The RAF has been known to use 'penny' washers. Strangely, 2 of the 3 RAF Hercules I've seen in flight were below me. Though I was not airbourne and they were...A friend of mine worked for a firm that overhauled C-130s,among other things. One fine day,a well worn C-130 came in and was duly lined up for overhaul and my friend, a sheet metal worker, was tasked to reskin the ramp. He noticed all these discs on the outer skin, each one a few inches apart.Upon closer examination,it turned out to be the national coin of the owner nation,each one with a hole drilled in it for a rivet, so that they acted like a large washer. The entire skin had to be replaced, as were many other skin panels of the aircraft.
Greek drachmas. Aircraft was riddled with corrosion and was essentially scrap but was rebuilt as new. I recall an old sweat in overhaul saying to me that, with certain exceptions, the further South and East you went, the worse the aircraft got. My personal favourite was a 767 that had been hauling horses,without a rubber cover on the floor. It came in for a C-check and when the lads took up the floor panels, the frames were corroded away from horse pee to about half their height. They reckoned that the floor panels were holding it together. The owner's rep simply shrugged and said "fix it" and it was and it flew out and the cheque was cashed.I am assuming it is a country who's currency is worth less than the price of the washer needed to cover out the worn out hole it was installed over.
I have seen and/or assisted with and/or signed off the ferry flight for several home depo spar repair repairs on planes ranging from 180/185s to bonanza to pa31-350s. It isn't airworthy, but with a special flight permit it can be safe for ferrying.Local C-172 got blown over on one wing tip in a storm. Bent the wing up about 6" at the tip and spars buckled at the strut attach fitting area. It was sold as a damaged aircraft to a man that took the wing tip off and shoved wood 2" by 4's in the lighting holes as far as he could and put the wing tip back on and flew it away. I kept checking on news for a C-172 crash, but he must have made it OK.
In 2002 the drachma ceased to be legal tender after the euro, the monetary unit of the European Union, became Greece's sole currency.