10 Star Trek Characters You Totally Forgot Existed
5. Chief Argyle
Before Lt (intentional) Geordi La Forge took over the reins in Main Engineering for TNG's season two, the show played around with a revolving door of chiefs through the first year.
Following the MacDougal and preceeding Logan, Lt Cmdr Argyle managed a rather legendary three episode run with Bill Yeager in the role. Appearing in Where No One Has Gone Before, Datalore and Lonely Among Us, Argyle may be one of those to carry the blame for reconstructing Data's evil twin if nothing else.
The story also goes that Argyle was considered as the permanent incumbent for the Chief Engineer role but a letter campaign that began to arrive at Paramount before his first appearance put paid to that as producers suspected there might be a little foul play. He may also have been a little too Scotty since Argyle had a slight Scottish accent although producers felt he was different enough from the Miracle Worker.
Interestingly he is referred to as "one of..." four chiefs by Riker which might further indicate that running a ship such as the Enterprise-D takes more than one top man at this point although this never returned to after season one.