[Ref AC 00-6B Chapter 17, AC 00-57] Mountain waves are a form of mechanical turbulence which develop above and downwind (Lee side) of mountains ridge. Risk of Mountain waves? Range: This mechanical turbulence may extend 600 miles (1,000 km) or more downwind from the mountain range. Intensity: This mechanical turbulence are classified as severe to […]
Category: What’s
What’s Radio Altimeter?
[Ref AVIA4019, ACE The Technical Pilot Interview 146/348] Radio Altimeters (RA) provide an accurate height measurement from 2,500 ft down to 50 ft (AGL – above ground level). Indeed, the function usually are binding with barometric altimeter in most commercial aircraft. How RA works? The basic principle of the radio altimeter is that a […]
What’s “Big aircraft” and “Small aircraft”
Aircraft can be classified into different types and categories based on different system. As far as I know, we can do it by: Aircraft Category – ICAO Standard Aerodrome Reference Code (a.k.a Airport Reference Code) Wake turbulence categories – ICAO standard Pilot license In short, it depends what application or situation we are talking about […]
What’s “Primary Systems”
[Ref. Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 7-1] The primary systems on most GA aircraft include but not limited to: Engine (engine itself + 6 sub-systems) propeller Airframe System electrical system Hydraulic System – e.g landing gear environmental control systems – e.g Oxygen system, Heating System Flight Control System Note : Flight Control system is […]
What’s Ground Clutter Suppress (GCS) Function?
[Ref Safety first #22 July 2016 – 1/23] What’s Ground Clutter Suppress (GCS) Function? GCS is a function of WX radar to suppresses the ground return from the display.
What’s Volcanic Ash Advisory (VAA) Messages?
[Ref BOM Australia Knowledge Centre, VAA message] Volcanic Ash Advisory (VAA) messages is a kind of SIGMET about volcanic activities. Volcanic Ash Advisory (VAA) messages are issued by 9 Volcanic Ash Advisory Centres (VAACs) over the world. They are located in Darwin (Australia), Anchorage (US), Buenos Aires (Argentina), London (UK), Montreal (Canada) Tokyo (Japan), Toulouse (France), […]
What’s “Lee side”
[Ref Wiki] Lee side the downwind from a referent point. In other words, the side in which the wind is blowing to.
What’s the coordinate of Hong Kong?
[Ref AIPHK, Google, pgc.umn.edu] What’s the coordinate of Hong Kong? It is a quite tricky question since coordinate aims to pinpoint a position (location) on the map – it is representing a point (express in latitude and Longtidue) in lieu of an area. Latitude is a position along a meridian of longitude – use to […]
What’s “insolation”?
[Ref ISBN 978-1-61854-262-5] Insulation, “日照” in Chinese, usually refers to the situation that the earth’s surface receives solar radiation. In daytime, peak insolation occurs around 1200LT, but maximum surface air temperature usually occurs during the mid-afternoon; At night, insulation is absent. Therefore, sun’s rays is the major reason causes uneven heating on the earth’s surface. […]
What’s SLG (Semi Levered Gear)?
[Ref Youtube, Boeing] SLG (Semi Levered Gear) is a design that can be found in B777-300ER. A “diagonal” hydraulic strut provides the energy to provide better takeoff performance. The design is used to increase takeoff capability, or provide increased tail clearance for the same weight and thrust as nonequipped airplanes. Below are two photos of triple-bogie. […]