11 March 1959: At Stratford, Connecticut, the prototype Sikorsky XHSS-2 Sea King, U.S. Navy Bureau of Aeronautics serial number (Bu. No.) 147137, company serial number 61001, makes its first flight. Sikorsky’s Assistant Chief Test Pilot Robert Stewart Decker is at the controls.
The Sikorsky SH-3A Sea King was the first of the S-61 series of military and civil helicopters, designated as HSS-2 until 1962. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. The fuselage is designed to allow landing on water. The helicopter was originally used as an anti-submarine helicopter.
The HSS-2 is 72 feet, 6 inches (22.098 meters) long and 16 feet, 10 inches (5.131 meters) high with all rotors turning. The helicopter’s width, across the sponsons, is 16 feet. The main rotors and tail can be folded for more compact storage aboard aircraft carriers, shortening the aircraft to 46 feet, 6 inches (14.173 meters). The empty weight of the HSS-2 is 10,814 pounds (4,905 kilograms). The overload gross weight is 19,000 pounds (8,618 kilograms).
The main rotor has five blades and a diameter of 62 feet, 0 inches (18.898 meters). Each blade has a chord of 1 foot, 6¼ inches (0.464 meters). The rotor blade airfoil was the NACA 0012, which was common for helicopters of that time. The total blade area is 222.5 square feet (20.671 square meters), and the disc area is 3,019 square feet (280.474 square meters). The tail rotor also has five blades and a diameter of 10 feet, 4 inches (3.150 meters). They each have a chord of 7–11/32 inches (0.187 meters). At 100% NR, the main rotor turns 203 r.p.m. and the tail rotor, 1,244 r.p.m.
The HSS-2 was powered by two General Electric T58-GE-6 turboshaft engines, which had a Normal Power rating of 900 horsepower, and Military Power rating of 1,050 horsepower; both ratings at 19,555 r.p.m. at Sea Level. The main transmission was rated for 2,000 horsepower, maximum. (Later models were built with more powerful T58-GE-8 engines. Early aircraft were retrofitted.)
The HSS-2 has a cruise speed of 125 knots (144 kilometers per hour) at Sea Level, and a maximum speed of 133 knots (153 kilometers per hour) at Sea Level. The service ceiling is 12,100 feet (3,688 meters). The hover ceiling at normal gross weight is 5,200 feet (1,585 meters), out of ground effect (HOGE), and 7,250 feet (2,210 meters), in ground effect (HIGE). The HSS-2 had a combat endurance of 4 hours and a maximum range of 500 nautical miles (575 statute miles/926 kilometers).
The Sea King was primarily an anti-submarine aircraft. It could be armed with up to four MK 43 or MK 44 torpedoes and one MK 101 nuclear-armed depth bomb. Other weapons loads included four MK 14 depth charges and four MK 54 air depth bombs.
In 1962, the HSS-2 was redesignated SH-3A Sea King. Many early production aircraft have remained in service and have been upgraded through SH-3D, SH-3G, etc. In addition to the original ASW role, the Sea Kings have been widely used for Combat Search and Rescue operations. Marine One, the call sign for the helicopters assigned to the President of the United States, are VH-3D Sea Kings.
Sikorsky produced the last S-61 helicopter in 1980, having built 794. Production has been licensed to manufacturers in England, Italy, Canada and Japan. They have produced an additional 679 Sea Kings.
11 March 1957: The Boeing jet airliner prototype, the Model 367-80, N70700, made a transcontinental demonstration flight from Seattle’s Boeing Field (BFI) to Friendship National Airport (BWI), Baltimore, Maryland. The aircraft commander was Boeing’s Chief of Flight Test, Alvin Melvin (“Tex”) Johnston. Test pilots James Russell (“Jim”) Gannett and Samuel Lewis (“Lew”) Wallick, Jr., completed the flight crew. The flight covered 2,350 miles (3,782 kilometers) and took 3 hours, 48 minutes.
Jet Airliner Crosses U.S. At Record Clip
Seattle-To-Baltimore Flight Made In 3 Hours, 48 Minutes
WASHINGTON, March 12 (AP) A Boeing 707 jet passenger plane set a new transcontinental speed record for commercial aircraft yesterday, flying the 2,325 miles from Seattle to Baltimore in 3 hours and 48 minutes.
At one point it attained a speed of 698 miles an hour.
A.M. (Tex) Johnston, Boeing chief of flight tests, said he would fly back to Seattle tomorrow with stops at Chicago’s O’Hare Airport and at Denver. He planned a series of local flights for congressmen, Pentagon officials and experts.
The big plane averaged 612 miles an hour for its Puget Sound-to-Chesapeake Bay flight, and sliced 10 minutes off the unofficial transport plane record it set between Seattle and Washington, D.C., in 1955.
There were 52 persons aboard, all but 20 of them newsmen.
‘Jet Stream’ Helps
The 707 left Boeing Field at 10:06 a.m., EST. East of Spokane at 31,000 feet, it hit the “jet stream,” a vast windstream with speeds of up to 125 miles an hour.
These winds enabled the plane to attain supersonic speeds in relation to the ground over northwestern Montana and northern Idaho. However, the plane was actually in subsonic flight and did not break the “sound barrier.”
While in the jet stream, the plane’s peak air speed was 596 miles an hour, but at one point the stream boosted this by 102 miles an hour, for a top speed of 698 in relation to the ground.
Fighter Holds Record
The official transcontinental speed record was set by a one-place F-84F jet fighter two years ago—652½ mph for the 2,446 miles from Los Angeles to New York City. [LCOL Robert R. Scott, USAF, 9 March 1955—TDiA]
The fastest unofficial transcontinental crossing listed by the Defense Department: 715 mph for the 2,700 miles from Riverside, Calif., to Boston last Jan. 25, by a Boeing B-47 bomber.
The 707 is to be delivered to its first airline buyers—Pan American and American—late next year and early in 1959.
The plane’s cost varies from 4½ to 5½ million dollars, depending on size and range, Various models will carry from 120 to 162 passengers.
—Toledo Blade, Tuesday, 12 March 1957, Page 2 at Columns 2–4
Boeing had risked $16,000,000 in a private venture to build the Dash 80 in order to demonstrate its capabilities to potential civilian and military customers, while rivals Douglas and Lockheed were marketing their own un-built jet airliners. Put into production as the U.S. Air Force KC-135A Stratotanker air refueling tanker and C-135 Stratolifter transport, a civil variant was also produced as the Boeing 707 Stratoliner, the first successful jet airliner. Though they look very similar, the 707 is structurally different than the KC-135 and has a wider fuselage.
The prototype Boeing Model 367-80 was operated by a pilot, co-pilot and flight engineer. The airplane’s wing was mounted low on the fuselage and the engine nacelles were mounted on pylons under the wing, as they were on Boeing’s B-47 Stratojet and B-52 Stratofortress. The wings and tail surfaces were swept to 35° at 25% chord, and had 7° dihedral. The Dash 80 was 127 feet 10 inches (38.964 meters) long with a wingspan of 129 feet, 8 inches (39.522 meters) and overall height of 38 feet (11.582 meters). The tail span is 39 feet, 8 inches (12.090 meters). The empty weight of the 367-80 was 75,630 pounds (34,505 kilograms) and the gross weight, 190,000 pounds (86,183 kilograms).
N70700 was powered by four Pratt & Whitney Turbo Wasp JT3C engines. This engine is a civil variant of the military J57 series. It is a two-spool, axial-flow turbojet engine with a 16-stage compressor and 2-stage turbine. The JT3C-6 (used in the first production 707s) was rated at 11,200 pounds of thrust (49.82 kilonewtons), and 13,500 pounds (60.05 kilonewtons) with water/methanol injection). The JT3C is 11 feet, 6.6 inches (3.520 meters) long, 3 feet, 2.9 inches (0.988 meters) in diameter, and weighs 4,235 pounds (1,921 kilograms).
These gave the 367-80 a cruise speed of 550 miles per hour (885 kilometers per hour) and a maximum speed of 0.84 Mach (582 miles per hour, 937 kilometers per hour) at 25,000 feet (7,620 meters). The service ceiling was 43,000 feet (13,106 meters). Its range was 3,530 miles (5,681 kilometers).
Boeing continued to use the 367–80 for testing, finally retiring it 22 January 1970. At that time, its logbook showed 2,346 hours, 46 minutes of flight time (TTAF). It was flown to Davis-Monthan Air Force Base, Tucson, Arizona, and placed in storage. In 1990, Boeing returned it to flyable condition and flew it back it to Renton where a total restoration was completed. Many of those who had worked on the Dash 80, including Tex Johnston, were aboard.
The pioneering airplane was presented to the Smithsonian Institution and is on display at the National Air and Space Museum, Steven V. Udvar-Hazy Center. The Boeing 367-80 was designated an International Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers.
Highly recommended: Tex Johnston, Jet-Age Test Pilot, by A.M. “Tex” Johnston with Charles Barton, Smithsonian Books, Washington, D.C., 1991