22 Ground Operation, Servicing & Human Factors Practice Questions & Answers

1. 1. A magnesium wheel assembly is burning after a brake fire. Which extinguishing method is correct, and why is water the wrong choice?

   • A.Use a halogenated (Halon) agent; interrupting the chemical chain reaction is most effective on Class D fires
   • B.Discharge CO2 onto the metal; oxygen displacement is the only mechanism that works on a Class D fire
   • C.Blanket the burning metal with a dry powder agent; water can be broken down by the hot metal and cause an explosive reaction that scatters molten material✓ Answer
   • D.Flood the fire with water; the cooling effect smothers a burning metal fire

   Burning magnesium is a Class D (combustible metal) fire that burns far above the temperature at which water dissociates, so water — and the rapid cooling produced by CO2 on hot metal — causes violent, explosive expansion that throws burning metal. Dry powder is correct because it blankets the metal and excludes oxygen without reacting with it; CO2 and halogenated agents are intended for Class B and C fires.

   Source: FAA-H-8083-30 Ch. 1, Fire Protection — Class D (combustible metal) firesReport a problem with this question

2. 2. Which statement about carbon dioxide (CO2) fire extinguishers is correct?

   • A.Once the frangible seal is punctured, a partially discharged CO2 bottle may be reinstalled without weighing or recharging
   • B.CO2 works by chemically interrupting the combustion chain reaction and is harmless in an enclosed area
   • C.CO2 is the preferred agent for burning magnesium because it cools the metal rapidly
   • D.CO2 extinguishes mainly by displacing oxygen, with some cooling, so it must be used with caution in a confined space because it can also deprive the operator of oxygen✓ Answer

   CO2 smothers a fire by displacing the oxygen around it and adds a cooling effect as it expands, which is why it is effective on Class A, B and C fires. Because the same oxygen displacement affects people, discharging CO2 in a confined or poorly ventilated space is dangerous to the operator; the expanding gas is also cold enough to cause frostbite, and a punctured bottle is considered spent and must be recharged and weighed.

   Source: FAA-H-8083-30 Ch. 1, Fire Protection — carbon dioxide (CO2) extinguishersReport a problem with this question

3. 3. Before servicing a piston-engine airplane, a technician verifies fuel grade by color. Which pairing is correct?

   • A.Grade 100LL is blue, grade 100 is green, and grade 80 is red✓ Answer
   • B.Grade 100LL is red, grade 100 is blue, and grade 80 is green
   • C.Grade 100LL is green, grade 100 is blue, and grade 80 is purple
   • D.All AVGAS grades are clear to straw colored; only turbine fuel is dyed

   AVGAS is dyed so the grade can be identified visually: 80 is red, 100 is green, 100LL is blue and 115 is purple. Turbine fuel is clear to straw colored and its piping and equipment are color-coded black, so color is the technician's quick cross-check that the fuel matches the grade required by the aircraft's TCDS and placards.

   Source: FAA-H-8083-30 Ch. 1, Fuel Servicing — AVGAS grade color codingReport a problem with this question

4. 4. Select the proper procedure for making the electrical connections when refueling an aircraft from a fuel truck.

   • A.Ground the aircraft, ground the fuel truck, bond the truck to the aircraft, then bond the nozzle to the aircraft before opening the filler cap; remove the connections in reverse order✓ Answer
   • B.Bond the nozzle to the aircraft first, then ground the truck, and ground the aircraft only after fuel flow has begun
   • C.Ground only the fuel truck, since the aircraft tires dissipate any static charge to the ramp
   • D.Attach the ground lead to the engine exhaust stack or a propeller blade, which are the approved grounding points

   Liquid fuel does not burn — its vapor does, and the ignition source in a fueling operation is a static spark generated by fuel flowing through hose and nozzle. Grounding the aircraft first, then the truck, then bonding the two and finally bonding the nozzle keeps every item at the same electrical potential before any vapor is released at the open filler, and the leads must contact bare metal or designated points, never the exhaust or propeller.

   Source: FAA-H-8083-30 Ch. 1, Fueling and Defueling — bonding and groundingReport a problem with this question

5. 5. Which statement about the fire guard stationed for an engine start is correct?

   • A.No fire guard is required if the brakes are set and the wheels are chocked
   • B.The fire guard should stand directly in front of the propeller arc so the operator can see the extinguisher clearly
   • C.The fire guard must be familiar with engine starting procedures and stand adjacent to the outboard side of the engine, in view of the person at the controls, with a CO2 extinguisher of at least 5-pound capacity✓ Answer
   • D.Any available person may serve as fire guard, standing behind the exhaust with a water-type extinguisher

   The fire guard exists to attack an induction or engine fire in the first seconds, so the person must know the starting sequence, be able to see and be seen by the operator, and be clear of the propeller arc and exhaust blast while still adjacent to the engine's outboard side. A CO2 extinguisher of at least 5-pound capacity is specified because CO2 can be directed into the air intake without leaving a damaging residue.

   Source: FAA-H-8083-30 Ch. 1, Engine Starting — fire guard dutiesReport a problem with this question

6. 6. An induction system fire develops while a reciprocating engine is being started. What is the correct procedure?

   • A.Have the fire guard discharge water into the carburetor air scoop while cranking continues
   • B.Stop cranking immediately, shut off the master switch and evacuate the area without further action
   • C.Continue cranking to get the engine started, which draws the fire back through the induction system and blows it out; if the engine will not start and the fire continues, discontinue the start and have the fire guard discharge CO2 into the engine air intake✓ Answer
   • D.Open the throttle fully and turn on the boost pump to flood the fire out with liquid fuel

   An induction fire is burning fuel in the intake tract, and a running engine restores suction that pulls the flame into the cylinders and extinguishes it, so the handbook procedure is to keep cranking and start the engine. Only if the engine will not start and the fire persists is the start discontinued and CO2 directed into the air intake by the fire guard; water is never used on a fuel fire and simply stopping without extinguishing leaves the fire burning.

   Source: FAA-H-8083-30 Ch. 1, Engine Fire During StartingReport a problem with this question

7. 7. During a turbine engine start the ITT rises rapidly toward the limit while the engine accelerates normally. What is occurring and what is the correct action?

   • A.A hot start, usually caused by an excessively rich fuel/air ratio — too much fuel or too little airflow; shut off the fuel immediately and abort the start✓ Answer
   • B.A no light-off condition; continue motoring the engine for 15 seconds with fuel and ignition on to clear the tailpipe
   • C.A normal start, since ITT always peaks above the limit before the starter cuts out; no action is needed
   • D.A hung (false) start, caused by too much airflow; advance the power lever to increase fuel flow and clear the condition

   A hot start is defined by EGT/ITT exceeding the specified limit during starting, and it results from an excessively rich fuel/air ratio — either too much fuel or insufficient compressor airflow from a weak starter or low battery. The fuel must be shut off at once because turbine temperature limits are exceeded in seconds and cause blade and combustor damage; a hung start, by contrast, is a light-off that stabilizes at a low rpm and never accelerates.

   Source: FAA-H-8083-30 Ch. 1, Unsatisfactory Turbine Engine Starts — hot startReport a problem with this question

8. 8. Which requirement applies when an aircraft is being towed with a tow bar?

   • A.The tow bar is designed to carry torsional loads, so the nosewheel may be turned past its steering stops when maneuvering in tight spaces
   • B.A qualified person must occupy the flight deck to apply the brakes if the tow bar fails or the aircraft begins to swing, and wing walkers are posted at the wingtips✓ Answer
   • C.The brakes should be applied lightly and continuously throughout the tow to keep tension on the tow bar
   • D.Wing walkers may be omitted whenever the towing speed exceeds a normal walking pace

   A brake rider is required because a failed tow bar or a swing leaves no other way to stop the aircraft, and wing walkers protect the wingtips and tail from obstacles. Tow bars are built to carry tension and compression only, so exceeding the nose gear's turn limits imposes torsional loads that damage the steering mechanism, and towing speed must never exceed the pace of the walking team.

   Source: FAA-H-8083-30 Ch. 1, Towing of AircraftReport a problem with this question

9. 9. An aircraft on the airport surface receives a flashing red light signal from the control tower. What does that signal mean?

   • A.Taxi clear of the runway in use✓ Answer
   • B.Exercise extreme caution
   • C.Return to the starting point on the airport
   • D.Cleared to taxi

   In the standard ATC light gun table for aircraft on the surface, flashing green means cleared to taxi, steady red means stop, flashing red means taxi clear of the runway in use, flashing white means return to the starting point on the airport, and alternating red and green means exercise extreme caution. Knowing the table matters because light signals are the only communication available when the radio fails, and a misread flashing red is a runway incursion.

   Source: FAA-H-8083-30 Ch. 1, Taxi Signals — ATC light gun signals (FAA AIM)Report a problem with this question

10. 10. Which practice is required when servicing an aircraft gaseous oxygen system?

    • A.Medical oxygen is an acceptable substitute because it is purer than aviator's breathing oxygen
    • B.The cylinder should be filled as rapidly as possible to shorten exposure time
    • C.Two people are required — one at the servicing cart valves and one observing aircraft system pressure — hands, tools and fittings must be free of oil and grease, and only Aviator's Breathing Oxygen may be used✓ Answer
    • D.Oxygen servicing may be performed at the same time as fueling as long as a fire extinguisher is standing by

    Oxygen itself does not burn, but combustibles ignite far more easily and burn hotter in an oxygen-rich atmosphere, and oxygen in contact with oil, grease or bituminous material forms a mixture that can explode from compression or impact — hence absolute cleanliness. Two people with communication between them are required so pressure can be watched while the valves are operated, filling is done slowly to limit the heat of compression, and only oxygen marked Aviator's Breathing Oxygen (Federal Specification BB-O-925A, Grade A) is approved because medical oxygen contains water that can freeze at altitude.

    Source: FAA-H-8083-30 Ch. 1, Oxygen System Servicing; Federal Specification BB-O-925A, Grade AReport a problem with this question

11. 11. Why must a propeller always be treated as though the ignition switch is ON?

    • A.Residual magnetism in the starter motor can turn the crankshaft without electrical power
    • B.Static electricity built up on the propeller blades can ignite the fuel/air charge in a cylinder
    • C.The impulse coupling stores enough spring energy to fire the engine up to 30 minutes after shutdown
    • D.A broken or disconnected magneto P-lead leaves the magneto ungrounded, so it can fire even with the switch off and a blade moved by hand can start the engine✓ Answer

    An aircraft magneto is self-contained and is switched off by grounding it through the P-lead; if that lead is broken, loose or the switch is faulty, the magneto remains live regardless of switch position. Because a single blade pulled through can then produce a firing impulse, the propeller is always treated as hot, the area is kept clear, and hand propping uses the call-and-response of fuel on, switch off, throttle closed, brakes on, followed by contact before the switch is turned on.

    Source: FAA-H-8083-30 Ch. 1, Safety Around Airplanes — hand propping and magneto P-leadReport a problem with this question

12. 12. Why is a written checklist used when performing an annual or 100-hour inspection, and what must it contain?

    • A.Only a checklist supplied by the airframe manufacturer is acceptable, and it may omit any item the technician judges inapplicable
    • B.A checklist is required, and it must include at least the scope and detail of the items listed in 14 CFR part 43, Appendix D, so that no required item is omitted✓ Answer
    • C.A checklist is an optional memory aid; an experienced technician may work from memory on a familiar model
    • D.A checklist is required only for a progressive inspection program, not for annual or 100-hour inspections

    The regulations require the person performing an annual or 100-hour inspection to use a checklist that includes at least the scope and detail of part 43, Appendix D, whether it is the manufacturer's list or one of the technician's own design. The checklist exists because an inspection is a systematic coverage task in which the most likely failure is omission, and a signed checklist also documents that each required area was actually examined.

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

13. 13. An airplane is suspected of having made a hard landing. Which statement about the resulting special inspection is correct?

    • A.Wrinkled wing skin is the most easily detected indication of excessive landing load, and the manufacturer's maintenance manual or instructions for continued airworthiness define the scope of the inspection✓ Answer
    • B.No special inspection is needed as long as the airplane landed at or below its maximum design landing weight
    • C.The technician may define the scope of the inspection at his or her discretion because no published data covers abnormal events
    • D.Discolored exhaust stacks and flat-spotted tires are the primary structural indications of a hard landing

    Because vertical velocity at touchdown cannot be judged reliably, a special (conditional) inspection is performed after any suspected hard landing even at or below maximum design landing weight, and an overweight landing triggers a separate inspection. Wrinkled wing skin is the most easily detected sign of excessive load, along with fuel leakage at riveted seams, and the manufacturer's data — not the technician's judgment — establishes exactly what must be inspected and to what depth.

    Source: FAA-H-8083-30 Ch. 10, Special Inspections — hard landingReport a problem with this question

14. 14. Which statement about liquid (dye) penetrant inspection is true?

    • A.It works best on porous castings because the porous surface holds more penetrant
    • B.It reveals subsurface flaws as well as surface flaws because the penetrant migrates through the material
    • C.It may be used only on ferromagnetic materials, since the developer relies on magnetic attraction
    • D.It may be used on almost any nonporous material, including aluminum, magnesium, stainless steel, plastics and glass, but it detects only defects that are open to the surface✓ Answer

    Penetrant inspection works by capillary action: the liquid is drawn into a discontinuity that is open to the surface and is then blotted back out by the developer to form a visible indication. That mechanism means a subsurface flaw with no surface opening produces no indication at all, and porous materials hold penetrant everywhere and mask real defects, while any nonporous material — magnetic or not — can be inspected.

    Source: FAA-H-8083-30 Ch. 10, Liquid Penetrant InspectionReport a problem with this question

15. 15. A steel landing gear part is being magnetic particle inspected for cracks that run parallel to its long axis. Which statement is correct?

    • A.The same procedure may be used on the aluminum parts of the assembly if the current is increased
    • B.Field orientation does not matter, because the particles are attracted equally to any discontinuity
    • C.Circular magnetization, produced by passing current through the part, creates a field that crosses those cracks at approximately a right angle and reveals them; the part must be demagnetized afterward✓ Answer
    • D.Longitudinal magnetization with a solenoid is required for cracks parallel to the axis, and demagnetizing afterward is unnecessary

    Magnetic particle indications form only where the magnetic flux is interrupted, so the flux must run approximately perpendicular to the defect: circular magnetization (current through the part) produces a concentric field that finds defects parallel to the part's axis, while longitudinal magnetization with a solenoid finds transverse defects. The method applies only to ferromagnetic materials, not aluminum, and the part must be demagnetized after inspection so residual magnetism does not attract debris or disturb instruments.

    Source: FAA-H-8083-30 Ch. 10, Magnetic Particle Inspection — circular vs. longitudinal magnetization and demagnetizationReport a problem with this question

16. 16. Which statement correctly compares eddy current inspection with radiographic (x-ray) inspection?

    • A.Eddy current can be used on any material including composites, and radiography requires no special personnel qualification
    • B.Eddy current requires the paint to be stripped and detects only surface flaws, while radiography gives the exact depth of every discontinuity
    • C.Both methods require the part to be removed from the aircraft and immersed in a couplant bath
    • D.Eddy current works only on electrically conductive materials, can find surface and subsurface flaws — often through paint — and requires a reference standard; radiography shows internal flaws and leaves a permanent record but does not indicate the depth of a discontinuity and is a radiation hazard✓ Answer

    Eddy current induces a circulating current in a conductive part and reads the change in impedance caused by a flaw, so it needs a conductive material and a reference standard of the same material with known flaws, but it can see below the surface and usually through paint. Radiography passes penetrating radiation through the part and records the differential absorption on film, which shows internal defects and gives a permanent record, but the image is a shadow — it cannot tell how deep in the thickness the discontinuity lies — and it requires radiation controls and highly skilled interpretation.

    Source: FAA-H-8083-30 Ch. 10, Eddy Current and Radiographic InspectionReport a problem with this question

17. 17. Which statement about visual inspection and its aids is correct?

    • A.Visual inspection with a 10-power magnifier will reliably detect subsurface cracks and internal corrosion
    • B.The area should be left dirty so that soil trapped in a crack makes the crack easier to see
    • C.The area should be cleaned first, a light directed at a shallow angle to the surface with the eye kept above the reflected beam helps reveal cracks, and a borescope extends visual inspection into cylinders, combustion sections and other internal areas✓ Answer
    • D.The light should always be held perpendicular to the surface, because a shallow angle hides surface irregularities

    Visual inspection is the cheapest and most immediate NDI method, but it works only on the surface and only if that surface is clean, since dirt, grease and old sealant hide cracks rather than reveal them. Light struck at roughly a 5 to 45 degree angle grazes the surface so an irregularity casts a shadow or breaks the reflected beam, a 10-power magnifier is used to confirm an indication, and mirrors and borescopes simply carry the same technique into areas the eye cannot reach directly.

    Source: FAA-H-8083-30 Ch. 10, Visual Inspection and borescope useReport a problem with this question

18. 18. The 'Dirty Dozen' used throughout aviation maintenance human factors training was originally identified by which organization, and what does the list represent?

    • A.Transport Canada; twelve common precursors of human error such as complacency, distraction, fatigue, pressure and norms✓ Answer
    • B.The NTSB; twelve categories used to classify maintenance-caused accidents
    • C.The FAA; twelve mandatory maintenance regulations that must be posted in every repair station
    • D.Boeing; the twelve investigative steps of the Maintenance Error Decision Aid (MEDA)

    Transport Canada developed the Dirty Dozen after a series of maintenance-related accidents, and the list — lack of communication, complacency, lack of knowledge, distraction, lack of teamwork, fatigue, lack of resources, pressure, lack of assertiveness, stress, lack of awareness and norms — names the conditions that most often precede a maintenance error. It is a training and prevention tool, not a regulation: each item is paired with practical safety nets, because human error cannot be eliminated but the conditions that invite it can be managed.

    Source: FAA-H-8083-30 Ch. 14, The Dirty Dozen (developed by Transport Canada)Report a problem with this question

19. 19. A technician is called away in the middle of a torque sequence on a flight control attachment. What is the recommended practice when returning to the job?

    • A.Go back at least three steps in the procedure before the point of interruption, and mark incomplete work by tagging it or leaving disconnected connectors plainly visible✓ Answer
    • B.Start the entire task over from step one and have a second technician re-sign every previous step
    • C.Resume at the exact step where the interruption occurred, since the technician clearly remembers the last fastener torqued
    • D.Have another technician finish and sign the sequence so the original technician does not have to return

    Distraction is estimated to cause about 15 percent of maintenance errors because the mind fills the gap by assuming a step was completed when it was not — the classic result is a fastener left untorqued or unsafetied. Backing up at least three steps forces physical re-verification of work already believed to be done, and tagging or leaving incomplete connections visible makes the unfinished state obvious to anyone, including a different technician on the next shift.

    Source: FAA-H-8083-30 Ch. 14, Dirty Dozen — Distraction and its safety netsReport a problem with this question

20. 20. What is meant by 'norms' as a human factors element in aviation maintenance?

    • A.The normal operating limits listed on the aircraft's type certificate data sheet
    • B.Unwritten rules or practices that an organization follows or tolerates; negative norms are dangerous because they depart from the approved data even though 'everyone does it that way'✓ Answer
    • C.The published dimensional tolerances a manufacturer specifies for a repair
    • D.The statistical average time allotted to a maintenance task in the labor guide

    Norms are unwritten practices that grow up to solve ambiguous or awkward problems and are then passed to newcomers as 'how we do it here,' which is exactly why they bypass the approved data and the checks built into it. A negative norm detracts from the established safety standard, and the safety net is to work only to current approved instructions and to challenge a practice that cannot be found in the manual, no matter how long it has been tolerated.

    Source: FAA-H-8083-30 Ch. 14, Dirty Dozen — NormsReport a problem with this question

21. 21. Which describes a proper shift or task turnover when a job must be continued by another technician?

    • A.Having the oncoming technician sign for the entire task once it is finished, so a single signature covers all the work
    • B.A face-to-face meeting in which the paperwork is reviewed, completed work is discussed and attention is drawn to the next step, backed by a written turnover, with each step signed off by the technician who actually performed it✓ Answer
    • C.Leaving a note on the work stand describing what is left to do, which is sufficient because the paperwork tells the whole story
    • D.An oral handover only, since written turnovers create conflicting records

    Turnover is the point where information is most easily lost, so the standard is both a written record and a face-to-face oral briefing — the absence of either is itself a warning that an error is likely, and a phone call substitutes only when a meeting is impossible. Each step must be signed by the person who performed it as it is performed, because once components are reinstalled over earlier work that work can no longer be verified, and the completed job must read as though one technician did all of it.

    Source: FAA-H-8083-30 Ch. 14, Shift and Task TurnoverReport a problem with this question

22. 22. At the end of a job inside a wing fuel bay, one small wrench cannot be accounted for, and the aircraft is scheduled to depart shortly. What is the correct professional action?

    • A.Release the aircraft, since a single small wrench is too light to cause damage and will be found at the next inspection
    • B.Sign the work off now to protect the schedule and file a Malfunction or Defect Report if a problem later develops
    • C.Do not release the aircraft; account for the tool under the tool control program, because a loose object left in the structure is foreign object damage that can jam controls or damage systems in flight✓ Answer
    • D.Release the aircraft and note the missing tool in the maintenance record so the next shift can look for it

    A tool control program exists so that every tool is accounted for before an area is closed, since a loose object inside a wing or control run can migrate under flight loads and jam a control, chafe wiring or puncture a tank. Schedule pressure is one of the Dirty Dozen, and the safety net is to communicate that more time is needed rather than rush: a technician must never sign for or release work that cannot be verified as correct.

    Source: FAA-H-8083-30 Ch. 1 (FOD and tool control) and Ch. 14 (Pressure; professionalism and integrity)Report a problem with this question

Practice questions based on 14 CFR Parts 43 and 65 and the FAA Aviation Maintenance Technician Handbook—General (FAA-H-8083-30). This site is not affiliated with or endorsed by the Federal Aviation Administration. This bank covers the GENERAL written test only; the Airframe and Powerplant written tests and the oral and practical exams are separate. Torque values, servicing quantities, corrosion rework limits, and inspection criteria always come from the manufacturer's current maintenance data 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 →