N THE 1940s and 1950s, the Air Force explored the potential of a supercargo carrier by flying its one-of-a-kind XC-99 on regular, often record,transport runs. It also was touted as a possible prototype for a newgeneration of commercial air carriers. The experiment lasted 10 years.

Then, for almost 50 years, the airplane was left open to wind and weather in aTexas field.

Now the big bird—one of history’s largest airplanes—will soon have a fittingplace in Air Force history. It is to be reassembled, restored, and enshrined at theUS Air Force Museum in Dayton, Ohio.

“The XC-99 may have to go on display outside for a short time initially,” said

Big Fella

USAF built only one XC-99, in 1947. Soon,this enormous aircraft will have a newhome at the US Air Force Museum.

By Bruce D. Callander

I

N THE 1940s and 1950s, the Air Force explored the potential of a supercargo carrier by flying its one-of-a-kind XC-99 on regular, often record,transport runs. It also was touted as a possible prototype for a newgeneration of commercial air carriers. The experiment lasted 10 years.

Then, for almost 50 years, the airplane was left open to wind and weather in aTexas field.

Now the big bird—one of history’s largest airplanes—will soon have a fittingplace in Air Force history. It is to be reassembled, restored, and enshrined at theUS Air Force Museum in Dayton, Ohio.

“The XC-99 may have to go on display outside for a short time initially,” said

Big Fella

USAF built only one XC-99, in 1947. Soon,this enormous aircraft will have a newhome at the US Air Force Museum.

By Bruce D. Callander

I

AIR FORCE Magazine / February 200472

museum spokesman Chris McGee,but the museum’s long-term planfor construction will open “lots ofspace,” much of which will be usedto display experimental aircraft.“The XC-99 will go into that [ex-perimental aircraft] building even-tually,” said McGee.

Everything about the XC-99 washuge. Its tail fin stood the height of afive-story building, some 57.5 feet.Its double-decker interior had 16,000cubic feet of useable payload space,enough to carry 400 fully equippedtroops or 50 tons of cargo. (The larg-est transport aircraft of the day—theC-97, which was based on the B-29bomber—could only carry about 100troops and less than half of the ton-nage.) The XC-99 carried 21,000 gal-lons of fuel. Its gross weight was322,000 pounds, which was distrib-uted over 10 tires, making it possiblefor the huge aircraft to land on any5,000-foot runway that could supportthe weight of the much smaller C-54.(A C-54 had a gross weight of only73,000 pounds.)

A company news release noted thatthe six engines of the XC-99 devel-oped as much horsepower as fivelocomotives. The engines weighedmore than 10 tons. The release alsonoted that the aircraft had more than60,000 square feet of sheet metal,more than one million rivets, andmore than 25 miles of wiring.

The XC-99 had various nicknames,among them “Aerial Goliath” and“Queen of the Skies.”

The XC-99 grew out of the B-36bomber, which was conceived anddeveloped in the midst of World WarII, when America feared that En-gland might fall to Germany and theUS would need to fly direct combatmissions from its own shores. TheB-36 was to be a truly intercontinen-tal bomber that could carry 10,000pounds of bombs more than 5,000miles and return. Until then, no air-craft had even approached the pro-posed range of 10,000 miles.

In October 1941, the Army AirForces selected a Consolidated Air-craft Corp. (later Convair) proposal,

The XC-99 comes in for a landing during its November 1947 maiden flight out ofLindbergh Field, Calif. It was, at the time, the world’s largest land aircraft. Thetransport required a 3,000-foot runway to take off and a 5,000-foot runway to land.

designated Model 35, as the mostpromising candidate. In November1941, Consolidated received a con-tract for two experimental aircraft tobe designated XB-36.

The first XB-36 was to be deliv-ered by May 1944, but when the warsituation in Europe improved, theprogram lost some momentum. TheXB-36 did not make its first flightuntil August 1946.

The bomber had a wingspan of230 feet. It was 163 feet long andstood more than 46 feet high. Itsgross weight was 265,000 pounds.It was powered by six Pratt &Whitney R-4360-25 radials; eachpusher-type engine generated 3,000horsepower as they turned 19-footpropellers. The wings were largeenough for the crew to walk up-right down a catwalk to reach the

engines for in-flight maintenance.It had a maximum speed of 346mph at 35,000 feet and a cruisingspeed of 216 mph.

It was the heaviest and largest landairplane to fly up to that time. It wasalso the first very large aircraft to beproduced in any quantity. The initialproduction contract called for 100bombers. The full production runwould be 385 aircraft.

The first production B-36A air-craft flew in August 1947. StrategicAir Command’s 7th Bomb Groupreceived its first B-36A in June 1948for crew training. The first combat-

The XC-99, shown on a flight line alongside B-50s—the Air Force’s workhorsebomber of the time—was derived from the B-36, but it was 20 feet longer, with atail 10 feet taller. XC-99 dwarfed its contemporary aircraft.

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The XC-99’s ample cockpit accommodated a sizeable crew. When the airplanewas in service, USAF noted that the pilot and flight engineer were responsiblefor overseeing more than 250 gauges, switches, and levers.

ready production version—the B-36B—flew in July 1948, almost ayear after the Air Force became aseparate service.

From B-36 to XC-99In 1942, as it was developing the

huge bomber, Consolidated beganpreliminary studies for turning out atransport version. The Army AirForces wanted to explore whether asupersize aircraft would be practicalfor rapid transport of large numbersof troops and much more cargo thanwas possible with contemporary air-lifters.

AAF in December 1942 gave thecompany a formal contract to producea test aircraft, dubbed XC-99. Becauseits development took a backseat to theB-36 bomber, however, the XC-99was not completed until 1947.

Early that year, the company an-nounced that the huge aircraft hadbeen moved outdoors for comple-tion. “No building at ConsolidatedVultee ... is high enough to house thegiant plane with its main landingwheels installed, or wide enough tohouse it with outer wing panels inplace,” stated the release. The XC-99 had the same wingspan as thebomber, but it was 20 feet longer andits tail was 10 feet higher.

Despite its huge size, aircrews thatflew it said that, once airborne, theXC-99 handled with ease. On land,its reversing propellers and tricyclelanding gear made it possible to backeasily into parking areas. It had a top

speed of 300 mph and a maximumrange, with minimum load, of 8,100miles.

The Air Force took formal deliveryof the XC-99 in May 1949. It firstwent to the 7th Bomb Wing at CarswellAFB, Tex., because the unit had expe-rience with the B-36 bomber. On June9, 1949, Capt. Deane G. Curry pilotedthe first Air Force flight of the hugetransport, making six landings duringthe mission. Curry subsequently madefive more flights, including a nightmission and an emergency landing atKelly AFB, Tex., where it underwentrepair and engine modifications.

In September 1950, the XC-99 wastransferred from Carswell to Kellyto begin its formal operational testprogram. According to an Air Forcenews release, it was one of the fewexperimental aircraft to clear its ini-tial development costs. Yet, its dayswere numbered as the jet age ap-proached.

Breaking RecordsDuring its relatively short life,

the XC-99 flew numerous missions,setting several records along theway. It flew its first cargo missionto Kelly in July 1950, with Col.Frederick Bell as pilot. That mis-sion, known as Operation Elephant,delivered 101,266 pounds of cargo,including engines and propellers forB-36s, from San Diego to Kelly andwas the first record-shattering flightof the XC-99. In another recordflight, the XC-99 would lift 104,000pounds from an airfield at 5,000-foot elevation.

The XC-99 test program routinelyinvolved twice weekly runs fromKelly to the aircraft depot at McClellanAFB, Calif. The aircraft would re-turn by way of other bases or depots,making pickups and deliveries.

In addition, the Air Force taskedthe huge transport with special mis-sions, such as the emergency trans-port of 42 C-54 aircraft engines toMcChord AFB, Wash., during theKorean War. The C-54s were flyinground-the-clock missions to resup-ply forces in Korea, so time was

The image at left shows one of the two huge tires initially used for XC-99landing gear. The image at right shows one set of the four-wheel system—used on production B-36s—that was retrofitted to the XC-99.

AIR FORCE Magazine / February 200474

critical. Col. T.W. Tucker, the firstXC-99 chief pilot and project of-ficer, delivered the engines—27 onthe lower deck and 15 on the up-per—on a single flight and landed atMcChord where he taxied the mon-ster aircraft down a 48-foot-wide stripwith only one foot of clearance oneither side of the aircraft.

From July 1951 to May 1952, anAir Force record shows, the behe-moth flew 600 hours and airliftedseven million pounds of equipmentand supplies. About half of that wentto support forces in Korea. One of itsprimary missions was to resupply SACunits that flew the B-36 bomber. Inthat role, the XC-99 flew thousandsof hours around the US and to SAClocations in the Caribbean.

In August 1953, the XC-99 madeits longest flight—12,000 miles—toRhein–Main AB, Germany, by wayof Bermuda and the Azores. It carriedmore than 60,000 pounds each way.At every stop, it attracted much at-tention from the public and the press.During 1953, the aircraft flew 200missions at an average cost of 13cents per ton-mile, less than half theton-mile cost of its contemporaries.

In May 1955, the transport ferriedcargo from Dover AFB, Del., to

USAF took formal delivery of the XC-99 in 1949 and flew the aircraft until 1957.Early in its brief tenure, the XC-99 received its upgraded landing configurationand a nose radar unit.

Keflavik, Iceland, destined for theDistant Early Warning Line project.(See “A Line in the Ice,” p.64.) It flewsix round-trips, delivering 380,000pounds of cargo. The aircraft carriedalternating crews and 31 maintenancetechnicians from Kelly. The techni-cians were able to make the few re-pairs needed during the 30,000 miles

of flying under extreme weather con-ditions.

The big bird was also seen at vari-ous air shows and open houses aroundthe country. One anecdote sums up thewonder the aircraft evoked at everystop. During an exhibit at Wright–Patterson AFB, Ohio, a woman askedCapt. Jim C. Douglas, the XC-99 pi-lot, how he got the aircraft off theground. He replied: “We fly it, lady.”To which, the woman retorted, “Youngman, what kind of a fool do you takeme for?”

The Death KnellThe XC-99 had proved it could

operate economically if given long-distance routes that would have 60,000to 80,000 pounds of cargo for trans-port at each end of the run. However,while that was possible during theKorean War, such loads were infre-quent after combat operations ceased.

By 1955, the Air Force was focusedon producing jet aircraft, so it droppedplans to start serial-production C-99s.With the phaseout of the B-36—rap-idly being replaced by the B-52—partscommon to both aircraft became scarce,and XC-99 maintenance became moreexpensive. In March 1957, the AirForce canceled XC-99 operations anddeclared the aircraft to be surplus.

Only 11 years later, the Air Force’scurrent supersize transport, the turbo-jet C-5 Galaxy, made its first flight.The C-5 has a 223-foot wingspan, sevenfeet less than that of the XC-99, butthe C-5 is longer, taller, and has twice

A double-decked cargohold allowed the XC-99to carry a record-breaking payload of104,190 pounds. Onemonth, the aircraft flewseven round-tripsbetween Texas andCalifornia, delivering anaverage of 75,531pounds of cargo pertrip—for a total of morethan one millionpounds.

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AIR FORCE Magazine / February 2004 75

These photos show the XC-99 weathered by the decades the aircraft was leftexposed to the elements in Texas. The Air Force Museum plans to refurbish thegiant aircraft before it goes on display.

the gross weight and cargo space. And,in the 1980s, the XC-99 lost the title tothe largest land airplane when the So-viet Union introduced the AntonovAn-225 with a wingspan of 290 feet—60 feet longer than that of the XC-99.Overall, the An-225 is 48 feet longer,about three feet higher, and can carryfive times the payload.

During its brief life, though, theXC-99 added to USAF’s knowledgeof airlifters and helped the servicedevelop improved loading and cargo-handling techniques. It had flown 60million pounds of cargo a total of 1.5million miles—the equivalent of 59trips around the world. It amassedmore than 7,400 flying hours.

After retiring the big aircraft, theservice briefly considered flying the

XC-99 to the Air Force Museum, butofficials decided it would cost toomuch to make it flyable again. It wasturned over to the Kelly disposal of-ficer for sale, but a sale date wasnever set because public reaction inSan Antonio was so negative. In-stead, the Air Force donated the air-craft to the Texas Disabled AmericanVeterans to be used only for “dis-play, ceremonial, and historical pur-poses,” according to a history of Kelly.

The DAV had 45 days to move theXC-99 from Kelly, where it stood on

the base’s north runway. After oneextension, the huge aircraft finallywas moved to an off-base location,northwest of the main Kelly runway.

For some 18 years, it was the prop-erty of the DAV and served as a his-toric tourist attraction. One-time com-mander of the Texas DAV ClemSearles was one of the key players inthe effort and often led tours himself.

However, in 1976, the DAV passedthe aircraft to the San Antonio Me-morial Air Museum, a nonprofitgroup that planned to raise money to

build a shelter to house it and torefurbish it. The amount needed was$6 million. Just moving the aircraft—at one point the group thought itwould place it on the Lackland AFB,Tex., parade ground—was estimatedto cost $135,000. The plan fizzledand so did an effort by the group toget the Air Force Museum interested.At that time, the Air Force Museumconsidered the project too expen-sive.

In the interim, ownership of theXC-99 became confusing. At onepoint, a Tennessee businessmanclaimed ownership and proposed turn-ing it into a restaurant. The San Anto-nio museum group maintained it still“owned” the big airplane, though.

Nothing developed, so, for years,it remained on or near Kelly, visibleto passersby and exposed to effectsof the weather. Remarkably, the gi-ant aircraft is in relatively good con-dition, according to the Air ForceMuseum’s McGee.

“Although the exterior appears tobe in poor shape,” said McGee, “theaircraft remains in good overall con-dition, considering it’s been exposedto the elements for 46 years. Theinterior structure remains sound.”

Plans call for the museum, once itcompletes its current construction ef-forts, to house the XC-99 among otherexperimental aircraft in the museum’sR&D hangar, located on the mainportion of Wright–Patterson. ■

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Bruce D. Callander is a contributing editor of Air Force Magazine. He served tours of active duty during World War II andthe Korean War and was editor of Air Force Times from 1972 to 1986. His most recent article for Air Force Magazine,“Jumper to Airmen: ‘Get in Shape,’ ” appeared in the January issue.