I have this question to put to members "how can a Folker F28 become a C-17?
A friend and I have been tracking a F28 registed VH-NHK for a company at Perth, Western Australia (WA) to day it showed up enroute from WIHH to YPPH and was being depicted as a C-17. Any takers as to how this sort of error could occur
regard
GeoffC
In fact it’s a Fokker 100 but your question stands.
Would have to see the flight plan to see what was entered although I can’t think of any reason why “C-17” should appear anywhere on it.
At least it didn’t show up as a Super Sabre (F-100) 
Probably a typo for the tail number or aircraft type.