The Boeing CH-47 Chinook entered into service 50 years ago. Though its subsystems have evolved over the years, the basic design remains the same. Given the US Army's current plans, the venerable Chinook might well be the first 100 year rotorcraft design... I'm willing to bet there will be at least a few of these magnificent machines still flying in 2062. Possibly even some of the very same aircraft that are flying right now... After all, the very first Chinook ever built is still in service and has seen multiple tours in Afghanistan. It's likely that the Vertol--before Boeing bought the company in 1960--engineers who were developing this aircraft back in the late 1950s couldn't have imagined their creation still being in service 50 years--let alone 100 years-down the line.
Here is a video from earlier in the year--it shows off some of the awesome capabilities of this machine.