ʻO ka Sikorsky H-19 Chickasaw (helu kumu hoʻohālike hui S-55) he helikopter multi-purpose i hoʻohana ʻia e ka US Army a me USAF.
Ua hana ʻia e ka Westland Aircraft ma ke ʻano he Westland Whirlwind ma United Kingdom.
Ua hoʻomaka ka hoʻomohala ʻana o ka H-19 e Sikorsky me ke kākoʻo ʻole o ke aupuni. Ua hoʻolālā mua ʻia ka helikopter ma ke ʻano he hoʻāʻo no kekahi mau manaʻo hoʻolālā hou i manaʻo ʻia e hāʻawi i ka hiki ke lawe i ka ukana i hui pū ʻia me ka mālama maʻalahi.
ʻO ka mea kūʻai mua ka USAF, nāna i kauoha i ʻelima mokulele YH-19 no ka loiloi; ʻO ka lele mua ʻana o ka YH-19 i ka lā 10 Nowemapa 1949.
Ua ukali ʻia me ka hāʻawi ʻana i ka YH-19 mua i ka USAF ma 16 ʻApelila 1950 a me ka hāʻawi ʻana i ka helikopter HO4S-1 mua i ka US Navy ma 31 ʻAukake 1950.