Category: BAK

What’s coffin corner?

Reference: , Ans: Coffin Corner can be explained by using below illustration. It is talking about when when the aircraft fly to an altitude where the aircraft reduces the speed, it will stall while the aircraft increase its speed, it will over the Mmo. Therefore, the margin for error is low.The coffin corner is Read More

What’s Variation, Deviation?

Reference : HKU Space Material True poles are the location of the geographic poles. Rightly, the true north pole is not at same location of magnetic north pole. Variation : angular difference between true direction and magnetic direction Deviation : angular difference different between magnetic direction and compass direction Read More

What’s Heading? What’s Track?

Reference: HKUSPACE Course Heading? Ans: Heading (HDG) refers to the direction in which the aircraft is pointing.   Track? (= Track Required, TR) Ans: Direction over the ground in which the aircraft is required to travel   Read More :- 10 *** Important: Drift is NOT the Track Error. Drift is the difference between heading Read More

What’s UTC?

Reference : HKUSPACE Course Material UTC – coordinated universal time – the time is based on the prime (or 0 degree meridian of longitude) through Greenwich near London. Read More

What’s CAVOK , What’s NCD, NSC

Reference source: CAVOK The visibility, RVR, weather and cloud groups are replaced by CAVOK (Cloud And Visibility OK) when the following conditions exist simultaneously: If there is no cloud below 5000 ft or below the highest minimum sector altitude (whichever is greater) and there is no towering cumulus or cumulonimbus, ‘NSC’ is reported. Note: Read More

Service ceiling v.s Absolute altitude

Service ceiling 指飛機無再多MAP for climb; Critical altitude 指turbocharged engine 發揮最大壓縮空氣能力既高度 As a normally aspirated aircraft climbs, it eventually reaches an altitude where the MAP is insufficient for a normal climb. This altitude limit is known as the aircraft’s service ceiling Critical altitude is the maximum altitude at which a turbocharged engine can produce its rated Read More

Six pack

Reference: Six pack: is a terms referring the six basic instruments that a pilot must know! From the top, on the most left is the Airspeed indicator (ASI), the Attitude indicator (AI) is in the middle, and the Altimeter (Alt) on the right At the bottom, on the most left is the  Turn coordinator Read More

What’s Wing Camber, What’s Chord line?

What’s Wing Camber? Ans: curvature of the aerofoil (wing) maximum distance between the mean camber line and the chord line   Mean camber line : imaginary line equidistance between the upper and lower surface of the wing, joining from the leading edge to trailing edge.   What’s Chord line? Ans: imaginary line joining from the Read More

點樣知機場QNH? 點樣知Local Pressure? How to know the QNH? How to know local pressure?

今日上完堂再唸左成個下午先好D 通左D, 所以一定要記底佢…小喇叭, 呢個Concept 好難明! Anyway, mark 低佢先! Reading (in feet)  = (Set QNH – Actual pressure level) * 30 For example, if the aerodrome is 30 feet Elevation and 當時QNH是1013, then Reading (in feet)  = (Set QNH – Actual pressure level) * 30 30 = ( 1013 – Actual pressure level )* 30 30/30 Read More

Why “Fly to low, watch below ; High to cold, watch below” ?

Ref Ace the technical pilot interview 2/E   Ans: Always remember : aneroid barometer is working based on MSL pressure (i.e pressure height) !   1.  FL formula Flight Level (Pressure Height) in feet = Height @ QNH + (1013 – QNH) * 30   Example: Now say 300 feet @ 1025 PH = 300 Read More

一次搞清楚 Q-code and Altitudes (Altimetry)

Ref Ace the technical pilot interview 2/E QFE : refer to the height (vertical distance) above ground level (with no relation to mean sea level) QNH : Altitude – refer to the height (vertical distance) above mean sea level QNE : Pressure Height = Flight level – refer to the height (vertical distance) above 1013 Read More

Maximum Glide Range?

Ans : two manoeuvre factors – 1. optimal angle of attack 2. minimum drag speed 當上面兩樣野做到又吾計wind , 理論上隻機就會飛 @ max L/D ratio 記著: 重量同max glide range 無關! 取決上面說的兩個操作factors – 大機同細機glide range 一樣 ! Read More

Pilot math

計數係惡夢 但方法還是有 🤭 Ref skybrary:   時間 Time 6 mins 0.1 hour 3 mins 0.05 hour   方位 Reciprocal Heading = HDG +200 – 20 or = HDG – 200 + 20 大過200就- 先 ; 細過200就+ 先 e.g 090 : 90 + 200 – 20 = 270 270 : 270 – 200 + 20 Read More

Ground effect 對不同flight status 的影響? (就Ground Effect 有咩係機師要知, 有咩要做?)

Ref Ch5 Ans: 機師要記著  – T/O phase not attempt to force the acft T/O with not sufficient takeoff speed (due IAS 假象!) never retract the landing gear or flaps prior to establish +ve rate of climb never retract the landing gear or flaps prior reaching MSA (minimum safe altitude)   Landing phase  reduce power to Read More

Ground effect 有咩影響? Significance of ground effect?

Ref Ch5 Ans:  Upwash↓ , downwash ↓  –> Wingtip vortices ↓  –> induced drag ↓  –> AOA need to be reduced for same CL  Local pressure on static source [position (installation) error] –> airborne IAS reduce 假象   Induced Drag 成因? What’s ground effect? Read More

What’s ground effect?

Ref Ch5 Ans: air cushion phenomenon The reason of ground effect is that the air that is trapped between the wing and the landing surface, as if there were an air cushion. When the plane is very close to the surface (say just before touchdown),  it would suddenly feel like the plane did not want Read More

Strategy to avoid wake turbulence?

Ref Ch5 Ans:  飛緊 : avoid similar flight path with 1000 ft vertical separation T/O : rotate before the point at which preceding acft rotated  LAND : approach above preceding acft’s flight path  LAND : touch down after the point where other’s wheel contact If doubt, 用 3 mins margin time (rule of thumb) For Read More

When the wingtip vortices are greatest?

Ref Ch5 Ans: heavy, clean, slow   Vortices 正比 Weight Vortices 反比 Wingspan Vortices 反比 Speed   所以大機, 無落FLAPS, TAKE OFF/APPROACH 果陣最勁~ 因為大機重, 無FLAPS 要產生升力, AOA 自然大, INDUCED DRAG as well as Wingtip vortices 就當然大   Read More

點解vortices 係 wingtip ? The formation of wingtip vortices~

Ref Ch5   Ans: pressure differential (between upper and lower surfaces of wing) air always moves from high pressure toward low pressure bottom : span-wise movement of air  (outward from fuselage to and around tips) upper surface : span-wise movement  (flow in toward fuselage and off the trailing edge) fuselage limits the inward flow – Read More

Induced Drag 成因?

Ref Chapter 5 Ans: air tends to flow from the high pressure area to low pressure area higher pressure at the bottom of airfoil vortices is created (at wing tip) – wingtip vortices vortices roll off, and create a downwash downwash points the relative wind downward lift is tilted  the more the tilted lift, the Read More

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