How to find the Dew Point? How to find Relative Humidity (RH)?
July 20, 2025
How to find the Dew Point? RH = 100 – (T-D) x 5 Example: RH 83% ; Temp 12C, then 83 = 100 – (12-D) x 5 (83-100) / (-5)= 12-D D = 12 – (83-100) / (-5) D = 8.6 degree C Rightly, we can interpret the relative humidity (find the RH) from
Dew Point Application – Calculate Cloud Base
July 20, 2025
Degree C Let’s say the temperature is 25°C and the dew point is 15°C. Convergence Rate (CR) = 2.5°C Temperature Dew Point Spread (TDS) = T-DP = 25 – 15 = 10°C TDS ÷ CR = 10 / 2.5 = 4 Multiply by 1000 = 4 * 1000 = 4000 feet Therefore, the estimated cloud
Dew point, Dew Point Spread
July 20, 2025
What’s Dew Point? Dew point, given in degrees, is the temperature at which the air can hold no more moisture. When the temperature of the air is reduced to the dew point, the air is completely saturated and moisture begins to condense out of the air in the form of fog, dew, frost, clouds, rain,
ISA Deviation
July 20, 2025
Example: FL290 ; OAT -47 degree C ISA standard = 15 – (feet /1000) * 2 ISA Deviation = OAT – ISA standard FL 290 : 29,000 feet, so ISA standard @ FL 290 = 15- (29*2) = -43 degree C ISA deviation = -47 – -(43) = ISA-4 degree C https://youtu.be/_oWqu12Dm6M?si=eUYvJoTQD_EOKKl2
Thermodynamics: Radiation, Conduction, Convection & Advection
July 20, 2025
https://youtu.be/0vdxlgRKx1k?si=a80FzWfEp2fsKj2K What’s Solar insolation?
Tropopause
July 20, 2025
What’s Tropopause? https://youtu.be/jTCWSjhhXgc?si=9Zf8eVJgx6TKOXDs Tropopause height and its significance? https://youtu.be/ZfGVHCJSDsw?si=qaqwuN4DSlX6uyiu https://youtu.be/dRI5gYrJmvo?si=NHQo3NtST_5f-9ei More Reference: https://code7700.com/tropopause.htm
Forward CG or Rearward CG?
June 15, 2025
好耐無溫書，曾經作為load control，一定會比人問同埋要考慮load頭定load尾好，by rule of thumb, 我果陣普遍幫佢裝頭，點解？ 係時候溫返書～ 一齊睇下AI分析先： Forward CG: https://youtu.be/a_33vmrV52s?si=WwrMtjkikczUpT3e Aft CG: In Summary: While a forward CG might be considered safer due to increased stability, pilots must balance this with the potential for increased drag and stall speed. Understanding the effects of both forward and aft CGs is crucial for safe and efficient flight
Aircraft Approach Categories: The What, Why and How
December 27, 2024
好耐無睇AViation 既野，今日見到篇文章吾錯： https://navigraph.com/blog/aircraft_approach_categories?utm_source=newsletter&utm_medium=email&utm_campaign=2413_n&utm_content=aircraft_approach_categories the aircraft’s indicated airspeed above the runway threshold (VAT speed). This, in turn, is equal to the highest value of the stall speed (VS0) multiplied by 1.3 or stall speed at 1G (Vs1g) multiplied by 1.23 of an aircraft in a normal landing configuration at its maximum certified landing mass. ICAO (the International
Back to basic: Law 法例
October 1, 2024
今日就黎對比一下香港,澳洲, 美國既航空例~ 香港 (Hong Kong) 香港既法規有主體條例 (Ordinance) 同子規例 (Regulations)… 係DOJ e-legislation 可以搵到相關既法規 (我統稱叫 「例」) https://www.elegislation.gov.hk/index/chapternumber?TYPE=1&TYPE=2&TYPE=3&LANGUAGE=E&p0=1&CAP_NO_FR=447&CAP_NO_TO=449 1 條主體條例 ; 7 條子法規 448 Civil Aviation Ordinance 448A Air Transport (Licensing of Air Services) Regulations 448B Hong Kong Civil Aviation (Investigation of Accidents) Regulations 448C Air Navigation (Hong Kong) Order 1995 448D Hong
Scale: VTC, VNC, WAC
October 1, 2024
Ref VFRG Chapter 1 P.5 1 cm in below charts – VTC : 1.35 NM (Nautical Miles) VNC : 2.7 NM (Nautical Miles) WAC : 5.4 NM (Nautical Miles) Visual terminal charts (VTC) simplified topographical charts highlighting features/ structures helpful to visual navigation at a 1:250,000 scale with airspace detail Visual navigation charts (VNC)
Supplemental Oxygen Requirements (Provision of oxygen)
September 26, 2024
USA : 12,500 feetAustralia : 10 000 feetHK: flight level （FL) 100 USA https://www.flyingmag.com/private-pilot-supplemental-oxygen-requirements/ 91.211 Supplemental oxygen. (a) General. No person may operate a civil aircraft of U.S. registry— (1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen
Cloud formation 夠竟係吸定放latent heat?
September 14, 2024
https://www.weather.gov/source/zhu/ZHU_Training_Page/clouds/cloud_development/clouds.htm Formation of cloud requires a continuation of the lifting process. It is assisted by the property of water of giving off heat when changing from vapor to liquid and solid states, the latent heats of condensation and of deposition, respectively. (If the vapor first changes to a liquid before freezing, then we also have
Disk brake (Disc brake)
September 8, 2024
Modern general aircarft (GA) and airliner are also use disc brake Types of disk brake (disc brake) Singel disc Multi-disc Composition of disc? Steel Carbon Modern airliner tends to use carbon multi-disc. Advantage of disc type actuator? more effective at slowing or stopping improve the issue on drum brake (less fading problem) light
