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The real Aviation Mechanic - General written test has 60 multiple-choice questions (3 options each), a 2-hour time limit, and requires 70% to pass. Questions are drawn across 12 knowledge areas. These follow the FAA-S-ACS-1 blueprint, and this bank mirrors those areas and their weights.
70 percent. Revise each knowledge area to that level in Revision Mode, then run the full exam simulation in Exam Mode before your test date.
The live test bank is not published. Our questions include the FAA's own published sample questions plus original questions written to the FAA-S-ACS-1 blueprint and grounded in the FAA handbooks (FAA-H-8083-30B, 31B and 32B) and 14 CFR, with the source cited in each explanation.
The full Aviation Mechanic - General bank contains 379 questions with explanations. The free sample gives you roughly two exams' worth per knowledge area.
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It is organised into 12 modules that follow the exam's own content areas: Fundamentals of Electricity and Electronics, Aircraft Drawings, Weight and Balance, Fluid Lines and Fittings, Aircraft Materials, Hardware, and Processes, Ground Operations and Servicing, Cleaning and Corrosion Control, Mathematics, Regulations, Maintenance Forms, Records, and Publications, Physics for Aviation, Inspection Concepts and Techniques and Human Factors. Each module is drilled and scored separately, so you can see exactly which areas are exam-ready and which still need work.
Last updated 6 July 2026. The bank is revised whenever the source material it cites changes, and every question carries the source its explanation is drawn from.
A selection of free questions with answers and explanations. Use the interactive modules above for timed, scored drills.
What is the value of the square root of 64 plus 4 squared?
Why: Square root of 64 is 8; 4 squared is 16; 8 + 16 = 24. FAA-H-8083-30B ch.3 (powers and roots).
Flareless (MS) fittings differ from AN flare fittings in that flareless fittings
Why: MS flareless fittings use a presetting sleeve that bites into the tube - no flare is formed on the tube end. FAA-H-8083-30B ch.9.
An aircraft burns 105 gallons of fuel during a 3.5-hour flight. What is the average fuel consumption?
Why: 105 gallons / 3.5 hours = 30 gallons per hour. FAA-H-8083-30B ch.3 (division).
A sheet metal repair requires 12 rivets for each of 14 wing ribs, plus 25 additional rivets for the doubler. How many rivets are required in total?
Why: 12 rivets x 14 ribs = 168, plus 25 for the doubler = 193 rivets. FAA-H-8083-30B ch.3 (multiplication and addition of whole numbers).
14 CFR part 65 contains regulations regarding the certification of
Why: 14 CFR part 65 contains the certification regulations for airmen other than flight crewmembers. 14 CFR part 65.
How many personnel are required to service an aircraft with gaseous oxygen?
Why: Two personnel are required to service an aircraft with gaseous oxygen: one at the control valves and one observing the pressure in the aircraft system, with communication between them. FAA-H-8083-30B ch.1.
Approximately what percentage of maintenance-related errors is estimated to be caused by distractions?
Why: It is estimated that 15 percent of maintenance-related errors are caused by distractions; a good practice is to go back three steps in the procedure when work resumes after a distraction. FAA-H-8083-30B ch.14.
Magnetic particle inspection can be used on which materials, and what must be done after the test?
Why: Magnetic particle inspection works on ferromagnetic materials only, detects surface and subsurface discontinuities, and the part must be demagnetized after the test. FAA-H-8083-30B ch.10.
A supplemental type certificate (STC) is issued when
Why: An STC approves a major modification of the type design; TCDSs and STCs are available through FAA databases and must be consulted for modified aircraft.
A drawing that describes a single part with all the information needed to fabricate it is called
Why: A detail drawing gives complete information for making one part; assembly drawings show how parts relate; installation drawings show how the unit installs on the aircraft. FAA-H-8083-30B ch.4.
What is the MEDA process, and who developed it?
Why: MEDA (Maintenance Error Decision Aid) was developed by Boeing; its goal is to investigate errors, understand root causes, and prevent accidents, instead of placing blame on the maintenance personnel. FAA-H-8083-30B ch.14.
Fretting corrosion between two mating surfaces is also known by what name, and is identified on a rivet how?
Why: Fretting corrosion occurs when mating surfaces at rest undergo slight relative motion; it has been called false brinelling, and the common example is the smoking rivet, identified by a black ring around the rivet. FAA-H-8083-30B ch.8.
When an aircraft is sold domestically, the Airworthiness Certificate
Why: When an aircraft is sold domestically, the Airworthiness Certificate is transferred with the aircraft at the time of sale. FAA-H-8083-30B ch.2.
Which of the following may cause erroneous scale readings?
Why: Parking brakes set can restrain the aircraft and cause erroneous scale readings during weighing. FAA-H-8083-30B ch.6.
A grounded wrist strap is worn when handling avionics circuit cards primarily to
Why: ESD from a charged body can destroy semiconductor devices; the strap bleeds static charge safely to ground. FAA-H-8083-30B ch.12.
What is the standard position for an aircraft taxi signalman relative to the aircraft?
Why: The standard position for a signalman is slightly ahead of and in line with the aircraft's left wingtip, staying far enough ahead to remain in the pilot's field of vision. FAA-H-8083-30B ch.1.
Centerlines on an aircraft drawing are drawn as
Why: Centerlines are made of alternating long and short dashes and mark the center of symmetrical objects or features. FAA-H-8083-30B ch.4.
If a part to be inspected for surface defects is made of a magnetic material, which inspection method is generally recommended?
Why: If the part in question is made of a magnetic material, magnetic particle inspection is generally recommended over penetrant inspection. FAA-H-8083-30B ch.10.
Charles' law states that a gas expands and contracts in what relationship to absolute temperature, provided pressure is constant?
Why: Charles' law: all gases expand and contract in direct proportion to the change in absolute temperature, provided pressure is held constant (V1T2 = V2T1). FAA-H-8083-30B ch.5.
According to the electron theory of current flow, electrons move through a circuit
Why: Electron flow is from negative to positive; conventional current is drawn in the opposite direction (positive to negative). FAA-H-8083-30B ch.12.
Examples of units used in the conventional (U.S. or English) measurement include
Why: Conventional (U.S./English) measurement units include the inch, ounce, and pound. FAA-H-8083-30B ch.3.
What is the correct grounding/bonding sequence when fueling an aircraft from a fuel truck?
Why: Ground the aircraft and then ground the truck; next, ground or bond them together by running a connecting wire between the aircraft and the fuel truck. FAA-H-8083-30B ch.1.
In a sectional view drawing, what sections illustrate particular parts of an object?
Why: Removed sections illustrate particular parts of an object, drawn outside the main view. FAA-H-8083-30B ch.4.
The 'Environment' element of the PEAR model addresses which two environments in aviation maintenance?
Why: A human factors program must address at least two environments: the physical workplace (ramp, hangar, shop) and the organizational environment that exists within the company. FAA-H-8083-30B ch.14.
A handle-length extension (cheater bar) must never be used on
Why: The handbook cautions against handle extensions on flexible beam-type wrenches; on other types a handle extension alone does not change the reading. FAA-H-8083-30B ch.7.
When installing a flexible hose assembly, the hose should be
Why: Hose shortens under pressure, so 5-8% slack is required; hose must never be installed twisted or taut. FAA-H-8083-30B ch.9.
What does the letter Q symbolize when measuring electrical charge?
Why: The letter Q symbolizes electrical charge, whose unit is the coulomb. FAA-H-8083-30B ch.12.
Which of the following tools is best to use when cutting soft aluminum tubing?
Why: A hand-operated wheel-type tubing cutter is best for cutting soft aluminum tubing. FAA-H-8083-30B ch.9.
From the control tower, a flashing green light signal directed at a taxiing aircraft means what?
Why: Standard taxi light signals: flashing green means cleared to taxi. FAA-H-8083-30B ch.1 (Figure 1-22).
Alclad aluminum sheet is aluminum alloy
Why: Alclad carries pure-aluminum surface layers whose natural oxide protects the stronger but less corrosion-resistant alloy core. FAA-H-8083-30B ch.7.
An angle that is greater than 90 degrees but less than 180 degrees is called
Why: Obtuse angles fall between 90 and 180 degrees; acute is less than 90; reflex is greater than 180. FAA-H-8083-30B ch.3 (geometric terms).
If a flared tube coupling nut is overtightened, where is the tube most likely to be weakened/damaged?
Why: Overtightening a flared coupling nut drives the sleeve edge into the tube, weakening it at the edge of the sleeve and the straight portion of the tube. FAA-H-8083-30B ch.9.
When referencing resistance in a parallel DC circuit, which of the following statements is true?
Why: In a parallel DC circuit the total current equals the sum of the currents through the individual branches. FAA-H-8083-30B ch.12.
One horsepower is equal to how much power?
Why: One horsepower equals 550 ft-lb/s, which is also 33,000 ft-lb/min, 375 mile-pounds per hour, or 746 watts. FAA-H-8083-30B ch.5.
Which statement describes a key characteristic of radiographic (x-ray) inspection?
Why: X-ray radiography detects surface and internal flaws, can inspect hidden areas, and produces a permanent record, but it is a safety hazard, expensive, and slow. FAA-H-8083-30B ch.10 (Figure 10-6).
What is meant by the term "residual fuel"?
Why: Residual fuel is the fuel remaining trapped in the tanks, lines, and engine after draining; it is included in the aircraft's empty weight. FAA-H-8083-30B ch.6.
When jacking an aircraft, the jacks must be placed
Why: Manufacturer-designated jack points carry the loads safely; jacking elsewhere risks structural damage. FAA-H-8083-30B ch.6.
How often must an aircraft receive a complete annual inspection?
Why: With some exceptions, all aircraft must have a complete inspection at least once each 12 calendar months (annual inspection, per 14 CFR 91.409). FAA-H-8083-30B ch.10.
If an aircraft CG is found to be at "24 percent" of MAC, "24 percent" is an expression of the
Why: A CG expressed as a percent of MAC is measured as the distance aft of the leading edge of the MAC (LEMAC). FAA-H-8083-30B ch.6.
Empty weight is 1,200 pounds at +15 inches. With only a 170-pound pilot at +10 inches aboard, the CG is approximately
Why: Moments: 1,200 x 15 = 18,000; 170 x 10 = 1,700; total 19,700 / 1,370 lb = 14.38, about +14.4 inches. FAA-H-8083-30B ch.6.
The pigtail at the end of a safety wire run should be
Why: The finished pigtail is 1/4-1/2 inch with 3-6 twists, bent back or under so it cannot snag or injure. FAA-H-8083-30B ch.7.
Fluid line fitting nuts should be tightened with a torque wrench primarily because
Why: Correct torque protects the sealing surfaces: too tight damages the flare/sleeve, too loose leaks. FAA-H-8083-30B ch.9.
How long does the holder of a certificate issued under 14 CFR part 65 have to notify the FAA after any change in permanent mailing address?
Why: A part 65 certificate holder must notify the FAA within 30 days of any change in permanent mailing address. 14 CFR 65.21.
An acceptable completed weld is characterized by
Why: A good weld is uniform in width with even ripples well feathered into the base metal, and free of gas pockets, porosity, and inclusions. FAA-H-8083-30B ch.10 (inspection of welds).
Prior to towing an aircraft across any runway or taxiway, what is required?
Why: Prior to any movement of aircraft across runways or taxiways, contact the airport control tower on the appropriate frequency for clearance to proceed. FAA-H-8083-30B ch.1.
How does shot peening a metal surface increase resistance to stress-corrosion cracking?
Why: Shot peening increases resistance to stress-corrosion cracking by creating compressive stresses on the surface, which must be overcome by applied tensile stress before the surface sees any tension load, raising the threshold stress level. FAA-H-8083-30B ch.8.
What type of line is normally used in a drawing or blueprint that indicates invisible edges or contours?
Why: Invisible (hidden) edges or contours are shown with a medium-weight line of short dashes evenly spaced. FAA-H-8083-30B ch.4.
The signature on a maintenance record entry made under 14 CFR 43.9 constitutes
Why: 14 CFR 43.9(a)(4): the signature constitutes approval for return to service only for the work performed, not for the whole aircraft.
What is the only advantage provided by a single fixed pulley?
Why: A single fixed pulley is a first-class lever with equal arms, so its mechanical advantage is 1; its only advantage is to change the direction of the pull. FAA-H-8083-30B ch.5.
According to Faraday's law, the voltage induced in a coil is proportional to
Why: Faraday's law: induced emf depends on the rate of change of flux linking the coil - the basis of generator action. FAA-H-8083-30B ch.12.
Filing or grinding a finished weld bead smooth is
Why: Welds are never filed or ground for appearance - that deprives the weld of part of its strength and can hide defects. FAA-H-8083-31B ch.5.
What is used to indicate that a surface must be machine finished?
Why: Finish marks indicate that a surface must be machine finished. FAA-H-8083-30B ch.4.
When calculating the new weight and balance for an aircraft, what is used to determine the operating CG range?
Why: The operating CG range used in weight-and-balance calculations is obtained from the Type Certificate Data Sheets. FAA-H-8083-30B ch.6.
The density of water, commonly used as the standard for comparing densities, is what value?
Why: Density is weight per unit volume; water has a density of 62.4 lb/ft3 at 4 degrees C (1 g/cm3 metric), the standard for comparing densities of other substances. FAA-H-8083-30B ch.5.
A drawing labeled 'SCALE 1/4' means
Why: Scale expresses drawing size relative to the real object: 1/4 scale draws the object quarter size. FAA-H-8083-30B ch.4.
Which high-strength aluminum alloys are especially susceptible to intergranular corrosion when improperly heat-treated?
Why: High-strength aluminum alloys such as 2014 and 7075 are more susceptible to intergranular corrosion if improperly heat-treated and then exposed to a corrosive environment. FAA-H-8083-30B ch.8.
At weighing, each main wheel scale reads 1,050 pounds at +70 inches and the nose wheel reads 300 pounds at -10 inches. The CG is located at
Why: Moments: (2 x 1,050 x 70) = 147,000; nose 300 x (-10) = -3,000; total 144,000 / 2,400 lb = +60.0 inches. Forgetting the negative nose moment gives 62.5. FAA-H-8083-30B ch.6.
The five basic stresses acting on aircraft structures are
Why: External forces manifest as tension, compression, torsion, bending, and shear (bending is itself a combination of tension and compression). FAA-H-8083-30B ch.5/ch.7.
How many simple machines are there, and on which two basic principles do all of them operate?
Why: There are six simple machines (lever, pulley, wheel and axle, inclined plane, screw, gear); physicists recognize only two basic principles: the lever and the inclined plane. FAA-H-8083-30B ch.5.
A fastener requires 240 inch-pounds of torque. Using a 10-inch torque wrench with a 2-inch drive-end extension in line with the wrench, the wrench should be set to
Why: Wrench setting = desired torque x wrench length / (wrench length + extension) = 240 x 10 / 12 = 200 in-lb; using a drive-end extension makes the formula mandatory. FAA-H-8083-30B ch.7.
A Technical Standard Order (TSO) is issued by whom?
Why: A Technical Standard Order (TSO) is issued by the Administrator (FAA). 14 CFR part 21 subpart O.
When using a standard torque table, nuts and bolts should be
Why: The torque table rules: do not lubricate (except corrosion-resistant parts or where instructed) and tighten by rotating the nut where possible. FAA-H-8083-30B ch.7.
The total piston displacement in a reciprocating engine is
Why: Total piston displacement is the volume displaced by all the pistons during one revolution of the crankshaft (one cylinder's displacement times the number of cylinders). FAA-H-8083-30B ch.3.
A measurement of 4.7519 inches rounded to the nearest hundredth is
Why: The hundredths digit is 5; the next digit (1) is less than 5, so the 5 stays: 4.75. FAA-H-8083-30B ch.3 (rounding).
Aircraft fluid lines are identified as to their contents by
Why: Lines carry color codes, contents words, and symbols; lines carrying physically dangerous materials are additionally marked PHDAN. FAA-H-8083-30B ch.9.
An aircraft weighs 2,350 pounds with a CG at +82.0 inches. A 50-pound package is added at +140 inches. The new CG is approximately
Why: New moment = 2,350 x 82 + 50 x 140 = 192,700 + 7,000 = 199,700; new weight 2,400 lb; CG = 199,700 / 2,400 = 83.2 inches. FAA-H-8083-30B ch.6.
Which is the most common form of corrosion found on aircraft?
Why: General surface corrosion (uniform etch or uniform attack) is the most common form; it appears as general roughening, etching, or pitting, often with a powdery deposit. FAA-H-8083-30B ch.8.
About how much slack should be left in a manila tie-down rope, and why?
Why: Since manila rope shrinks when wet, about 1 inch of slack needs to be provided for movement; too much slack lets the aircraft jerk against the ropes. FAA-H-8083-30B ch.1.
When tightening the B-nut on a hose or line fitting, the mechanic should
Why: Holding the fitting with a second wrench prevents twisting the line or hose while the B-nut is torqued. FAA-H-8083-30B ch.9.
A 6-ohm resistor is connected in series with two 10-ohm resistors that are in parallel with each other. The total circuit resistance is
Why: The parallel pair: 10 x 10 / 20 = 5 ohms; adding the series 6 ohms gives 11 ohms total. FAA-H-8083-30B ch.12.
To measure a shaft's outside diameter to one ten-thousandth of an inch (0.0001), the proper tool is
Why: The vernier scale divides each 0.001 inch into ten parts of 0.0001 inch; standard micrometers resolve 0.001. FAA-H-8083-30B ch.11 (measuring devices).
Bernoulli's principle states that as the velocity of a fluid increases, what happens to its static pressure?
Why: Bernoulli's principle: the static pressure of a fluid decreases at points where the velocity increases, provided no energy is added or removed. This creates lift over a wing and reduced pressure in a venturi. FAA-H-8083-30B ch.5.
Which statement correctly describes the common civil turbine fuels?
Why: Three civil turbine fuels are JET A and JET A-1, made from kerosene, and JET B, a blend of kerosene and AVGAS. FAA-H-8083-30B ch.1.
Phantom lines on an aircraft drawing are used to show
Why: Phantom lines (one long dash followed by two short dashes) indicate alternate positions of moving parts or repeated detail. FAA-H-8083-30B ch.4.
Which oxygen is approved for use in aircraft breathing oxygen systems?
Why: Only oxygen marked 'Aviator's Breathing Oxygen' that meets Federal Specification BB-0-925A, Grade A, or its equivalent is to be used; medical oxygen contains water that can freeze and industrial oxygen may contain impurities. FAA-H-8083-30B ch.1.
A sectional view of a part is used on a drawing to show
Why: Sectional views expose interior features by showing the part as if cut open along the cutting plane. FAA-H-8083-30B ch.4.
Manufacturer-specified maintenance intervals contained in the FAA-approved airworthiness limitations section must be
Why: 14 CFR 43.16 and 91.403(c): each person must comply with the mandatory replacement times and inspection intervals in the airworthiness limitations section.
A maintenance record entry made after completing maintenance must include, among other items,
Why: 14 CFR 43.9(a): the entry must contain a description (or reference to acceptable data), the completion date, the name of the person performing the work, and the authorized signature with certificate type and number.
On a micrometer, which parts are the fixed parts and which are the movable parts?
Why: The fixed parts of a micrometer are the frame, barrel, and anvil; the movable parts are the thimble and spindle. Turning the thimble rotates the spindle. FAA-H-8083-30B ch.11.
Rigid tubing and flexible hose sizes are measured, respectively, by
Why: Rigid tube size is its OD (in sixteenths); flexible hose size is based on its ID. FAA-H-8083-30B ch.9.