Airplay ... excellent post! Kudos to you for finding that AC
Of particular interest are paragraphs 5-f and 5-n of the requirements, and paragraph 3-e of Appendix I.
From the information in the AC
, the party responsible for installing such equipment on board the aircraft must first select the appropriate EMI parameters based on the airframe design standards, then prove to the FAA that their equipment meets these standards when installed in the aircraft.
For battery operated equipment that passengers would bring onboard, obviously the electrical load analysis, crashworthiness issues and conducted emissions would not apply, only radiated emissions. Airlines obviously base their policies on examining various common consumer products that passengers might use onboard, then determine what level of risk is reasonable given that all of these equipments cannot possibly be tested.
I suspect the reason they do not allow equipment to be used below 10,000 feet is that there is too little margin to regain control of the aircraft in case a serious interference should occur.
Back to the subject of video equipment, I recall when Delta was transitioning to BusinessElite, they gave out portable video players on aircraft that did not have the new in-seat systems. These players were not like the ones you buy in a store -- they looked rather "institutional" in design. I am sure they were specially designed for airborne use, and tested by DL
's engineering department to assure compliance to EMI requirements.