Not really prohibiting, just making it impossible...specially for smaller operators.
I had a sneeky peek at the manuals Iberia wrote to get approval from AESA. It included Ipad’s in pressure chambers, and heating test to see if there would be any explosion or other complications to be expected...
In my opinion trying to re-invent the wheel considering that half the world is already using Ipads in cockpits.
Furthermore there were very concerned how any company would monitor if the navdata updates were performed in due time. They preferred the old fashioned Jeppesen envelopes...
AESA wanted an independent power source to be installed in the cockpit, to be able to continously charge the Ipad’s.
German LBA accepted an Operations Manual stating that at the start of any flight one of two Ipad’s in cockpit shall be at 80% minimum. No requirement for any additional power source.
So there are German planes flying within Spanish terretory, with an Ipad which might be below 80%, not under continous charging and which could explode........and the Spanish operators still fighting with the AESA to get an approval to use Ipad’s.
(as you can see I am totally not frustrated with THE AESA ;-) )