American production, black & white (I believe), so guessing mid-50s to early 60s. Caught only last ~15-20 minutes of movie (about 45-50 years ago) on TV, so can’t help with other scene(s). Likely a “B” movie, but unsure. Actor unknown. Climactic scene(s) included: an activated or damaged atom bomb (capsule shaped) sitting on or near runway at base or airport, then being chained to either a bomber or helicopter by hero pilot who sacrifices self to radiation exposure and flies bomb away from city (over ocean?). Bomb explodes, killing hero pilot. Disaster averted.

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