Why can’t safety features like parachutes, be added to airplanes to help ease them to the ground, when its inevitable that the plane will crash?


Why can’t safety features like parachutes, be added to airplanes to help ease them to the ground, when its inevitable that the plane will crash?

In: Physics

The same reasons planes don’t already land with parachutes. They kinda sorta have to keep going forward, because that’s how planes work.

The vast majority of air accidents wouldn’t actually benefit from a parachute assembly anyway. In a situation where an aircraft is inevitably plummeting to the ground, a parachute assembly isn’t likely to help. It’ll either not deploy properly, completely rip itself apart, or at best will violently swing the aircraft around.

Plus if you have even one engine running still, which is quite probable, your parachutes are going to be completely ineffective.

Some stunt planes do

As for an airliner, they’re too big for a parachute to be effective, due to the cube sqaure law. If I scale a plane up to double the size, it’s mass increases by a factor of 8 (x2 in length x2 in height, x2 in width = x8).

A parachute works by producing a drag force to counter weight. The force of drag the parachute produces is proportional to it’s surface area, but the surface area only increases by a factor of 4 if it’s size is doubled (x2 in width, x2 in length).

So if I want to equip a plane with a parachute, the size of the parachute relative to the plane has to be larger the heavier the plane is. Once you get to an airliner size, there is no parachute that can actually slow it’s descent enough that could actually fit inside the plane.

It’s not inevitable the aircraft will crash.

Aircraft have many duplicate systems and back ups.

For example, the flying controls only need one set of hydraulics to work. But each engine drives a separate hydraulic pump and circuit. Some aircraft even have a third powered by a ram air

Technically the aircraft only needs 1 flying control computer. However some aircraft have 4. Which cross monitor each other in case one of them malfunctions.

On the aircraft I work on they have 5 different ways of creating electricity. An AC generator per engine, a DC generator per engine and a transformer rectifier unit and a battery. If one system fails the others will take over. Essential systems are given priority on the electrical power available

Then there’s the high quality of maintenance done on aircraft. Parts are regularly checked and replaced every few hours even if they could be ok. Any work done by a technician will be tested afterwards or independently inspected.

The pilots will be highly trained with 1000s of flying hours. And routinely tested in a flight simulator and medical examinations.

Then look at the flightradar24.com website at how many aircraft are flying per day….Everyday. 100,000s of aircraft are routinely flying without incident,

TDLR: airliners are considerably much safer than cars and trucks.

If a plane is going down and you just rip open chutes, you’re going to rip that plane apart.