Perf 01 : Important Definition(CS)

Short Notes – Definitions

Ceilings

• Absolute Ceiling: Altitude where rate of climb becomes zero.
• Service Ceiling: Altitude where climb rate reduces to about 300 ft/min.
• Aerodynamic Ceiling: Altitude where low-speed and high-speed buffet Mach numbers meet.
• Manoeuvre Ceiling: Altitude providing 0.3 g margin from both buffets.

Aerodrome & Declared Distances

• Aerodrome: Area for landing and departure of aircraft.
• Aerodrome Elevation: Highest point of landing area.
• Aerodrome Reference Point: Geographic centre of aerodrome traffic zone.
• TORA: Take-off run available.
• TODA: TORA + clearway.
• ASDA: TORA + stopway.
• LDA: Landing distance available.
• Balanced Field: ASDA equals TODA.

Aircraft & Structure

• Aircraft: Machine supported by air reactions.
• Aeroplane: Power-driven heavier-than-air aircraft.
• Airframe: Structure excluding engine propellers.
• ACN/PCN: Aircraft load vs pavement strength comparison.

Speeds (Key Performance)

• V1: Decision speed (stop or continue).
• VR: Rotation speed.
• V2: Take-off safety speed.
• VMCA: Air minimum control speed.
• VMCG: Ground minimum control speed.
• VMU: Minimum unstick speed.
• VMBE: Maximum brake energy speed.
• VFE: Max flap extended speed.
• VLE/VLO: Landing gear extended / operating speeds.
• VSR: Reference landing speed.

Take-off & Climb Performance

• Climb Gradient: Height gained per distance ×100.
• Gross Performance: Average fleet capability.
• Net Performance: Gross reduced for safety margins.
• Gross Height / Net Height: Heights used for obstacle clearance.
• OEI Continuous Power/Thrust: Unlimited duration after engine failure.

Runway Conditions

• Dry Runway: No moisture affecting braking.
• Damp Runway: Moist but not shiny.
• Wet Runway: Reflective surface moisture.
• Contaminated Runway: >25% covered with water (>3 mm).
• Hydroplaning Speed: Wheel lifts off water layer.

Atmosphere & Altitude

• Pressure Altitude: Altimeter set 1013 hPa.
• Density Altitude: ISA altitude with same density.
• Flight Level: Pressure surface referenced to 1013 hPa.
• OAT: Ambient air temperature.
• ICAO Standard Atmosphere: 15°C, 1013 hPa, standard lapse rate.

Flight Mechanics

• Lift: Force perpendicular to airflow.
• Drag: Opposes thrust.
• Thrust: Forward engine force.
• Angle of Attack: Wing chord vs airflow.
• Load Factor: Load compared to aircraft weight.
• Mach Number: TAS / speed of sound.

Operational Terms

• Alternate Airport: Backup landing aerodrome.
• Go-around / Baulked Landing: Discontinued landing.
• Missed Approach: Procedure after aborting approach.
• Rejected Take-off (RTO): Abandon take-off for safety.
• Windshear: Sudden wind speed/direction change.

Motions of Aircraft

• Pitch: About lateral axis.
• Roll: About longitudinal axis.
• Yaw: About vertical axis.

Engines & Propellers

• Maximum Continuous Power/Thrust: Unlimited duration rating.
• Take-off Power/Thrust: Time-limited high rating.
• Specific Fuel Consumption: Fuel per unit thrust.
• Turbojet: Turbine drives compressor.
• Turboprop: Turbine drives propeller.
• Variable Pitch Propeller: Adjustable blade angle.