Looking very nice on approach to Cleveland is the oldest operational Twin Otter, NASA's MSN 4 N607NA, which is just a few months short of 50 years old.
Originally delivered to the Province of Ontario in 1966, it was acquired by NASA in 1972.
|MSN 4 - DHC-6-100 N607NA|
NASA Glenn Research Center
Cleveland, OH 16-Jun-2015