Boeing YC-14 (Model 953) Tactical Airlifter Transport Aircraft Prototype

Specifications

Year: 1976
Status: Cancelled
Manufacturer(s): Boeing Company - USA
Production: 2
Capabilities: Transport; X-Plane;

Crew: 3
Length: 131.73 ft (40.15 m)
Width: 129.00 ft (39.32 m)
Height: 48.39 ft (14.75 m)
Weight (Empty): 117,749 lb (53,410 kg)
Weight (MTOW): 250,996 lb (113,850 kg)

Power: 2 x General Electric CF6-50D turbofan engines developing 51,000lb of thrust each.

Speed: 503 mph (810 kph; 437 kts)
Ceiling: 44,997 feet (13,715 m; 8.52 miles)
Range: 3,191 miles (5,135 km; 2,773 nm)
Rate-of-Climb: 1,935 ft/min (590 m/min)

Operators: United States (cancelled)

The United States Air Force (USAF) attempted to replace the long-running, prop-driven Lockheed C-130 "Hercules" tactical transport during the mid-1970s. With production beginning in 1954, the high-winged, four-engined C-130 had been in service for several decades up to that point and a myriad of variants were ultimately realized when the USAF established the Advanced Medium STOL Transport (AMST) competition of 1968 to seek a standardized successor. From the RFP (Request For Proposal) of 1972, Boeing's entry into the competition became its "YC-14" and this was set against the McDonnell Douglas "YC-15" prototype.

The C-130 set the standard for successful medium-class transports with its high-mounted wings and elevated empennage. The mounting of the engines along these wing elements forced a "T-style" tail unit to be used to help clear prop-wash. The cockpit was set over the short nose assembly for a commanding view and the elevated tail unit allowed for excellent access to the cargo hold from the rear. Performance-wise, the C-130 could operate from little-prepared airfields which added a rugged quality to the series still appreciated today.

With this in mind, Boeing engineers returned with a similar design arrangement in the Model 953 - save for propeller-driven propulsion. Instead, a pair of large turbofan engines took their place on the wing leading edges in the form of 2 x General Electric CF6-50D engines of 51,000lb thrust each - the exhaust blowing over the trailing edge flaps. The operating crew numbered three and internal capacity ranged from 150 combat-ready troops to 69,000lb of cargo. Overall length became 131.7 feet with a wingspan of 129 feet and height of 48.3 feet. Empty weight was 117,500lb against a Maximum Take-Off Weight (MTOW) of 251,000lb.

Boeing and McDonnell Douglas each had their designs selected from a field of five entries and each were awarded prototype contracts for two examples. Boeing prototype 72-1873 went to the air for the first time on August 9th, 1976 and the second example followed as 72-1874 in time. The formal USAF head-to-head competition began in November of 1976 at Edwards AFB and this phase lasted into mid-1977.

In the end, neither design was adopted for further development nor serial production due to the fact that the USAF had begun moving away from tactical-minded airlifters and towards strategic-minded types. To rework the two designs would have required considerable modifications so the AMST program was ended before the start of 1980. From there, the USAF moved on a new initiative - the "C-X" program which yielded the C-17 "Globemaster III" still in service today.

McDonnell Douglas was eventually merged into the Boeing brand label in August of 1997 - thus the C-17 design, originating from McDonnell Douglas, today exists as a Boeing product.

Armament

None.

Variants / Models

• YC-14 - Base Prototype Designation; two examples completed for testing.
• Model 953 - Boeing company designator