Just going to leave this here

Bingo.
Technically the heli would stay and the train would move forward. The pilot will move forward away from the heli and the rear wall will move toward it. Newtons 1st law.
Of course the air in the car is being shoved forward by the walls of the train so there may be some air resistance acting on the heli but, probably unnoticeable.

Joking that the heli will hit the back wall so back down then forward. The correct joke would be stay down forward

 

Nope, nope, nope.

Well, more precisely, it would depend on your point of view.

The helicopter, to an outside observer would remain stationary until it hit the back wall of the train car, at which point it would begin moving forward with the train, and likely fall to the floor and continue moving with the train.

From the viewpoint of a passenger on the train, though, yes, the helicopter would appear to move towards the back wall and fly into it.

 

Standing in the same railcar shine a flashlight at the forward wall. Does the train slow down? Light certainly can't speed up....

 

There will be a helicopter flown in my van this afternoon.

 

You want the answer? Put your bike in an enclosed trailer on the kickstand and don't tie it down... Drive to the track and open your door.. Damn this brings back the treadmill nightmares...

 

Same thing happens in my wife's FJ. She swears there is a leak or something. When I 'splain its the heavier, cold air moving forward because of momentum, she looks at me like I've been dropping acid!
Kinda dumb, for a smart woman.

 

Look up SmarterEveryDay.

 

The heli blades are acting against the air in the car. The air in the car is influenced by the walls in the car.
If the car moves, the heli moves. (In theory. Air will compress. How much, who knows).

 

That's what I want to see. It's going to move with the air in the van but how much that air moves is the question. Hope we don't put an eye out LOL

 

It goes without saying you will get this on video

 

Can I change my answer? The blades work well against the air in the vertical axis, ut offer little resistance in the horiz. axis. The heli will probably smack the back wall. If the train were to move up and down however, the heli would move with the car.

 

Yep, that's him!

 

Back of the car will hit the heli...the heli won't hit the back of the car.

 

What if the doors and windows are open? ;-)

 

What if the helicopter was bolted to the floor, with a Saturn V rocket strapped to it?

 

Depends on bolt grade.

 

Ah, but the balloon is connected to the train. The air in the train will have an effect on the balloon as the train moves. Now if they created a vacuum in the train and removed all of the air there would be no "connection" and no effect.

 

After I made that post, I started to say "it depends on your perspective".

If you are sitting on the train, the helicopter will move. If you are standing on the outside, looking through the windows, the helicopter will not move (at least not until it smacks against the back wall of the train ).