Awesome details of a helicopter rotor. It's a PZL W-3 Sokół (english: Falcon) - a medium-size, twin-engine, multipurpose helicopter developed and manufactured by Polish helicopter company PZL-Świdnik (now AgustaWestland Świdnik). Taken during air picnic at 23rd Air Base in Mińsk Mazowiecki.
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Camera: Canon EOS 70D + EF-S 55-250mm STM