Falling from an aircraft effects?

AI Thread Summary
Dropping an object from an aircraft involves several forces, including gravity and air resistance, which affect its trajectory. A light box may experience unusual behavior due to air displacement, potentially leading to safety risks for the flight crew. The box will initially retain the aircraft's forward velocity but will decelerate due to air resistance until it reaches terminal velocity. Concerns about upward turbulence generated by rotor wash could lead to the box being drawn back towards the rotor, which poses additional risks. Understanding these dynamics is crucial for ensuring safe operations during aerial deployments.
dingpud
Messages
198
Reaction score
1
Falling from an aircraft...effects?

Deploying something from an aircraft or helo...what are the different forces that are going to act on that object, or rather, where would I find information about that. Say a relatively light box is dropped out of a moving helo, how would I go about figuring out what happens to the box if the helo is moving at V knots and the box is LxWxH and its mass is M? I figured that it the box is too light, some sort of air displacement could cause it to act "odd" and could cause a serious accident or injury to the flight crew.

Any help would be greatly appreciated.

thanks
______________________________________________________________
***never stop learning***
 
Physics news on Phys.org
Not sure what you mean by "act "odd"... I don't see how dropping a box that is "too light" could cause a "serious accident". The forces on a dropped object I know about are gravity, air friction, and perhaps the push of a rotor, all of which push things from an aircraft away from the aircraft.
 
Well, if you're throwing something out of an airplane, it's going to slow down because of air resistance, and may hit other parts of the exterior as it does so...possibly including jet intakes/props, depending on where it's ejected from the fuselage. This might harm the crew...not directly, of course, but the results may not be pretty.

In terms of a general effect on the box...it will accelerate towards the ground at 9.8m/s^2, less air resistance, until it hits critical velocity. It's initial forward speed relative to the ground will be the velocity of the aircraft it's thrown from for a very short time, until it slows down because air resistance.

Perhaps what you are thinking about in your reference to a "light box" is some form of turbulence along the hull that would throw it back in. If so...that is theoretically possible, but incredibly difficult to calculate...and you'd need a CRAY on hand to do it.
 
Greetings !

Could it be that you wanted to imply low mass density ?
Well, abviously if the mass density of the object is lesser
than that of the air at the drop altitude it will go up.
If its greater than it will go down. I believe, that if the mass density is considrably greater than that of the surrounding air, this
effect will be neglagible compared to gravity and air resistence.

As others here said with a jet engine its pretty simple to figure out
the effect, but with a rotor it could be a lot more difficult.

Live long and prosper.
 
Turbulence I guess.

I think what I was looking for was if any upward turbulance, towards the rotor, was generated by the rotor. I wouldn't want the package to somehow be sucked, or blown back up into the general vicinity of the rotor.

Thanks for all the input.
 
Due to the constant never ending supply of "cool stuff" happening in Aerospace these days I'm creating this thread to consolidate posts every time something new comes along. Please feel free to add random information if its relevant. So to start things off here is the SpaceX Dragon launch coming up shortly, I'll be following up afterwards to see how it all goes. :smile: https://blogs.nasa.gov/spacex/
Back
Top