May 28, 1971 (Friday)
- Portugal resigns from UNESCO.
- A Berlin-based CV-990A operated by Modern Air Transport, with 45 passengers on board, is unexpectedly denied permission to enter Bulgarian airspace, as a result of a new policy adopted by that country's then communist government to deny any aircraft whose flight had originated or was going to terminate at a West Berlin airport the right to take off and land at any of its airports. The plane lands safely back at Berlin's Tegel Airport.
- Died: Audie Murphy, 45, American actor, killed when his private plane crashes into Brush Mountain, near Catawba, Virginia. The pilot and four other passengers are also killed.
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