What’s International Standard Atmosphere (ISA)
April 29, 2024
Ref: https://skybrary.aero/articles/international-standard-atmosphere-isa ISA is known as the ICAO Standard Atmosphere, ISA is a standard against which to compare the actual atmosphere at any point and time. ISA condition, at mean sea level:
What is the Geographic (True) North Pole?
April 29, 2024
Ref: https://gisgeography.com/magnetic-north-vs-geographic-true-pole/ The Earth rotates on the geographic north and south poles. The geographic north and south poles are where lines of longitude (meridians) converge in the north. The south and north poles are directly opposite to one another. The North Pole is located in the middle of the Arctic Ocean. Scientists have tried marking the North Pole.
CAD 54 syllabus v.s EASA syllabus
April 28, 2024
If you have read the CAD 54 and EASA website, you will find that there are slightly different between HK CAD syllabus and EASA (European Union Aviation Safety Agency) syllabus. For more as well as the most updated information, we can obtain from their official website. Below are my summary: HK CAD – ref CAD54
Otto cycle vs Brayton cycle – PV diagram
April 26, 2024
Ref: https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Thermodynamics/Thermodynamic_Cycles/Brayton_Cycle https://www.nuclear-power.com/nuclear-engineering/thermodynamics/thermodynamic-cycles/brayton-cycle-gas-turbine-engine/theory-of-brayton-cycle-brayton-engine/ https://www.mas.bg.ac.rs/_media/istrazivanje/fme/vol39/3/01_jdoric.pdf Idea gas formula: PV= nRT The typical four-stroke cycle (otto cycle) is described as a constant volume heat addition cycle. The combustion is so rapid that the piston does not move during the combustion process, and thus combustion is assumed to take place at constant volume The Brayton process is the
Wheel and Carcass
April 22, 2024
Vocab: Parts of wheel Rim flange barrel center disc spoke lug hole center hole Description of carcass sidewall tread Flat tire bulges on tire cut or scores on tire under inflated , properly inflated , over inflated creep detected on tire – when the creep marks are not aligned
What’s glide ratio?
April 14, 2024
Ref FTA material, Skybrary https://skybrary.aero/articles/glide-performance#:~:text=Description,altitude%20lost%20in%20that%20distance. The glide ratio for the DA40 is approximately 10:1 What’s glide ratio? The Glide ratio of an aircraft is the distance of forward travel divided by the altitude lost in that distance. (It is talking about same unit~) Below is another example: For every 1.45 NM (2.68km
What’s Entity
April 14, 2024
https://corporatefinanceinstitute.com/resources/management/entity/ Entity An organization created by one or more individuals to carry out the functions of a business and maintains a separate legal existence for tax purposes
Hot topic : Turbofan Engine
April 7, 2024
How does a turbofan engine work? https://aeroreport.de/en/video/wie-funktioniert-ein-turbofan-triebwerk Air is ingested, compressed, combusted and then expelled. The GE90-115B on B777-300ER Gearbox Turbofan Engine ? https://aeroreport.de/en/good-to-know/wie-funktioniert-ein-turbofan-triebwerk-aufbau-eines-triebwerk In conventional engines, the low-pressure turbine and the fan sit on one shaft, but here the gearbox decouples the two components. This lets the components run at their optimum
The properties of air
April 6, 2024
Ref Ref FAA-H-8083-25C version 2023 Air is fluid To describe the properties of air, we need to know various key terminology at the beginning Viscosity Friction Pressure Density Temperature Viscosity “friction” of fluid is used to describe the resistance of flowing high viscosity means “thick” and resist flowing low viscosity means “thin” and flow
一次搞清楚Ceiling
April 6, 2024
Ref FAA-H-8083-25C version 2023 5-24, 7-12, 11-8,12-17 Ceiling related to metrology? Ceiling is the lowest layer of clouds reported as being broken (5/8) or overcast (8/8) OR the vertical visibility into an obscuration like fog or haze Ceiling related aircraft performance? absolute ceiling : the altitude at which the aircraft has no excess
When the air is stable?
April 5, 2024
Ref: https://skybrary.aero/articles/lapse-rate 到底咩情況下parcel of air 叫stable? To answer this question, we need understand few concept: 咩係Lapse rate 咩係環境上面既Lapse rate 咩係pacel of air 既Lapse rate Lapse Rate is the rate at which temperature changes with height in the Atmosphere. In my language, how many degree Celsius drop when vertical distance increase for a fixed number.
Airport code and Aircraft Registration
April 5, 2024
What is the difference between ICAO airport code and IATA airport code? For example, Hong Kong IATA: HKG ICAO: VHHH Ans ref: POE ICAO codes are used for aviation-related operational and safety purposes, while IATA codes are mainly used for commercial and airline-related activities. ICAO codes are four-letter alphanumeric codes; IATA codes are three-letter
