Unfortunately old airplanes do cause problems. You can maintain an old aircraft as much as you like but there are still areas were age problems can be catastrophic. Think back to the roof peeling off the Aloha Airlines 737-200. What about the miles and miles of old brittle wiring that cannot be inspected, just waiting for a chance to short out and cause a fire. Having flown many an old aircraft, the older they get the more unreliable they get.
RIP Ozjet.