basically "flew to failure" of certain sub components
Fully aware of that practice.
The Sikorsky S76 had its hydraulic pumps lifed as 'on condition'. I had one fail about 60 miles out of Aberdeen. The weather was lousy and I had to go around from an ILS at Aberdeen and proceed IFR to Kinloss on one hydraulic pump knowing that the S76 will not fly without it. It was No 2 so the undercarriage blowdown covered their newly concreted ramp with hydraulic fliud. They were not happy.
The quill shaft had sheared. The other pump I was flying on had 600 hours more than the one that had failed.