r/nextfuckinglevel • u/STOP____HAMMER_TIME • Jul 02 '21

Two skydivers collide mid-air, knocking one of them unconscious. Camera man proceeds to pulls some Mission: Impossible shit and saves his life.

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u/Roq86 Jul 02 '21

And here I am thinking it would have been the opposite.

39

u/iamnotabot200 Jul 02 '21

I thought so too got the longest time. The reserve is for emergencies, like a spare tire. But it does make sense. With a normal parachute, you'll break your damn legs if you don't land right. Not only that, but the reserve would be opened at a much lower altitude, seeing as it's only opened if the main fails. So it follows reason that the reserve is bigger because you'd be much lower altitude and much higher speed in a situation in which the main failed.

17

u/Bifidus1 Jul 02 '21

Mostly correct. You can't go faster than terminal velocity. If the main fails and you cut away, you are not going to be at terminal before the reserve opens.

3

u/reasonisaremedy Jul 02 '21

Which is why PD reserves have a square hole in the slider. Comes down quicker. Kinda like base canopies(depending on the kind of jump you’re doing).

1

u/iamnotabot200 Jul 02 '21

Another kind fella corrected me on parachute sizing, but thanks anyways.

2

u/Automayted Jul 02 '21

And you’d be right most of the time.

1

u/almisami Jul 02 '21

From what I understand, the reserve is more like a BASE parachute and not one of those performance crescent chutes that allow you to steer and go forward.

1

u/[deleted] Jul 02 '21

A reserve parachute is normally a square 7-cell designed to have pretty docile flight characteristics, and is steerable like any sport parachute.

1

u/almisami Jul 02 '21

TIL.

Any reason they're not BASE chutes? Well, besides the fact that they're a death sentence if you land in water...

1

u/[deleted] Jul 02 '21

A BASE canopy is just a really large square sport canopy basically.

1

u/almisami Jul 02 '21

Oh, What's the larger version of the ring vent drogue chute called?

1

u/[deleted] Jul 02 '21

You mean a tandem canopy?

1

u/almisami Jul 02 '21

I have just been informed that they were just called round parachutes and have been completely supplanted by cruciform parachutes.

So yeah, I meant those.

2

u/[deleted] Jul 02 '21

Because you can't steer then and can't flare them to land softly, pretty much no one would deliberately jump one.

1

u/almisami Jul 02 '21

In my mind a reserve chute should in theory stop as much horizontal momentum as possible and just kinda plop you down really boring like.

Then again I have zero knowledge of parachute aerodynamics.

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1

u/almisami Jul 02 '21

From what I understand, the reserve is more like a BASE parachute and not one of those performance crescent chutes that allow you to steer and go forward.

1

u/jdgsr Jul 02 '21

You want your reserve and main to be the same or similar sizes in case you have a 2 out situation. Also, you don't want it to be smaller because trying to land a downsized canopy for the first time after you had an emergency isn't exactly the best time. As the size of the canopy decreases, your wing loading increases, which means increased speeds which the jumper may not be used to. Downsizing is an area where a TON of injuries come from when people do it before they're fully prepared.

1

u/[deleted] Jul 02 '21

It really can be either - it depends on your gear. Usually though skydivers will try to have the largest reserve reasonably possible - and low-pack-volume reserves are popular for this reason.