Ah the world of BIZJETS.
A "tougher" citation...great idea...how hard would it be to have double nav lights, MEL'able to just one on each wing? On the old DC9, we had two nav lights (uncolored) beneath each colored wing lens.
A retrofit to a AIRLINER hardend ciation...hmmm.
I wish you could just build brand new NorthAmerican - Rockwell Sabreliners...maybe a more fuel efficent engine but no big changes!
with all the over-runs (thinking carlsbad, calif) a gadget to say (after touchdown) 2000 feet to stop with current braking! (of course the pilot would have to know that there was only 1000 feet left).
good luck with your ideas and remember digital isn't always better! Hey how about modifying pressure vessels to allow a 3000 foot cabin at 35,000ft?
j