Intermediate Aerospace interview questions

150 questions with answers (AER-151 to AER-300). Try each one aloud before reading the answer.

Incompressible Aerodynamics

AER-151 · What are the main types of drag?

Parasitic drag (skin friction, form/pressure drag and interference drag), induced drag (from lift and the trailing vortex system) and wave drag (from shocks at transonic and supersonic speeds).

AER-152 · What are winglets for?

They weaken the wingtip vortex and recover some of its energy as forward thrust, reducing induced drag without the structural cost of a full span increase.

AER-153 · What is the induced drag coefficient formula?

C_Di = C_L²/(π·e·AR), where e is the span efficiency (Oswald) factor. Induced drag falls with higher aspect ratio and higher e.

AER-154 · What does the Kutta–Joukowski theorem state?

Lift per unit span equals L′ = ρ·V∞·Γ, where Γ is circulation around the airfoil.

AER-155 · What is the Kutta condition?

Flow must leave a sharp trailing edge smoothly. This fixes the circulation and therefore the lift on an airfoil in potential flow theory.

AER-156 · What does thin airfoil theory predict for lift-curve slope?

A lift-curve slope of 2π per radian (about 0.11 per degree), with the aerodynamic centre at the quarter chord.

AER-157 · What is the aerodynamic centre?

The point about which the pitching moment coefficient does not change with angle of attack, near the quarter chord for subsonic airfoils.

AER-158 · How does finite span affect lift-curve slope?

Downwash reduces the effective angle of attack, so a = a₀/(1 + a₀/(π·e·AR)), lower than the 2D value.

AER-159 · Why is an elliptical lift distribution ideal?

It produces uniform downwash along the span and minimum induced drag for a given lift and span (e = 1).

AER-160 · Laminar vs turbulent boundary layer?

Laminar layers have smooth, layered flow and low skin friction but separate easily. Turbulent layers mix momentum, have higher skin friction, but resist adverse pressure gradients and separation better.

AER-161 · Why does flow separate?

An adverse pressure gradient decelerates the low-energy fluid near the wall until wall shear stress falls to zero and the flow reverses and detaches.

AER-162 · How do leading-edge slats work?

They create a slot that energises the upper-surface boundary layer with high-energy air, delaying separation and allowing a higher stall angle and C_L,max.

AER-163 · What do vortex generators do?

Small vanes that create streamwise vortices, mixing high-energy outer flow into the boundary layer to delay separation.

Compressible & High-Speed Flow

AER-164 · Why are swept wings used on jet aircraft?

Sweep reduces the velocity component normal to the leading edge (M·cos Λ), raising the critical Mach number and delaying the transonic drag rise.

AER-165 · What is drag divergence Mach number?

The Mach number where wave drag causes drag coefficient to rise sharply, commonly defined where dC_D/dM = 0.1. It is slightly above critical Mach.

AER-166 · What is a supercritical airfoil?

An airfoil with a flatter upper surface and aft camber that weakens the upper-surface shock, raising drag divergence Mach number or allowing thicker wings.

AER-167 · State the area–velocity relation for isentropic flow.

dA/A = (M² − 1)·dV/V. Subsonic flow speeds up in a converging duct; supersonic flow speeds up in a diverging duct.

AER-168 · What is the Prandtl–Glauert correction?

A subsonic compressibility correction: C_p = C_p,0/√(1 − M²). Valid for thin bodies up to about Mach 0.7.

AER-169 · Why is total pressure lost across a shock but total temperature conserved?

A shock is adiabatic, so total enthalpy and total temperature stay constant, but it is irreversible, so entropy rises and total pressure falls.

AER-170 · What is the critical pressure ratio for choking in air?

p*/p₀ = (2/(γ+1))^(γ/(γ−1)) ≈ 0.528 for γ = 1.4. Below this back-pressure ratio a convergent nozzle chokes.

AER-171 · What is aerodynamic heating?

Heating of the vehicle surface as the boundary layer slows high-speed flow, converting kinetic energy into heat; it approaches stagnation temperature at the wall.

AER-172 · Why do supersonic aircraft have thin, sharp wings?

Wave drag scales roughly with (t/c)², and sharp leading edges allow attached oblique shocks instead of strong detached bow shocks.

AER-173 · What is shock-induced separation?

When a shock's adverse pressure jump thickens or separates the boundary layer, causing buffet, drag rise and loss of control effectiveness.

AER-174 · What is a detached bow shock?

A curved shock that stands ahead of a blunt body, or of a wedge whose deflection angle exceeds the maximum for an attached oblique shock.

AER-175 · Why are re-entry capsules blunt?

A blunt shape creates a strong detached bow shock that stands off from the surface, so much of the heat goes into the shock layer gas and convective heating is reduced.

AER-176 · How do you calculate stagnation temperature at Mach 2 for T = 217 K?

T₀ = T(1 + 0.2·M²) = 217 × (1 + 0.8) = 390.6 K.

Gas Turbine Propulsion

AER-177 · Turbojet vs turbofan: which is more efficient at subsonic cruise and why?

The turbofan. It accelerates a larger mass of air by a smaller velocity, so less kinetic energy is wasted in the jet and propulsive efficiency is higher. It is also quieter.

AER-178 · What is propulsive efficiency?

η_p = 2/(1 + V_j/V₀), the ratio of useful thrust power to the rate of kinetic energy added to the flow. It rises as jet velocity approaches flight speed.

AER-179 · What determines ideal Brayton cycle thermal efficiency?

η_th = 1 − 1/r_p^((γ−1)/γ), so it depends only on pressure ratio r_p in the ideal cycle.

AER-180 · What is overall efficiency of a jet engine?

η_o = η_th × η_p, the thrust power divided by fuel energy release rate.

AER-181 · Why are gas turbines multi-spool?

Separate shafts let low- and high-pressure compressors run at their own best speeds, improving stall margin, efficiency and starting.

AER-182 · What is compressor surge?

A breakdown of flow through the whole compressor where it cannot sustain the pressure rise, causing flow reversal, loud bangs and possible flame-out.

AER-183 · What is rotating stall?

Stalled cells that rotate around the compressor annulus at a fraction of rotor speed, causing vibration and loss of pressure rise; it can lead to surge.

AER-184 · How is compressor stall prevented?

With variable inlet guide vanes and stators, bleed valves, multiple spools and control schedules that keep the operating line below the surge line.

AER-185 · Why is turbine entry temperature (TET) important?

Higher TET increases specific thrust and cycle efficiency, but is limited by blade materials, cooling and coatings.

AER-186 · How are turbine blades cooled?

Compressor bleed air flows through internal passages (convection and impingement) and exits through holes to form a protective film on the surface.

AER-187 · Why does thrust drop as altitude increases?

Air density and mass flow fall, so thrust falls roughly in proportion to density ratio, partly offset by colder air and ram recovery.

AER-188 · What is a geared turbofan?

A turbofan with a gearbox between fan and low-pressure turbine, letting the fan turn slowly and the turbine fast, each near optimum, allowing higher bypass ratios.

AER-189 · What does an engine pressure ratio (EPR) gauge show?

The ratio of exhaust total pressure to inlet total pressure, used on some engines as the primary thrust-setting parameter.

Rocket Propulsion

AER-190 · What is specific impulse and why is higher better?

Isp = F/(ṁ·g₀), thrust per unit weight flow of propellant in seconds. Higher Isp means more Δv from the same propellant mass.

AER-191 · Typical Isp of common propellant combinations?

Roughly 250–300 s for solids, about 300–350 s vacuum for LOX/kerosene, about 450 s vacuum for LOX/LH₂, and over 1,500 s for ion thrusters.

AER-192 · What is characteristic velocity c*?

c* = p_c·A_t/ṁ, a measure of combustion performance independent of the nozzle.

AER-193 · What is thrust coefficient C_F?

C_F = F/(p_c·A_t), a measure of nozzle performance. Thrust F = C_F·p_c·A_t.

AER-194 · What is nozzle expansion ratio?

ε = A_e/A_t. Optimum expansion occurs when exit pressure equals ambient pressure.

AER-195 · What is an over-expanded nozzle?

A nozzle whose exit pressure is below ambient. Ambient pressure acts against it, causing thrust loss and possibly flow separation inside the nozzle.

AER-196 · What is an under-expanded nozzle?

A nozzle whose exit pressure is above ambient, so gas keeps expanding outside the nozzle and some potential thrust is lost.

AER-197 · Gas-generator vs staged-combustion cycle?

In a gas-generator cycle, turbine exhaust is dumped overboard, which is simpler but wastes propellant. In staged combustion, turbine exhaust goes into the main chamber, giving higher chamber pressure and Isp at greater complexity.

AER-198 · What is the expander cycle?

Fuel is heated in the cooling jacket and drives the turbopump before entering the chamber. Used with hydrogen, it is limited in chamber pressure by heat transfer.

AER-199 · What is regenerative cooling?

Circulating fuel or oxidiser through channels in the chamber and nozzle walls before injection, absorbing heat and recovering it into the propellant.

AER-200 · How does grain geometry affect solid rocket thrust?

Burning surface area versus time sets thrust. Star or finocyl grains can give neutral, progressive or regressive thrust profiles.

AER-201 · What is combustion instability?

Coupling between combustion heat release and chamber acoustics that drives pressure oscillations, which can destroy an engine. Baffles and injector design suppress it.

AER-202 · What is the burn-rate law for solid propellant?

Saint-Robert's law r = a·p_cⁿ, where n is the pressure exponent; n must be below 1 for stable combustion.

Flight Mechanics & Stability

AER-203 · What is the criterion for longitudinal static stability?

dC_m/dα < 0 about the CG: a nose-up disturbance must create a nose-down restoring moment.

AER-204 · What does the horizontal tail contribute to stability?

Because it is far behind the CG, any increase in angle of attack creates extra tail lift and a nose-down restoring moment, moving the neutral point aft.

AER-205 · What are the longitudinal dynamic modes?

The short-period mode (fast, well-damped pitch oscillation) and the phugoid (slow, lightly damped exchange of speed and height at almost constant angle of attack).

AER-206 · What are the lateral-directional dynamic modes?

The roll subsidence (fast, non-oscillatory), the spiral mode (slow, can be divergent) and the Dutch roll (coupled yaw–roll oscillation).

AER-207 · What is Dutch roll and how is it controlled?

A coupled oscillation of yaw and roll, common in swept-wing jets with strong dihedral effect relative to directional stability. A yaw damper adds rudder inputs to damp it.

AER-208 · What is spiral instability?

A slow divergence in which a small bank leads to increasing bank and a tightening descending turn. It occurs when directional stability is large relative to dihedral effect.

AER-209 · How does CG position affect stability and control?

A forward CG increases stability but requires more elevator for rotation and landing flare. An aft CG reduces stability and control forces and can become unstable.

AER-210 · What is stick-free stability?

Stability with the elevator allowed to float freely. It is usually lower than stick-fixed stability because the floating elevator reduces tail effectiveness.

AER-211 · What is the bank angle for a 2g level turn?

n = 1/cos φ, so cos φ = 0.5 and φ = 60°.

AER-212 · What is the turn radius formula?

R = V²/(g·tan φ). Higher speed or a lower bank angle increases the radius.

AER-213 · What is a spin?

An autorotation in which one wing is more stalled than the other, giving a combined roll, yaw and steep descent. Recovery generally uses opposite rudder and forward elevator.

AER-214 · Why are canards used on some aircraft?

A foreplane produces positive (lifting) trim instead of the download of a conventional tail and can stall first to protect the main wing. It complicates stability and flap integration.

AER-215 · What are Euler angles?

Roll (φ), pitch (θ) and yaw (ψ) angles describing aircraft attitude relative to an Earth-fixed frame via successive rotations.

Aircraft Performance

AER-216 · What is the Breguet range equation for jets?

R = (V/(c·g))·(L/D)·ln(W₀/W₁), with c the TSFC per unit time. Range rises with speed × L/D and with fuel fraction.

AER-217 · What is the Breguet endurance equation for jets?

E = (1/(c·g))·(L/D)·ln(W₀/W₁). Maximum endurance occurs at maximum L/D.

AER-218 · At what condition is drag minimum in level flight?

When induced drag equals parasite drag, giving C_L = √(π·e·AR·C_D0) and maximum L/D.

AER-219 · Speed for maximum range for jet vs propeller aircraft?

A propeller aircraft maximises range at maximum L/D. A jet maximises range at maximum √C_L/C_D, a speed about 1.32 times the minimum-drag speed.

AER-220 · What is the drag polar?

C_D = C_D0 + K·C_L², with K = 1/(π·e·AR). It relates drag to lift for the aircraft.

AER-221 · How do you convert EAS to TAS?

TAS = EAS/√σ, where σ = ρ/ρ₀. At density ratio 0.25, TAS is twice EAS.

AER-222 · What is Mach 0.8 TAS at 11 km ISA?

At 11 km T = 216.65 K, a = √(1.4×287×216.65) ≈ 295 m/s, so TAS ≈ 236 m/s.

AER-223 · What factors affect take-off distance?

Weight (roughly ∝ W²), density altitude, wind, runway slope and surface, flap setting, thrust and C_L,max.

AER-224 · What is balanced field length?

The runway length where accelerate-stop distance equals accelerate-go distance after an engine failure at V1.

AER-225 · What is the absolute ceiling?

The altitude at which maximum rate of climb is zero; the aircraft can only just hold level flight at one speed.

AER-226 · Best angle of climb vs best rate of climb?

Vx (best angle) maximises excess thrust and height per distance, for clearing obstacles. Vy (best rate) maximises excess power and height per time.

AER-227 · What is the coffin corner?

The high-altitude condition where low-speed stall speed and high-speed buffet or Mach limit converge, leaving a narrow speed margin.

AER-228 · How much does the stall speed rise in a 60° banked turn?

Stall speed scales with √n. At 60° bank n = 2, so V_s rises by √2, about 41%.

Aircraft Structures

AER-229 · How does a wing carry its loads?

Lift is passed from skin to ribs to spars. Spar caps and skin–stringer panels carry bending as tension and compression, spar webs carry shear, and the closed wing box carries torsion.

AER-230 · What is shear flow?

Shear force per unit length along a thin wall, q = τ·t (N/m). It is the basic quantity in thin-walled section analysis.

AER-231 · What is the Bredt–Batho formula?

For a closed thin-walled section under torque, T = 2·A·q, where A is the area enclosed by the wall mid-line and q is the constant shear flow.

AER-232 · What is the shear centre?

The point in a cross-section through which a transverse load must pass to cause bending with no twisting.

AER-233 · What is hoop stress in a pressurised fuselage?

σ_h = p·r/t, twice the longitudinal stress p·r/(2t). This is why longitudinal skin cracks are a greater concern.

AER-234 · What is the safe-life design philosophy?

Parts are designed to have a fatigue life with a large scatter factor and are retired before cracks are expected, as with landing gear.

AER-235 · What is fail-safe design?

A structure with multiple load paths or crack stoppers so that if one element fails, the remainder carries the load until the failure is found.

AER-236 · What is damage tolerance?

A philosophy assuming flaws exist from the start. Inspection intervals are set so cracks are found before they grow to critical size.

AER-237 · What is the V–n diagram?

A plot of load factor versus airspeed showing the flight envelope. It is bounded by stall curves, positive and negative limit load factors and dive speed.

AER-238 · Typical limit load factors for transport aircraft?

About +2.5 g (up to +3.8 g at lower weights) and −1.0 g in the clean configuration, per CS-25/FAR 25.

AER-239 · What is a gust load?

The extra load factor from a vertical gust that suddenly changes angle of attack, Δn ≈ ρ·V·U·a/(2·W/S) before alleviation factors.

AER-240 · What is diagonal tension in skin panels?

After a thin web buckles in shear, it carries load as tension along diagonal folds, which aircraft structures deliberately exploit to save weight.

Aerospace Materials

AER-241 · Why are composites used in aircraft?

High specific strength and stiffness, excellent fatigue and corrosion resistance and tailorable properties. They save weight and allow part consolidation.

AER-242 · What is a laminate layup notation such as [0/±45/90]s?

Ply angles relative to the reference axis; "s" means symmetric about the mid-plane. 0° plies carry axial load, ±45° carry shear and 90° carry transverse load.

AER-243 · Why are composite laminates made symmetric and balanced?

Symmetry removes bending–extension coupling, so the laminate does not warp on curing. Balance (equal +θ and −θ plies) removes extension–shear coupling.

AER-244 · What is delamination?

Separation between plies of a laminate, often from impact, manufacturing defects or free-edge stresses. It severely reduces compression strength.

AER-245 · What is BVID?

Barely visible impact damage: internal composite damage from impact that leaves little surface indication. Designs must carry ultimate load with BVID present.

AER-246 · What is precipitation hardening in aluminium alloys?

Solution treatment, quenching and ageing that form fine precipitates that block dislocation motion, raising strength (e.g., T6 temper).

AER-247 · Why is galvanic corrosion a concern between CFRP and aluminium?

Carbon is cathodic to aluminium, so in contact with moisture the aluminium corrodes. Glass-fibre isolation plies, sealants and titanium fasteners are used.

AER-248 · What is fracture toughness?

K_IC, a material's resistance to crack propagation, in MPa·√m. Fast fracture occurs when K = Y·σ·√(πa) reaches K_IC.

AER-249 · What is the Paris law?

da/dN = C·(ΔK)ᵐ, the fatigue crack growth rate per cycle as a function of stress intensity range.

AER-250 · Why are aluminium-lithium alloys used?

Each 1% lithium reduces density and raises stiffness. Newer Al-Li alloys give better fatigue crack growth resistance than conventional alloys.

AER-251 · What is autoclave curing?

Curing prepreg laminates under heat and pressure in a vessel to consolidate plies and remove voids, giving high-quality parts at high equipment cost.

AER-252 · What are ceramic matrix composites (CMCs) used for?

Hot-section parts such as turbine shrouds and nozzles. They withstand higher temperatures than superalloys at about one-third of the density.

Orbital Mechanics

AER-253 · What is the vis-viva equation?

v² = μ(2/r − 1/a). It gives orbital speed at any radius for an orbit of semi-major axis a.

AER-254 · What is the orbital period formula?

T = 2π·√(a³/μ). For a 400 km circular LEO, a = 6,778 km gives T ≈ 92.6 minutes.

AER-255 · What is specific orbital energy?

ε = v²/2 − μ/r = −μ/(2a). Negative for closed orbits, zero for parabolic and positive for hyperbolic.

AER-256 · How much faster is escape velocity than circular velocity?

v_esc = √2 × v_circ at the same radius, about 41% higher.

AER-257 · What is a plane-change manoeuvre and why is it costly?

A burn to change inclination: Δv = 2v·sin(Δi/2). It scales with orbital velocity, so it is best done at apoapsis or combined with other burns.

AER-258 · What is the J2 perturbation?

The effect of Earth's equatorial bulge, which causes regression of the ascending node and rotation of the line of apsides.

AER-259 · What is a Molniya orbit?

A highly elliptical, 12-hour orbit at about 63.4° inclination, where apsidal rotation from J2 is zero, giving long dwell over high latitudes.

AER-260 · What is atmospheric drag's effect on LEO satellites?

It removes energy, lowering the orbit and, paradoxically, raising orbital speed. Drag grows with solar activity and lower altitude, eventually causing re-entry.

AER-261 · What are Lagrange points?

Five positions in a two-body system where a small body can stay fixed relative to the two large bodies. L1, L2 and L3 are unstable; L4 and L5 are stable for mass ratios above about 25.

AER-262 · What is a gravity assist?

A flyby of a planet that rotates the spacecraft's velocity relative to the planet, changing its heliocentric speed and direction without propellant.

AER-263 · What is the sphere of influence?

The region around a body within which its gravity dominates the trajectory, used in the patched-conic approximation.

AER-264 · What is a ground track?

The path traced on Earth's surface by the point directly below a satellite. Its shape depends on inclination, period and Earth's rotation.

Spacecraft Systems

AER-265 · How is a solar array sized?

From end-of-life power demand plus losses, accounting for eclipse charging, cell efficiency, degradation, temperature and sun angle.

AER-266 · What is battery depth of discharge (DoD) and why limit it?

The fraction of capacity used per cycle. LEO missions see thousands of cycles per year, so DoD is kept low to achieve long cycle life.

AER-267 · What is momentum dumping?

Reaction wheels accumulate momentum from external torques until they saturate. Thrusters or magnetorquers apply an external torque to unload them.

AER-268 · What is gravity-gradient stabilisation?

Passive attitude control using the tidal torque that aligns a spacecraft's long axis with the local vertical.

AER-269 · Spin-stabilised vs three-axis-stabilised spacecraft?

Spin-stabilised spacecraft use gyroscopic stiffness, which is simple but makes pointing instruments harder. Three-axis-stabilised spacecraft control all axes actively for precise pointing at greater complexity.

AER-270 · What is a star tracker?

A camera that images star fields and matches them to a catalogue to determine attitude with accuracy of arc-seconds.

AER-271 · How does a spacecraft reject heat?

By thermal radiation from radiators, per Q = ε·σ·A·T⁴. High-emissivity, low-absorptivity surfaces are used.

AER-272 · What is a link budget?

An accounting of transmit power, antenna gains, path loss and noise to find received signal-to-noise ratio and margin for a communication link.

AER-273 · What is free-space path loss?

FSPL = (4πd/λ)², growing with the square of distance and frequency. It dominates deep-space communication design.

AER-274 · What are single-event effects?

Faults caused by single energetic particles: bit flips (upsets), latch-ups and burnouts. Mitigated with rad-hard parts, EDAC and watchdogs.

AER-275 · What is total ionising dose?

Accumulated radiation dose that degrades electronics over mission life; shielding and rad-tolerant parts manage it.

AER-276 · What is outgassing?

Release of volatiles from materials in vacuum that can contaminate optics and sensors. Low-outgassing materials and bake-outs are required.

Avionics, Navigation & Control

AER-277 · Why does INS drift over time?

Gyro and accelerometer biases and noise are integrated, so velocity errors grow linearly and position errors grow faster with time.

AER-278 · What is a Kalman filter used for in navigation?

It optimally fuses noisy measurements, such as GNSS and INS, using a system model, estimating states and their uncertainty in real time.

AER-279 · What is ARINC 429?

A unidirectional avionics data bus with one transmitter and up to 20 receivers, using 32-bit words.

AER-280 · What is MIL-STD-1553?

A dual-redundant, command/response military data bus at 1 Mbit/s controlled by a bus controller.

AER-281 · What is AFDX?

Avionics Full-Duplex Switched Ethernet (ARINC 664 Part 7), a deterministic switched Ethernet network with virtual links and bandwidth guarantees.

AER-282 · What is Integrated Modular Avionics (IMA)?

An architecture where many functions share common computing modules with robust time and space partitioning (e.g., ARINC 653), reducing weight and LRU count.

AER-283 · What is a flight management system (FMS)?

A computer that manages the flight plan, lateral and vertical navigation and performance predictions, and guides the autopilot and autothrottle.

AER-284 · What is RNAV and RNP?

RNAV is area navigation along any desired path. RNP adds onboard performance monitoring and alerting to a specified accuracy (e.g., RNP 0.3 nm).

AER-285 · What is a VOR?

A VHF ground beacon that lets an aircraft determine its magnetic bearing from the station.

AER-286 · What are flight control laws in fly-by-wire aircraft?

Software modes, such as normal, alternate and direct, that translate pilot inputs into surface commands and may include envelope protection.

AER-287 · How does a ring laser gyro work?

Two laser beams travel in opposite directions around a closed path. Rotation causes a frequency difference (Sagnac effect) proportional to angular rate.

AER-288 · What is a radar altimeter?

A downward radio altimeter measuring height above terrain from reflected signal time, used for approach, autoland and terrain warning.

Aeroelasticity, Certification & Safety

AER-289 · Why does flutter speed matter in certification?

The aircraft must be free from flutter with margin beyond its design dive speed. Large-aircraft rules require analysis to an envelope enlarged 15% in equivalent airspeed beyond V_D/M_D, backed by flight test.

AER-290 · How is flutter prevented?

By mass balancing control surfaces, raising torsional stiffness, keeping bending and torsion frequencies apart, and placing mass ahead of the elastic axis.

AER-291 · How does sweep affect divergence?

Aft sweep makes bending reduce tip angle of attack (wash-out), which delays divergence. Forward sweep makes bending increase angle of attack, lowering divergence speed.

AER-292 · What is a ground vibration test (GVT)?

A test where the aircraft is excited by shakers to measure natural frequencies, mode shapes and damping, which validate the flutter model.

AER-293 · What is a failure hazard assessment (FHA)?

An early system-safety step that identifies failure conditions and classifies them as catastrophic, hazardous, major, minor or no safety effect.

AER-294 · What are the quantitative probability targets for failure conditions in CS-25?

Catastrophic: extremely improbable (under 1×10⁻⁹ per flight hour). Hazardous: under 1×10⁻⁷. Major: under 1×10⁻⁵.

AER-295 · What is ARP4754A?

The guideline for development of civil aircraft and systems, covering requirements, development assurance levels and validation, used with ARP4761 safety assessment.

AER-296 · What is DO-254?

The design assurance guidance for airborne electronic hardware, especially complex devices such as FPGAs and ASICs.

AER-297 · What is fault tree analysis?

A top-down method linking a failure event to its causes through AND/OR gates to compute probability and find single points of failure.

AER-298 · What is the Swiss cheese model?

Reason's model in which accidents occur when holes in successive defensive layers (design, procedures, training, supervision) line up.

AER-299 · What is MSG-3?

The maintenance steering group method used to develop scheduled maintenance tasks for transport aircraft from system and structural analysis.

AER-300 · What is bird-strike certification?

Demonstration that windshields, structure and engines withstand specified bird impacts, such as engine ingestion tests per CS-E/FAR 33.

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