Complex sentence: The Iroquois' original designation of HU-1 led to its nickname "Huey", which remained in common use even after the official designation was changed to UH-1 in 1962.
Split into simpler sentences: The Iroquois' was originally designated HU-1, which led to its "Huey" nickname. The helicopter has remained in common use after the official designation was changed to UH-1 in 1962.