What’s “isogonic line” and “agonic line”?
May 6, 2024
Isogonic line: lines on chart showing the places where have same magnetic variation. Agonic line: lines on chart showing the places where magnetic variation is zero. What’s Variation, Deviation?
一次搞清幾時True heading 幾時Magnetic heading
May 5, 2024
Ref https://www.casa.gov.au/resources-and-education/publications/industry-guides/pilot-guides/visual-flight-rules-guide With reference to AIP HKG GEN 2.1 With reference to AIP Australia GEN 2.1: With reference to CASA Visual Flight Rules Guide (VFRG): Wind – ref to True: Aerodrome weather and forecast Grid point wind and temperature (GPWT) forecast Notes: also ref AIP GEN 3.50 Wind – ref to Magnetic: Aerodrome weather
Magnetic Compass
May 5, 2024
Ref https://www.aviation.govt.nz/licensing-and-certification/pilots/flight-training/flight-instructor-guide/compass-use/ A magnet bar that is freely suspended horizontally will swing so that its axis points roughly north-south. The end of the magnet that points toward the earth’s north magnetic pole is called the north-seeking pole of the magnet. What’s Variation, Deviation?
Errors on gyroscope instrument – Wander = Real Wander + Total apparent Wander
May 5, 2024
“Wander” – describe the situation when the gyroscope’s spin axis away from its fixed direction (reference datum) Due to its rigidity, the spin axis of a perfect gyro should continue to point in a fixed direction. Any movement of the spin axis away from this fixed direction is known as gyro wander. Depending on the
Slip v.s Skid on Inclinometer (coordination ball)
May 5, 2024
Ref Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25C (Full Version) Chapter 5 Correct by step on the ball Ball at higher wing – skid : Tail out from turning radius – indicated by ball to higher wing Centrifugal force greater than horizontal lift Correct by reduce the ROT (rate of turn) AND/OR increase in bank
What’s gimbal in gyroscope instrument?
May 5, 2024
Ref Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25C (Full Version) Chapter 8 What’s gimbal? Ans: the component which can limits the planes in which the gyro can tilt. Ref https://www.pilot18.com/wp-content/uploads/2017/06/2-INS-Gyro-Instruments.pdf Gyro types depend on the number of planes of freedom of movement. Freedom of movement is achieved by mounting the gyro in gimbal rings. Space
Turn Coordinator (TC) vs Turn and Slip Indicator (TI)
May 5, 2024
Type of gyro used in TC and TI? Ans: Horizontal gyro – rotate around horizontal axis! The major difference between TC and TI? The gimbal that holds the gyro in a TC is tilted for 30 degree. Turn Coordinator: ✔ rate of turn (yaw) ✔ roll rate (bank) Turn Indicator: ✔ rate
Generator v.s Alternator
May 2, 2024
Also Ref. https://www.electricaltechnology.org/2020/05/difference-between-alternator-generator.html/amp 不要中毒太深 睇下好喇 For PPL and even CPL, basically, generator and alternator are the same thing…. Main Differences between Alternator and Generator Alternator: A machine that only converts mechanical energy into AC electrical energy. Generator: can generate either of both Alternating current AC or Direct Current “DC”.
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
