During the first year or so of their manufacture, the later Gen Soviet fighters, LaGG-3, Yak-1, Yak 7 etc. were often flown with the canopy off because they were known to get stuck in flight and pilots were scared of being trapped inside in the event of their aircraft being heavily damaged or suffering engine failure. This cost something like 100 kph in speed so needless to say, it was a 'drag'...