Glide angle

…Gliders usually do not have propulsors, and therefore cannot fly steadily in the wind, but they can fly steadily downwards while moving forward, which is called gliding. The angle that the flight path makes with the horizontal plane during gliding is called the glide angle or descent angle. The ratio H / X of the horizontal flight distance traveled by gliding from a certain altitude H to X is the tangent of the glide angle, and its reciprocal X / H is called the glide ratio, and its value is equal to the ratio of lift L to drag D , or the so-called lift-drag ratio L / D . …

*Some terminology explanations that mention "glide angle" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…グライダーは通常推進器をもたず，したがって無風時での定常水平飛行はできないが，前進しながら降下するという定常降下飛行は可能で，これを滑空と呼ぶ。また滑空時に飛行経路が水平面となす角を滑空角glide angleまたは降下角と呼ぶ。ある高度Hから滑空して進んだ水平飛行距離Xとの比H/Xが滑空角の正接で，その逆数X/Hを滑空比glide ratioといい，その値は揚力Lと抗力Dとの比，いわゆる揚抗比L/Dに等しい。…

※「glide angle」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報