Aerodynamic/hydrodynamic drop pod

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Discussion Overview

The discussion explores the feasibility of designing a drop pod that allows a person to be dropped from a helicopter at high altitudes and safely enter the ocean, experiencing an acceptable deceleration rate and subsequently bobbing back to the surface. The conversation touches on theoretical designs, practical applications, and alternative methods for safe water entry.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant wonders if a drop pod shape could be designed to allow safe water entry from a helicopter, questioning the laws of physics involved.
  • Another participant suggests that such a device could be beneficial for rescue swimmers, referencing the dangers of high jumps into water and the need for controlled entry angles.
  • A different viewpoint proposes that a long and narrow cone shape could theoretically work, but doubts its practicality due to size constraints and the need for a safe deceleration path.
  • One participant mentions the use of landing rockets as a potential method for safely descending from great heights, noting their application in military contexts.
  • Another participant suggests using a bungee rope instead of a pod, proposing a method where the helicopter calculates height and rope length to drop a person safely into the water.
  • Concerns are raised about the risks associated with using a bungee cord, particularly regarding disconnection and the potential for injury from the cord or rotor blades.
  • A participant recalls a NASA project aimed at delivering payloads from space, speculating on the implications if a person could be dropped from the space station.
  • One participant hypothesizes about the mechanics of a bungee cord, suggesting it could convert potential energy into kinetic energy to aid in a swimmer's descent.

Areas of Agreement / Disagreement

Participants express a range of ideas and concerns, with no consensus on the best approach to achieve safe water entry from a helicopter. Various methods are proposed, including the drop pod and bungee cord, but disagreements about their feasibility and safety remain evident.

Contextual Notes

Participants highlight limitations regarding the practicality of designs, safety concerns with high-altitude drops, and the need for controlled entry into water. The discussion reflects uncertainty about the effectiveness of proposed methods and the assumptions underlying their feasibility.

72Zorad
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First, this is just something I've wondered for fun...not serious, and just wonder if if the laws of physics make this possible.

Would it be possible to create a drop pod shape such that a person could be dropped from a helicopter from a high altitude and have it hit the water (ocean) such that the occupant experiences an acceptable deceleration rate then it bobs back to the surface?

Thanks,
 
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72Zorad, Although I have no suggestions to offer, the device you are asking about just might prove useful for rescue swimmers who jump out of helicopters to save lives. Here is an excerpt from the wiki page:

"Water entry shock
Although water entry close to the surface is relatively uneventful, the density of water makes it harder for it to move out of the way when penetrated at high speeds, as occurs when jumping into water from great heights.

Mild bruising to being knocked unconscious can occur from very high jumps, especially if entry angle can not be controlled and the jumper is burdened by coiled rope and other heavy rescue equipment. In some situations the rescuers can themselves need to be rescued if they are injured by making a very high jump entry into water.

Generally rescue jumpers try to get as close to the water surface as is practical before jumping out of the rescue vehicle. In ocean rescues during intense storms, helicopters often must stay high to keep clear of large ocean waves, which also have very deep troughs. In these conditions, the jumper tries to time his jump to occur at the crest of the wave action."
http://en.wikipedia.org/wiki/Rescue_swimmer
 
Such a shape obviously exist. A very long and narrow cone would do just that. Question is, whether one can be created of practical size, and that's very unlikely. It will have to be comparable in size to the length of safe deceleration path. So while it can be somewhat smaller than similar device for impact with hard ground, it's not going to be enough to make it practical.

Your best bet for falling from great heights is landing rockets. These have been used to drop military equipment. Might be possible to make something that can bring a human down safely.
 
My thought was a thrill ride for those crazy people who base jump and such. Recently saw a show where a guy used one of those sailing suits to land in a pile of boxes without a parachute. Last guy who tried that mixed the boxes and died. This could another one of those first. First to intentionally survive a free fall to Earth (intentionally) without a parachute.

Mind you, not me...I have no desire to leave the planet without a dependable engine, wings, and good pilot to bring me safely down.
 
You don't need a pod why not use a bungie rope.
Helicopter calculates height to ocean,length of rope selected,person dropped to water.
The dissconection of the rope once the diver feels wet feet.
 
Buckleymanor said:
You don't need a pod why not use a bungie rope.
Helicopter calculates height to ocean,length of rope selected,person dropped to water.
The dissconection of the rope once the diver feels wet feet.

rotor blade, bungee cord, high wind, heavy sea, what could possibly go wrong?
 
d3mm said:
rotor blade, bungee cord, high wind, heavy sea, what could possibly go wrong?
Now't if you are dissconected at the helicopter end.
Cutting the rope at the other end, that would be asking for trouble.If you consider a pod drop and the broken bones involved with that I would rather take my chances with a bungee and someone reliable on board.
Second thoughts it might be a good idea to be inside a pod as well to stop the cord hitting you on your head.
 
Last edited:
I believe NASA was working on a project to deliver small payloads from the space station to earth. It was to be an unmanned pod that could be guided to its destination from orbit. The concept is extremely useful for space travel. Imagine if a single person could be dropped from the space station!
 
Buckleymanor said:
Now't if you are dissconected at the helicopter end.

My hypothesis is that the bungee cord will contract and fall, converting its elastic potential energy and its gravitational potential energy to kinetic energy and deliver it to the swimmer.
 
  • #10
d3mm said:
My hypothesis is that the bungee cord will contract and fall, converting its elastic potential energy and its gravitational potential energy to kinetic energy and deliver it to the swimmer.
Makes sense, see second thoughts post 269.
 

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