Two spools v.s Triple spools
August 4, 2024
References: Difference between Two Spool Engines and Three Spool Engines – FlyFA Aircraft Maintenance Engineering 3-Spool-Engine Concept | aircraftengineering (wordpress.com) What is triple spool design on the RB211? what are the advantages/disadvantages? A 3 spool engine is one that has three sets of compressors before the combustor and three sets of turbines behind it. A
Cooling Methods in Turbine Blades
August 4, 2024
Reference: Cooling Methods in Turbine Blades | Turbomachinery blog (softinway.com) thermal barrier coating on the turbine blade (Blade Passive Protection) internal cooling – maintains the blade metal temperature below the outside gas temperature by heat transfer to internal cooling air – include convection cooling and impingement cooling, where cooling air runs through channels within the
PUDSUC – 口訣 : pitot static blockages
August 4, 2024
Reference: Instrument failure: the test of trust | Flight Safety Australia PUDSUC A pitot blockage will cause airspeed to underread on descent (vice versa on climb). A static blockage will cause airspeed to underread on climb (vice versa on descent).
[GA piston engine] What’s full throttle height?
August 3, 2024
Full throttle height – Depending on the power setting, as an aircraft climbs (fitted with a fixed-pitch propeller), a height is reached eventually where the throttle will be fully open to maintain that power setting. Important concept: An aicraft can have various power setting! Each power setting has a full-throttle height! Read more
[GA Piston Engine] Effect of Increasing Height on Power Output
August 3, 2024
(On a ‘standard’ day) Aicraft climbs / fly high –> output of the engine decreases for two reasons: decrease in atmospheric pressure – reduces the manifold pressure and thus the flow of air into the cylinders (a similar effect to closing the throttle) – can be compensated for by progressively opening the throttle decrease in
Too lean, Too rich, CCM, Best power, Best economy
August 3, 2024
Notes: The carburettor measures the weight of air passing through the induction manifold and uses this measurement to regulate the amount of fuel discharged into the air stream (according to a predetermined schedule). What’s rich, lean and CCM? Rich: 1:8 Chemically Correct fuel/air Mixture (CCM): 1:15 Lean: 1:20 In theory, the ‘correct’ quantity
What’s Feathering? (Propeller)
July 21, 2024
Ref untitled (cast-safety.org) 原文: “On a variable pitch propeller, the drag can be minimized by rotating the blades until they are edgewise to the flight direction. This is called feathering the propeller.” Why we need “feathering the propeller”? / When we need to “feathering the proeller”? When an engine is shutdown in flight, an
到底HKO 幾耐UPDATE 一次METAR/TAF?
June 16, 2024
Ref AIP VHHH Part 1 GEN – GEN 3.5 METEOROLOGICAL SERVICES 3 Meteorological Observations and Reports 3.1 Weather Observers are on duty H24 at the AMO and I-AMO to make routine meteorological observations and to issue reports at half-hourly intervals. Reports of routine observations are issued as local routine report for dissemination at the aerodrome and as METAR for dissemination
一次搞懂香港,澳洲, 美國的Cloud base / Cloud ceiling
June 16, 2024
話說上堂老師教Cloud Base 同 Cloud Ceiling 既分別 METAR / TAF 報既cloud 都係AGL? 同埋提我地一個好重要既Concept: METAR 同 TAF 報既Cloud information 都是AGL! 到底邊到有講…都真係搵左幾耐! Hong Kong AIP HONG KONG – GEN 1.7 DIFFERENCES FROM ICAO STANDARDS, RECOMMENDED PRACTICES AND PROCEDURES “Cloud ceiling” in relation to an aerodrome means the vertical distance from the elevation of the aerodrome to the
What is global circulation?
June 9, 2024
Knowledge from this clip: Global Circullation is one of the drivers for climate and phenomenon: Jet Steam Previling wind Engergy (heat) from sun reachs the earth by radiation Earth itself is an irregularly shaped ellipsoid Energy is much more concentrated near the equator Earth is tilted, sun light cannot reach the poles at all time In
