上次過講過spinning 同spiral dive 係唔一樣嘅，今日就同大家講下咩係spiral dive
**spinning link https://www.hkcockpit.com/forum/principles-of-flight/spinning? **
Spiral dive 其實就係turning 嘅時候唔夠lift，然後飛機以一個spiral 嘅軌跡下降~
Spiral dive 嘅特點有幾個:
1.下降率高 (high descent rate)
2. 速度高 (high airspeed)
3. 冇失速 (not stalled)
4. Nose pointing downward
5. 方向改變(Changing heading)
Spiral dive 嘅 instrument indication 大概就會係以下呢幅圖咁~
咁遇到spiral dive 可以點做呢~?
1. Idle throttle (避免aircraft overspeed，因為係spiral dive 嘅情況airspeed 已經好高，如果冇 idle throttle 最後over speed limit可能會structural damage)
2. Level the wing (停咗個spiral)
3. Pull up (要慢慢pull，因為airspeed 咁高又pull 得太急嘅話load factor 會好大，有機會造成structural damage同埋high speed stall，仲有就係load factor 太高機師會有可能black out 架~
講住咁多先，有機會再同大家分享下 human factor (illusion) 同stability (directional stability vs lateral stability) 對 spiral dive 有咩影響~