The two giants Bell and Sikorsky often make people forget about the third large company that made the helicopter a reality back in the late 1940s: P.V. Engineering Forum, later known as Piasecki Helicopters and then Piasecki Vertol. The company's assets were purchased by Boeing in the late 1950s, and though it now carried the name Boeing Vertol, the model numbering system carried on from where Piasecki had left off.
Frank Piasecki then set up a new business under his own name and came up with the Model 16-H PATHFINDER helicopter, which unfortunately failed to attract customers. Today his name and vision are being avenged as the name Piasecki is once again, half a century after takeover by Boeing, back in the military procurement business for a SPEEDHAWK conversion of a UH-60 designated X-49A.
Here is a list of model numbers. The former part of the list deals with Piasecki models. The latter part presents the Boeing Vertol models.
Pv.1 helicopter project
Pv.2 small helicopter
Pv.3 US Navy XHRP-X DOGSHIP , HRP-1 RESCUER rescue helicopter dubbed "Flying Banana"
Pv.11 utility helicopter developed from PV-2 for USN
Pv.12 large version of PV-14 for USN, project only
Pv.14 US Navy XHJP-1 utility helicopter
Pv.15 USAF YH-16 TRANSPORTER large transport helicopter (first prototype)
Pv.17 US Navy HRP-2 RESCUER
Pv.17? COMMUTER projected civilian version of HRP-2
Pv.17? CONNECTOR projected civilian version of HRP-2
Pv.17? DE LUXE projected civilian version of HRP-2
PD-/PV-18 US Navy HUP-1 RETRIEVER production version of Pv.14
PV-18 US Navy HUP-2 / HUP-3 / HUP-4 RETRIEVER / US Army H-25A ARMY MULE
PH-21 civilian same as Model 44A
PD-/PV-22 USAF YH-21 WORKHORSE tandem rotor helicopter
PA-39 GARGANTUA? concept of utilizing multiple helicopters joined together to lift a common payload
PH-/PV-42 USAF H-21A WORKHORSE military transport helicopter (AV 166)
PV-42 USAF H-21B WORKHORSE redesignated as CH-21B / Canada CH-125
PV-43 US Army H-21C SHAWNEE redesignated as CH-21C
(P)V-44A civilian transport helicopter, a civil version of PV-42 (AV 247,248)
(P)V-44B civilian float version
(P)V-44C civilian
PV-44 US Navy HKP-1 / Canada CH-127
PV-45 USAF YH-16A TRANSPORTER (initially designated H-27)
PH-55 RETRACTOPLANE , using rotor blades with reverse taper
59K US Army VZ-8P SKY CAR / AIRGEEP
59N US Navy 'PA-59' SEAGEEP
59H US Army VZ-8P( B ) AIRGEEP II "bent" in the middle so that the rotors were tilted fore and aft
(P)V-63 HUP-4 RETRIEVER, a HUP-2 (PV-18) fitted with an 800 hp R-1820 engine
(P)V-71 US Army XH-21D SHAWNEE
V.76 USAF VZ-2V experimental tilt-wing VTOL aircraft
PA-97 HELI-STAT large aircraft made up of a blimp and four H-21 fuselages; developed from PA-39 (PA-97-212/B)
105 Model 44 fitted with two 825 hp Lycoming T-53 turboshafts, prototype only
V.107 US Navy HRB-1 SEA KNIGHT redesignated as CH-46A
V.107 USAF XH-49A redesignated as XCH-46B, then canceled
V.107 Y/HC-1A redesignated as Y/CH-46C
V.107 SEA KNIGHT (US Navy CH-46D,-46E,-46F / HH-,UH-46D / VH-46F)
V.107 Canada CH-113 LABRADOR (107.II-9)
V.107? Canada CH-113A VOYAGEUR
V.107A no details
V.114 US Army YCH-1B CHINOOK redesignated as YCH-47A
V.114A US Army HC-1B CHINOOK redesignated as CH-47A (AV 259)
V.114A civilian variant (Type certificate H3EA)
V.114 US Army CH-47B CHINOOK
V.119 tilt-wing project (V.119F)
V.137 SC tri-service VTOL transport project, competing with XC-142A (SS-478A)
V.143 ACH-47A armed enemy suppression CHINOOK with externally mounted 20mm cannon, nose turret with grenade launcher and miniguns.
V.145 CH-47D CHINOOK version with T55-L-712 engines
BV.147 tilt-wing VTOL project
157 smaller inter-city helicopter project based on CHINOOK
160 tilt-rotor project
165 Australia CH-47C CHINOOK
166 VHL warm-cycle helicopter project (166-006)
167 larger inter-city helicopter project based on CHINOOK
BV.173 Canada CH-147 CHINOOK
176 Spain HT.17 export CH-47C
V.179? US Army YUH-61A UTTAS multirole helicopter
V.179 civilian projected civilian version of UH-61
V.189 no data
V.219 "CH-47C Plus" export version for Egypt, Greece, Iran, Italy, Morocco and Libya
222 tilt-rotor project using the fuselage, tail and undercarriage of a Mitsubishi MU-2J, engines in wing-tip pods
227 heavy crane project
BV.234 US Army CH-47C CHINOOK and civilian version
234ER civilian extended range version
234LR civilian long-range version
234MLR civilian long-range version
234UT civilian ultility version
234-68 projected stretched version of Model 234
235 US Army AAH contender, mock-up only
237 LAMPS III competitor of S-70L (or crane personnel carrier??)
297 US Army pre-H-62 heavy crane project
298 100-passenger flying crane project
299 flying crane project with payload 3-4 tons higher than Model 298
301 US Army XCH-62A HLH (Heavy Lift Helicopter) winner, later canceled
307 projected stretched version of Model 234 for 225 passengers
308 Argentine version of CH-47C CHINOOK for Argentine Air Force
309 Argentine version of CH-47C CHINOOK built in Italy, some for Argentine Army
309 Canada CH-147 CHINOOK no details as to difference with BV-173
347 CHINOOK version with wings
352 HC Mk.1 / HC Mk.1B / HC Mk.2 / HC Mk.2A / HC Mk.3 / etc. CHINOOK for UK (CH-47C)
360 Advanced Technology Demonstrator for the CHINOOK made of all-composite materials
414 CHINOOK international military version of CH-47D (BV-414-100)
NOTES:
- Later Piasecki designs are the PA-1, PA-2, 16-H PATHFINDER, 116H-1A and the recent AIRSCOUT
- Boeing Vertol later built the Bölkov Bö-105 under license as the EXECUTAIRE
- Two Boeing Models (71 and 90) are retractoplane design but don't seem to fit in this list