Points well made Graybeard, names are confusing I guess, For a ‘box’ change, a technician (or in actual fact an airframe/engine Licensed Engineer) can issue a CRS. (Provided that no external test equipment is used, and the aircraft in question has a BITE Go/No Go system). As a scanner is technically an antenna only an Avionics Licensed Engineer may issue a CRS for a scanner change. Licensing here in the UK heavily splits into specialised Mechanical/Avionic disciplines, whereas the A&P is more general in it’s scope. (Don’t get me wrong, I know several A&P guys in JFK, a couple of which are among the best engineers I’ve ever known). The Mechanical licensed guy here will have limited avionics knowledge/certification powers.
Yep, the biggest danger from a modern radar is to be clocked in the head by the scanner.
I have to admit, I too have often wondered about the DME, Transponder and lower TCAS antennas radiating all this power downwards, onto baggage loaders, refuelers etc, no warning lables on these, and they’re powered all of the time.
Back to the radar switched off issue; on my previous high-flying aircraft, (cruise was betwwen 50 & 60,000'), we also tinkered with the idea of switching the radar to STBY during taxi. This was because the old AVQ-30 stabilisation was constantly fighting the nodding of the nose during taxi, causing premature failures of the antenna servo system and bearings.
Keep posting GB, you know your stuff.
Last edited by M2dude; 31st January 2010 at 00:20.