CAAB AME B2 Exam cheat sheet

Order of operations (BODMAS): brackets, orders, division and multiplication left to right, then addition and subtraction left to right.

Percentage change = ((new value − old value) / old value) × 100%.

Circle area = πr²; circumference = 2πr; sphere volume = (4/3)πr³; cylinder volume = πr²h.

Pythagoras: c² = a² + b²; trigonometric ratios: sin θ = opposite/hypotenuse, cos θ = adjacent/hypotenuse, tan θ = opposite/adjacent.

Sine rule: a/sin A = b/sin B = c/sin C; cosine rule: a² = b² + c² − 2bc cos A.

Index laws: aᵐ × aⁿ = aᵐ⁺ⁿ; aᵐ / aⁿ = aᵐ⁻ⁿ; (aᵐ)ⁿ = aᵐⁿ; log(ab) = log a + log b.

Quadratic formula: x = [−b ± √(b² − 4ac)] / (2a) for ax² + bx + c = 0.

Mean = sum of values / number of values; median = middle value of an ordered data set.

SI base units include metre (length), kilogram (mass), second (time), ampere (current), and kelvin (temperature).

Newton's second law: F = ma; weight W = mg, with g approximately 9.81 m/s² near the Earth's surface.

Work = force × distance; power = work / time; kinetic energy = ½mv²; gravitational potential energy = mgh.

Pressure = force / area; hydrostatic pressure p = ρgh, where ρ is density and h is depth.

Density ρ = m/V; specific gravity is density relative to water (1000 kg/m³).

For a fixed mass of ideal gas, PV/T is constant; absolute temperature in kelvin must be used.

Speed of sound in air is approximately 340 m/s at 15°C; wave speed v = fλ.

Heat transfer occurs by conduction, convection, and radiation.

Snell's law for refraction: n₁ sin θ₁ = n₂ sin θ₂, with angles measured from the normal.

Ohm's law: V = IR; power P = VI = I²R = V²/R.

Series resistors: R_total = R₁ + R₂ + …; parallel resistors: 1/R_total = 1/R₁ + 1/R₂ + ….

Series capacitors: 1/C_total = 1/C₁ + 1/C₂ + …; parallel capacitors: C_total = C₁ + C₂ + ….

Inductive reactance X_L = 2πfL; capacitive reactance X_C = 1/(2πfC); impedance Z = √(R² + (X_L − X_C)²).

For a sine wave, RMS value = peak value / √2.

Ideal transformer: Vp/Vs = Np/Ns and Ip/Is = Ns/Np.

Three-phase power P = √3 × V_L × I_L × cos φ for a balanced load.

Battery capacity is expressed in ampere-hours (Ah); internal resistance causes terminal voltage to fall under load.

Kirchhoff's current law: the algebraic sum of currents at a node is zero; voltage law: sum of emfs equals sum of potential differences around a loop.

A silicon diode is forward biased at about 0.7 V and has low resistance; in reverse bias it has high resistance until breakdown.

A Zener diode operates in controlled reverse breakdown and is used for voltage regulation or clamping.

For an NPN transistor, the base-emitter junction is forward biased and the base-collector junction reverse biased in the active region; β = Ic/Ib.

Ideal op-amp: infinite open-loop gain and input impedance, zero output impedance; inverting gain = −Rf/Rin; non-inverting gain = 1 + Rf/Rin.

First-order RC low-pass filter cutoff frequency: f_c = 1/(2πRC).

An oscillator requires positive feedback with loop gain at least 1 and a total phase shift of 360°.

A linear regulator dissipates power equal to (Vin − Vout) × I; a switching regulator typically has higher efficiency.

A bipolar transistor can be used as a switch by driving it between cutoff and saturation.

Binary place values increase by powers of 2: 1, 2, 4, 8, 16, 32, … from the least significant bit.

Logic gates: AND outputs 1 only when all inputs are 1; OR outputs 1 when any input is 1; XOR outputs 1 when inputs differ.

An n-bit ADC with reference voltage Vref has resolution Vref/2ⁿ.

ARINC 429 is a unidirectional serial bus using 32-bit words; CAN is a bidirectional bus.

ECAM/EICAS present engine and system parameters plus abnormal checklists; colour conventions distinguish warnings, cautions, and advisories.

LCD displays use polarisers and a backlight; CRT displays use an electron beam and phosphor screen.

MOS devices are susceptible to ESD damage; grounded wrist straps and conductive packaging are used for protection.

Redundancy architectures may be fail-safe or fail-operational; dissimilar redundancy reduces common-mode failure.

Aluminium alloy 2024 contains copper and has high strength but lower corrosion resistance; 7075 contains zinc and has very high strength.

Galvanic corrosion occurs when dissimilar metals are joined in the presence of an electrolyte; the more anodic metal corrodes.

Carbon-fibre composites have high strength-to-weight ratio; impact damage may cause delamination not visible externally.

Fastener grip length must match the thickness of the parts being joined; correct torque and locking are required.

Ball, roller, and needle bearings carry radial and/or axial loads and require correct lubrication and preload.

Spring types include compression, extension, and torsion; stress relaxation reduces spring force over time.

O-ring seals require correct material compatibility, groove dimensions, and lubrication to seal effectively.

Heat treatments include annealing, normalising, hardening, and tempering, each altering strength, hardness, and ductility.

Torque wrenches require periodic calibration against a traceable standard; torque is normally applied to the nut unless the procedure states otherwise.

Lockwire must be installed so that tension tends to tighten the fastener; pigtails are twisted and bent in the specified direction.

Common NDT methods: visual, dye penetrant, magnetic particle, eddy current, ultrasonic, and radiographic inspection.

ESD precautions include grounded wrist straps, conductive mats, and protective packaging for electrostatic-sensitive devices.

Foreign object debris control includes tool accounting, inspection, and secure storage of loose items.

Maintenance documentation includes task cards, work orders, inspection records, and the certificate of release to service.

Calibration provides traceability to national or international standards and confirms instrument accuracy within tolerance.

Fuel tank safety procedures address ignition sources, bonding, and confined-space entry.

Lift L = ½ρV²SC_L, where ρ is air density, V is true airspeed, S is wing area, and C_L is lift coefficient.

Increasing angle of attack raises lift up to the critical angle, beyond which the wing stalls.

Bernoulli's principle states that in steady incompressible flow, higher fluid speed corresponds to lower static pressure.

Mach number M = V/a, where a is local speed of sound; critical Mach number is reached when local airflow first becomes sonic.

Boundary layers may be laminar or turbulent; flow separation increases pressure drag and can cause stall.

A forward centre of gravity increases longitudinal static stability; an aft centre of gravity reduces it.

Ailerons control roll, elevators control pitch, and the rudder controls yaw.

Flaps increase both lift coefficient and drag, allowing lower approach speeds.

Load factor n = L/W; in a level turn, load factor increases and stall speed rises.

The SHELL model places liveware (people) at the centre, interacting with software, hardware, environment, and other liveware.

The Swiss cheese model describes accident causation as alignment of weaknesses in multiple defensive layers.

Fatigue impairs reaction time, attention, and decision-making; circadian rhythms affect alertness over a roughly 24-hour cycle.

Hypoxia reduces mental performance and judgement before noticeable physical symptoms occur.

Complacency can cause omitted checks or acceptance of non-standard conditions.

Effective communication uses standard phraseology, read-back, and confirmation to reduce misunderstanding.

Errors can be classified as slips, lapses, mistakes, and violations.

Human memory is reconstructive and subject to bias; written records and checklists reduce reliance on recall.

ICAO, established by the Chicago Convention, sets international standards and recommended practices through its annexes.

EASA Part-66 defines aircraft maintenance licence categories and privileges; B2 covers avionics and electrical systems.

EASA Part-145 governs approved maintenance organisations, including facilities, personnel, procedures, and quality systems.

EASA Part-M addresses continuing airworthiness and maintenance requirements for aircraft.

Airworthiness Directives are mandatory and must be complied with; Service Bulletins are generally not mandatory unless incorporated by an AD or regulation.

The Minimum Equipment List permits operation with specified equipment inoperative under stated conditions.

A Certificate of Release to Service is issued after maintenance to certify that the work has been completed satisfactorily.

Occurrence reporting requires reporting of accidents, serious incidents, and defined occurrences to the competent authority.