My vote for 'Greatest Moment' is sometime in 1996, when the then AlliedSignal (now part of Honeywell) introduced the enhanced ground proximity warning system (EGPWS). It's no exaggeration to say that the invention of these avionics - the most important ever to be developed to improve aviation safety - has saved many thousands of lives that would have been lost to the scourge of controlled flight into terrain (CFIT).
Honeywell's Don Bateman, considered by many to be the father of EGPWS, had been helping to make inroads into reducing the mounting toll of fatalities caused by CFIT in the 1970s with the use of basic GPWS, which relied on a downward-looking radio altimeter, but this provided only a few seconds of warning of an impending crash and tended to suffer from false alarms.
The breakthrough came in the 1990s when highly accurate GPS-derived positioning information was married to a digital terrain database, to overcome many of the limitations of earlier systems. The result was a dramatic reduction in CFIT accidents, which had been causing 100s of deaths a year.
It is arguable that the airline industry would not have been able to grow in the way it has over the past decade without the moment that saw this essential technology enter into airline service.