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 adiabatic?
September 7, 2024
Reference Adiabatic process – Wikipedia No heat transfer (= heat does not enter or leave the system) A type of thermodynamic process that occurs without transferring heat or mass between the thermodynamic system and its environment.
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
How The Aircraft’s Air Brake Works
September 4, 2024
根據呢條片 – B777 B777 用 disc-brakes?! Main gear wheels – carbon disc-brakes Nose gear wheels – do not have brakes Braking system – 3大層次 Normal 用Right hydraulic Alternate/ Reserve 用Center hydraulic Accumulator 用Right hydraulic Functions: Store pressure Parking brake Wheel brakes B777 用 Hydraulic to power the brake system! 而B777 用的actuator 是carbon discs! Braking
Airmanship
August 31, 2024
Reference: Skybrary Airmanship – Definition “Airmanship” is the consistent use of good judgment and well-developed skills to accomplish flight objectives. This consistency is founded on a cornerstone of uncompromising flight discipline and is developed through systematic skill acquisition and proficiency. Below are the Tony Kern Model : Discipline – a.k.a Flight Discipline – ability
What’s VFR, IFR?
August 29, 2024
Back to basic: 揸車就無instrument driving…不過睇黎指日可待…講番揸飛機… Reference: Skybrary, VFRG (CASA) VFR Visual Flight Rules (VFR) are the rules that govern the operation of aircraft in Visual Meteorological Conditions (VMC) (conditions in which flight solely by visual reference is possible). Because of the limited communication and/or navigation equipment required for VFR flight, a VFR aircraft may be subject to
Depressurization (Decompression)
August 28, 2024
Reference: https://www.touringmachine.com/Articles/commercial/3407/
A350 cockpit
August 25, 2024
Cockpit 3D https://visites360.aircaraibes.com/a350virtual/index.html 5 reasons pilots love flying the A350 Reference: https://aircraft.airbus.com/en/5-reasons-pilots-love-flying-the-a350 Designed by pilots for pilots pilots are involved in design process Six large touchscreen displays excellent cross-cockpit visibility optimum flexibility for displaying information introduction of touchscreens Enhanced to reduce workload and raise awareness dual Head Up Display (HUD) ‘What if’ function
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
Fun fact : Prime Meridian 會變嗎? (Prime meridian ≠ International Reference Meridian)
August 25, 2024
Reference: https://www.rmg.co.uk/stories/blog/astronomy/prime-meridian-unmoved 21 Aug 2015 In August 2015 a paper was published by scientists in the US explaining why the Prime Meridian at the Royal Observatory Greenwich is 102 metres to the west of the prime meridian used by satellite based navigation and timekeeping, known as the International Reference Meridian or IRM. The paper created
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
Eddy Dissipation Rate (EDR) – 一個同turbulence intensity 有關既詞彙!
August 24, 2024
Reference: https://www.flyingmag.com/how-do-you-interpret-an-eddy-dissipation-rate/ EDR quantifies turbulence for a specific aircraft, and it’s not a measure of the likelihood of turbulence—just the intensity. ERR – Eddy Dissipation Rate 的三件事 refer to specific aircraft (type specific) describe the intensity of turbulence 同turbulence 發生機率無關 EDR 愈高代表Turbulence 對果類機既影響愈大 EDR is an observed or forecast value that is
VHHH windshear and turbulence information
August 24, 2024
Reference: https://www.hko.gov.hk/en/aviat/articles/files/booklet_4th_edition.pdf Two ways to deliver W/S or TURB information in VHHH Warning – via Voice-ATIS, Digital-ATIS (D-ATIS) Alert – generated automatically by the real time “up-to-the-minute” Windshear and Turbulence Warning System (WTWS), but passed to the aircraft via ATC Two levels of of Windshear alerts Microburst alert (MBA) – expect headwind loss of
