A few posters have commented on how the aircraft 'feels' wrong on short final with the gear up, because of the lack of drag associated with extended gear. I think this is another reason (along with no gear unsafe warning system) why Yak52s feature highly among the 'gear up' accident stats.
The gear doesn't actually retract on a '52. It folds horizontal, but is still out in the slipstream creating quite a lot of drag.
Of course, the Russians weren't daft when they designed the aeroplane. If landed gear-up (it is a trainer, after all) it touches down on the folded-back but still rotatable main wheels and the tail skid. Even the brakes can still be used in the roll-out!
Ivan simply jacks it up, fits a new prop, straightens the flaps, and goes flying again (that's why it has a wooden prop and brick-built reduction gearbox). But in UK we condemn the engine as shock loaded and the incident becomes ver very expensive indeed!