| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| XHCH-1 | McDonnell | cancelled |
| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| XHJD-1 | Whirlaway | McDonnell | 2 Pratt & Whitney R-985 Twin Wasp Junior | XHJH-1 | |
| XHJH-1 | Whirlaway | McDonnell | 2 Pratt & Whitney R-985 Twin Wasp Junior | XHJD-1 | |
| XHJP-1 | Piasecki | 1 Wright R-975-34 Whirlwind | 5 | ||
| XHJS-1 | Sikorsky | 1 Wright R-975-34 Whirlwind |
| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| HNS-1 | Hoverfly | Sikorsky | 1 Warner R-550-3 Super Scarab | 1 | R-4B |
| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| XHOE-1 | Hornet | Hiller | 2 Hiller 8RJ2B | YH-32 | |
| XHOG-1 | Gyrodyne | 1 Nelson H-59 | 1 | XRON-1 | |
| XHOK-1 | Kaman | 1 Pratt & Whitney R-1340-48 Wasp | 2 | ||
| HOK-1 | Kaman | 1 Pratt & Whitney R-1340-48 Wasp | 2 | OH-43D | |
| XHOS-1 | Sikorsky | 1 Franklin O-405-9 | |||
| HOS-1 | Sikorsky | 1 Franklin O-405-9 | R-6A | ||
| HOS-1G | Sikorsky | 1 Franklin O-405-9 | |||
| HO2S-1 | Sikorsky | 1 Pratt & Whitney R-985-AN-3 Twin Wasp Junior | H-5A, R-5A | ||
| HO3S-1 | Dragonfly | Sikorsky | 1 Pratt & Whitney R-985-AN-5 Twin Wasp Junior | ||
| HO3S-1G | Dragonfly | Sikorsky | 1 Pratt & Whitney R-985-AN-5 Twin Wasp Junior | ||
| HO3S-2 | Dragonfly | Sikorsky | cancelled | ||
| XHO3S-3 | Dragonfly | Sikorsky | 1 Pratt & Whitney R-985-AN-5 Twin Wasp Junior | ||
| HO4S-1 | Sikorsky | 1 Pratt & Whitney R-1340-57 Wasp | |||
| HO4S-2 | Sikorsky | 1 | cancelled | ||
| HO4S-3 | Sikorsky | 1 Wright R-1300-3 | UH-19F | ||
| HO4S-3G | Sikorsky | 1 Wright R-1300-3 | HH-19G | ||
| HO5S-1 | Sikorsky | 1 Franklin O-425-1 | |||
| HO5S-1G | Sikorsky | 1 Franklin O-425-1 |
| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| HRB-1 | Sea Knight | Boeing Vertol | 2 General Electric T58-GE-8B | CH-46A | |
| XHRH-1 | McDonnell | 2 Allison T56-A-4 | cancelled | ||
| XHRP-1 | Rescuer | Piasecki | 1 Pratt & Whitney R-1340-AN-1 Wasp | ||
| HRP-1 | Rescuer | Piasecki | 1 Pratt & Whitney R-1340-AN-1 Wasp | ||
| HRP-1G | Rescuer | Piasecki | 1 Pratt & Whitney R-1340-AN-1 Wasp | ||
| HRP-2 | Rescuer | Piasecki | 1 Pratt & Whitney R-1340 Wasp | ||
| HRS-1 | Sikorsky | 1 Pratt & Whitney R-1340 Wasp | |||
| HRS-2 | Sikorsky | 1 Pratt & Whitney R-1340 Wasp | CH-19E Chickasaw | ||
| HRS-3 | Sikorsky | 1 Wright R-1300-3 | CH-19E Chickasaw | ||
| HRS-4 | Sikorsky | 1 Wright R-1820 Cyclone | |||
| XHR2S-1 | Sikorsky | 2 Pratt & Whitney R-2800 Double Wasp | 3 | ||
| HR2S-1 | Sikorsky | 2 Pratt & Whitney R-2800 Double Wasp | 3 | CH-37C | |
| HR2S-1W | Sikorsky | 2 Pratt & Whitney R-2800 Double Wasp | 3 | ||
| XHR3S-1 | Sikorsky | 2 General Electric T58 | CH-3C |
| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| XHSL-1 | Bell | 1 Pratt & Whitney R-2800-50 Double Wasp | 4 | ||
| HSL-1 | Bell | 1 Pratt & Whitney R-2800-50 Double Wasp | 4 | ||
| XHSS-1 | Seabat | Sikorsky | 1 Wright R-1820 | 1 | |
| HSS-1 | Seabat | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | 1 | SH-34G |
| HSS-1F | Seabat | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | SH-34H | |
| HSS-1L | Seabat | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | LH-34D | |
| HSS-1N | Seabat | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | 1 | SH-34J |
| HSS-1Z | Seabat | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | 1 | VH-34D |
| HSS-2 | Sea King | Sikorsky | 2 General Electric T58-GE-8B | RH-3A, SH-3A | |
| HSS-2A | Sea King | Sikorsky | 2 General Electric T58-GE-10 | SH-3D | |
| HSS-2B | Sea King | Sikorsky | 2 General Electric T58-GE-10 | 4 | SH-3H |
| HSS-2Z | Sea King | Sikorsky | 2 General Electric T58-GE-8B/8F | VH-3A |
| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| HTE-1 | Hiller | 1 Franklin O-335 | 3 | ||
| HTE-2 | Hiller | 1 Franklin O-335-6 | 3 | ||
| HTK-1 | Kaman | 1 Lycoming O-435-4 | 3 | TH-43 | |
| HTK-1K | Kaman | 1 Lycoming O-435-4 | 0 | ||
| HTL-1 | Bell | 1 Franklin O-335-1 | 2 | YR-13 | |
| HTL-2 | Bell | 1 Lycoming O-435 | 2 | H-13 | |
| HTL-3 | Bell | 1 Franklin O-335 | |||
| HTL-4 | Bell | 1 Lycoming O-435 | 2 | TH-13L | |
| HTL-5 | Bell | 1 Franklin O-335-5 | |||
| HTL-6 | Bell | 1 Lycoming O-435 | 2 | TH-13M | |
| HTL-7 | Bell | 1 Lycoming O-435 | 2 | TH-13N |
| Model | Designation | Manufacturer | Engine(s) | Crew | Other |
|---|---|---|---|---|---|
| HUK-1 | Kaman | 1 Pratt & Whitney R-1340-52 Wasp | 3 | UH-43C | |
| HU2K-1 | Seasprite | Kaman | 1 General Electric T58 | UH-2A | |
| HU2K-1U | Seasprite | Kaman | 1 General Electric T58 | UH-2B | |
| HUL-1 | Bell | 1 Lycoming O-435 | 2 | UH-13P | |
| HUL-1G | Bell | 1 Lycoming O-435 | 2 | HH-13Q | |
| HUL-1M | Bell | 1 Allison T63 | HUL-2, UH-13R | ||
| HUL-2 | Bell | 1 Allison T63 | HUL-1M, UH-13R | ||
| HUM-1 | McCulloch | 1 Franklin O-335 | 2 | ||
| HUP-1 | Retriever | Piasecki | 1 Wright R-975-34 Whirlwind | 5 | |
| HUP-2 | Retriever | Piasecki | 1 Wright R-975-42 Whirlwind | 5 | UH-25B |
| HUP-2S | Retriever | Piasecki | 1 Wright R-975-42 Whirlwind | 5 | |
| HUP-3 | Retriever | Piasecki | 1 Wright R-975-42 Whirlwind | 5 | H-25A Army Mule, UH-25C |
| HUS-1 | Seahorse | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | 1 | UH-34D |
| HUS-1A | Seahorse | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | 1 | UH-34E |
| HUS-1G | Seahorse | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | 1 | HH-34F |
| HUS-1L | Seahorse | Sikorsky | 1 Wright R-1820-84B/84D Cyclone | 1 | LH-34D |
| HU2S-1G | Sea Guard | Sikorsky | 1 General Electric T58-GE-8B | 2 | HH-52A |