Runway Declared Distance

Runway 嘅作用當然係要黎比飛機takeoff/landing，但其實T/O & LDG 都有Definition~

Takeoff Definition:

由 Brake release point (BRP) 至screen height 呢個距離就係takeoff 啦~

Screen height for Class A aircraft is 35ft; Screen height for Class B aircraft is 50ft~

Landing Definition:

無論係Class A aircraft 定係 Class B aircraft 都好，由 50ft above landing threshold 開始至 aircraft full stop 嘅距離就係landing ~

要知道夠唔夠takeoff/landing distance，首先要了解一條runway 係分左邊幾個部分~

Clearways

Clearways 嘅範圍係指runway 後面嘅範圍，呢個範圍係位於runway center line 之後同埋係機場嘅管轄之下，而且飛機takeoff 之後係可以即刻飛過嘅，所以 Clearways嘅入面除左 threshold lights 之外係唔可以有其他障礙物~

Stopways

Stopways 嘅範圍係runway 後面以center line 為中心嘅一段距離，呢段距離可以support 到飛機嘅重量，同埋可以比 Rejected takeoff (RTO) 嘅飛機有多一段減速距離~

The Takeoff Run Available (TORA)

Threshold to Threshold 嘅距離就係 TORA~

The Takeoff Distance Available (TODA)

TORA + Clearway = TODA，同埋計TODA嘅時候 Clearway 嘅上限係 TORA 嘅50% ; 如果冇Clearway，TODA = TORA

Aircraft’s required takeoff distance一定要細過 TODA 先可以Takeoff ~

The Accelerate – stop Distance Available (ASDA)

TORA + Stopway = ASDA; 如果冇 stopway，ASDA = TORA

Aircraft’s required accelerate – stop distance 一定要細過 ASDA~

Landing Distance Available (LDA)

Threshold to Threshold 嘅距離就係 LDA; 如果有Displaced Threshold 就過左 Displaced Threshold 先開始計LDA~

下面呢幅圖就總結晒以上講過嘅野~

如果大家都明嘅話，可以睇埋下面唔同種類嘅 combination~

最後，比多條題目大家計下~

Runway 09 TORA = ? Runway 27 TORA = ?

Runway 09 ASDA = ? Runway 27 ASDA = ?

Runway 09 TODA = ? Runway 27 TODA = ?

Runway 09 LDA = ? Runway 27 LDA = ?

Answer:

Runway 09 TORA = 2000m Runway 27 TORA = 2000m

Runway 09 ASDA = 2300m Runway 27 ASDA = 2350m

Runway 09 TODA = 2580m Runway 27 TODA = 2350m

Runway 09 LDA = 1850m Runway 27 LDA = 2000m