Warbird Information Exchange

The Douglas C-132 was a proposed transport aircraft, based on the company's C-124 Globemaster II. Design studies began in 1951 but the project was cancelled in 1957 by the USAF. No prototype was built and the project did not get past the mock-up stage. The C-132 was to be powered by four 15,000 shp (11,000 kW) Pratt & Whitney XT57 (PT5) turboprops, mounted on a swept wing. An air refueling version, the XKC-132 was also proposed, but it would only have utilized the probe and drogue air refueling system and that system, used primarily by the US Navy, did not find favor with the USAF. One XT57 was installed in the nose of a C-124 (AF serial number 52-1069) for testing. Projected speed was to be 418 knots (774 km/h) with a range of 2,200 nautical miles (4,100 km) and a maximum payload of 137,000 pounds.

Development
In January 1951, the United States Air Force (USAF) issued a request for a preliminary design of a heavy cargo transport aircraft. The aircraft needed the ability to transport 100,000 pounds (45,000 kilograms) of payload 4,000 miles (6,500 kilometers; 3,500 nautical miles). By December 1952, the USAF selected a proposal from the Douglas Aircraft Company, which would serve as a cargo transport and as an air-to-air refueling tanker. The Douglas design was given the designation of C-132 by April 1953,[5] and a mockup of the C-132 was built in February 1954. Douglas announced in December 1954 that the C-132 would be powered by the Pratt & Whitney T57 engine, a new turboprop in the 15,000 equivalent shaft horsepower (11,000 kilowatts) class. The T57 would be flight tested on a Douglas C-124 Globemaster II testbed aircraft. The USAF expected the T57 engine to be flown experimentally within two years, and it hoped the engine would be operational within five years.

At about the same time, USAF leadership began speaking about a turboprop aircraft that could transport 80 short tons (160,000 lb; 73,000 kg) across the Atlantic Ocean in ten hours. The next month, the USAF confirmed that the C-132 was the aircraft with that capability, which meant the C-132 would have more payload capacity than three Douglas C-124Bs, then the largest cargo transport aircraft. In November 1955, the USAF announced that the mockup would be moved from Douglas's main Santa Monica, California factory to its Tulsa, Oklahoma plant, where production of the C-132 would occur if a production contract was awarded. The mockup was set up in the Tulsa factory by January 1956. While the move was being made, flight testing of the T57 engine was planned for early 1956, but the engine did not fly until early autumn of 1956. In its May 1956 congressional testimony, the USAF praised the C-132 tankering capabilities, including its large capacity, low cargo costs per ton-mile, and ability to fly at high altitudes, but it then canceled the tanker version of the aircraft in mid-1956. The USAF offered more details about the C-132 in October, now describing an overload payload of 200,000 lb (91,000 kg), a cruise speed of Mach 0.8, and a maximum speed higher than Mach 0.9. Another report at the beginning of November stated that Douglas had begun "cutting tin" on the C-132, which was described as a 430-knot (500-mile-per-hour; 800-kilometer-per-hour) aircraft with a payload capacity of 150,000 lb (68,000 kg) and the ability to carry 300-400 troops or passengers.

First flight was originally planned for April 1957, but the target slipped to mid-1959. The USAF had planned to buy 30 aircraft, and they would be delivered at an annual rate of six aircraft, beginning in early 1961.

On February 14, 1957, the USAF issued a news release describing the C-132 as the new "giant of the airways," which would weigh over 500,000 lb (230,000 kg), carry 200,000 pounds, travel at a cruise speed faster than 400 kn (460 mph; 740 km/h), transport a 28-short-ton (56,000 lb; 25,000 kg) light tank, and have the ability to take off and land on conventional-length runways through its undercarriage setup of two nose wheels and 16 main landing gear wheels. The news release, which was carried widely in American mass-circulation newspapers and magazines, also had photographs of the C-132 mockup in Tulsa. However, the USAF retracted its statement five days later, saying that it only had a development contract with Douglas to build two C-132 prototypes, and that it was considering the termination of the project. The unauthorized news release embarrassed the USAF, since the upcoming fiscal 1958 defense budget contained almost no money for new transport aircraft. In its retraction, the USAF did not mention that on December 31, 1956, it had already sent a report to the United States Congress, informing them of its decision to remove the C-132 from its aircraft program.

The project was officially cancelled on March 20, 1957, after $104 million had been allocated and $70 million of non-recoverable costs had been spent on the program. Oklahoma's congressional delegation pushed back against the cancellation, and Douglas publicly campaigned for C-132 funding restoration to improve the nation's airlift capability and allow for long-range transport of intercontinental ballistic missiles. Douglas also denied rumors that problems with the development of the engine caused the cancellation. Douglas did not respond to assertions that budget restrictions and increasing requirements from the Strategic Air Command were responsible, although in June 1956, a former USAF research and development official testified to the United States Senate that C-132 program initiation was withheld for two years, even after they had determined that the engine development risk was manageable enough to support the program's go-ahead. However, the project was not revived. No prototype was built, and the project did not get past the mockup stage.

Design
The C-132 was to be powered by four 15,000 shaft horsepower (11,000 kW) Pratt & Whitney T57 turboprops, mounted on a swept wing. The T57 was to be the most powerful turboprop engine in existence at the time. It also would have used the largest propeller at the time, the 20-foot diameter (6.1-meter) Hamilton Standard B48P6A propeller. The T57 turboprops provided 5,000 pounds-force (22 kilonewtons; 2,300 kilograms-force) of residual jet thrust. The XKC-132 air refueling version would only have utilized the probe and drogue (P&D) air refueling system. That system, used primarily by the US Navy, did not find favor with the USAF. Projected speed was to be 418 kn (481 mph; 774 km/h) with a range of 2,500 mi (4,100 km; 2,200 nmi) and a maximum payload of 137,000 lb (62,000 kg).

The C-132 was a triple-decker aircraft with a cargo space measuring 95 ft (29 m) long, 17 ft (5.2 m) wide, and 12+1⁄2 ft (3.8 m) high. The main cargo hold had a usable volume of 15,662 cubic feet (443.5 cubic meters). The aircraft had a dual wheel nose landing gear, while the main landing gear had 16 wheels arranged in two coaxial quadruple wheel units that operate in tandem under each side of the fuselage.

Specifications (C-132)
Data from McDonnell Douglas aircraft since 1920 : Volume I, The Encyclopedia of World Aircraft

General characteristics

Crew: Pilot, co-pilot, navigator, systems engineer, and 3-member relief team.
Capacity: 800 troops
Length: 183 ft 10 in (56.03 m)
Wingspan: 186 ft 8 in (56.90 m)
Wing area: 4,201 sq ft (390.3 m2)
Max takeoff weight: 389,500 lb (176,674 kg) cargo configuration
469,225 lb (212,837 kg) tanker configuration
Powerplant: 4 × Pratt & Whitney T57-P-1 turboprop engines, 15,000 shp (11,000 kW) each
Propellers: 4-bladed Hamilton Standard Model B48P6A[26] hollow-steel, single-rotation,[36] constant-speed fully-feathering reversible propellers, 20 ft (6.1 m) diameter
Maximum blade chord: 22 in (56 cm)
Length: 5 ft 6 in (1.7 m)
Weight: 3,600 lb (1,600 kg)
Performance

Cruise speed: 460 mph (740 km/h, 400 kn) or more for the cargo transport version;[20] 512 mph (824 km/h; 445 kn) at 20,000 ft (6,100 m) altitude for the tanker version. 
Range: 2,950 mi (4,750 km, 2,560 nmi) carrying 175,000 lb (79,000 kg) of cargo; 3,500 mi (5,600 km; 3,000 nmi) carrying 100,000 lb (45,000 kg) of cargo.
Combat range: 2,475 mi (3,983 km, 2,151 nmi) transferring 19,550 US gal (16,280 imp gal; 74,000 l) of fuel.
Service ceiling: 39,000[2] ft (12,000 m)

Below photos of the YC-132 mockup at Douglas-Tulsa:

_________________
[Thread title is ridiculous btw]

Nice shots Mark: it always amazes me the sheer effort that went into mock-ups back then.

Nice to see different photos, usually you see the same few (including #3 here) over and over.

But considering the troubles Douglas had with the C-133, perhaps it's best that the Air Force passed on this one.

_________________
Remember the vets, the wonderful planes they flew and their sacrifices for a future many of them did not live to see.

I look at the C-132 and see a scaled down C-5 with turboprops. Then I think of the C-5 and how it might have (arguably) been a better airplane if it had turboprops. I'd bet range, payload, and short field performance would have all improved.

Very interesting concepts... The C-132 and a turboprop C-5.

Amazing concept of which I'd never heard of before... Thanks!

Reminds me very slightly of the Saunders Roe Princess flying boat...

Large turboprops often sound attractive, but they do have downsides, and I imagine a clean sheet turboprop in the late 1960's that could have been developed in the timeframe for the C-5 would have had huge challenges. We would have been talking about something much more powerful (25,00HP??) and larger than the 15,000HP engine for the C-132 or the massive Soviet turboprops, or perhaps 6 engines in the 15,000HP class. Likely would have been a contra prop with huge vibration, noise, propeller, gearbox and resonance challenges. The C-133 with 7,500HP class engines was beset with vibration and fatigue issues that were never really solved. The 1990's An-70 (15,000HP class) and 2010's A-400 (11,000HP class) have had engine/gearbox issues. Only now in 2023 are we seeing some un-ducted fans (not really turboprops) that look promising to replace large turbofans- but the blade technology and understanding is much better than it was in the late 1960's.

My thought is a turboprop engine for a C-5 class aircraft was a bridge to far, or if it had made it there would have been huge problems and the poor thing would have shaken itself to death.

Sandiego89

I agree 100%.
Thanks for doing the research to back up the concerns I alluded to in my brief post.

The fatigue issue is worth mentioning.
On Feb 6, 1970, a C-133 came apart over Nebraska due to fuselage fatigue while carrying a CH-47 back to Boeing in Pennsylvania for rebuild after Vietnam service. This in a decade old aircraft with relatively few cycles.
Apparently, prop vibration was a huge issue despite a complex prop synchronized system.
Later, 133s had their fuselage reinforced with bands, but despite this, the 1970 accident occurred.

If you read the history of the C-133, you see the issues with large turboprop and see what worked well for a C-130 class aircraft doesn't mean it will work for a larger aircraft.

Any short field advantages of the C-132 over a C-5 class aircraft would have been moot since it would have been too large, heavy and valuable to operate routinely from short fields.

And spending money to develop the large turbofans was a much better investment since turboprops for the C-132 wouldn't have found many (any?) applications anywhere else.

_________________
Remember the vets, the wonderful planes they flew and their sacrifices for a future many of them did not live to see.

With absolutely no knowledge on the subject, I always assumed the problems with the C-133's turboprops were simply the development cycle. Not enough engines in service to work out all the bugs, and since there was no next step engine in the works, the development cycle simply stopped, leaving problems unsolved.

Kyleb.

A brief look at the C-133 losses show engines were not the primary caused of accidents. If course that is not to say they didn't have issues and "routine" failures.
One loss over water (thus no substantial wreckage) is theorized to have been an engine issue.
The other nine losses were: Airframe fatigue, fire on the ramp,
prop electrical issue causing a ditching, icing leading to a stall,
two stall accidents at low altitude, and two other over water losses which they think may have been from power on stalls at heavy weights. Finally, a suspected case spatial disorientation.

Data from :Remembering an Unsung Giant, The Douglas C-133 Cargomaster and its people by Cal Taylor, Firstfleet Publishers, 2005. Page 321.

_________________
Remember the vets, the wonderful planes they flew and their sacrifices for a future many of them did not live to see.

As far as this point goes, I was thinking the ability to operate (loaded) from normal runways - not the 8-10k' runways a C-5 needs fully loaded. I'm not talking Alaska STOL competition type stuff. Also, I realize the -M upgrades have probably helped there.

-Kyle (Who remembers standing at the East end of runway 11 at Dobbins AFB in 1968 when the C-5 made its first flight on a Sunday morning.)

I believe that Douglas produced at least one large model of the airplane for display. I think it is still here in Tulsa.
kevin

_________________
FOUND the elusive DT-built B-24! Woo-hoo!!!

It would not surprise me if Douglas had a large model for the lobby of the Tulsa factory since that is where the C-132 would have been built.

Douglas had Allyn, its "go to" maker of metal desk models make some large C-132s for VIPs.
Years ago I saw one somewhere, but I can't remember where.
IIRC, they were about the size of their 124 model, so smaller than than 1/72 scale...perhaps 1/100th?

They also did metal 1/72 scale C-124s (one of which I have), C-133s, and C-118s..as well as a B-66 in 1/48, as well as DC-8s.

Speaking of large scale airlift models, when I was at Officer Training School in the early 80s, they had a huge model of a C-5, probably left over from the Paris Air Show or something. It was a cut away and inside were 1/48th scale Chinook helicopters (the old, rare Aurora kit)...so you can imagine the size.

_________________
Remember the vets, the wonderful planes they flew and their sacrifices for a future many of them did not live to see.

The "problem" with turboprops wasn't power for the US. It was speed and it was "progress". The speed issue is simple - the turboprop (and even UDF) have a finite speed limit. That limit can be pushed up marginally, but once the tips go supersonic, you're about done. The technology of the time basically gave you two ways - big fat, short blades, of thin, long ones. Scimitar wasn't really a possibility yet. The second part (progress) isn't so simple in fact, but in practice is straightforward. The US Military never really wanted turboprops. The Pentagon saw turboprops as a "stepping stone" to a pure jet military. They were willing to use them in specialized roles or secondary roles, but they didn't want to put a ton of money into what was, in their view, an interim step. When the first high-bypass turbofans showed promise, they pulled the plug on large turboprops because they were "the future". It's always been an interesting study point for me when I get the chance to read through the early days of US Military turboprop operations and how much they had to fight to prove the turboprop's place and what might have been had we gone purely turbojet.

It would be interesting to get a comparison of turboprop to pure jets, if there are any "Apple to Apple" examples.

Perhaps one would be the TU-95 and B-52...IF one could get honest info on development, maintenance and operational issues from Russia. They have similar first-flight and IOC dates.

Another, though not a perfect match specification-wise would be the A-400 and C-17.

_________________
Remember the vets, the wonderful planes they flew and their sacrifices for a future many of them did not live to see.

A400M: always an 'M', never a hyphen.