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  • Pioneer
    Rank 5 Registered User
    • Aug 2005
    • 722

    The giant Douglas XC-132, what could have been

    A design that I think that may have made a big difference to the US Military, especially the US Army, that was never to unfortunately eventuate was the Douglas Model 1814 / XC-132 Long-range, heavy transport / cargo aircraft.
    This aircraft was started in 1951 under the title of program SS-402L Heavy Airlift Transport
    This massive and potential transport, would have given the USAF and US Army a transport aircraft the likes and capability of that of the Soviet Antonov An-22 Cook.
    But due to problems with the development of its Pratt & Whitney XT57 turboprop design of 15,000 shp each (which I think was not pursued, through more want and fascination with straight turbojets of the time) the entire program was cancelled.
    I wonder if it would have been cancelled, had the US Military known that its lift-capability and range would be in such demand in Vietnam.
    Instead the USAF would have to rely on older, slower and less capable and efficient types like the Douglas C-124 Globmaster and Douglas C-133 Cargomaster, which would have to soldier on until the arrival of the truly strategic Lockheed C-5A Galaxy.
    Attached Files
  • TinWing
    Rank 5 Registered User
    • Sep 2005
    • 950

    #2
    To be fair, the smaller, far less ambitious C-133 had a relatively short service life due engine problems and unexpected fatigue issues. Some might say that the C-133 should have been cancelled as well.....

    Could the larger C-132/KC-132 have been a success?

    Perhaps, but it would appear that the decision to cancel was the right one at the time. Boeing's 717/C-135 has been one of the most successful and enduring programs in the history of aviation.

    Comment

    • firstfleet
      Rank 5 Registered User
      • Mar 2005
      • 23

      #3
      C-133 and C-132

      If one considers 15 years a short service life, then the C-133 had that. In that time, despite engines that did not meet manufacturer's promises and propellers that pushed the limits of the technical envelope, the C-133 proved to be the first true heavy airlifter. It carried hundreds of ICBMs to and from deployment bases. It moved NASA cargo all over the world, whether rockets to launch sites or tracking equipment to Madagascar and Australia. In the Vietnam War, C-133s moved military equipment that no other airplane could load from the US to the combat zone and even within the theater.

      The C-132 was ill-timed to go into service. The USAF decided to go to jets, first the C-135 and, later, the C-141. There was no funding in the FY 57 budget for the C-132. The C-132 would have been the largest turboprop airplane built, for many years. Its refueling variant woud have been able to tank up three fighters simultaneously. The engines and propeller flew a few times, sticking from the nose of a C-124 like a gigantic cigar. The propeller was built by Hamilton Standard, 22' in diameter with a 24" tip chord. For the time, that might have cut entirely through the technical envelope.

      The complete story of the C-133 is in my new book, Remembering an Unsung Giant: The Douglas C-133 Cargomaster and Its People. The book is now available from Firstfleet Publishers. It will soon be available from Midlands Counties Publishing or Air Britains. With 330+ illustrations in 428 pages, the C-133 is described in the fullest possible detail. The book also includes a chapter on the C-132.

      Cal Taylor
      Last edited by firstfleet; 2nd March 2006, 06:33. Reason: typo
      Cal Taylor
      firstfleet@aol.com
      The C-133 Project
      http://www.angelfire.com/wa2/c133bcargomaster/home.html

      Comment

      • Schorsch
        Severely Transonic
        • Aug 2005
        • 3843

        #4
        Very doubtful if the C-132 would have become a real great thing. Aviation technology progressed so fast that large aircraft could efficiently be built as jets in early 60s. Note that props were only adopted because jets at that time just sucked. The B-52 for example hardly made it with its eight jets. It was nearly as large as the An-22 but much faster.

        Generally, the pursuit for jet-transports greatly helped civil aviation in the pioneer days of jet airliners.
        Publicly, we say one thing... Actually, we do another.

        Comment

        • TinWing
          Rank 5 Registered User
          • Sep 2005
          • 950

          #5
          Originally posted by firstfleet
          The C-132 was ill-timed to go into service. The USAF decided to go to jets, first the C-135 and, later, the C-141. There was no funding in the FY 57 budget for the C-132. The C-132 would have been the largest turboprop airplane built, for many years. Its refueling variant woud have been able to tank up three fighters simultaneously. The engines and propeller flew a few times, sticking from the nose of a C-124 like a gigantic cigar. The propeller was built by Hamilton Standard, 22' in diameter with a 24" tip chord. For the time, that might have cut entirely through the technical envelope.
          I have always wondered why the United States attempted various high horsepower turboprops such as the T34 and T57 without using contrarotating props?

          Were any of the C-133's vibration and fatigue problems related to the use of a three bladed prop with the 6,500 to 7,500 horsepower T34?

          Another big question mark is whether the development of the T57 (derived from the prolific J-57) would have been just as troubled as the T34's career?

          Comment

          • TinWing
            Rank 5 Registered User
            • Sep 2005
            • 950

            #6
            Originally posted by Schorsch
            Very doubtful if the C-132 would have become a real great thing. Aviation technology progressed so fast that large aircraft could efficiently be built as jets in early 60s. Note that props were only adopted because jets at that time just sucked. The B-52 for example hardly made it with its eight jets. It was nearly as large as the An-22 but much faster.

            Generally, the pursuit for jet-transports greatly helped civil aviation in the pioneer days of jet airliners.
            So how does the turboprop Airbus A400M fit into your theory?

            You mention the An-22, but the performance of that type was compromised by the straight wings.

            The swept wing XC-132 was far closer in performance to the similarly powered Tu-95 "Bear."

            It is all to easy to forget that the An-22 was far later than the C-132, but was a far less ambitious project.

            Comment

            • Schorsch
              Severely Transonic
              • Aug 2005
              • 3843

              #7
              Originally posted by TinWing
              So how does the turboprop Airbus A400M fit into your theory?

              You mention the An-22, but the performance of that type was compromised by the straight wings.

              The swept wing XC-132 was far closer in performance to the similarly powered Tu-95 "Bear."

              It is all to easy to forget that the An-22 was far later than the C-132, but was a far less ambitious project.
              It fits easily: the A400M is, like the An-70 or C-130, a tactical transporter. It sacrifices speed in favor for short TO and landing and stronger structure. The C-141 and C-5 were strategic transports, they can land on shorter runways, but normally they go from airport to airport. The C-17 is in-between, but much more expensive and actually the only jet-transport built since 1980 (except the An-124, which is also a strategic transport).

              The C-132 would not have been a tactical transporter but a strategic transporter. It would have been outclassed by jet-powered aircraft after less than 10 years of service.

              BTW: the A400M has a top-speed very close to that of some jet-transporters.
              Publicly, we say one thing... Actually, we do another.

              Comment

              • Bager1968
                Rank 5 Registered User
                • May 2005
                • 3635

                #8
                "BTW: the A400M has a top-speed very close to that of some jet-transporters."


                REALLY?????
                When was the flight test that produced that speed?

                Until those tests are conducted, you really should use the words "planned to have a top speed", "supposed to have", or "designed to have"... as even with the modern techno-whiz-bang, "gee whiz aren't these CAD programs great we don't need any real-world testing", "fire the human engineers the computer can design it all" aircraft industry, sometimes planes just don't fly the way they were meant to!!

                Don't start claiming actual performance until it actually does what you claim it can!!
                Germany, Austria and Italy are standing together in the middle of the pub, when Serbia bumps into Austria, and spills Austria's pint.

                Comment

                • Schorsch
                  Severely Transonic
                  • Aug 2005
                  • 3843

                  #9
                  Originally posted by Bager1968
                  "BTW: the A400M has a top-speed very close to that of some jet-transporters."


                  REALLY?????
                  When was the flight test that produced that speed?

                  Until those tests are conducted, you really should use the words "planned to have a top speed", "supposed to have", or "designed to have"... as even with the modern techno-whiz-bang, "gee whiz aren't these CAD programs great we don't need any real-world testing", "fire the human engineers the computer can design it all" aircraft industry, sometimes planes just don't fly the way they were meant to!!

                  Don't start claiming actual performance until it actually does what you claim it can!!
                  Don't tell me about flight test! If you are so knowlegdable (or at least pretend to be) about it you should know that predicting airspeed is not too difficult, especially if dealing with subsonic airflow. There might be restrictions in terms of engine power output but the proposed M0.72 can be met. Normally there is always room to increase engine power by some percent. It is very unlikely to meet the drag divergence mach number or buffet onset at your design mach number.
                  Publicly, we say one thing... Actually, we do another.

                  Comment

                  • firstfleet
                    Rank 5 Registered User
                    • Mar 2005
                    • 23

                    #10
                    C-133 props and vibration

                    Originally posted by TinWing
                    I have always wondered why the United States attempted various high horsepower turboprops such as the T34 and T57 without using contrarotating props?

                    Were any of the C-133's vibration and fatigue problems related to the use of a three bladed prop with the 6,500 to 7,500 horsepower T34?

                    Another big question mark is whether the development of the T57 (derived from the prolific J-57) would have been just as troubled as the T34's career?
                    Based upon what I have learned in the last six years, the answer is definitely "Yes." The Curtiss props had long blades, with an 18' diameter. THe tip chord was over 7", and tip speed was M 1.03 during takeoff and climb and M .97 at cruise. Tips on the inboards were close to the fuselage and sonic impingement on the airframe was huge. Also, because the T34s did not meet manufacturer's specs, the airframe was lightened three times before metal was even cut. So, it was even more susceptible to vibration effects than a more robust structure might have been.

                    I believe the props were pushing the technical envelope of the time. The 24' Hamilton prop on the C-132 might have cut through the envelope. They had a square-cut tip with a 24" chord. From earlier readings, other manufacturers were working on prop issues. I remember that the Britannia was advertised as the "whispering giant," because its prop tips were designed to mitigate tip noise. There was certainly a difference between the C-130A, with three-bladed props, and later models, with four-blade paddle designs. High-time Herk pilots in those days would cup their ear and say, "What's that? I fly A-models."

                    Knowing all of the problems the C-133 had with nose case failures, I can only imagine the issues there would have been with contrarotating props. Perhaps, though, the overall load on the nose case gearing might have been lessened with more blades to convert turbine power to thrust. I wonder how the TU-95 fared with nose cases.

                    At the time, the T57 might have had similar problems as the T34, simply because of the nose case issues. Even, then, however, it appears that large propeller technology was a dying craft, from what I have read of the time. The designers of the T57 (one is Dick Mulready) remark on how few there were who knew anything aobut propeller gearing.
                    Cal Taylor
                    firstfleet@aol.com
                    The C-133 Project
                    http://www.angelfire.com/wa2/c133bcargomaster/home.html

                    Comment

                    • TinWing
                      Rank 5 Registered User
                      • Sep 2005
                      • 950

                      #11
                      Originally posted by firstfleet
                      Based upon what I have learned in the last six years, the answer is definitely "Yes." The Curtiss props had long blades, with an 18' diameter. THe tip chord was over 7", and tip speed was M 1.03 during takeoff and climb and M .97 at cruise. Tips on the inboards were close to the fuselage and sonic impingement on the airframe was huge. Also, because the T34s did not meet manufacturer's specs, the airframe was lightened three times before metal was even cut. So, it was even more susceptible to vibration effects than a more robust structure might have been.
                      The C-133 makes an interesting comparison with the Shorts Belfast. The production Belfast featured 16' props with four blades, driven by 5,730shp Rolls-Royce Tynes - less powerful than the 6,500-7,500hp T-34, but still worthy of technical comparisons.

                      The Belfast had an even shorter military carreer than the C-133 - although there is still at least one Belfast flying in commercial service today.

                      It should be admitted that the Belfast was a smaller, less powerful, less ambitious design, though.

                      Comment

                      • Arthur
                        a plane pour moi
                        • Jan 2000
                        • 9056

                        #12
                        Originally posted by TinWing
                        I have always wondered why the United States attempted various high horsepower turboprops such as the T34 and T57 without using contrarotating props?
                        The US did try to develop contrarotating props, but the aircraft flying with 'em all had very miserable reliability records concerning the gearboxes driving those props. Experience with the XT-37 for the YRB-35, and the XT-40 powering the Convair Tradewind series (R3Y and P5Y) probably ment the end for US contrarotating props - too bad, i really like the Tradewind a lot (excuse for gratuitous pic).

                        Note that the first Tu-95 prototype also crashed because of it's prop gear failing.
                        Attached Files
                        Regards,

                        Arthur
                        The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.
                        Bertrand Russell

                        Comment

                        • firstfleet
                          Rank 5 Registered User
                          • Mar 2005
                          • 23

                          #13
                          Italian analysis of heavy airlifters

                          Originally posted by TinWing
                          The C-133 makes an interesting comparison with the Shorts Belfast.
                          In the course of writing the C-133 book, I was contacted by Simone Frigiero, an Italian aero engineering student at the University of Turin. He and two classmates, Carlo Di Marino and Gianluca Frangi, were doing a required project to analyze a particular airplane in comparison to similar contemporary airplanes. They found the C-133 web site and contacted me for information.

                          They compared the C-133 to the Belfast, Constellation, C-124, C-5, C-130, C-141 and AN-22. I received a DVD with their complete report, but it was in Italian. So, I could only look at the pictures. Someday, I'll find someone who can translate it. It is quite lengthy.

                          When I told another C-133 person about the project, he remarked "It's too bad Douglas didn't do an engineering analysis before they built the C-133." A cheap shot, perhaps, but understandable, knowing about the airplane's history.
                          Last edited by firstfleet; 17th March 2006, 19:50. Reason: typos
                          Cal Taylor
                          firstfleet@aol.com
                          The C-133 Project
                          http://www.angelfire.com/wa2/c133bcargomaster/home.html

                          Comment

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