Consolidated C - 87 Liberator Express The Consolidated C - 87 Liberator Express was a transport derivative of the B - 24 Liberator heavy bomber built during World War II for the United States Army Air Forces . A total of 287 C - 87s were factory - built alongside the B - 24 at the Consolidated Aircraft plant in Fort Worth , Texas . Converted former C - 87s were the basis for a USAAF flight engineer trainer designated as the AT - 22 , a United States Navy VIP transport designated as the RY , and a Royal Air Force VIP transport designated as the Liberator C . IX . Design and development . The C - 87 was hastily designed in early 1942 to fulfill the need for a heavy cargo and personnel transport with longer range and better high - altitude performance than the C - 47 Skytrain , the most widely available United States Army Air Forces transport aircraft at the time . The first C - 87 prototype was based on a damaged B - 24D , serial " 42 - 40355 " , that crashed at Tucson Municipal Airport # 2 on 17 February 1943 . Six Consolidated Aircraft employees riding as passengers were killed and several others were injured . The prototype was converted into a transport configuration by various modifications , including deletion of the gun turrets and other armament along with the installation of a strengthened cargo floor , including a floor running through the bomb bay . The glassed - in bombardier compartment of the B - 24 was replaced by a hinged metal cap to allow front cargo loading . A cargo door was added to the port side of the fuselage , just forward of the tail , and a row of windows was fitted along the sides of the fuselage . The C - 87 could be fitted with removable seats and racks to carry personnel or litters in place of cargo . In its final configuration , the C - 87 could carry between 20 and 25 passengers or 12 , 000 lbs of cargo . Because of war production bottlenecks and shortages , many C - 87 aircraft were fitted with turbosuperchargers producing lower boost pressure and power than those fitted to B - 24s destined for combat use , and ceiling and climb rate were accordingly adversely affected . C - 87A VIP transport . In 1942 and 1943 , several C - 87 aircraft were converted into VIP luxury passenger transports by adding insulation , padded seats , dividers , and other accommodations . The modified aircraft was capable of carrying 16 passengers , and given the designation C - 87A . One C - 87A in particular , serial " 41 - 24159 " , was exclusively converted in 1943 to a presidential VIP transport , the " Guess Where II " , intended to carry President Franklin D . Roosevelt on international trips . Had it been accepted , it would have been the first aircraft to be used in presidential service , i . e . the first Air Force One . However , the Secret Service , after a review of the C - 87 ' s controversial safety record in service , flatly refused to approve the " Guess Where II " for presidential carriage . The " Guess Where II " was then used to transport senior members of the Roosevelt administration . In March 1944 , the " Guess Where II " transported Eleanor Roosevelt on a goodwill tour of several Latin American countries . Operational history . Most C - 87s were operated by the U . S . Air Transport Command and flown by civilian crews from U . S . civil airlines . The planes were initially used on transoceanic routes too long to be flown by the C - 47 . After the Japanese invasion of Burma in 1942 , the C - 87 was used for flying war material from India to American and Chinese forces over " The Hump " , the treacherous air route that crossed the Himalayas . When the route was established , the C - 87 was the only readily available American transport with high - altitude performance good enough to fly this route while carrying a large cargo load . The C - 87 was plagued by numerous problems and suffered from a poor reputation amongst its crews . Ernest K . Gann , in " Fate is the Hunter " said , " They were an evil bastard contraption , nothing like the relatively efficient B - 24 except in appearance . " Complaints centered around the clumsy flight control layout , frequent engine problems , hydraulic leaks , and a disconcerting tendency to lose electrical power in the cockpit during takeoff and landing . The C - 87 did not climb well when heavily loaded , a dangerous characteristic when flying out of the unimproved , rain - soaked airfields of India and China ; many were lost in collisions with terrain soon after takeoff . Ernest K . Gann ' s book recounts a near - collision with the Taj Mahal after takeoff in a heavily loaded C - 87 . The aircraft ' s auxiliary long - range fuel tanks were linked by improvised and often leaky fuel lines that crisscrossed the crew compartment , choking flight crews with noxious gasoline fumes and creating an explosion hazard . The C - 87 also had a tendency to enter an uncontrollable stall or spin in the event of inflight airframe icing , a frequent occurrence over the Himalayas in the days before accurate weather forecasting ( Gann said they " . . . could not carry enough ice to chill a highball " ) . The aircraft could also become unstable in flight if its center of gravity shifted due to improper cargo loading . This longitudinal instability arose from the aircraft ' s hasty conversion from bomber to cargo transport . Unlike a normal cargo transport , which was designed from the start with a contiguous cargo compartment with a safety margin for fore - and - aft loading variations , the bomb racks and bomb bays built into the B - 24 design were fixed in position , greatly limiting the aircraft ' s ability to tolerate improper loading . This problem was exacerbated by wartime exigencies and the failure of USAAF Air Transport Command to instruct loadmaster s in the C - 87 ' s peculiarities . The design ' s roots as a bomber are also considered culpable for frequently collapsing nosegear ; its strength was adequate for an aircraft that dropped its payload in flight before landing on a well - maintained runway , but it proved marginal for an aircraft making repeated hard landings on rugged unimproved airstrips while heavily loaded . The C - 87 was rapidly displaced on the front lines by the Douglas C - 54 Skymaster and Curtiss C - 46 Commando , which offered similar performance combined with greater reliability and more benign flight characteristics . Some surviving C - 87 aircraft were converted into VIP transports or flight crew trainers , and several others were sold to the Royal Air Force .