Why don't airlines have parachutes for passengers?
為什么民航上不給乘客配備降落傘？
原文地址：https://www.quora.com/Why-dont-airlines-have-parachutes-for-passengers
There are four reasons why you don't find a parachute under your seat on commercial airlines.
基于以下幾個原因，所以你坐商業航班的時候才不會在座位下面找到降落傘。
Parachutes are bulky, heavy and expensive. They would not even fit under your seat, they would occupy a lot of space and add a lot of weight. They would also need regular inspection and repacking. To provide several hundred per airplane would add significantly to costs, making flying much more expensive.
降落傘笨重而且昂貴。那些降落傘甚至不能塞在你的座位那里，也就是說會占用大量的空間和額外的重量。同時還需要定期的檢查和重新打包。在每個航班上增加幾百個降落傘會顯著增加飛行成本。Passengers are not trained to use them. Without a minimum of training most people would not even be able to strap the parachute on correctly, never mind open it and land safely. Even on the ground and with plenty of time this is not easy. In the confined space of an airliner and in a high-stress situation it would be even more difficult.
乘客沒有受過適當訓練。在沒有基本訓練的情況下乘客不懂如何打包降落傘，更不用提什么打開和安全降落了。即使是在地面上，花上大把的時間這也不是什么容易事兒。在客機上空間有限同時人員高度緊張，事情只會更加復雜。There isn't a convenient way to jump out of typical airliners. You would need to redesign aircraft with a special jumping exit. Just jumping out of normal side-facing airplane doors or emergency hatches you would probably hit the wing or the tail. You would need to install a ramp on the rear of the cabin.
離開飛機沒有什么方便的方法。為了增加一個跳傘口就需要重新設計飛機。通過常規的飛機側門或者緊急艙門跳傘可能會讓你撞到機翼或者機尾。這樣你就得給給你在背部裝個斜板。There are very few situations where it would save anybody. You would have to be in a situation, in daylight, over land where there is no hope of a landing but plenty of time to get everyone out. I can only think of a single case in the entire history of civil aviation where it could have been useful -- The United Flight 232 case (Wikipedia United Airlines Flight 232) -- but then only if the aircraft had been redesigned with a rear exit. Even in that case jumping was as risky as staying aboard.
這種拯救乘客方式限制太多。這樣的條件包括場景，在白天，下面也不是陸地自然也就無法降落，但有充足的時間讓每個乘客逃生。在歷史上這么多的空中險情中，我只能想出一個案例來運用降落傘這種逃生方式，那就是The United Flight 232 case (Wikipedia United Airlines Flight 232)，但如果飛機通過重新設計然后只能加了一個背部出口，即使是在這種情形下跳傘也和留在飛機里面一樣危險。
