FAR Section 91.21
c) Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used.
How wise is it to not exercise the only collateral you have to get paid on what you are owed?
When you take out a student loan, are you pocketing the cash? No, you are immediately paying your tuition. The schools are owed nothing, they are extorting on behalf of the lender.
Math is like love -- a simple idea but it can get complicated. -- R. Drabek