Model Variants (Including Prototypes)
YH-19 - Evaluation Models; 5 such examples produced.
H-19A - 50 examples produced; USAF version based on the YH-19 evaluation model; fitted with R-1340-57 powerplant of 600 horsepower; became the UH-19A model with redesignation in 1962.
SH-19A - Air-Sea Rescue Variant of H-19A model; redesignated to HH-19A in 1962.
H-19B - Fitted with R-1300-3 powerplant of 700 horsepower; 264 examples produced; redesignated to UH-19B in 1962.
SH-19B - Air-Sea Rescue Variant of H-19B model; redesignated to HH-19B in 1962.
H-19C - US Army Version of H-19A model; 72 examples produced; redesignated to UH-19C in 1962.
H-19D - US Army Version of H19B model; 301 examples produced; redesignated to UH-19D in 1962.
HO4S-1 - US Navy Version of H-18A model; 10 examples produced.
H04S-2 - Proposed US Coast Guard Version
H04S-3 - Joint US/Canadian use; became the UH-19F and H04S-3 designations for US/Canada respectively; fitted with R-1300-3 700 horsepower engine.
HO4S-3G - US Coast Guard Version based on the HO4S-3 model; 30 examples produced; redesignated to HH-19G in 1962.
HRS-1 - USMC version based on the HO4S; 60 examples produced; accommodation for up to 8 combat ready personnel.
HRS-2 - Based on the HRS-1 model series with upgrades; 101 examples produced.
HRS-3 - 105 examples produced along with conversions from HRS-2 models; new production models based on HRS-2 models; fitted with R-1300-3 powerplant of 700 horsepower; redesignated to CH-19E in 1962.
HRS-4 - Proposed model based on the HRS-3; fitted with R-1820 radial engine of 1,025 horsepower.
UH-19A - 1962 redesignation of H-19A model
HH-19A - 1962 redesignation of SH-19A model
UH-19B - 1962 redesignation of H-19B model
HH-19B - 1962 redesignation of SH-19B model
CH-19E - 1962 redesignation of HRS-3 model
UH-19F - 1962 redesignation of HO4S-3 model
HH-19G - 1962 redesignation of HO4S-3G model
S-55 - Commercial Version; fitted with R-1340 engine of 600 horsepower.
S-55A - Commercial Version; fitted with R-1300-3 engine of 800 horsepower.
S-55C - Commercial Version; based on the S-55A model; fitted with R-1340 engine of 600 horsepower.
S-55T - Commercial Version; Fitted with Garrett-AIRResearch TSE331-3U-303 engine of 650 horsepower.
S-55QT - Commercial Touring Conversion Model
OHA-S-55 Heli-Camper - Commercial Conversion for promotional use.
OHA-S-55 Nite-Writer - Commercial Conversion for inflight advertising.
OHA-S-55 Bearcat - Commercial Conversion Model for agricultural use.
OHA-S-55 Heavy Lift - Commercial Conversion Model with heavy-duty crane system.
QS-55 Aggressors - Conversion models used as flying targets.
OHA-AT-55 Defender - Armed Military Model
Whirlwind HAR21 - Royal Navy Model based on the HRS-2 model.
Whirlwind HAS22 - Royal Navy Model based on H04S-3 model.