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B377PG Pregnant Guppy

Among the difficulties facing the Apollo program in the 1960s and early 1970s was how to move large rocket stages from the contractor facilities where they were built to the launch pads in Florida. In 1961, John M. Conroy of Aero Spacelines, Inc., proposed modifying a Boeing Stratocruiser airliner with a bulging fuselage. Despite the ungainly appearance of the "Pregnant Guppy" as it came to be called and despite Conroy's nearly running out of cash and credit during the conversion, the project was successful. Besides air transport, the only other way to get the Apollo rocket stages from California to Florida was on a slow boat through the Panama Canal. The Guppy aircraft cut not just days, but weeks and months out of the schedules.

Guppy aircraft played a significant role in meeting NASA's launch schedules since the Apollo days. When President Kennedy declared the goal of reaching the moon before 1970, the Pregnant Guppy 377PG and Super Guppy 377SGT-F helped to make it possible. California-based Aero Spacelines met the requirement with the Guppy, which was developed in 1962. Aero Spacelines flew over two million miles in support of NASA's Gemini, Apollo and Skylab programs, airlifting mammoth yet delicate components and equipment.

The Douglas organization possessed a reservoir of experience in the transportation of rockets by aircraft. The Douglas Thor IRBM had been freighted regularly on transcontinental and intercontinental flights by Douglas C-124 Globemasters, and the company was confident that this mode of transport was practical because its own aerial operations had not damaged any rocket or its systems. The Thor, however, had been designed for airborne shipment, and the situation was now reversed. Douglas was ready to listen when approached with an unusual scheme: the modification of an existing aircraft to completely enclose the rocket stage with an airplane's fuselage.

The idea of a bloated cargo airplane originated with an imaginative group associated with John M. Conroy, aerial entrepreneur of an outfit aptly named Aero Spacelines, Incorporated, in Van Nuys, California. Aero Spacelines intended to acquire surplus Boeing B-377 Stratocruisers. About 1960, Conroy and some partners acquired title to over a dozen four-engined airliners, used mainly by Pan Am and Northwest Orient on their intercontinental routes during the Stratocruiser's heyday in the 1950s. The Conroy group at first planned to use the planes for nonscheduled air carry operations, but airlift for Air Force rockets also looked promising. By 1961, plans had progressed to fly NASA's new family of large launch vehicles.

Drawing heavily on his own financial resources, Conroy pushed the idea of his bulbous, "volumetric" airplane despite the considered opinion of many aircraft engineers and aerodynamicists that no plane could be distorted and distended enough to swallow an S-IV rocket stage and still be able to fly. But Conroy was persuasive. R. W. Prentice, who managed the S-IV logistics program at Douglas, remembered him as real "swashbuckler," the sort of aviation character that reminded him of the cartoon hero named "Smilin'Jack." Conroy apparently found some kindred souls among influential Douglas executives, because he persuaded the company to go along with him on a presentation to NASA and MSFC. Some of the NASA managers were unconvinced, but the energetic Conroy touched a responsive chord in MSFC's visionary director, Dr. Wernher von Braun. As John Goodrum, chief of MSFC's logistics office, recalled the sequence of events, von Braun warmed to the idea from the start. The idea was innovative and its boldness appealed to him. Neither MSFC nor NASA Headquarters could allocate substantial funds to such a project at the time. Nevertheless, buoyed by the interest evinced at both Douglas and MSFC, Conroy decided to plunge ahead, although there was no guarantee of a contract.

The first phase of the project called for lengthening the fuselage (by inserting the cabin section of another Stratocruiser) to accommodate the S-IV stage. After the flight test of that modification, phase two called for the enlargement of the plane's cabin section to approximately double its normal volume. The swollen, humpbacked addition to the original Boeing airframe was originally fabricated as a nonstructural element stuck on the top of the fuselage. This alteration allowed test pilots and engineers to conduct flight tests and analyze the altered flying characteristics in comparative safety. The first flight occurred on 19 September 1962, followed by more than 50 hours of cross-country trials and other experimental flights. Satisfied that the reconfigured aircraft could indeed fly, workmen finally cut away the original inner fuselage and the massive external shell was mated to the basic airframe as a load-bearing structure. The name Aero Spacelines selected for its unique plane was a natural. The former Stratocruiser became a B-377 PG: the Pregnant Guppy. The new plane had cost over $1,000,000.

The Guppy's designers intended to make the plane a self-contained cargo transportation system. The fuselage separated just aft of the wing's trailing edge to load and unload the S-IV and other cargoes. The ground crew unloaded and attached three portable dollies to the rear part of the plane and disengaged the various lines, cables, and bolts connecting the fuselage sections. The rear portion was then rolled back to expose the plane's cavernous hold.

In the course of work on the Guppy, Conroy began running out of cash and credit. He figured he needed some tangible support from NASA in the form of an endorsement to keep his creditors at arm's length. On 20 September 1962, only one day after the first air trials of the reconfigured prototype cargo version, Conroy and an adventuresome flight crew took off for a demonstration tour. At this stage of the plane's development, the B-377's original fuselage was still intact, and the massive hump attached to the outside was held up by an interior framework of metal stringers and wooden two-by-fours. Conroy had to get a special clearance from the Federal Aviation Administration which allowed him to proceed eastward from Van Nuys, as long as he avoided major population areas en route. Following several interim stops, the Pregnant Guppy flew to Huntsville, where Conroy wanted to demonstrate the plane to MSFC officials and perhaps get some form of unofficial encouragement to enable him to continue the plane's development.

He landed at the airstrip of the Army's Redstone Arsenal, a facility shared jointly by MSFC and the Army. The Guppy was visited by a mixed group of scoffers and enthusiasts, including von Braun. While some onlookers made sour jokes about the reputed ability of the awkward-looking plane to fly Saturn rocket stages from the Pacific to the Atlantic coast, von Braun was delighted. With both time and money in short supply, Conroy wanted to pull off a convincing test of the Guppy's ability to fly a heavy load. Because there was no time to install enough sandbags in the hold to simulate the proposed cargo capacity, the plane was completely gassed up with a load of aviation fuel to make up the weight difference. MSFC's logistics chief, John Goodrum, observed the proceedings, and most of the people around him seemed very doubtful of the plane's potential. "In fact," remembered Goodrum, "there were some pretty high ranking people who stood right there and shook their heads and said it just wouldn't fly-there is no way!"

With Conroy at the controls, the big plane lumbered down the runway and into the air. The pair of MSFC observers aboard this first flight included Julian Hamilton, a key manager in Saturn logistics programs, and Herman Kroeger, a member of the von Braun group since the V-2 program in Germany and a former test pilot. Even with the number one and two engines out, the plane could maintain course and altitude with only light control. This feat so impressed ex-test pilot Kroeger that he lapsed into German in describing it to his colleagues after the plane landed. Von Braun was so interested that he wanted to fly in the airplane. The MSFC director crawled in the airplane and took off, to the consternation of those still dubious about the airworthiness of the fuel-heavy airplane braced on the inside by a wooden framework. The flight was uneventful, and informal contract talks began the same day. There was little doubt that Conroy needed some firm support. His finances were in such bad shape that he reached Huntsville only by borrowing some aviation gas from a friend in Oklahoma, and MSFC agreed to supply him with enough gas to fly home to California.

Conroy was able to supply information for more serious contract negotiations by late fall of 1962. Conroy reported in a letter to von Braun that performance of the Pregnant Guppy guaranteed cruising speed in excess of 378 kilometers per hour. The correspondence also revealed the growing extent of MSFC cooperation and support for the proposed Guppy operations involving cooperation from military bases, although no official contracts had been signed. Aero Spacelines planned to keep critical spares at strategic locations along its route structure to reduce downtime in case of malfunctions. This arrangement included the special allocation of a "quick-engine-change" unit at Patrick AFB, Florida, near the launching sites of Cape Canaveral. NASA also planned to arrange for Aero Spacelines to purchase supplies of fuel and oil at the military bases along the Guppy's route.

In the spring of 1963, the space agency was planning the first two-stage launch of the Saturn I vehicle, designated SA-5. The first four launches had carried inert second stages, and SA-5 had special significance as the first of the giant Saturn boosters to have both stages "live" and operational. The agency was growing anxious over the delivery of the S-IV-5 stage because of a time slippage caused by test problems, and the Pregnant Guppy would save considerable time by flying the stage from California to the Cape in 18 hours, as opposed to 18-21 days via ship. In a letter dated 25 April 1963, NASA's Director of Manned Space Flight, D. Brainerd Holmes, emphasized the Guppy's importance to Associate Administrator Robert Seamans. Holmes wanted to make sure that the FAA was "advised of NASA's vital interest" in securing the Pregnant Guppy's prompt certification so that lost time could be made up in the delivery of the S-IV-5 stage. Holmes pointed out that NASA had also made several telephone calls to FAA officials.

As evidence of NASA's growing commitment to Guppy operations, Aero Spacelines was finally awarded a contract from MSFC, to cover the period from 28 May-31 July 1963, to complete the plane's tests and make an evaluation as soon as possible. The FAA awarded the B-377 PG an airworthiness certificate on 10 July, and MSFC immediately conducted a transcontinental trial flight with a simulated S-IV stage aboard. In September 1963, the Pregnant Guppy flew the S-IV stage for the fifth Saturn I launch from California to Florida.

Although the Pregnant Guppy did not receive its final certification as a transport craft until 13 November 1963, NASA relied on the plane to carry Apollo spacecraft hardware to Houston during the late summer months, and in mid-September the Pregnant Guppy took on the S-IV-5 stage at Sacramento for delivery to Cape Kennedy for the launch of SA-5. Technical problems in the first stage delayed the launch for many weeks, but the two-stage rocket finally made a successful flight on 29 January 1964.

The aircraft also carried Gemini launch vehicles, Apollo command and service modules, Pegasus meteoroid detection equipment, F-1 engines for the Saturn V, an instrument unit for the Saturn I, and other large NASA cargo. The Guppy saved up to three weeks in transit time and effected substantial savings in transportation costs, and won endorsements and long-term contracts from NASA officials. The plane was operated by MSFC but carried a variety of NASA freight including launch vehicles for the Gemini program, Apollo command and service modules, hardware for the Pegasus meteoroid detection satellite, F-1 engines, the instrument unit for Saturn I, and "other general outsized NASA cargo.

For these reasons, as well as NASA's concern for the larger space hardware in the Saturn IB and V programs, NASA managers expressed interest in correspondingly larger aircraft. Because the S-IVB stage was larger than the S-IV, it would require a larger plane if air operations were to be continued. A larger plane could carry the instrument unit for both the Saturn IB and the Saturn V as well as the Apollo lunar module adapter unit. Moreover, a second plane could serve as a backup for the original Guppy. At one point in the discussions about a second-generation aircraft, serious consideration was given to the conversion of an air transport large enough to handle the S-II second stage of the Saturn V.

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Page last modified: 07-07-2011 02:27:30 ZULU