Pratt & Whitney Engine Designations

overscan (PaulMM)

Administrator
Staff member
Joined
27 December 2005
Messages
16,888
Reaction score
21,589
This topic is to discuss internal Pratt & Whitney engine designations.

I'm going to start with the F100/F401

JTF22A-2 Used on early Space Shuttle design. JP4-fueled , nonaugmented.
JTF22A-4 Used on early Space Shuttle design. Hydrogen-fueled , nonaugmented derivative of the F401-PW-400 turbofan engine.
JTF22A-6 Used on early Space Shuttle design. JP4-fueled , nonaugmented.
JTF22A-24 F401-PW-400 for F-14B & XFV-12A (P&W provided table from 1974 testimony to Congress) "30,000lb thrust class" 27:1 compression ratio, 3649lb weight, 3.5/10/2/2 layout.
JTF22A-25 F100-PW-100 engine used on F-15 23:1 compression ratio, 3036lb weight, diameter 47 in, length 191 in, 3/10/2/2 layout.
JTF22A-25A as above
JTF22A-26A YF401 derivative used on General Dynamics Model 201 CTOL version
JTF22A-26C F401 derivative for the GD/Vought V-1600 naval F-16
JTF22A-27 Seen on General Dynamics FX-404 and Model 401B drawings. Presumably higher thrust.
JTF22A-30 F401, 27,575lb thrust, used on LTV V-517 / V-520
JTF22A-30A F100 or F401 derivative with vectored nozzle used on the General Dynamics Model 200. 26,800lb thrust.
JTF22A-30B F100 or F401 derivative with vectored nozzle used on the Grumman Model 607A. 15,650lb/27,500lb thrust.
JTF22A-33 F100-PW-220
JTF22B-2 Used on early Space Shuttle design
JTF22B-25 F100 derivative for the Vought Model 1601. 15,600lb dry, 25,500lb afterburning.
JTF22B-36 mentioned in article no details.

The suffix numbers appear to be purely sequential in date order.
 
Last edited:
Good stuff. Not sure if other internal P&W designation systems are welcome as additions (or would be better in a new thread).

Anyhoo, since Pratt's JT is well-covered, here are the PT designations ...

Pratt & Whitney 'PT' (Propeller Turbine) Designation Series

PT1 - (Project) 1943 Pratt & Whitney T32 free-piston gas turbine
- PT1: Ground tested 1943, cancelled in favour of PT2 turboprop
-- https://web.archive.org/web/20110125190748/http://enginehistory.org/P&W/Museum/Recips/PT1_1.jpg

PT2 - 1950 P&W T34 Turbo-Wasp axial-flow turboprop
- PT2 : T34 Turbo-Wasp originally funded by US Navy
-- T34-P-1 : 5,700 shp, for US Navy, never completed (??)
-- XT34-P-2 design contract issued 1945, tested January 1948
-- XT34 flew Sept 1950, nose of Boeing 299Z/B-17G (44-85734)
- PT2 : Orig. USAF military applications, except unbuilt variants
- PT2F-1: 5,500 shp, civil version of 5,531 shp T34-P-6
-- PT2F-1 was intended to power the Lockheed L-1249B
- PT2G-3: 5,600 shp, for Lockheed L-1449 (& poss. L-1549)
-- YT34-P-1: 5,550 shp, flown on Douglas YC-124B tanker/transport
-- XT34-P-2: 4,100 ehp, 1st run January 1948.
-- XT48-P-2 : 9,140 ehp, twinned T34s for USN VP-HL patrol a/c
-- T34-P-3 : 5,500 shp, Douglas C-133A Cargomaster, x 35
-- YT34-P-5 : 5,700 shp, Boeing YC-97J flying test beds, x 2
-- YT34-P-6 : 5,300 shp, Douglas YC-124B flying test bed
-- YT34-P-6A: 5,500 shp, Lockheed R7V-2 flying test beds, x 4
-- YT34-P-6A: 5,500 shp, Lockheed YC-121F flying test beds*
-- * Ex-USN R7V-2s 630 (USAF 53-8157) & 631 (USAF 53-8158)
-- T34-P-7W: 7,100 shp w/ water inj'n, C-133A, Boeing 377SG
-- T34-P-7WA: 6,500 shp,* re-eng'd Douglas C-133A airframes
-- * Power output presumably measured without water injection
-- T34-P-9W: 7,500 shp w/ water injection, Douglas C-133B, x 15
-- YT34-P-12A: (Project) 7,500 shp, meant for Lockheed R7V-2

PT3 - (Project) 1952 US Navy turboprop (see reply #3)
- XT-52-P-2: Became basis for 1954 JT8 / J52 turbojet

PT4 - (Project) - Pratt & Whitney DoD T45, cancelled
- PT4 : XT45 turboprop intended for Boeing XB-52
-- Devel. into JT4A/J75, 17,500 lbf axial-flow turbojet

PT5 - 1953 turboprop for high subsonic military a/c, x 6
- PT5 : 15,000 hp XT57 turboprop deriv. of J57 turbojet
-- XT57 : 1956, test-flown in the nose of Douglas C-124
-- T57-P-1: 15,000 shp, intended for USAF Douglas C-132
-- T57-P-?: Nuclear powerplant adaptation for US Navy*
-- * Option for Convair Saro Princess conversion
-- https://www.secretprojects.co.uk/threads/pratt-whitney-t57-turboprop.19240/

PT6 - 1960 P&WC 'reverse flow' turboprop/turboshaft family
- PT6 : Begun as 1958 United Aircraft of Canada DS-10
- PT6A: Turboprop family, producing 580 to 1,940 shp
-- (I won't list PT6A variants since their well-covered)
-- US DoD designations: T74-CP-8, T74-CP-10, T74-CP-12,
-- T74-CP-14, T74-CP-700, T74-CP-702, and T101-CP-100
- ST6 : Stationary power plant and APU, PT6A deriv.
- PT6B: Turboshaft for helicopters, 981 to 1,940 shp
-- 1960 proposal for UH-1 w/ 2 x PT6B engines for DND
-- PT6B-36A: 2 x 981 shp, Sikorsky S-76B
-- PT6B-36B: 2 x 981 shp, Sikorsky S-76B
-- PT6B-37A: 1 x 1,000 shp, A119/AW119 Koala
-- PT6B-67A: 3 x 1,940 shp, AVIC AC313 (Z-8 update)
- ST6B: PT6B derived turboshaft for racing cars
-- STP Paxton Turbocar: 1967, 550 hp ST6B-62
-- Lotus 56/56B: 1967/1971, 500-600 hp STN6/76
- PT6C: Turboshaft for helicopters, based on PT6A-67
-- PT6C-67A : 2 x 1,940 hp, Agusta-Bell/Leonardo AW609
-- PT6C-67C : 1,500-to-1,679 shp, single exhaust
-- PT6C-67C : Leonardo AW139, 2 x PT6C-67Cs
-- PT6C-67C1: Higher take-off power than PT6C-67C
-- PT6C-67C1: 2 x 1,679 shp Boeing MH-139A Grey Wolf
-- PT6C-67D : Variant devel. for 2002 P&WC UH-1H upgrade*
-- PT6C-67D : 1 x 1,400 shp P&WC UH-1H Plus upgrade
-- * DynCorp chosen as conversion kit installer**
-- ** UH-1H Global Eagle for US Border Patrol
-- Orig. w/ Temsco, now Temsco Helicopters Bell 205
-- PT6C-67E : Updated, higher-power PT6C-67C devel.
-- PT6C-67E : EEC, fuel control unit, 30-minute AEO
-- PT6C-67E : 2 x 1,776 shp, Eurocopter EC175/Airbus H175
- PT6T: 1967 Twin-Pac coupled PT6As, single gearbox
-- PT6T-3 : 1,800-1,875 shp, PT6A-34 power sections
-- PT6T-3A: PT6T-3 w/ aluminum alloy gearbox housing
-- PT6T-3B: Higher single-section rating, 'T-6 compressor
-- PT6T-3B: US DoD military designation, T400-CP-400
-- PT6T-3BE: Revised gearbox, PT6T-3B power sections
-- PT6T-3BF: PT6T-3B with higher 30-minute OEI rating
-- PT6T-3BG: PT6T-3BE w/ higher 30-minute OEI rating
-- PT6T-3D : Higher-power PT6T-3B, impr. hot section
-- PT6T-3DE: Improv. PT6T-3D w/ 30-minute OEI rating
-- PT6T-3DF: '3DE with impr. hot section, Bell 412EP
-- PT6T-4 : Typo (??) associated with Agusta AB 212
-- PT6T-? : US DoD military designation, T400-CP-401
-- PT6T-6 : 1,875 shp, impr. higher-powered PT6T-3
-- PT6T-6 : US DoD military designation, T400-WV-402
-- PT6T-6B: Improv. gearbox, PT6T-6 power sections
-- PT6T-9 : 1,855 shp, '3DF w/ impr. hot section/EEC

PT7A - 1979 PT6A successor/larger turbine series
- PT7A : Orig. intended to power DHC-X/DHC-8
- PT7A-1 : Redesignated in PW 100 series
_____________________________________________________

So, obvious question: Anyone know what the heck the PT3 was?
 
Last edited:
Yes.

PT3 was a 1952 Navy turboprop engine XT-52-P-2 with a high pressure ratio and a 7:1 transonic compressor. By 1954 the T52 became the basis of the twin-spool 12:1 compression ratio JT8/J-52 turbojet.

Source: Jack Connors, The Engines of Pratt & Whitney: A Technical History
 

Well there was an advertisement I saw in a 1978 or 79 issue of Armed Forces Journal International (AFJI) that promoted the "F401-PW-29C" for the F-14 engine competition against the F101DFE. (The Navy defunded the F401 from that competition and handed it to GE on a silver platter) I took the "29C" to be the 30,000 lb thrust version (for XFV-12 as well?) as opposed to the 28,090 lb thrust version flown on the F-14 in 1973. I have never found anything about it though. Possibly only Pratt's facility in Florida that built the F401 has that information.
 

Please donate to support the forum.

Back
Top Bottom