Composite(RCA) video line in cable to lightning port to display video on iphone 6

Hello all,

I was wondering if its possible to use my iphone6 as a secondary screen to view what is happening on another device?

More specifically I am talking about using an RCA cable which will plug into the lightning port of the iphone6.

I am into remote controlled hobbies and recently got into FPV(first person view). So a camera strapped to my plane transmits the video signal to my monitor with a receiver and I can see what the plane sees. I have an option on my monitor or FPV goggles to plug into a video in/out cable which then can be plugged into a secondary screen for bystanders to watch. Instead of carrying around another screen I was thinking why cant my iphone just display it?

Here is a diagram ( http://i.imgur.com/I7rc3hCl.jpg ) how the camera system works and if you look at OPTION 1 and OPTION 3, it shows a secondary monitor (the first monitor is in the FPV goggles). Why cant I just connect my iphone and display what the goggles see?

Anyone know how this can be done?

Thanks!

K