Pre-Flight

Pre-flight covers everything before the engine is started. Legal basis: NCO.OP.135 Flight preparation (EASA Part-NCO) and NCO.GEN.135 Documents, manuals and information to be carried.

Checklist obligation

A pilot must conduct a pre-flight check by checklist before every flight — this is mandatory, not optional (EASA NCO.OP.135, POH requirement). Even highly experienced pilots use the checklist — otherwise individual items are statistically a cause of accidents.

Source of data — flight manual

Performance, operating instructions and limitations of an aircraft are provided by the manufacturer in the flight manual (POH / AFM). In particular:

Correct oil level and oil specification: in the flight manual.
Performance data (take-off / landing distance, climb, cruise): in the Performance section.
Operating limitations (Va, Vne, MTOM, CG range): in the Limitations section.
Emergency procedures: in the Emergency section.

A) Personal and aircraft documents

Pilot carries:

Pilot licence (valid)
Medical Class 2 or higher (valid)
Language Proficiency Certificate
ID document (national ID / passport)
Logbook (at least last 90 days; online log often accepted)

On board (NCO.GEN.135):

C of A (Certificate of Airworthiness) and ARC (Airworthiness Review Certificate)
C of R (Certificate of Registration)
Aircraft Radio License
AFM / POH
Current Mass & Balance / Weight & Balance
Noise Certificate
Insurance certificate where required (national)
Flight plan (if required)
Current charts and publications (AIP, NOTAM extract, current AIRAC)

B) Met and NOTAM briefing

METAR/TAF for departure, destination, alternate.
GAFOR / SIGMET / AIRMET / GAMET for the route area.
SIGWX / WINTEM for cruise altitude.
NOTAMs along the route (airspace active, airfields closed, GPS jamming …).
Sunrise/sunset if near night-VFR boundary.

C) Flight planning

PLOG completed (see Subject 060).
Mass and balance calculated — under MTOM, CG within range.
Performance (TO distance, climb, landing distance) from POH at current temperature, pressure altitude, runway condition, weight.
Fuel per NCO.OP.125 (see Subject 060).
Flight plan filed if required (often not mandatory for short VFR in EU).

D) Walk-around inspection

Per POH list, typical sequence:

Cockpit: master off, key out, brakes on, control cable tension checked, fuel selector ON both.
Left wing: leading edge (dents, cracks), aileron free movement, flap, fuel sample drained (water/sediment), tank contents, cap closed.
Nose: propeller (no damage, securely attached), spinner, cowling (screws, cracks), air intake (bird nest, ice, dirt), shock absorber, steering.
Nose / main gear: tires (pressure, cracks, tread), brakes, axle pins, hydraulic drips.
Right wing: mirror image of left.
Fuselage: antennas, static ports clear, pitot/AOA clear (covers off!), tail bumper.
Empennage: elevator/rudder free movement, trim tabs, static port.
Fuel sample at the bottom drain.

Control-surface check (critical — airworthiness)

From the cockpit test control surfaces — yoke input must produce the correct aerodynamic deflection:

Pilot input	Left aileron	Right aileron
Yoke LEFT	DEFLECTS DOWN	deflects up
Yoke RIGHT	deflects up	DEFLECTS DOWN

If deflections are reversed or do not occur: the aircraft is NOT airworthy — control cables are wrongly rigged (e.g. after maintenance) and the aircraft would roll in the opposite direction. Cancel flight, notify maintenance.

Same for elevator and rudder:

Yoke back → elevator deflects UP.
Left pedal → rudder deflects LEFT.

Snow and ice — must be completely clean

An aircraft must be completely free of snow and/or ice before take-off to be airworthy (EASA SERA.2010, ICAO Annex 6). Even a thin ice layer or snow on the wings dramatically changes the airfoil profile:

Loss of lift (up to 30 % with a thin rime ice layer).
Stall speed increase.
Possible stiffening of control surfaces.
→ De-icing on the apron or before engine start.

No AVGAS 100LL available

If no AVGAS 100LL is available for refuelling at the airfield (and the aircraft requires AVGAS 100LL per POH), the pilot should:

Not continue the flight until AVGAS 100LL can be refuelled.
Use no substitute fuel (auto-gas only when explicitly approved by STC — e.g. MOGAS-STC for certain types).
If critical: divert to a field with available fuel before running out.

Defective cabin heat → CO risk

A defective cabin heat (heat muff at exhaust manifold with crack) can introduce carbon monoxide (CO) into the cabin. Symptoms: pungent smell, fatigue, headache (see lesson "Carbon Monoxide (CO)").

On suspicion or known defect:

Cabin heat OFF.
Open windows and fresh-air vents.
Continue or divert depending on severity.
Report to maintenance — heat-muff crack is a standard 100-hour inspection point.

E) Cockpit preparation

Documents check (see above).
Seat belts (all seats): tested, tight.
Avionics master OFF during engine start (unless POH says otherwise).
Radio frequencies pre-set (ATIS, tower, departure).
GPS database current (check AIRAC cycle).
NAVs (VORs) pre-set.

Engine start — pilot seat must be occupied

Under no circumstances may an aircraft engine be started manually (e.g. by hand-propping) with the pilot seat unoccupied and brakes not set. Risk: the aircraft moves off uncontrolled with the engine running — severe property damage and fatal accidents have resulted.

→ If hand-propping is unavoidable (starter failure): a fully qualified person must be in the cockpit with brakes, fuel selector, magnetos, and throttle under control.