AERODROME OPERATIONS TRAINING – MODULE 2 Aircraft Operations and Systems LEARNING OUTCOME Participants will gain an overview of aircrafts operations, and systems including: Principles of flight Propulsion systems Navigation systems and Performance With access to performance graphs they will be able to calculate take off and landing weights and payload range capability PRINCIPLES OF FLIGHT NEWTONS 3 LAWS 1. A body continues to maintain its state of rest or of uniform motion unless acted upon by an external unbalanced force. 2. F = ma: the net force on an object is equal to the mass of the object multiplied by its acceleration. 3. To every action there is an equal and opposite reaction. PRINCIPLES OF FLIGHT LIFT Bernoulli’s Theorem When the speed of a fluid increases the pressure decreases Reaction to wing deflecting air downwards PRINCIPLES OF FLIGHT LIFT and DRAG Lift = Coefficient Lift x ½ (air density x v2 x S) Drag = Coefficient Drag x ½ (air density x v2 x S) PRINCIPLES OF FLIGHT LIFT – STALL ANGLE OF ATTACK PRINCIPLES OF FLIGHT FOUR FORCES AIRCRAFT IN FLIGHT Lift = Weight Thrust = Drag FLIGHT CONTROLS – 3 AXIS Lateral axis – pitch controlled by elevators Longitudinal axis – roll controlled by ailerons Vertical axis – yaw controlled by rudder FLIGHT CONTROLS Flight controls vary the effective angle of attack of the given lifting surface thus varying the amount of force (lift) produced. FLIGHT CONTROLS - FLAPS Increase angle of attack and surface area thus enabling wing to produce more lift and drag at lower speeds (take-off/landing) AIRCRAFT TURNING Roll Turn PROPULSION SYSTEMS - PROPELLERS Powered by either piston engine or gas turbine (turbo-prop) Cross section an aerofoil like a wing but varying pitch angle due to tip travelling faster than hub. Fixed pitch compromise between takeoff and cruise speed. Variable pitch enable optimum pitch setting thru out speed range PROPULSION SYSTEM – TURBO-JET Oldest form of jet engine, still in use for high speed aircraft such as supersonic military aircraft. •Not efficient – high fuel consumption •High noise levels PROPULSION SYSTEM – TURBO-FAN High thrust levels, fuel efficient, quiet, limited mainly to sub-sonic NAVIGATION SYSTEMS Basic: Compass, clock, maps, Dead-reckoning, visual fixes Ground Based Radio Aids: ADF/NDB, VOR, DME, ILS Aircraft: Inertial Navigation System (INS) Space: Global Navigation Satellite System (GNSS) or GPS Integrated: Flight Management System (FMS) NAVIGATION SYSTEM – NDB/ADF NDB- Non-Directional Beacon Ground based subsystem Transmitting a simple radio signal on the M/F broadcast band. Signal follows curvature of earth so can be used at greater distances than line of sight navaids ADF- Aircraft subsystem consisting of radio receiver and directional indicator showing relative bearing to NDB. When read in conjunction with compass a magnetic bearing can be established Limitations: Outdate system subject to number of errors – Night, Terrain, Electrical, Coastline, Bank. High pilot work load (not able to be coupled to auto-pilot) NAVIGATION SYSTEM - VOR VHF Omni-directional Range (VOR) Ground subsystem consists of a transmitter Broadcasting coded navigation signal on VHF 108-117.95 MHz. 2 methods of transmitting Doppler and Conventional. Navigation signal aligned to magnetic north. Limited to line of sight. Aircraft subsystem consists of radio receiver and omni bearing selector (OBS) with CDI and To/From indicator. Desired course to/from the VOR is selected on OBS and CDI centres when on course. NAVIGATION SYSTEM - ILS Instrument Landing System (ILS) – Ground sub-system Consists of two major components Localizer providing azimuth guidance with respect to the runway centreline. Localizer array installed on up wind end of Runway and transmits signal in VHF band 108 – 111.95 MHz Glide-slope providing vertical flight path guidance normally 3° with 50ft threshold Crossing height. Glide-slope antenna Installed abeam touchdown zone transmits Signal in UHF band 329-335MHz. Ranging information is also provided By DME or Marker beacons NAVIGATION SYSTEM - ILS ILS Aircraft Sub-system ILS is selected on same nav receiver as VOR with GS automatically selected to paired Localizer Frequency. ILS nav information displayed on same CDI as VOR but OBS is inhibited. •Top display aircraft is on localizer course and on GS •Centre left of localizer course and above GS •Bottom right of localizer course and below GS Category 1 minima down to 200ft – 800m vis Category 2 minima down to 100ft – 350m vis Category 3 A 50ft – 200m, B 0ft – 50m, C 0ft – 0m NAVIGATION SYSTEM – DME & TRANSPONDER Aircraft DME system interrogates ground station And times delay in reply which it displays as a slant Distance in NM to the station. Ground station normally co-sited with VOR or ILS ATC transponder works in reverse to DME whereby ground secondary surveillance radar (SSR) interrogates aircraft transponder and times delay in response along with azimuth of bearing to display aircraft position to controller. Also able to send unique aircraft identifier (Mode A) and other info such as altitude (Mode C) and data (Mode S) NAVIGATION SYSTEM - RNAV AREA NAVIGATION (RNAV) Using ground based navaids requires aircraft to route via overhead the various navaids whereas RNAV capability permits direct Routing. Initially RNAV capability was limited to large jet aircraft equipped with INS and system Accuracy only supported enroute Nav. GPS (GNSS) has now given This capability to all aircraft and enhanced accuracy to enable instrument approaches similar to VOR/DME capability RNAV - DEVELOPMENTS RNP: Required Navigation Performance – figure of aircrafts nav Capability within 95% of time. • RNP 10 – Oceanic enroute, • RNP 4 – Domestic enroute • RNP 0.3 Non-precision approach BARO/VNAV modern aircraft capability of vertical navigation profile Similar to ILS although not to same accuracy GNSS: Augmentation systems GBAS, SBAS PBN: Performance Based Navigation – ICAO strategy for managing the implementation of all of the above RNAV technologies INTERNATIONAL STANDARD ATMOSPHERE ISA is an atmospheric model of how the pressure, temperature, density, and viscosity of the Earths atmosphere change over a wide range of altitudes. Provides a standard to certify aircraft performance. Height ft Temp °C Pressure hPa Lapse rate °C/1000ft 0 15.0 1013.2 1.98 36,000 -56.5 226 0 AIRCRAFT CERTIFICATION Two main certification standards for air transport aircraft• United States FAR 25 • European JAR 25 Both standards very similar and either acceptable for NZ CAA. Certification includes strict take-off and landing performance requirements. Air Operator Certification requires additional margins over the base certified performance as per CAR Part 121 Subpart D. (b) Each holder of an air operator certificate shall ensure that, for each aeroplane it operates, the landing weight for the estimated time of landing at the destination aerodrome and at any alternate aerodrome allows a full stop landing on a dry runway from a point 50 feet above the threshold within— 60% of the landing distance available at the destination and at any alternate aerodrome for a turbojet or turbofan powered aeroplane; TAKE-OFF PERFORMANCE Take-off Run (TORA) SOT – Vlof Take-off Distance (TODA) SOT – 35ft Accelerate/Stop (ASDA) SOT-V1- Stop Landing Distance (LDA) 50ft over THR Balanced field length: TORA=TODA=ASDA TAKE-OFF GRAPH Calculate Max Take-off Weight Runway length 2000m Sea Level Temperature ISA Runway Dry Flaps 15 LANDING GRAPH Calculate maximum landing weight Runway length 1814m Sea level Runway wet PAYLOAD RANGE GRAPH Calculate Available Payload Take-off weight from slide 25 Distance 2000nm OEW PRACTICAL EXERCISE 1.Does the aircraft stall speed remain constant or vary with weight? 2.To roll the aircraft to the right requires the left aileron to go …..? 3.What ground navaid does the aircraft ADF utilise? 4.What is the aircraft relative position to the ILS course and glideslope from the CDI below? PRACTICAL EXERCISE - PERFORMANCE 1. Calculate the maximum take-off weight for a Boeing 777-200 for Runway 2000m. SL given Temperature ISA +15, runway dry 2. Calculate the maximum payload for the above for a 3800nm flight using an OEW of 136,000kg 3. Calculate runway distance required to land an Airbus A320 at MLW given altitude 2000ft, runway wet.