[Ref PPL Instruction Kit Vol1 (306) – 9th Edition, V9.2 P.3] What’s AoA? Angle of attack (AoA or α) is the angle between the direction of relative airflow (RAF) and the chord line of an aerofoil #What’s AoA WHY the concept of angle of attack (AoA) is important? Relationship between AOA and CP? Relationship between AoA, Thrust and Level […]
Category: Definition / Terminology / Jargon
What’s fatigue? (ICAO)
[Ref HK CAD 372, ICAO Annex 6, AVIA4004 Handout] What’s fatigue? Fatigue is the physiological state of reduced mental or physical performance capability Fatigue can result from sleep loss or extended wakefulness, circadian phase, or workload (mental and/or physical activity) that can impair a crew member’s alertness and ability to safely operate an aircraft or […]
Pitch v.s Blade angle (Propeller)
[Ref. Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 7-4] Angle of Incidence (AoI) of blade (= pitch) ≠ blade angle However, pitch is largely determined by blade angle and so two terms are often used interchangeably – again, “Pitch” is not exactly the “blade angle”! What’s “Pitch”? “Pitch” is the distance in inches, which the propeller would screw […]
Mountainous Area (ICAO)
[Ref Jeppesen] What’s “Mountainous Area” ? In ICAO definition, an area of changing terrain profile where the changes of terrain elevation exceed (>) 3000ft (900m) within a distance of 10NM #mountain #area
What’s Missed Approach?
[Ref Jeppesen] What’s “Missed Approach”? Missed Approach — is a maneuver conducted by a pilot when an instrument approach cannot be completed to a landing. For IFR pilot, even they decide to execute a missed approach prior to the Missed Approach Point (MAP), they must continue along the final approach to the MAP. In other words, missed approach […]
MORA – Minimum Off-Route Altitude
[Ref Jeppesen] What’s Minimum Off-Route Altitude (MORA)? This is an altitude derived by Jeppesen. The MORA provides known obstruction clearance 10NM either side of the route centerline including a 10NM radius beyond the radio fix reporting or mileage break defining the route segment. For terrain and man-made structure clearance refer to Grid MORA. Read More – […]
Traffic Alert Collision Avoidance System (TCAS)
[Ref Jeppesen, FAA-H-8083-15B – Instrument Flying Handbook Page 5-30 to 5-34, FAA AIM] What ‘s Traffic Alert and Collision Avoidance System (TCAS) ? TCAS is an airborne collision avoidance system (ACAS), that is based on radar beacon signals which operates independent of ground-based equipment. Traffic alert systems receive transponder information from nearby aircraft to help determine their […]
Thunderstorm icing
[Ref Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 12-24] Updrafts in a thunderstorm support abundant liquid water with relatively large droplet sizes in the upward current. When water content carried above the freezing level, the water becomes supercooled. When temperature in the upward current cools to about –15 °C, much of the remaining water vapor sublimates […]
“funnel cloud” vs “tornado” vs “waterspout”
[Ref Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 12-23] What’s funnel cloud, tornado and waterspout ? All this three weather phenomena are high-speed vortex extending downward from the cumulonimbus base, and the difference is that: Funnel cloud does not reach the surface; Tornado touches a land surface; Waterspout touches a water surface Formation of funnel cloud Should the air being […]
Towering Cumulus (TCU)
[Ref Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 12-16] What’s “Towering Cumulus (TCU)”? Towering Cumulus (TCU) is a type of cloud with extensive vertical development. TCU indicate areas of instability in the atmosphere, and the air around and inside them is turbulent. TCU is potential to develop into cumulonimbus (CB) or thunderstorms.