Tag Archives: Civil Transport

16 October 1956

Boeing 377 Stratocruiser N90943, Pan American World Airways' Sovereign of the Skies, seen over San Francisco, circa 1947. (University of Washington Libraries Digital Collections, TRA0138)
Boeing 377 Stratocruiser N90943, Pan American World Airways’ Sovereign of the Skies, seen over San Francisco, circa 1947. (University of Washington Libraries Digital Collections, TRA0138)

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.

USCGC Pontchartrain (WHEC 70) circa 1958. (U.S. Coast Guard)
USCGC Pontchartrain (WHEC 70) circa 1958. (U.S. Coast Guard)

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.

USCGC Pontchartrain (!CG 70), photographed 9 September 1959. (United States Coast Guard)
USCGC Pontchartrain (WHEC 70), photographed 9 September 1959. (United States Coast Guard)

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.

Pan American World Airways Flight 6, a Boeing 377 Stratocruiser, ditches in the North Pacific Ocean near USCGC Pontchartrain (WHEC 70), 6:15 am., 16 October 1956. (U.S. Coast Guard)
Pan American World Airways Flight 6, a Boeing 377 Stratocruiser, ditches in the North Pacific Ocean near USCGC Pontchartrain (WHEC 70), 6:15 am., 16 October 1956. (U.S. Coast Guard)
Capatin Richard N. Ogg was the last to leave his ship, 16 October 1956. (U.S. Coast Guard)
Captain Richard N. Ogg was the last to leave his ship, 16 October 1956. (U.S. Coast Guard)

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.

Sovereign of the Seas sinks into the Pacific Ocean, 16 October 1956. (U.S. Coast Guard)
Sovereign of the Skies sinks into the Pacific Ocean, 16 October 1956. (U.S. Coast Guard)

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 color photograph of a Pan American World Airways Boeing 377 Stratocruiser in flight. (Pan Am)
A color photograph of a Pan American World Airways Boeing 377 Stratocruiser in flight. (Pan Am)

A U.S. Coast Guard film of the incident can be seen at:

© 2016, Bryan R. Swopes

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7 October 1963

Prototype Learjet 23 N801L, first flight, 7 October 1963. (Lear)
Prototype Learjet 23, N801L, first flight, 7 October 1963. (Lear Jet Corporation)

7 October 1963: The first of two Learjet 23 prototypes, N801L, makes its first flight at Wichita, Kansas, with test pilots Henry G. Beaird 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).

The airplane is powered by two General Electric CJ610-4 turbojet engines which have a maximum continuous thrust rating at Sea Level of 2,700 pounds (12.010 kilonewtons) at 16,500 r.p.m., and 2,850 pounds of thrust (12.677 kilonewtons) at 16,700 r.p.m., for takeoff (5 minute limit). The CJ610 is a single-shaft axial-flow turbojet with an 8-stage compressor and 2-stage turbine. 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.

© 2016, Bryan R. Swopes

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21 January 1976

British Airways' Concorde G-BOAA departing Heathrow, 11:40 a.m., 21 January 1976. (Adrian Meredith/British Airways)
British Airways’ Concorde G-BOAA departing Heathrow, 11:40 a.m., 21 January 1976. (Adrian Meredith/British Airways)

21 January 1976: The first scheduled supersonic passenger airliners, British Airways’ Concorde G-BOAA and Air France’ Concorde F-BVFA, took off simultaneously at 11:40 a.m. G-BOAA departed London Heathrow enroute Bahrain, and F-BVFA departed Paris enroute Rio de Janero, with a stop at Dakar.

British Airways' Concorde G-BOAA. (Unattributed)
British Airways’ Concorde G-BOAA. (Unattributed)

The British Airways’ flight, using call sign “Speedbird Concorde,” was crewed by Captain Norman Victor Todd, Captain Brian James Calvert and Flight Engineer John Lidiard. Chief Test Pilot Ernest Brian Trubshaw, CBE, MVO, was also aboard.

G-BOAA arrived on time at 15:20. F-BVFA, after a delay at Dakar, arrived at Rio de Janeiro at 19:00.

Four British Airways Concorde supersonic airliners in formation flight. (British Airways)
Four British Airways Concorde supersonic airliners in formation flight. (British Airways)

© 2016, Bryan R. Swopes

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20 January 1932

Imperial Airways' Handley Page H.P. 42E, G-AAXF, Helena, in flight. (San Diego Air and Space Museum)
Imperial Airways’ Handley Page HP.42, G-AAXF, Helena, in flight. (San Diego Air and Space Museum Archive)
Imperial Airways "Speedbird" logo,from a baggage lable, ca. 1933
Imperial Airways “Speedbird” logo, from a baggage label, 1933

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.

‘ON wednesday, Jan. 20, the first load of mails left Croydon for Cape town and intermediate stations by Imperial Airways service. Our two maps show the route which will be followed, the stages for each day and the types of aircraft used on each section.” —FLIGHT The Aircraft Engineer and Airships, No. 1204, Vol. XXIV. No. 4, 22 January 1932 at Page 74

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.

Imperial Airways' Handley Page H.P. 42 G-AAXF, Helena, at Gaza. (Library of Congress)
Imperial Airways’ Handley Page H.P. 42 G-AAXF, Helena, at Gaza. (Library of Congress)

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 89 feet, 9 inches (27.356 meters) long. The upper wing had a span of 130 feet (39.624 meters). The overall height of the airplane was 27 feet (8.230 meters). 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 HP.42 had a cruise speed of 96 miles per hour (155 kilometers per hour) and a maximum speed was 120 miles per hour (193 kilometers per hour). Its range was 500 miles (805 kilometers).

Imperial Airways' Handley Page H.P. 45, G-AAXF, Helena, being moved by a ground crew. (State Library of New South Wales)
Imperial Airways’ Handley Page H.P. 45, G-AAXF, Helena, being moved by a ground crew. (State Library of New South Wales)

During ten years of operation, no lives had been lost on an H.P. 42, a record believed unique in civil aviation. 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 H.P. 42s had been destroyed.

An advertisement for Imperial Airways from the Illustrated London news, 2 July 1932, at Page 27.
An advertisement for Imperial Airways from the Illustrated London news, 2 July 1932, at Page 27.

© 2017, Bryan R. Swopes

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3 January 1981

One of the first Boeing 707 airliners delivered to Pan American World Airways, Clipper Maria, N707PA. (Pan Am)
One of the first Boeing 707 airliners delivered to Pan American World Airways, N707PA. (Pan Am)

3 January 1981: Pan American World Airways retired its last Boeing 707 airliner. Pan Am had been the launch customer for the 707. On 20 October 1955 the airline ordered 20 707s, and later ordered 130 more. The first one, Clipper America, a 707-121, N707PA, was delivered 15 August 1958. On 26 October 1958, N711PA, also named Clipper America, made the first regularly scheduled transatlantic flight by a jet airliner. (At least three Pan Am 707s carried the name Clipper America. N709PA was renamed Clipper Tradewind. N710PA, was renamed Clipper Caroline. N711PA was renamed Clipper Mayflower.)

The Boeing Model 707-121 was a four-engine jet transport with swept wings and tail surfaces. The leading edge of the wings were swept at a 35° angle. The airliner had a flight crew of four: pilot, co-pilot, navigator and flight engineer.

The 707-121 was 145 feet, 1 inch (44.221 meters) long with a wing span of 130 feet, 10 inches (39.878 meters). The top of the vertical fin stood 42 feet, 5 inches (12.929 meters) high. The 707 pre-dated the ”wide-body” airliners, having a fuselage width of 12 feet, 4 inches (3.759 meters). The airliner’s empty weight is 122,533 pounds (55,580 kilograms). Maximum take off weight is 257,000 pounds (116,573 kilograms).

The first versions were powered by four Pratt & Whitney Turbo Wasp JT3C-6 turbojet engines, producing 11,200 pounds of thrust (49,820 kilonewtons), and 13,500 pounds (60.051 kilonewtons) with water injection. This engine was a civil variant of the military J57 series. It was a two-spool axial-flow turbojet engine with a 16-stage compressor and 2 stage turbine. The JT3C-6 was 11 feet, 6.6 inches (3.520 meters) long, 3 feet, 2.9 inches (0.988 meters) in diameter, and weighed 4,235 pounds (1,921 kilograms).

At MTOW, the 707 required 11,000 feet (3,352.8 meters) of runway to take off.

The 707-121 had a maximum speed of 540 knots (1,000 kilometers per hour). It’s range was 2,800 nautical miles (5,186 kilometers).

The Boeing 707 was in production from 1958 to 1979. 1,010 were built. Production of 707 airframes continued at Renton until the final one was completed in April 1991. As of 2011, 43 707s were still in service.

Pan American World Airway's Boeing 707-139B, N778PA, Clipper Skylark, along with many of her sisterships, in storage at Marana Air Park, Arizona.
Pan American World Airway’s Boeing 707-139B, N778PA, Clipper Skylark, along with many of her sisterships, in storage at Marana Air Park, Arizona. (Goleta Air & Space Museum)

© 2017, Bryan R. Swopes

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