Presentation on theme: "All Weather Takeoff and Landing"— Presentation transcript:
1All Weather Takeoff and Landing HPA GroupBrett MatherRyan Beach
2Requirements Technology All weather takeoff and landing is broken up into the following sections:RequirementsTechnology
3All-Weather Terminal Area (ATWA) Operations Basic Types of AWTA approach and landing operationsVisual ApproachAircraft is being operated in normal visual flight rules (VFR) and normal instrument flight rules (IFR)Instrument ApproachInstrument approach procedures permit descent in IFR conditions to allow for a safe landing.Standard instrument approaches include International Civil Aviation Organization (ICAO), standard Navigation Aids (ILS, MLS, VOR, VOR/DME, NDB), as well as approaches based on ATC radar services.
4All-Weather Terminal Area (ATWA) Operations (cont’d) Requirements for VFR (FAR Part )Regardless of ATC clearance, no pilot may takeoff or land when the reported ceiling and visibility is less than:Day Operation: 1,000 ft ceiling and 1 mile visibilityNight Operation: 1,000 ft ceiling and 2 mile visibilityWhere local surface visibility restrictions exist (smoke, dust, blowing snow, etc.) the visibility for day and night operations may be reduced to ½ mile provided all flight beyond 1 mile from the airport can be accomplished outside of the surface visibility restriction.
5All-Weather Terminal Area (ATWA) Operations (cont’d) Requirements for IFR (FAR Part )Prior to takeoff, the pilot must obtain ATC clearance and must pass weather conditions specified in operation specifications manual take-off minimums.Prior to the final approach segment of the instrument approach, the destination airport must issue a weather report with above-minimum weather conditions for the pilot to pass the final approach fix.If the pilot has entered the approach and an updated weather with below-minimum weather conditions, the pilot may continue until decision height.At the DH, the pilot may continue to touch down if:A normal touchdown will occur within the touchdown zone.The flight visibility agrees with the instrument approach procedure being usedIn a category I approach, one of the following visual references must be identified:
6All-Weather Terminal Area (ATWA) Operations (cont’d) Requirements for IFR (FAR Part ) (cont’d)The approach light systemThe touchdown zone or touchdown zone markingsThe touchdown zone lightsThe runway or runway markingsThe runway lightsThe thresholdThe threshold markingsThe threshold lightsThe runway end identifier lightsThe visual approach slope indicator
7Decision Height (DH, ft.) Runway Visual Range (RVR, ft.) All-Weather Terminal Area (ATWA) Operations (cont’d)Categories of Instrument Approach ProceduresCategoryDecision Height (DH, ft.)Runway Visual Range (RVR, ft.)Alert Height (AH, ft.)Equipment allowedCAT IDH > 200RVR > 1800N/ACAT II200 > DH > 100RVR > 1200CAT IIIa100 > DHRVR > 700100Fail-passive & fail-operationalCAT IIIb50 > DH700 > RVR > 150Fail-operationalCAT IIIcCAT IIIc landing has no limit on DH and RVR, but is currently unauthorized
9Technologies for All Weather Takeoff and Landing Aircraft DesignElectronicsRunway Design
10Aircraft Design Stronger landing gear for rough landings Landing gear swivelFirst used on Boeing to accomplish tighter turns on the ramp but is consistently used for crosswind landingsBetter tire designBrighter aircraft lights with upgraded high intensity discharge (HID) bulbsExample design problem associated with weather: Tail Dragger aircraft taxiing in a strong cross wind can cause the plane to weathervane due to the light weight tail with small force on the tail wheel.Michelin Tire Design
11Electronics Air Traffic control (ATC) Better weather prediction and detailed weather reportsPilots must be informed of landing conditions (wind speed/direction, runway surface conditions)Auto-pilot can execute landings in conditions of poor visibility that would be impossible otherwiseSophisticated systems can also execute landings in severe crosswind conditionsTechnology to improve visibilityFog defeating system converts signals from on-board sensors and airport navigational aids into a holographic image of the approaching runway, which is projected onto a glass screen between the pilot and the windshield.
12Friction Measurement / Testing Device Runway DesignRain Snow/ice landingWet and icy runways are the leading cause of landing accidents worldwideNASA Joint Winter Runway Friction Measurement Program developed for braking tests for aircraft and friction measurement ground vehicles in the U.S. and CanadaLanding Surface Quality EvaluationVisual inspection to determine the type of contaminant (rain, snow, etc) and the extent of its coverageThickness of contaminantFriction MeasurementLighting Systems (brightness can often be controlled by the pilot)Chemical treatment for snow and ice (FPD (freezing point depressant)Better runway surface (Grooved runway reduce hydroplaning based on research from NASA in 1968)Some surfaces designed to retain anti icing chemicalsGrooved RunwayFriction Measurement / Testing Device
13Runway Design / Electronics ISL (instrument landing system)Primarily consists of two subsystems: one for lateral guidance (Localizer), one for vertical guidance (Glideslope or GlidePath)Marker beacons are used to measure how far until landingAll of these systems emit signals at different frequencies that are translated by electronics to determine the position of the aircraftILS LocalizerILS Localizer
14Runway Design / Electronics MLS (Microwave landing system)Microwave landing system are all weather landing systems that are similar to ILS.Fewer transmitter stations needed for MLS (usually a single box)Approach Azimuth station, Elevation station, and Range StationMLS ElevationAzimuth Measurement Range
15ElectronicsWAAS / GPS (Wide Area Augmentation System / Global Positioning SystemWAAS is a system that improves the accuracy of GPS from the original 4-20 meter accuracy to a 2-3 meter accuracy by removing error cause by the earths ionosphereThis system basically ended the development of MLSNormal GPS is not accurate enough to land a plane but with WAAS capability it is now possible.New techniques such as Differential GPS can be even more accurate (calibrates GPS by measuring known fixed locations)