A short, conversational check that you have broad basic knowledge, not deep detail on any one subject.

The technical interview is usually brief (around 15 to 20 minutes). The assessor is ticking boxes: they want to hear the key idea, then they move on. They often start with one question and jump to a related one, so the conversation can go anywhere. It falls into three themes, your ATPL theory, the aircraft you have flown, and the 737.

Questions are usually steered by your background. A candidate with an engineering background should expect more technical questions about the aircraft, while a candidate from a social-sciences background is more likely to get CRM or human-factors questions.

Questions marked Hot come from assessment feedback in the last six months. The rest are long-standing favourites.

The theory questions that come up most: meteorology, aerodynamics, instruments and performance.

Meteorology

• HotWhere do you find turbulence, and what causes it?Mechanical, thermal, frontal, wind-shear, mountain-wave and CAT near jet streams.
• HotWhat is a jet stream? What phenomena go with it, and how would you cross one?Narrow high-altitude wind core near the tropopause; brings CAT; cross at 90° and change level to clear it fast.
• HotHow can you anticipate clear air turbulence (CAT)?SIGWX charts, jet-stream position and PIREPs, no reliable onboard detection.
• HotHow does a thunderstorm form, and what are the stages?Needs moisture, instability and a lift trigger; cumulus → mature → dissipating.
• HotYou have a storm cell ahead on takeoff, what are the hazards?Wind shear/microburst, gusts, hail, turbulence, lightning, heavy rain, downdraughts.
• HotHow do you avoid a thunderstorm in the cruise? And if the wind is coming from your left?Deviate ~20 nm, upwind of the cell (hail drifts downwind), into the wind, so to the left here.
• HotWhat is a microburst, and what is windshear?Windshear = sudden change in wind speed/direction; microburst = intense local downdraught spreading out at the surface.
• HotWhich system detects windshear, and how does it work (Doppler)?Predictive windshear from the weather radar (Doppler frequency shift), plus a reactive GPWS-based warning.
• HotWhat is a temperature inversion, and how does it affect performance?Warmer air above colder; very stable, poor mixing; degrades climb/engine performance and traps haze.
• HotRead back this METAR group for me (for example MI, SH, VC, SN, GR, BR, FG, TSRA).MI shallow, SH showers, VC vicinity, SN snow, GR hail, BR mist, FG fog, TSRA thunderstorm with rain.
• What is the minimum wind speed that defines a jet stream?60 kt or more.
• Temperature 15°C, dew point 14°C, what weather would you expect?~1° spread → very humid → mist/fog or low cloud likely.
• How does a low- or high-pressure system drive the weather?Lows: rising air, cloud, precip, wind; highs: sinking air, settled/clear.
• What is the definition of twilight?Period after sunset/before sunrise; civil twilight = sun 6° below the horizon.

Principles of flight & high-speed aerodynamics

• HotWhy are the wings swept? What angle, and why not more?Raises M_crit/delays compressibility; more sweep costs low-speed lift and handling, a compromise (~25°).
• HotWhat is M_crit? What is Mach tuck, and what is Mach trim?M_crit = Mach where flow first goes sonic; Mach tuck = nose-down from aft shock/CP shift; Mach trim adds nose-up to counter it.
• HotWhat is the critical engine, and why is it critical?The one whose failure most degrades control/performance; on a conventional twin the left (P-factor, descending blade further from centreline).
• Where does a swept wing tend to stall first, and why?At the tips (spanwise flow) → pitch-up risk; hence washout, fences, vortilons.
• What is the Mach number, and roughly what level do you change from an IAS to a Mach reference?TAS ÷ local speed of sound; change to Mach at the crossover, ~FL290.
• What is the absolute ceiling versus the service ceiling? Can you reach the service ceiling at MTOW?Absolute = zero climb rate; service = 100 ft/min left; not at MTOW, burn down or step-climb.
• What is dihedral, and what does it do?Upward wing angle giving lateral (roll) stability.
• What are spoilers for, and how do they work?Reduce lift / add drag, speedbrake in flight, lift-dump and roll assist on the ground.
• Does a single-engine piston aircraft have a P-factor?Yes, asymmetric blade loading yaws the nose (left with a clockwise prop) at high AoA.
• What is a deep stall on a T-tail aircraft?Stalled-wing wake blankets the high tailplane → loss of pitch authority, hard to recover.
• Explain wake turbulence.Wingtip vortices from lift; worst heavy/clean/slow; sink and drift downwind → separation minima.

Instruments & air data

• HotWhat is a pitot tube, and what is a static port? Which instruments use each?Pitot = total pressure (ASI); static = static pressure (ALT, VSI).
• HotThe pitot blocks with ice in the climb (or descent), what does the airspeed do, and how do you fly (pitch and power)?Acts like an altimeter: over-reads in the climb, under-reads in the descent; fly known pitch + power.
• HotWhat is a radio altimeter, and which systems use it (for example the GPWS)?Height AGL below ~2500 ft; feeds GPWS/EGPWS, autoland and minima callouts.
• HotWhat is TAT? Is it higher or lower than the real air temperature, and why?Total Air Temperature: higher than SAT, because ram/kinetic heating adds a rise.
• HotDoes TAS increase or decrease with altitude for a fixed IAS, and why?Increases, lower air density with height.
• HotYou set 1023 instead of 1013 on the altimeter, are you higher or lower than indicated? What is this error called?Subscale ~10 hPa too high → altimeter under-reads (~280 ft low) → you are actually higher; a pressure-setting error.
• What is a gyroscope, and which of your instruments used one?Rigidity & precession; attitude indicator, heading indicator/DG, turn coordinator.
• You take off with the pitot cover left on, what does the airspeed show?Reads low or zero, no ram/dynamic pressure.

Performance & flight planning

• HotYour destination is forecast foggy, what conditions make an alternate legal?Alternate forecast at/above its planning minima for the ETA window, with fuel to reach it.
• HotWhy do we carry contingency fuel? What is final reserve fuel, and how much is it?Contingency (~5% of trip fuel) covers the unexpected in flight, such as wind or routing that differs from the plan, ATC re-routes, or a level lower than planned. Final reserve = 30 min holding at 1500 ft.
• HotWhen do you call “MAYDAY FUEL”?When usable fuel on landing at the nearest suitable will be below final reserve.
• HotWork through a simple crosswind calculation.Crosswind = wind × sin(angle); rule of thumb 30°≈½, 45°≈0.7, 60°≈full.
• HotFlying in cold or hot weather, how do indicated altitude and airspeed change, and how many feet do you add or subtract per degree?Cold → altimeter over-reads (true lower) → add corrections; ~4 ft per 1000 ft per °C from ISA.
• HotWhy must you be careful flying into very cold weather?True altitude is below indicated, apply cold-temperature corrections to minima and terrain clearance.
• What is TODA? What are a stopway and a clearway? Can you taxi on a clearway?TODA = TORA + clearway; stopway = paved area to stop in; clearway = obstacle-free area beyond, no taxiing on it.
• What is screen height?The height the aircraft must reach or clear over the runway end. Takeoff: 35 ft dry, 15 ft wet. Landing: 50 ft over the threshold.
• What is V_MCG, and can it be higher than V1?Min speed for directional control on the ground with an engine out; V1 is not set below V_MCG.
• What are CAT I / II / III minima? What are planning minima? What is the difference between MDA and DA?DA (precision, no level-off) vs MDA (non-precision, don’t go below). CAT I: DH 200 ft, RVR 550 m. CAT II: DH 100 ft, RVR 300 m. CAT III: IIIA DH below 100 ft, RVR 200 m; IIIB DH below 50 ft, RVR 75 m; IIIC no DH, RVR 0. Planning minima are applied at the planning stage.
• What is TUC at 40,000 ft?Time of useful consciousness ~15 to 20 seconds.
• Why might a runway have a permanently displaced threshold?Approach obstacles, noise, or declared-distance limits (landing displaced, takeoff can use full length).

Navigation, communication & surveillance

• HotWhat would you do in the event of a radio / communications failure?Squawk 7600, continue per last clearance / expected route and level, follow lost-comms rules, try other means.
• HotWhat is the difference between VHF and HF?VHF line-of-sight, short range, clear; HF long-range sky-wave for oceanic, noisier.
• HotDo you have to monitor HF continuously?No, SELCAL chimes when they call you.
• HotExplain datalink / CPDLC.Text clearances/messages between crew and ATC; cuts R/T, used oceanic and remote.
• HotTell me about the North Atlantic tracks, routing, required equipment and position reporting.Organised daily tracks; need MNPS/PBN plus HF or CPDLC; position reports at waypoints.
• HotWhat is TCAS? What are the two alert types, which one do you manoeuvre for, and what do you tell ATC after an RA?TA (advisory, don’t manoeuvre) and RA (follow it, even against ATC); report “TCAS RA”, then “clear of conflict”.
• HotWhat is the difference between the GPWS and the EGPWS? Explain the EGPWS.GPWS is reactive (radio alt, modes 1 to 7); EGPWS adds a terrain database + GPS for predictive look-ahead and a terrain display.
• You get a TCAS RA to climb at your service ceiling. What do you do?Follow the RA with the performance available; it may not achieve the full rate.
• What equipment is required to fly in Class D airspace, and what are the differences between airspace classes?D: two-way radio and a clearance (transponder as required); classes differ by IFR/VFR mix, clearance and separation.
• What is CFIT, and what is UPRT?CFIT = Controlled Flight Into Terrain: an airworthy aircraft, under the control of the crew, is flown unintentionally into terrain, water or an obstacle, usually with no awareness by the crew until too late. UPRT = upset prevention & recovery training.

Icing & unreliable airspeed

• HotWhat are the effects of icing conditions on the aircraft?Added weight and drag, disrupted lift and stall margin, blocked probes, AoA/control effects, use anti-/de-ice.
• HotUnreliable airspeed, what are your actions?Disconnect A/P, A/T and FD; set memory pitch + thrust; then use the QRH tables.
• HotWhat is the difference between a windshear escape manoeuvre and a go-around?Escape: max thrust, wings level, follow FD/pitch, don’t change configuration; go-around is the normal missed approach with config changes.

Expect to be walked through the aircraft you trained on: engines, systems and how you handled failures.

Swap the types below for the ones you actually flew (C152/C172, PA28, DA42, PA44/Seminole, DR400, A320, B737…). The assessor uses your aircraft as the starting point and jumps from there.

Talking about your aircraft

• HotTell me about your multi-engine aircraft.
• HotTell me about your flight school, how many aircraft, what types, the airport and facilities.
• HotWhich airspace did you fly in, and what are the dangers at the airports you used?
• HotWhat are the differences between two types you flew (for example C150 vs C172, or a DR400 vs the rest)?

Piston engines & propellers

• HotWhat causes carburettor icing, and how do you prevent it? Explain the carb-heat system.
• HotHow is cockpit heating produced, and what is the risk (carbon-monoxide poisoning)?
• HotWhen you press the starter, why does the propeller turn (direct-drive engine)?
• HotWhat is the Otto cycle, and how does it differ from a turbine engine?
• HotWhat is the difference between a FADEC diesel and a carburetted engine?
• Where are the fuel tanks, and are there any extra fuel pumps?
• Can you feather the propeller? What happens if a propeller suddenly stops?

Multi-engine handling

• HotWhich is the critical engine, and why? (And why does a twin like the DA42 or Seminole sometimes not have one?)
• HotHow are counter-rotating propellers achieved?
• HotWhat is V_MCA, and what is the rotation speed? Why is rotation higher?
• HotWalk me through the engine-failure procedure (“dead foot, dead engine”).
• What flaps are fitted, and what setting would you use landing with and without a crosswind, and why?

Systems & induction

• HotHow is electrical power generated, and what failures can occur?
• HotDescribe the anti-ice and hydraulic systems on your twin (for example the PA44).
• HotWhat is the difference between a normally-aspirated and a turbocharged engine?
• HotHow does a turbocharged engine cool the intake air (intercooler)?
• HotWhat are slats and flaps, and how do they differ from those on the 737?
• What is the difference between a turbocharger and a supercharger?

The 737 questions that come up again and again. Start broad, then be ready to go one level deeper.

Note: the depth of these questions usually depends on your MCC. Candidates who did their MCC on the 737 tend to get more detailed 737 questions, while those coming from an A320 MCC are generally asked at a more basic level.

Many of these are covered on the MAX Differences page and in the systems courses.

The aircraft & NG vs MAX

• HotTell me about the 737.
• HotWhat are the differences between the 8200 and the -800, inside and outside?
• HotWhat is MCAS on the 737-8200? What does it do, and can you comment on the accidents?
• Why does the 8200 have 197 seats?
• Why is there no OFF position on the 8200 landing-gear lever, and what is the OFF position for on the -800?

Engines

• HotWhat are the differences between the CFM56-7B and the LEAP-1B?
• HotWhy is the MAX more efficient than the -800?
• HotWhat is the bypass ratio, and what are the NG and MAX values?
• HotThe LEAP is quieter, why do we care about keeping noise low?
• Explain in simple terms how a jet engine works (intake, compression, combustion, turbine, exhaust).
• What does the turbine drive, and how many spools are there? What is the main driven component (the fan)?
• What does the APU provide, and what is its power output?

Wings, flaps & slats

• HotDuring a flaps-5 takeoff ENG2 fails, can you retract the flaps?
• What is the difference between flaps and slats? How are the slats and engine cowls heated?
• What are the flap gates at 1 and 15 for?
• Why would you take off at flaps 1?
• Why are the wings swept, and how much dihedral does the 737 have?
• What are the “spikey” things below the wings (static dischargers / vortex generators)?

Pressurization & air

• HotHow is the 737 pressurised? What are the PACKs for?
• What position is the outflow valve in during the cruise?
• You are at FL410 and the outflow valve opens fully, what happens?

Hydraulics

• HotWhat are the hydraulics used for, and how many systems are there?
• HotHow do you brake if you lose all hydraulics? How do you de-ice the wings?
• What is powered by system A and what by system B?
• What is the PTU / landing-gear transfer unit?

Electrical, gear & brakes

• HotTell me about the electrical system. How is AC converted to DC?
• Tell me about the landing gear. What would you do if the gear did not retract?
• What is this antenna on the fuselage?

Ice, probes & windows

• HotWhere are the heated probes and vanes, and which are heated?
• Which system, captain or first officer, heats window L3 / R3? Explain window heating.

Warnings, surveillance & abnormals

• HotWhat are your actions for a windshear event near the runway?
• HotYou have a fire in the main landing gear in the cruise. What do you do? (Go to the QRH.)
• What is TCAS on the 737? Do you have to follow an RA? What is the call for “Go Around, One Engine Inoperative”?
• How many pitots are there on the 737?
• Tell me about the 737 fire protection and suppression.

How you answer matters as much as what you know, they are looking for a trainable, honest cadet.

• “I don’t know” beats a bluff. If you are unsure, say so, or say it is an educated guess and reason it out. A confident wrong answer looks worse than an honest gap.
• Get to the point. The assessor wants the key idea, then moves on. Give the short, correct answer first; add detail only if asked.
• Steer the conversation. They jump from topic to topic, so lead toward the subjects you know well. Whatever you are comfortable talking about, bring it up.
• Show you are trainable. If the assessor explains something, engage with it and ask a follow-up. If they do not, it is fine to ask “what would the answer be? I’d like to know.”
• Be humble, not cocky. Do not oversell past experience. They want a trainable cadet; everything else is a nice-to-have. Humble candidates often get an easier ride.
• Recover from mistakes. Catching and correcting an error is a good sign, do not let one slip rattle you.
• Prioritise a busy request. The assessor may pack several instructions into one message, deal with them in order of importance and read them back.