Two H-21B used for engine test, 1958-1960. Piston engine replaced by either one or two gas turbine engine of two different marks. Both later retrofitted with piston engines and delivered as UH-21B, 1962.

List of Operators of Piasecki H-21D | |
From | Organisation with model H-21D | |||||
1952 |
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Construction Numbers on database of H-21D | ||||||
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Construction Numbers | Help Us | |
C/N | Year | History | ||
B-167 | 1958 | ![]() | ||
B-168 | 1958 | ![]() | ||