Hi there weasel
In aircraft maintenance anything is possible and the great law of Sod usually prevails. Not quite C-Ducts but check out the following extract from this air accident investigation report -
As the aircraft rotated for take off, both fan cowl doors detached from the No 1 Powerplant and struck the aircraft. The doors were destroyed and localised damage resulted to the No 1 Powerplant and its pylon, the left wing, the left flaps and slats, the fuselage and the fin. The evidence indicated that the doors had probably remained unlatched, after having been closed following maintenance prior to the accident flight and had been torn off their pylon attachment hinges by aerodynamic forces as the aircraft rotated. There are no conspicuous cues to indicate an unlatched condition when the doors are closed and no flight deck indication. Three walk-round inspections had been conducted after the doors had been closed.
After this the repective maintenance org quickly added fan cowls to their list of dupe inspections.
It is also interseting to note the AAIB recommended that the CAA also made it a requirement for similar aircraft types !
I dread to think what would happen if a C-Duct came off !!!!
