On Wednesday, November 22, the Russian aircraft K-7, claimed to be the largest landplane in the world, crashed near Kharkhoff, 420 miles south-west of Moscow. Fourteen lives were lost. It is reported that M.K.A. Kalinin, the designer and director of the Kharkhoff aeroplane works, and Snegeriff, one of the best-known pilots in Russia, are among the dead. It seems that sabotage is suspected by the authorities, for the O.G.P.U. (Soviet secret police) is represented on the commission of experts investigating the disaster. Twenty trial flights had been successfully made before the crash.
The design and construction of the K-7 took five years. She had a span of 208 ft., weighed about 20 tons and accommodated 120 passengers. She was considered a big stride forward in the approach to the “all-wing” aircraft, and most of the accommodation and equipment was in the wing. A few days before the accident the existence of the K-7 was revealed to the general public by “Pravda.” It was declared that the aircraft represented a “victory of the utmost political importance,” as she was constructed entirely of Soviet steel from the mills at Duiepropetrovsk. Hitherto Russia had [imported] materials for her aircraft.
—The Aircraft Engineer, Supplement to FLIGHT, 30 November 1933, at Page 1201.
The K-7 was designed by Konstantin Alekseevich Kalinin and built over a two-year period at the Kharkov State Aircraft Manufacturing Company factory at Kharkov, Ukraine. It was intended as either a heavy bomber in military service or as a civil transport. The K-7 was the largest airplane built up to that time.
The K-7 was an effort to perfect a “wing only” aircraft. The tail surfaces were supported by tail booms. It was operated by a crew of 11 and could carry up to 120 passengers in compartments inside the wings. The K-7 was 28.00 meters (91 feet, 10.4 inches) long with a wingspan of 53.00 meters (173 feet, 10.6 inches). The extremely large wing had an area of 254.00 meters².
As originally built the airplane was powered by six 2,896.1-cubic-inch-displacement (47.459 liter) liquid-cooled, supercharged, Mikulin AM-34 single overhead cam (SOHC) 60° V-12 engines mounted in nacelles on the leading edge of the wing. The engines were rated at 750 horsepower, each, and drove two-bladed propellers. When it was determined that power was insufficient, a seventh and then an eighth engine were added to the trailing edge in pusher configuration.
The K-7 had an empty weight of 21,000 kilograms and maximum weight of 40,000 kilograms. It’s cruise speed was 204 kilometers per hour (127 miles per hour) and the maximum speed was 234 kilometers per hour (145 miles per hour). The service ceiling was 5,500 meters (18,045 feet) and the range was 1,000 kilometers (621 miles).
In military configuration, the K-7 would be armed with 20 mm cannon and 7.62 mm machineguns. A bomb load of up to 16,000 kilograms (35,274 pounds) would be carried.
The Kalinin K-7 made only 7 test flights before it crashed. 15 of the 20 persons aboard were killed. Kalinin was not among the dead, as had been report by Flight in the article above. One of the two tail booms failed. Some suggested that sabotage was involved. A government commission determined that the structure of the tailbooms was sufficiently strong, but that oscillations induced by aerodynamic flutter led to the failure.
During World War I, Konstantin Kalinin was awarded the Order of Sv.Stanislav. He had been given the Order of the Red Banner of Labor in 1935. However, during the Stalin purges, on 23 October 1938, he was executed as an enemy of the state.
16 October 1956: Pan American World Airways’ Flight 6 was a scheduled around-the-world passenger flight. The final leg, Honolulu to San Francisco, was flown by a Boeing Model 377 Stratocruiser with civil registration N90943, and named Sovereign of the Skies.
The airplane had a flight crew of 7 and carried 24 passengers. The aircraft commander was Captain Richard N. Ogg, a veteran pilot with more than 13,000 flight hours accumulated over twenty years. First Officer George L. Haaker, Flight Engineer Frank Garcia, Jr., and Navigator Richard L. Brown completed the flight crew. The cabin crew were Purser Patricia Reynolds, who had been with Pan Am for over ten years, and Stewardesses Katherine S. Araki and Mary Ellen Daniel.
The flight from Honolulu to San Francisco was estimated to take 8 hours, 54 minutes. Captain Ogg had the airplane fueled for a total flight time of 12 hours, 18 minutes.
Flight 6 departed Honolulu at 8:24 p.m., Hawaii Standard Time, 15 October (06:24, 16 October, GMT), and climbed to 13,000 feet (3,962 meters) on course.
4 hours, 38 minutes after takeoff, Flight 6 requested a pre-planned climb to 21,000 feet (6,400 meters), at a point about half-way—in terms of flight time—between the departure point and destination, what is dramatically called “The Point of No Return” in suspense movies. (Actually, this is called the Equal Time Point: Taking into consideration forecast winds, the time to fly back to the departing point is the same as the time to continue toward the destination.)
On leveling at the new cruise altitude at 1:19 a.m. (HST), First Officer Haaker reduced engine power. The propeller for the Number 1 engine, the outside engine on the left wing, suffered a prop governor failure and began to overspeed, with engine r.p.m. actually exceeding the limits of its tachometer. This created a very dangerous condition: If the propeller turned fast enough, it could be torn apart by centrifugal force. (See This Day In Aviation, 22 March 1956, for an example.)
The crew was unable to feather the propeller, which would cause its four blades to turn parallel to the slip stream, and increasing the load on the engine while reducing aerodynamic drag. The engine and propeller continued to turn at dangerously high speed so Captain Ogg decided to force the engine to stop by cutting off its lubricating oil supply. This caused the engine to seize but the propeller continued to “windmill.”
The drag caused by the propeller slowed the airplane considerably and the three remaining engines had to run at high power for the Boeing 377 to maintain its altitude. The Number 4 engine (the outer engine on the right wing) was developing only partial power at full throttle. At 2:45 a.m., it began to backfire and had to be shut down.
The airplane began to descend toward the ocean’s surface.
With the drag of the windmilling Number 1 propeller and only two engines running, Sovereign of the Skies could fly at just 140 knots (161 miles per hour/259 kilometers per hour), not fast enough to reach San Francisco or to return to Honolulu before running out of fuel. The navigator estimated that they would run out of fuel 250 miles (402 kilometers) from land.
The United States Coast Guard kept a high endurance cutter on station between Hawaii and California, at a point known as Ocean Station November. This ship provided assistance with weather information, radio communications and was available to assist should an emergency arise aboard trans-Pacific airplanes.
On 16 October 1956, this cutter was USCGC Pontchartrain (WHEC 70), under the command of Commander William K. Earle, USCG. Pontchartrain was a 255-foot (77.7 meter) Lake-class patrol gunboat built by the U.S. Coast Guard ship yard at Curtiss Bay, Maryland, and commissioned 28 July 1945. The ship was redesignated as a high endurance cutter in 1948. Pontchartrain had a complement of 143 men.
The ship was 254 feet (77.42 meters) long, overall, with a beam of 43 feet, 1 inch (13.13 meters) and draft of 17 feet, 3 inches (5.25 meters). Its full load displacement was 1,978 tons (1,794 Metric tons). It was powered by a Westinghouse turbo-electric drive of 4,000 shaft horsepower and was capable on making 17.5 knots (20.41 miles per hour, or 32.41 kilometers per hour). Its maximum range was 10,376 miles (19,216 kilometers).
Pontchartrain was armed with a single 5-inch/38-caliber naval gun forward. It carried Hedgehog anti-submarine mortars and Mk 23 acoustic-homing antisubmarine torpedoes.
Captain Ogg notified Ponchartrain that he intended to ditch the airliner near the ship. The Coast Guard provided Captain Ogg with wind and wave information—five-foot (1.5 meter) swells, wind at eight knots (4 meters per second) from the northwest—and advised the best heading for ditching. The ship laid a trail of foam to mark this course.
At 6:15 a.m., at approximately 90 knots airspeed (104 miles per hour/167 kilometers per hour), the Boeing 377 landed on the water. A wing hit a swell, spinning the airplane to the left. The tail broke off and the airplane began to settle.
Injuries were minor and all passengers and crew evacuated the airliner. They were immediately picked up by Pontchartrain.
Captain Ogg and Purser Reynolds were the last to leave the airplane.
Twenty minutes after touching down, at 6:35 a.m., Sovereign of the Skies sank beneath the ocean’s surface.
Pan American’s Sovereign of the Skies was a Boeing Model 377-10-29, construction number 15959, originally operated by American Overseas Airlines as Flagship Holland, and later, Flagship Europe. Pan Am acquired the airliner during a merger. On 16 October 1956, the airplane had accumulated 19,820:51 total time on the airframe (TTAF) since it was built.
The Boeing 377 was a large, four-engine civil transport which had been developed, along with the military C-97 Stratofreighter, from the World War II B-29 Superfortress long-range heavy bomber. It utilized the wings and engines of the improved B-50 Superfortress. The airplane was operated by a flight crew of four. It was a double-deck aircraft, with the flight deck, passenger cabin and galley on the upper deck and a lounge and cargo compartments on the lower. The airliner was pressurized, and could maintain Sea Level atmospheric pressure while flying at 15,500 feet (4,724 meters). The Model 377 could be configured to carry up to 100 passengers, or 28 in sleeping births.
The Stratocruiser was 110 feet, 4 inches (33.630 meters) long with a wingspan of 141 feet, 3 inches (43.053 meters) and overall height of 38 feet, 3 inches (11.659 meters). Empty weight was 83,500 pounds (37,875 kilograms) and the maximum takeoff weight was 148,000 pounds (67,132 kilograms). Sovereign of the Skies had a gross weight of 138,903 pounds (63,005 kilograms) when it took off from Honolulu.
The airliner was powered by four air-cooled, supercharged 4,362.49-cubic-inch-displacement (71.489 liter) Pratt & Whitney Wasp Major B6 four-row, 28-cylinder radial engines which had a Normal Power rating of 2,650 horsepower at 2,550 r.p.m., and 2,800 horsepower at 2,550 r.p.m. Maximum Continuous. It produced 3,250 horsepower at 2,700 r.p.m. for takeoff (3,500 horsepower with water injection). The engines drove four-bladed Hamilton-Standard Hydromatic, 24260 constant-speed propellers with a diameter of 17 feet, 0 inches (5.182 meters) through a 0.375:1 gear reduction. The Wasp Major B6 was 8 feet, 0.50 inches (2.451 meters) long, 4 feet, 7.00 inches (1.397 meters) in diameter, and weighed 3,584 pounds (1,626 kilograms).
The 377 had a cruise speed of 301 miles per hour (484 kilometers per hour) and a maximum speed of 375 miles per hour (604 kilometers per hour). During testing by Boeing, a 377 reached 409 miles per hour (658 kilometers per hour). Its service ceiling was 32,000 feet (9,754 meters) and the range was 4,200 miles (6,759 kilometers).
Boeing built 56 Model 377 Stratocruisers, with Pan American as the primary user, and another 888 military C-97 Stratofreighter and KC-97 Stratotankers.
A U.S. Coast Guard film of the incident can be seen at:
7 October 1963: The first of two Learjet 23 prototypes, N801L, makes its first flight at Wichita, Kansas, with test pilots Henry Grady (“Hank”) Beaird, Jr., and Robert S. Hagan. A light twin-engine business jet, the Learjet 23 is considered a “first” because it was designed from the start as a civil aircraft.
The Learjet 23 is operated by two pilots and can carry six passengers. It is 43 feet, 3 inches (13.183 meters) long with a wingspan of 35 feet, 7 inches (10.846 meters) and overall height of 12 feet, 7 inches (3.835 meters). It has an empty weight of 6,150 pounds (2,790 kilograms) and maximum takeoff weight of 12,499 pounds (5,670 kilograms).
A characteristic of all Learjets is the 13° sweep of their wings’ leading edges, and the straight trailing edge.
The airplane was powered by two General Electric CJ610-4 turbojet engines. The CJ610 is a single-shaft axial-flow turbojet with an 8-stage compressor and 2-stage turbine. The CJ610-4 has a maximum continuous power rating of 2,700 pounds (12.010 kilonewtons) at 16,500 r.p.m. at Sea Level, and 2,850 pounds of thrust (12.677 kilonewtons) at 16,700 r.p.m., for takeoff (5 minute limit). The engine is 3 feet, 4.50 inches (1.029 meters) long, 1 foot, 5.56 inches (0.446 meters) in diameter, and weighs 403 pounds (183 kilograms).
The Learjet 23 has a cruise speed of 518 miles per hour (834 kilometers per hour) at 40,000 feet (12,192 meters) and a maximum speed of 561 miles per hour (903 kilometers per hour), 0.82 Mach, at 24,000 feet (7,315 meters). The service ceiling is 45,000 feet (13,716 meters) and its maximum range is 1,830 miles (2,945 kilometers).
Lear Jet Corporation built approximately 100 Learjet 23s.
The first prototype was damaged beyond economical repair while simulating an engine failure on takeoff during flight testing, 4 June 1964. The accident was attributed to pilot error. N801L had accumulated just 194 flight hours.
20 January 1932: Imperial Airways’ Handley Page HP.42, G-AAXF, named Helena, departed Croydon Aerodrome, South London, England, on the first leg of the airline’s new transcontinental mail service to South Africa. The flights would leave Croydon at 12:30 p.m. on Wednesday and arrive at Cape Town on Friday, ten days later.
The route was London, Cairo, Khartoum, Juba, Nairobi, Mbeya, Salisbury, Johannesburg and Cape Town.
The initial flights carried mail only, but scheduled passenger service was soon added. The cost of the flight from London to Cape Town was £130.
The HP.42 was a large four-engine biplane built by Handley Page Limited, Hertfordshire, for Imperial Airlines’ long-distance routes. There were two models, the HP.42, for the eastern routes to India and Africa, and the HP.45 for the western flight. (Imperial Airways designated them as “H.P. 42E” and “H.P. 45W.”) The HP.42 could carry 20 passengers and a large amount of baggage. The HP. 45 could carry up to 38 passengers, but less baggage. The variants used different engines. Two of the HP.45 variant, of which Helena was one, were converted to the HP.42 configuration.
The HP.42 was operated by a flight crew of four and could carry six passengers in a forward compartment and twelve aft. The airliner was of all-metal construction, covered in duralumin sheet. It was 89 feet, 9 inches (27.356 meters) long. The upper wing had a span of 130 feet, 0 inches (39.624 meters), and the lower, 94 feet, 0 inches (28.651 meters). The overall height of the airplane was 27 feet (8.230 meters). The lower wing had an unusual configuration with the section inboard of the engine angled upward so that its spars crossed over the passenger cabin, rather than through. The empty weight was 17,740 pounds (8,047 kilograms) and maximum takeoff weight was 28,000 pounds (12,701 kilograms.)
The HP.42 was powered by four air-cooled, supercharged 1,752.788-cubic-inch-displacement (28.723 liter) Bristol Jupiter XI F 9-cylinder radial engines with a compression ratio of 5:1, which had a normal power rating of 460 horsepower at 2,000 r.p.m., and produced a maximum of 510 horsepower at 2,250 r.p.m., each. Two engines were mounted in nacelles between the upper and lower wings, and two were mounted on the lower wing. All four engines were left-hand tractors, driving four-bladed propellers through a 2:1 gear reduction. The Jupiter XI weighed 880 pounds (399 kilograms). The throttles were arranged so that the upper engines could go to full throttle only after the lower engines, rather than simultaneously.
The HP.42 had a cruise speed of 96 miles per hour (155 kilometers per hour) and its maximum speed was 120 miles per hour (193 kilometers per hour). The airliner’s range was 500 miles (805 kilometers).
Several aircraft were placed in service with the Royal Air Force at the beginning of World War II. Helena was damaged in a hard landing, and after inspection, was scrapped. By 1941, all HP.42s had been destroyed.
31 December 1985: At 5:14 p.m., Central Standard Time, a Douglas DC-3C, N711Y,¹ crash-landed in a field near DeKalb, Texas. The airplane struck a wire and several trees and was extensively damaged. The airplane, already on fire, was completely destroyed.
The pilot and co-pilot escaped through cockpit windows, but all seven passengers, including singer Rick Nelson, died.
N711Y was a Douglas C-47A-25-DK Skytrain twin-engine military transport, serial number 42-108981, built at the Midwest City Douglas Aircraft Company Plant, Oklahoma City, Oklahoma, circa 1943–1944. Following U.S. military service, the transport was operated in Brazil. The Skytrain had been converted to a civil DC-3C in 1959, and registered N136H. At one time the airplane had been owned by the DuPont family, and later by singer Jerry Lee Lewis. It was registered to the Century Equipment Co., Los Angeles, California, 13 March 1981.
At 5:08 p.m., the pilot informed Air Traffic Control that he had a problem and was going to divert from the intended destination of Dallas, Texas, to Texarkana. At 5:11 p.m., ATC received a call from N711Y saying that there was smoke in the cockpit. At 5:12 p.m., it was seen on radar at an altitude of 600 feet (183 meters). The airplane disappeared from radar at 5:14 p.m.
Witnesses reported seeing the airplane descending in a left turn to line up with a farm field. It was trailing smoke. Small pieces of metal fell off which started several small fires. The DC-3 struck two power wires suspended about 30 feet (9 meters) above the ground, then a utility pole and several trees.
The pilot and co-pilot, who were both severely burned, gave differing statements as to what had occurred. The National Transportation Safety Board investigation found that there had been an in-flight fire in the passenger cabin which had probably started in the on-board cabin heater. The board concluded that the pilot in command did not follow proper procedures or check lists.
The Douglas C-47 Skytrain is an all-metal twin-engine, low wing monoplane transport with retractable landing gear. It was operated by a minimum flight crew of two pilots, a navigator and a radio operator. The wing is fully cantilevered and the fuselage is of semi-monocoque construction. Control surfaces are fabric-covered. The C-47A variant used a 24-volt electrical system.
The C-47 is 64 feet, 5½ inches (19.647 meters) long with a wingspan of 95 feet (28.956 meters) and height of 17 feet (5.182 meters). The wing center section is straight, but outboard of the engine nacelles there is 5º dihedral. The wings’ leading edges are swept aft 15.5°. The trailing edges have no sweep. Empty weight of the C-47A is 17,257 pounds (7,828 kilograms) and the maximum takeoff weight is 29,300 pounds (13,290 kilograms).
The C-47 is powered by two 1,829.4-cubic-inch-displacement (29.978 liter) air-cooled, supercharged R-1830-92 (Pratt & Whitney Twin Wasp S1C3-G) two-row 14-cylinder radial engines. These had a maximum continuous rating for normal operation was 1,060 horsepower at 2,550 r.pm., up to 7,500 feet (2,286 meters), and 1,200 horsepower at 2,700 r.p.m., at Sea Level, for takeoff. Each engine drives a three-bladed Hamilton Standard Hydromatic constant-speed full-feathering propeller with a diameter of 11 feet, 6 inches (3.505 meters) through a 16:9 gear reduction. The R-1830-92 is 48.19 inches (1.224 meters) long, 61.67 inches (1.566 meters) in diameter, and weighs 1,465 pounds (665 kilograms). (N711Y had been re-engined with Pratt & Whitney R-1830-75 engines, rated at 1,350 horsepower at 2,800 r.p.m.)
The C-47 has a cruising speed of 185 miles per hour (298 kilometers per hour) at 10,000 feet (3,048 meters) and service ceiling of 24,100 feet (7,346 meters).
The C-47 could carry 6,000 pounds (2,722 kilograms) of cargo, or 28 fully-equipped paratroopers. Alternatively, 14 patients on stretchers could be carried, along with three attendants.
The C-47A served with the United States Air Force until 1971. Hundreds of C-47s and DC-3s are still operational, worldwide.
¹ N711Y was registered to Century Equipment, Inc., Los Angeles, California. The airplane was sold to Rick Nelson on 2 May 1985, but was never re-registered.