Photo credit: Wikipedia
Here’s a fascinating Blackfive post on a Focke-Wulf Fw 190 Würger discovered intact in a Russian forest in 1989, and then, later, restored to flying condition in the U.S.
The original discovery lead to the plan being moved to England, and then it’s eventual restoration in California.
Per the post, a fascinating discovery was made that probably explained why the 190 went down:
A technician from Vintage Wings took apart the engine to find a dirt clod in an oil line, which had pinched off the lubrication. Consequently, an internal shaft overheated and failed, disabling the fuel and oil pumps, which led the engine to fail.
How did that dirt clod get in there? It was a new engine, just installed. BMW did not do major engine maintenance in the field. When an engine needed repair they removed the entire "power egg," the engine on its mount, and shipped it back to the factory in Germany. Some of the work was performed by slave labor. One theory is that a slave laborer sabotaged the engine, stuffing some dirt downstream from the oil filter, so that the engine only worked for a few minutes.
Paul Rätz made it only a few miles before he was captured and not shot on the spot. He was instead taken prisoner where he remained for sixteen years, released by the Soviets in 1959. Only ten percent of the German prisoners taken captive by the Soviets survived, so Rätz was double lucky. His opinion may differ. Unfortunately, Rätz died in 1989, having never learned his airplane had been found. Perhaps it was better for him never to know he spent sixteen years in a Soviet prison because his plane had been sabotaged, that a tiny little dirt clod had determined his fate. However, his family learned that his fighter had been recovered. They have the clock.