Those of you who give Narco avionics a bad name are not telling the whole truth, some of the stuff like the ADF and some of the DME units are very poor while the later transponders anf NAV/COM’s showed good reliability as did their KNS80 equivalent.
Narco also had a thing called the Starnav, it was the first and last GA multi sensor navigation box, it could mix VOR, DME, GPS & Loran to give IFR area navigation and was so far ahead of the field that no one outside the airline business understood it.
Given better marketing and a better display it would have left Garmin for dead but Narco was on the ropes by then and it disappeared into obscurity.
My vote for the thing that should never have left the drawing board is the dual mag.
The GNS430/530 user interface. You always intuitively twiddle the wrong knob.
The dual mag does seem like a dumb idea.
A and C, I’m happy with my late ’80s Narco comm and nav radios. They work fine and I have working spares for each that cost $600 (for both). Radios are an aircraft accessory for me, not a key point of interest 
I like carbs better than fuel injection, ideally with gravity feed, no pumps mechanical or electrical, interconnected vents and no left/right fuel selector. The safest fuel system there is for my use and no hot start issues. I’d choose fuel injection for aerobatics, not for my more typical use. The carb feature that I wouldn’t certify is the rubber slide diaphragm on the Bing carbs used by Rotax. If the diaphragm cracks the throttle closes and it stays there. I have the same Bing carbs on one of my motorcycles and carry a spare, which I have installed once on the side of the road.
(photo is not a Bing, its a different motorcycle carb but the design is the same)
2) Fuel selectors outside the direct field of vision of the pilot. Very bad user interface design, encouraging deadly mistakes for no reason.
Out of view is one bit but (almost) out of reach is worse. I need quite some gymnastics to reach mine.
Automatically deployed slats, flaps and landing gears. These things have killed far more people than they saved.
I remember one rather interesting moment in my AN2 flying when the automatic slats suddenly extended. Needless to say, i agree with you there! Even worse is the possibility that only one set of flaps extends/retracts if the CB of the other set pops. Happened to a pal of mine on an agricultural AN2. He ended up plowing a field in a very unplanned manner, ending with a flip over and a 180° inverted “parking”. Took 3 weeks to fix that airplane….
Any fuel system that wholly needs a second electrical pump in the event of a mechanical failure.
Pretty much all of them then?
Autopilots that will stall an aircraft because they’re trying to maintain altitude.
Again pretty much all of them safe the very last fully digital AP’s. Mine will do it as well, so you have to be careful. Yet, if you want a proper stall protection in an AP, you need to include IAS or AOA, which is not an easy thing to do.
Re the other posts: Looks like everyone has his pet dislike for something or the other. Combine all the posts here and most of our fleet would be gone :)
Any fuel system that wholly needs a second electrical pump in the event of a mechanical failure.
Pretty much all of them then?
It surely hasn’t escaped your attention that most Cessnas and a great many other carbureted planes have nothing but a hose and gascolator between tank and engine?
Re the other posts: Looks like everyone has his pet dislike for something or the other. Combine all the posts here and most of our fleet would be gone :)
It certainly seems that way. 
The problem is when somebody assumes their needs are universal.
The problem is when somebody assumes their needs are universal.
EASA?
Absolutely agree about magnetos. Had both of them almost broken internally and it became clear only while inspection. Few more hours of flight could cause full engine failure. Starter is another lousy stuff. Not crucial in-flight, but may cause many troubles on intermediate stop (as happened with me last year). 300 hours from new state and got broken shaft inside.
A fuel selector that goes from left, through OFF to right!
High and low wing airplanes, Helicopters and other heavier than air machines. Too dangerous for me. Oh yea, those 150,000 GNS430 and 530 units, them too, stupid people voted with their purchase. :)
Agreed with dual mag. Out of curiosity, since I have one, what are the failure cases regarding
million scenarios where one side kills the other and the engine is out.
Warm regards.
