge taken out of one discharge valve must not be fitted to a different valve assembly, because contact protrusion varies between units and electrical continuity may not exist.

    Source: FAA Aviation Maintenance Technician Handbook — Powerplant, discharge cartridge service lifeReport a problem with this question

22. 22. Under the certification rules for transport category airplanes, what must the engine fire extinguishing system provide?

    • A.Two discharges, each able to produce an adequate concentration of the agent✓ Answer
    • B.Two discharges, of which the second may be an inert gas purge of the zone
    • C.One discharge for each engine, plus one shared reserve for the whole airplane
    • D.One discharge, backed up by a portable extinguisher carried on the flight deck

    Transport category airplanes must have two discharges available to each designated fire zone, and each discharge must be able to build an adequate concentration of agent, because a fire can reflash after the first shot is swept away by nacelle airflow. A one-shot system is the minimum for commuter airplanes and is acceptable for auxiliary power units and fuel-burning heaters. In a two-shot installation, two-way check valves keep the reserve charge from flowing back into the emptied container.

    Source: 14 CFR 25.1195; FAA Aviation Maintenance Technician Handbook — Powerplant, fire extinguishing systemsReport a problem with this question

Practice questions based on the Aviation Mechanic Airman Certification Standards (FAA-S-ACS-1), 14 CFR parts 43, 65, and 91, and the FAA Aviation Maintenance Technician Handbook—Powerplant (FAA-H-8083-32). This site is not affiliated with or endorsed by the Federal Aviation Administration. This bank covers the POWERPLANT written test only; the General and Airframe written tests and the oral and practical tests are separate. Torque values, running clearances, compression limits, magneto timing angles, spark plug gaps, temperature and pressure limits, servicing quantities, and overhaul intervals always come from the manufacturer's current maintenance data, the type certificate data sheet, and the applicable airworthiness directives — never from a practice test. Confirm current eligibility and testing requirements with the FAA before you test. About the A&P mechanic certificate →