Drum brakes
September 8, 2024
Drum brake – not used on modern aircraft Basic component of drum brake? Drum – the moving part ; A hollow, cylindrical metal component that is attached to the wheel hub and rotates with it. It is the surface against which the brake shoes press to create friction. Brake shoes – the static part ;
Clouds 雲
September 8, 2024
Ref: https://cloudatlas.wmo.int/en/clouds.html 雲係一種同水有關既大氣現象 A cloud is a hydrometeor consisting of minute particles of liquid water or ice, or of both, suspended in the atmosphere and usually not touching the ground. It may also include larger particles of liquid water or ice, as well as non-aqueous liquid or solid particles such as those present in fumes, smoke or
Types of meteors (WMO)
September 8, 2024
Ref : https://cloudatlas.wmo.int/en/general-classification-of-meteors.html (4) Four types of meteors (WMO): 水 moisture related 光 light related 電 electrical related 塵 dust and particle related Meteors present a great diversity of character. However, by considering their constituent particles or the physical processes surrounding their occurrence, meteors can be classified into four groups: hydrometeors, lithometeors, photometeors and electrometeors. 大氣現象呈現出多種多樣的特徵。但是，根據它們的組成粒子或它們發生期間的物理過程，大氣現象可以分為四組：水凝物、大氣塵粒現象、大氣光學現象 和 大氣電學現象。
meteor (流星) ; meteor (大氣現象)
September 8, 2024
Today, let us do some revision on basic. Ref : https://cloudatlas.wmo.int/en/meteorological-definition-of-a-meteor.html Meteorological definition of a meteor – according to the World Meteorological Organization (WMO) In meteorology, a phenomenon observed in the atmosphere or on the surface of the Earth is known as a meteor. 在氣象學中，在大氣層或地球表面觀測到的現象稱為大氣現象。 It may be a form of precipitation, a suspension
Manual on the Observation of Clouds and Other Meteors (WMO)
September 7, 2024
What’s Anabatic wind , Katabatic wind?
September 7, 2024
Ref Anabatic Wind | SKYbrary Aviation Safety, Katabatic Wind | SKYbrary Aviation Safety Air flow travelling up a facing slope of an orographic surface (eg. hill, mountain). A cold flow of air travelling down an orographic slope (eg. hill or mountain). Please be reminded that Katabatic wind does not heat up adiabatically! 而Anabatic
Depressurization (Decompression)
August 28, 2024
Reference: https://www.touringmachine.com/Articles/commercial/3407/
民航機的空調系統
August 25, 2024
Function of air condition system improve passenger comfort – air conditioning ventilation – exchange fresh air maintain cabin pressure Component of air conditioning system? B777/A350 for example – Bleed air (from APU/Engine) -> Primary heat exchanger ->air cycle machine (compressor) -> Main heat exchanger -> air cycle machine (Turbine) -> Water separator -> Mixer
Gust front v.s Microburst?
August 24, 2024
Microburst affect smaller area (say around 2.5 miles), and short-lived (last for 5-10 minutes) Gust front affect wider area (say up to 20 miles) A microburst is a small concentrated downburst that produces an outward burst of strong winds at or near the surface. Microbursts are small — less than 4 km across — and short-lived, lasting
Typical causes of windshear and turbulence at VHHH?
August 24, 2024
Ref: https://www.hko.gov.hk/en/aviat/articles/files/booklet_4th_edition.pdf (6) Six typical causes of windshear and turbulence in Hong Kong: Terrain induced strong winds blowing across the hills over Lantau Island to the south of the airport (account for 75% of reported windshear) Sea breeze account for 15% of reported windshear Gust front (thunderstorm related) Microburst (thunderstorm related) Building induced Low level
Turbulence v.s Wind Shear
August 24, 2024
With reference to HKO publication: Windshear – sustained change (i.e lasting more than a few seconds as experienced by the aircraft) in the wind direction and/or speed, resulting in a change in the headwind or tailwind encountered by an aircraft change in lift (usually decrease lift), and cause the aircraft to go below the intended
Thunderstorm, CB?
August 23, 2024
(4) four main types of thunderstorm Single-cell small, and isolated storm Multi-cell a cluster of single-cell Squall line a line of thunderstorm Super cell very strong thunderstorm, and capable of producting tornadoes https://youtu.be/zUNEFefftt8?si=32eI_5NQVILuZ9xh Criteria of forming thunderstorm (CB) unstable atmoshpere (warm air) moisture (larage amount) lifting mechanism (trigger action) (5) five types of
DME – Distance Measure Equipment
August 21, 2024
Function of DME? provide distance information (measure the slant distance between the DME station and aircraft) Component of DME? DME ground station (usually combined with VOR) Aircraft DME unit Principle of DME? DME unit onboard the aircraft, that send out interrogation signal to ground DME station Ground DEM station give reply – send
ILS-Z, Y, X?
August 21, 2024
What can be different? ILS frequency Waypoint Descend profile CAT type RNP requirement MAP (miss-approach) procedure
ILS – Instrument Landing System
August 21, 2024
ILS (Instrument Landing System) is used for precision approach, particular useful for low visibility condition and/or bad weather. Component of ILS Localizer Glide slope Distance Measuring Equipment (DME) or Marker Beacons Runway lights 留意飛機方向!!! Function of each components: Localizer Guide the aircraft to the centerline of the runway (lateral guidance) Glide slope Guide the
Endurance? Range?
August 18, 2024
Range is affected by: fuel on board fuel flow (how fast the fuel is burnt)! Fuel flow increase (i.e burn more fuel) –> range will reduce. Range can be said as the distance the aircraft can go per unit of fuel ( Distance NM/ Fuel kg) Range can be translated into specific range
