Speaking (or writing) of getting to retirement, when I worked at Bankstown, I was asked to accompany a young, inexperienced bloke on a bank run. He'd been flying with another bloke on this run, but not yet experienced enough to do it on his own. The usual pilot was unavailable (ill, or something. I forget why). I didn't work for this company so wasn't familiar with the route or routine. This was pre-GPS.
We did the trip. There were some issues but the worst was the last sector. Young bloke in the LH seat, me supervising. Returning to YSBK at night in IMC over the Blue Mountains to the west. En-route, and without any fix whatsoever - not even a groundspeed check - he decided it was time to start descent into YSBK, using the LSALT step downs.
I had to stop him. He said that's what the other pilot did. The problem, in my mind, was that hadn't confirmed - or determined - he had passed the mountains! Not even a groundspeed calculation. Everything based on flight plan times.
Debriefing afterwards, I had to emphasize that were there headwinds stronger than forecast, or a TAS less than planned, we would have descended into the mountains - but he had no way of knowing that. I said that if he wanted to descend early he needed to pre-determine x-bearings (+ tolerances) from navaids to give fixes to allow that.
In my mind was a historical crash written about in the old ASD ('crash comics'. Nothing so useful in its abysmal replacement!) about a plane that used ded. reckoning for its descent and the winds weren't as expected. End result was a premature interaction with the Great Dividing Range.