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Description
| Manufacturer: | Piasecki | |
| Base model: | H-16 | |
| Designation: | YH-16 | |
| Version: | A | |
| Nickname: | Transporter | |
| Designation System: | U.S. Air Force | |
| Designation Period: | 1948-Present | |
| Basic role: | Helicopter | |
| Status: | Prototype | |
Specifications
| Not Yet Available |
Recent comments by our visitors
| Jeri Peterson , CA | From J.P.Spencer "Whirlybirds: A History of the U.S. Helicopter Pioneers", 1998
"Eighteen months after the H-21, the Piasecki YH-16 Transporter — the other new tandem machine ordered by the Air Force — took to the air at Philadelphia International Airport. On October 23, 1953, company personnel and military officials watched the majestic helicopter take off, hover, and fly forward and sideways during a successful twelve-minute maiden hop flown by Harold Peterson and Phil Camerano. "It was just like watching an ocean liner pick up and fly," recalled Ken Meenen. The Transporter was by far the largest helicopter then flown. It was 23.8m long and topped by two overlapping rotors each 25m in diameter. In-flight vibration was low and of a loping nature. Bonded and tapered all-metal rotor blades (built using a new company process) combined milled-aluminum skins, aluminum honeycomb filler, and a leading-edge balance weight that also served as a mechanical fastener for the skins. A USAF requirement for a wide-ranging helicopter capable of rescuing downed strategic bomber crews had given rise to the new helicopter. The hefty fuel capacity required to meet its specified 2250km range in part dictated its size. Without the extra fuel, the capacious aircraft also had possible military application as a large troop and cargo transport. With this alternate use in mind, the company announced that the Transporter could carry forty passengers or three light trucks loaded through its rear ramp. These capabilities appealed to the U.S. Army, which saw in the H-16 an answer to several helicopter mission requirements of its own. It therefore joined the USAF in sponsoring further development of the YH-16 (the "Y" prefix denoted reclassification from experimental to service-test status). The helicopter's utility was limited, however, because it was underpowered despite two 1650hp Pratt & Whitney r-2180 radial engines. Like the Dogship before it, the YH-16 lifted as much as it did only because of very low disc loading that compromised other aspects of its performance. Greater power was clearly needed to realize the design's potential. Turbine power provided the answer. Smaller, lighter, more powerful, and more reliable than piston power, turboshaft engines then promised to revolutionize the entire helicopter industry. Two 1800shp Allison T38 units were accordingly adapted to the Piasecki design to create the world's first twin-turbine helicopter. Designated YH-16A, this second aircraft took to the air in July 1955 with Harold Peterson and George Callaghan at the controls. When it set an unofficial speed record of 267km/h the following year, prospects for the H-16 program could not have looked brighter. Piasecki had met a challenge others had thought impossible (Sikorsky had declined to bid for this same USAF contract). In the process, the company had once again extended the technological boundaries of rotary-wing flight. In December, the YH-16A broke apart in the air and crashed near the Delaware River, killing Peterson and Callaghan as they returned from a test flight in New Jersey. Investigators determined that the rear rotor shaft had failed, allowing the blades to desynchronize and wobble into the plane of those of the forward rotor. In fact, a frozen bearing in the test instrumentation had precipitated this failure by allowing a steel-tube standpipe, placed within the aluminum rotor shaft to guide wires from the instrumented blades, to undetectably inscribe a deepening groove within the shaft. This tragic accident caused the H-16 program to be scrapped, preempting the sixty-nine-passenger YH-16B Turbotransporter (a conversion of the YH-16 then in progress), which would have flown with two 3700shp Allison T56 engines. It also preempted Frank Piasecki's vision of interchangeable under-body pods for the rapid transport of differing loads such as field operating rooms, communications centers, and mobile repair centers. A tall stilt landing gear had already been designed to let the YH-16B accommodate such pods." 08/23/2006 @ 09:53 [ref: 13968] |
| Jeri Peterson , CA | S.Harding "U.S.Army Aircraft since 1947", 1990
"In 1946 the Army Air Forces awarded Piasecki Aircraft a contract for the development of a tandem rotor helicopter intended for use in the long-range search and rescue (SAR) role. The resultant Piasecki Model PV-15 was originally given the military designation XR-16 (R denoting rotorcraft under the World War II system), though this was changed to XH-16 in June 1948. The Air Force placed an order for two service test and evaluation aircraft in June 1949, and subsequently allocated the serial numbers 50-1269 and -1270 for these machines. At the time of its inception the H-16 was the largest helicopter in the world, having a fuselage almost as capacious as that of the contemporary Douglas DC-6/C-54. Though originally intended for the SAR role the Transporter, as the H-16 was ultimately named, evolved during the design process into a heavy-lift craft equipped with a tail loading ramp and optimized for troop and cargo transport. In this role the aircraft could carry up to forty troops or three light trucks within its fuselage, the interior of which was kept clear of obstructions by mounting the engines and all dynamic components in the upper fuselage. The H-16 was also capable of transporting large exterior cargo pods, and was equipped with variable-height landing gear legs in order to accommodate pods of varying sizes. The first Transporter (serial 50-1269) was powered by two 1650hp Pratt & Whitney piston engines and made its first flight in October 1953 with the designation YH-16. During construction the second prototype (50-1270) was modified to Model PV-45 standard through the replacement of its piston engines with two 1800shp Allison turboshafts. The change in powerplants and inclusion of various structural modifications prompted a redesignation to XH-27 in October 1952, though this was changed to YH-16A prior to the aircraft's first flight in 1955. Both H-16 variants were at times fitted with varying types of experimental horizontal tail surfaces, one of which incorporated large end-plate rudders, but none of these designs were adopted for permanent use. The Air Force ultimately decided against procuring the H-16 for operational use, and in 1955 the YH-16 was turned over to the Army for evaluation. The Army found the piston-driven Transporter to be underpowered and therefore awarded the reorganized Vertol company a contract for the machine's conversion to turbine power. The aircraft was duly equipped with two 2100shp Allison turboshafts, modified to carry up to fifty troops, and redesignated YH-16B. Despite these improvements the type was ultimately judged to be unsuited to sustained operations under field conditions, and the Army terminated the H-16 test programme in mid-1956." 08/23/2006 @ 09:48 [ref: 13967] |
| Jeri Peterson , CA | Some statistics courtesy of Piasecki.com website:
Model YH-16A Mission Rescue & Transport Crew 3 Passengers 40 or 32 Litters Engines (2) Allison YT38-A-10 hp 1,800 each Rotor diameter 82 ft Fuselage length 78 ft Weight empty 22,506 lb Useful load 11,071 lb Max. speed 146 mph Cruising speed 140 mph Range 230 miles Ceiling with normal load 19,100 ft 08/23/2006 @ 09:18 [ref: 13966] |
| Jeri Peterson , CA | This is excerpted from the "GoldEagle4" website and has more details:
"The H-16 "Transporter" was developed in response to a USAF requirement for a long-range helicopter to rescue downed aircraft crews. At the time, it was the largest helicopter in the world. The rotor-disk was 82 ft in diameter, the fuselage was 134 ft long, and the gross weight was 32,000 lbs. The first prototype, the XH-16 had two 1,650 hp P&W R-2180 radial engines, one in front and one in the rear, and first flew on 23 October 1953. The second prototype, the YH-16A, had two Allison YT-38 turboshaft engines of 1,800 hp each. The YH-16A set a world speed record of 166 mph in early Jan 1956. Later that month, after matching the world altitude record of 24,500 ft, while in descent, a failure in some component of the temporary flight-test equipment in the tail pylon, caused the helicopter to break-up in flight, killing the two Piasecki test pilots. The YH-16 program was cancelled in April 1956." 08/23/2006 @ 08:20 [ref: 13962] |
| Jeri Peterson , CA | From a Piasecki Helicopter Corporation newspaper article in December 1955:
"The YH-16A Turbo Transporter makes its firt public appearance at the International Side of Philadelphia International Airport on December 6th. Powered by two Allison T-38 turbines, the YH-16A was demonstrated to over 300 military, press and PHC representatives most of whom watched from inside the building. At the luncheon, which followed the flight demonstration, President Don R. Berlin report the YH-16A has flown at altitudes up to 12,000 feet and has recorded a speed of 166 miles per hour, during airspeed calibration runs, paced by an Air Force fixed-wing airplance equipped with specially calibrated air-speed system. This is 10 mph faster than the existing official helicopter speed record." From the Piasecki Helicopter Corporation newsletter the following January: "At about 3:55pm in the afternnon of Thursday, 5 January 1956, Harold Peterson and George Callahan lost their lives in the tragic crash of the YH-16A near Swedesboro, New Jersey." The YH-16A "world's largest transport helicopter" did not go into production and in March 1956 the company was sold to Vertol of the Boeing Aircraft Company. 08/23/2006 @ 07:58 [ref: 13960] |
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