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About Bryan Swopes

Bryan R. Swopes grew up in Southern California in the 1950s–60s, near the center of America's aerospace industry. He has had a life-long interest in aviation and space flight. Bryan is a retired commercial helicopter pilot and flight instructor. View all posts by Bryan Swopes →

16 February 1965, 14:37:03 UTC

February 16, 2025Space FlightAS-103, Cape Kennedy Air Force Station, Douglas Missile & Space Division, Fairchild Stratos Corporation, Launch Complex 37B, Micrometeoroid detectors, Pegasus A (Pegasus I), Pratt & Whitney RL10A-3S, Rocketdyne Division of North American Aviation Inc., Rocketdyne H-1, SA-9, Saturn I, Saturn I Block II, Saturn S-IVBryan Swopes

16 February 1965: At 9:37:03 a.m., Eastern Standard Time (14:37:03 UTC), Pegasus A (later redesignated Pegasus I), a satellite designed to detect meteoroid impacts in Earth orbit, is launched from Launch Complex 37B at the Cape Kennedy Air Force Station, Cape Kennedy, Florida, aboard a Saturn I Block II launch vehicle. The satellite is enclosed in a boiler plate Apollo Command and Service Module.

The all-up vehicle is designated AS-103. The combined first and second stage launch vehicle is designated SA-9. It consisted of an S-I first stage (S-I-9) and S-IV second stage (S-IV-9). The boilerplate Apollo CSM is identified as BP-16.

The three Pegasus satellites were the only ones to use a Saturn launch vehicle. Pegasus A was the largest satellite launched up to that date, with a mass of 1,451.5 kilograms (3,200 pounds).

This was the eighth flight of a Saturn I rocket, and the fourth for a Saturn IV second stage.

AS-103 lifted off from a 47 foot × 47 foot (14.33 × 14.33 meters) square metal pedestal. At the center of the pedestal was a 32-foot diameter dodecagon-shaped opening for the rocket engines’ exhaust. A twin-sloped flame deflector under the pedestal was coated with a concrete-like heat-resistant material to minimize damage to the deflector.

The trajectory of AS-103. (NASA Press Kit 65-38)

At T+8 seconds, AS-103 began a roll and pitch maneuver, taking it to a flight azimuth of 105°. The roll maneuver ended 15 seconds later. The Saturn I reached Mach 1 at T+54 seconds, and the maximum dynamic pressure (max Q) at T+66. The pitch program was completed at T+138. At T+140.22, the four inboard H-1 engines were cut off (IECO), and the outer engines, 5.34 seconds later (OECO). At this time, AS-103 had reached an altitude of 55 miles (89 kilometers), and was 44 miles (77 kilometers) downrange. It was traveling at 6,000 miles per hour (9,656 kilometers per hour).

The Saturn I first stage was jettisoned. Four solid fuel retro rockets were to slow the first stage, but one malfunctioned shortly after ignition. The first stage impacted the ocean surface at T+718.95, 961.29 kilometers (597.32 miles) down range. (N. 25.8155, W. 71.3491)

At T+148.12, the command to start the six RL10 engines of the second stage was sent. The two stages had separated by 10.95 meters (35.93 feet) at engine ignition. (the minimum requirement was 3 meters/9.8 feet.) Ten seconds later, the Launch Escape System was jettisoned.

After about 8 minutes, at T+631.659, the S-IV-9 engines were cut off and the vehicle was inserted into orbit 1,200 miles, (1,931 kilometers) downrange, with a velocity of 8,091.1 meters per second (29,128 kilometers per hour/18,099 miles per hour).

At T+813, the Command and Service Module was separated, and at T+863.4, the Pegasus wings began to deploy. This took 39.6 seconds. These panels had an overall span of 96 feet (29.261 meters) and width of 14 feet (4.267 meters). They carried 208 detector panels. Each panel was 3 feet, 4 inches × 1 foot, 8 inches × 1 inch (1.016 x 0.508 x 0.0254 meters).

A 50-second video of this evolution can be seen on YouTube at:

Pegasus I stabilized in a 430.00 × 523.00 kilometer (267.19 × 329.33 miles) elliptical orbit with a period of 94.10 minutes. As residual fuel (approximately 700 pounds) from the S-IV second stage, which remained attached to the satellite, vented, Pegasus began to tumble.

Pegasus I had about eighty times the detecting area than the Explorer I satellite, which had been launched 31 January 1958. By late May 1965, more than 70 meteoroid hits had been detected.

NASA issued a contract to build three Pegasus satellites, two for flight and third as a backup, to the Fairchild Stratos Corporation in February 1963. (Fairchild Hiller Corporation after 1964.) Final assembly took place at the Aircraft-Missiles Division, Hagerstown, Maryland. (In fact, all three were launched.) Pegasus A was transported by aircraft and arrived at Cape Kennedy Air Force Station on 20 December 1964.

“In this photograph, the Pegasus, meteoroid detection satellite is installed in its specially modified Apollo service module atop the S-IV stage (second stage) of a Saturn I vehicle for the SA-9 mission at Cape Kennedy. Personnel in the service structure moved the boilerplate Apollo command module into place to cap the vehicle. The command and service modules, visible here, were jettisoned into orbit to free the Pegasus for wing deployment. The SA-9 was launched on February 16, 1965.”
(NASA)

When stored inside the boiler plate command and service module, the satellite was 17 feet, 4 inches (5.283 meters) long, 7 feet, 0 inches (2.134 meters) wide, and 9.5 inches (24.13 centimeters) deep.

Pegasus I was deactivated 29 August 1968. Its orbit decayed and it reentered the Earth’s atmosphere 17 September 1978. BP-16, the boilerplate Apollo CSM, remained in orbit until 10 July 1985.

Diagram from “RESULTS OF THE EIGHTH SATURN I LAUNCH VEHICLE TEST FLIGHT SA-9” MPR-SAT-FE-66-4, at Page 97)

AS-103 consisted of a Saturn I Block II first stage, S-I-9; a S-IV second stage, S-IV-9; a boilerplate Apollo Command and Service Module, BP-16; with a Launch Escape System tower. It had a height of approximately 57.3 meters (187.99 feet). It weighed 1,110,941 pounds (503,914 kilograms) at First Motion, including 878,179 pounds (398,335 kilograms) of propellant.

S-I-9 was the last Saturn S-I first stage to be built at NASA’s Marshall Space Flight Center in Huntsville, Alabama. (SA-8, SA-10, and the following Saturn first stage boosters were produced by the Chrysler Corporation Space Division at NASA’s Michoud Assembly Facility in New Orleans, Louisiana.) The Block II variant was modified for use by the United States Air Force to launch it’s proposed X-20 Dyna-Soar manned orbital vehicle. The most visible modification are the very large fins for enhanced stability, along with four smaller stub fins. These fins extended radially 9 feet (2.7 meters) from the thrust structure, and each had a surface area of 121 square feet (11.24 square meters). S-I-9 was barged to the Cape Kennedy Air Force Station, arriving there 30 October 1964.

Saturn I Block II first stage. 1. TV Camera, 2. Movie Camera, 3. Hydrogen Chill-Down Duct, 4. Cable Tunnel, 5. Four Turbine Exhaust Ducts, 6. Four Stub Fins, 7. Eight H-1 Engines, 8. Four Fins, 9. Heat Shield, 10. Firewall, 11. Anti-Slosh Baffles, 12. One 105-inch (2.667 meters) Diameter LOX Tank, 12. Anti-Slosh Baffles Eight 70-inch (1.778 meters) diameter Tanks, 13. Instrument Compartment (typical F-1 & F-2), 14. Four Retro-Rockets. (NASA MSFC-9801761)

S-I-9 was 80.3 feet (20.275 meters) long and 21.4 feet (6.523 meters) in diameter. Eight Redstone 5 feet, 10 inch (1.778 meters) diameter rocket fuel tanks, with four containing the RP-1 fuel, and four filled with liquid oxygen, surrounded a 8 feet, 9 inch (2.667 meter) diameter Jupiter rocket fuel tank containing liquid oxygen. The stage was powered by eight uprated Rocketdyne H-1 engines. The eight engines produced 1,500,000 pounds of thrust (6,672 kilonewtons) at Sea Level.

The Saturn S-IV-9 second stage was built by the Douglas Aircraft Company’s Missile & Space Division, Huntington, Beach, California. It was 41.5 feet (12.65 meters) long and 18.5 feet (5.64 meters) in diameter and had an empty weight of about 14,000 pounds (6,350 kilograms). It carried 100,386 pounds (45,534 kilograms) of propellant. The stage was powered by six Pratt & Whitney RL10A-3 rocket engines. The six engines produced 88,976 pounds of thrust (395.785 kilonewtons). The stage was coated with a special heat resistant paint developed by the Illinois Institute of Technology, Chicago. The S-IV stage was transported by aircraft and arrived at the Cape Kennedy Air Force Station 23 October 1964.

“Fairchild technicians check out the extended Pegasus meteoroid detection surface. The Pegasus was developed by Fairchild Stratos Corporation, Hagerstown, Maryland, for NASA through the Marshall Space Flight Center. After being placed into orbit around the Earth, the satellite unfolded a series of giant panels to form a pair of wings measuring 96 feet across.” (NASA)

NASA considered the Saturn S-I series to be remarkably successful. Up to this time, new rockets failed at a rate of 50% during two to three dozen tests.

16 February 1946

February 16, 2025Aviationc/n 5101, Dimitry D. Viner, First Flight, Helicopter, Jimmy Viner, NC92813, NX92800, Pratt & Whitney R-985 AN-5, Pratt & Whitney Wasp Jr. T1B4, Prototype, Sikorsky Aircraft Corporation, Sikorsky S-51, Test PilotBryan Swopes

The prototype Sikorsky S-51 commercial helicopter, NX19800, in flight between Bridgeport and East Hartford, Connecticut, 1946. (Sikorsky Historical Archive) — The prototype Sikorsky S-51 commercial helicopter, NX92800, in flight between Bridgeport and East Hartford, Connecticut, 1946. (Sikorsky Historical Archive)

16 February 1946: The Sikorsky S-51 prototype, NX92800, made its first flight. The test pilot was Dimitry D. (“Jimmy”) Viner, who later made the first civilian rescue using a helicopter. The S-51 was the first helicopter intended for commercial use, though it was also widely used by military services worldwide. (The prototype was later delivered to Aéronavale, French Naval Aviation.)

Dimitry D. ("Jimmy") Viner with a Sikorsky S-51, the civil version of the R-5. (Sikorsky Historical Archive) — Dimitry D. (“Jimmy”) Viner with a Sikorsky S-51, N5219, the civil version of the R-5. (Sikorsky Historical Archive)

The S-51 was a commercial version of the Sikorsky R-5 series military helicopters. It was a four-place, single engine helicopter, operated by one pilot. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction.

The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs and covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)

Sikorsky S-51 three-view illustration with dimensions. (Sikorsky Historical Archives)

The helicopter’s fuselage was 41 feet, 1¾ inches (12.541 meters). The main rotor had a diameter of 48 feet, 0 inches (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.568 meters) giving the helicopter an overall length of 57 feet, ½ inch (17.386 meters). It was 12 feet, 11-3/8 inches (3.947 meters) high. The landing gear tread was 12 feet, 0 inches (3.658 meters).

The S-51 had an empty weight of 4,050 pounds (1,837.05 kilograms) and maximum takeoff weight of 5,500 pounds (2,494.76 kilograms). Fuel capacity was 100 gallons (378.5 liters).

Sikorsky S-51 NC92813, Los Angeles Airways, departs on a commercial flight, Los Angeles, California, 1947. (LAT) — Sikorsky S-51 NC92813, Los Angeles Airways, departs on a commercial flight, Los Angeles, California, 1947. (Los Angeles Times)

The helicopter was powered by a 986.749-cubic-inch-displacement (16.170 liter) air-cooled, supercharged, Pratt & Whitney Wasp Jr. T1B4 (R-985 AN-5) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine had a compression ratio of 6:1 and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.

The S-51 had a maximum speed (V_NE) of 107 knots (123.1 miles per hour/198.2 kilometers per hour). Range was 275 miles (442.6 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914.4 meters).

Of 220 helicopters in the S-51 series built by Sikorsky, 55 were commercial models. Westland built another 159 helicopters under license.

One of Los Angeles Airways' Sikorsky S-51 helicopters takes off from roof of the the Terminal Annex Post Office, Los Angeles, California, 1 October 1947. (Los Angeles Times Photographic Archive/UCLA Library) — One of Los Angeles Airways’ Sikorsky S-51 helicopters takes off from roof of the the Terminal Annex Post Office, Los Angeles, California, 1 October 1947. (Los Angeles Times Photographic Archive/UCLA Library)

Дмитро Дмитрович Вінер (Dimitry Dimitrovich Viner) was born in Kiev, Ukraine, Imperial Russia, 2 October 1908. He was the son of Dimitry Nicholas Weiner and Helen Ivan Sikorsky Weiner, a teacher, and the sister of Igor Ivanovich Sikorsky.

At the age of 15 years, Viner, along with his mother and younger sister, Galina, sailed from Libau, Latvia, aboard the Baltic-American Line passenger steamer S.S. Latvia, arriving at New York City, 23 February 1923.

“Jimmy” Viner quickly went to work for the Sikorsky Aero Engineering Company, founded by his uncle, Igor Sikorsky.

Dimitry Viner became a naturalized United States citizen on 27 March 1931.

Viner married Miss Irene Regina Burnett. They had a son, Nicholas A. Viner.

On 29 November 1945, Jimmy Viner and Captain Jackson E. Beighle, U.S. Army, flew a Sikorsky YR-5A to rescue two seamen from an oil barge which was breaking up in a storm off of Fairfield, Connecticut. This was the first time that a hoist had been used in an actual rescue at sea.

A Sikorsky R-5 flown by Jimmy Viner with Captain Jack Beighle, lifts a crewman from Texaco Barge No. 397, aground on Penfield Reef, 29 November 1945. (Sikorsky Historical Archive)

In 1947, Viner became the first pilot to log more than 1,000 flight hours in helicopters.

Dimitry Dimitry Viner died at Stratford, Connecticut, 14 June 1998, at the age of 89 years.

16 February 1932

February 16, 2025Aviation33-139, First Flight, Glenn L. Martin Co., Martin B-10, Martin Model 123, Martin Model 139, Martin XB-10, Martin XB-907, Martin XB-907A, Prototype, Wright CycloneBryan Swopes

Martin XB-907 in flight. (U.S. Air Force 060511-F-1234S-002)

16 February 1932: First flight, Glenn L. Martin Co. Model 123, designated XB-907 by the U. S. Army Air Corps. It was a streamlined all-metal mid-wing monoplane with retractable landing gear. It had an internal bomb bay. The airplane was flown by a single pilot and had two gunners, all in open cockpits.

The Model 123 was a private venture, designed and built at a cost of more than $200,000.

On 26 February 1932, the Model 123 was flown from the Martin plant in Middle River, Maryland, to the Aberdeen Proving Grounds by a U.S. Army Air Corps crew.

The XB-907 was powered by two air-cooled, supercharged 1,823.129-cubic-inch-displacement (29.875 liter) Wright Cyclone SR-1820-E nine-cylinder radial engines, rated at 600 horsepower, each. The engines were covered by Townend rings to reduce drag and improve cooling.

The prototype was tested at Wright Field. The airplane reached a maximum speed of 197 miles per hour (317 kilometers per hour) at 6,000 feet (1,829 meters). Recommendations for modifications were made, and Martin upgraded the prototype to the XB-907A configuration (Martin Model 139), which was then designated XB-10 by the Air Corps, with the serial number 33-139.

Martin XB-907A, right profile. (U.S. Air Force)

Martin increased the XB-907A’s wingspan from 62 feet, 2 inches (18.948 meters) to 70 feet, 7 inches (21.514 meters). The engines were upgraded to Wright R-1820-19s, rated at 675 horsepower. Full NACA cowlings were installed.

The Army then ordered 48 production airplanes.

The XB-907 would be developed into the Martin B-10 bomber.

U.S. Army Air Corps Martin B-10B of the 28th Bombardment Squadron, Philippine Islands 28 November 1939. (U.S. Air force)

15 February 1961, 09:05 UTC

February 15, 2025Aviation17624, Aircraft Accident, Boeing 707-329 Intercontinental, BRU, Brussels-Zaventem Airport, IDL, Idlewild Airport, Jean Roy, Laurence Owen, Laurie Owen, Ludovic Marie Antoine Lambrechts, OO-SJB, SABENA Flight SN548, Societé Anonyme Belge d'Exploitation de la Navigation Aérienne, United States Figure Skating AssociationBryan Swopes

Boeing 707-329 OO-SJB, Sabena Flight 548. (© Guy Van de Merckt)

Commandant de Bord Ludovic Marie Antoine Lambrechts, Officier de l’Ordre del Couronne, Chevalier de l’Ordre de Leopold. (1917–1961)

15 February 1961, 09:05 UTC: This Boeing 707-329 airliner, registration OO-SJB, under the command of Captain Ludovic Marie Antoine Lambrechts and Captain Jean Roy, was enroute from Idlewild Airport, New York (IDL) to Brussels-Zaventem Airport (BRU) as SABENA Flight SN548, when three miles (4.8 kilometers) short of the runway at an altitude of 900 feet (274 meters), it pulled up, retracted its landing gear and accelerated.

The airliner made three 360° circles, with the angle of bank steadily increasing to 90°. The 707’s wings then leveled, followed by an abrupt pitch up. OO-SJB spiraled into a nose-down dive and crashed into an open field 1.9 miles (3 kilometers) northeast of Brussels and all 61 passengers and 11 crew members and 1 person on the ground were killed, including the entire U.S. Figure Skating Association team, their families, coaches, judges and officials.

“FIGURE 3: SABENA, Boeing 707, OO-SJB, accident 2 km NE of threshold of runway 20 at Brussels National Airport, Belgium, 15 February 1961” —ICAO Circular 69-AN/61, Page 58

Wreckage of Sabena Flight 548, 15 February 1961. — Wreckage of SABENA Flight SN548, Brussels, Belgium, 15 February 1961.

The cause of the crash was never determined but is suspected to be a mechanical failure in the flight control system:

Probable Cause

Having carried out all possible reasonable investigations, the Commission concluded that the cause of the accident had to be looked for in the material failure of the flying controls.

However, while it was possible to advance certain hypotheses regarding the possible causes, they could not be considered entirely satisfactory. Only the material failure of two systems could lead to a complete explanation, but left the way open to an arbitrary choice because there was not sufficient evidence to corroborate it.

—ICAO Circular 69-AN/61, Page 55, Column 2

The Federal Aviation Administration’s comments were included in the accident report:

“Of the several hypotheses evolving from findings in the accident report, we believe the most plausible to be that concerned with a malfunction of the stabilizer adjusting mechanism permitting the stabilizer to run to the 10.5-degree nose-up position. If such a malfunction occurred and the split flaps and spoilers procedure (inboard spoilers and outboard flaps extended) not employed, the only means to prevent the aircraft from pitching up into a stall would be to apply full forward column and enter a turn in either direction.”

“It is apparent from the recorded impact positions that the split flaps and spoilers technique was not used. The wing flaps were found in the up position and had the inboard spoilers been extended both would have been up at impact and the speed brake handle would not have been in the neutral position as found.”

—ICAO Circular 69-AN/61, Page 56, Column 2

Societé Anonyme Belge d’Exploitation de la Navigation Aérienne (SABENA) was the national airline of Belgium. It was based at Brussels and operated from 1923 to 2001.

The United States Figure Skating Association team, boarding SABENA Flight SN548 at Idlewild Airport, New York, 14 February 1961. From left in front row are: Deane McMinn, Laurence Rochon Owen, Steffi Westerfeld and Rhode Lee Michelson. From left on the bottom: Douglas Ramsay, Gregory Kelley, Bradley Lord, Maribel Y. Owen, Dudley Richards, William Hickox, Ray Hadley Jr., Laurie Hickox, Larry Pierce, Ila Ray Hadley, Roger Campbell, Diane Sherbloom, Dona Lee Carrier, and Robert and Patricia Dineen. (U.S.F.S.A.)

This February 13, 1961 edition of Sports Illustrated was found in the burned-out wreckage of SABENA SN548. U.S.F.S.A. figure skater Laurence Rochon Owen’s photograph is on the cover. The 16-year-old skater is second from the left in the team photograph, above.

SABENA Flight SN548 was a Boeing 707-329 Intercontinental, OO-SJB, Boeing serial number 17624. It made its first test flight 13 December 1959 at Renton, Washington, and was delivered to SABENA in January 1960. At the time of the accident, it had just 3,038 total flight hours (TTAF). The airplane had undergone a Type II overhaul just 37 hours before the crash. ¹

The Boeing 707 was a jet airliner which had been developed from the Model 367–80 prototype, the “Dash Eighty.” It 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 707-329 Intercontinental is 152 feet, 11 inches (46.611 meters) long with a wing span of 145 feet, 9 inches (44.425 meters). The top of the vertical fin stands 42 feet, 5 inches (12.928 meters) high. The wing is considerably different than on the original 707-120 series, with increased length, different flaps and spoilers, and the engines are mounted further outboard. The vertical fin is taller, the horizontal tail plane has increased span, and there is a ventral fin for improved longitudinal stability. The 707 pre-dated the ”wide-body” airliners, having a fuselage width of 12 feet, 4 inches (3.759 meters).

SABENA Boeing 707-329 OO-SJD, a sistership of the accident aircraft, at Nice Côte d’Azur Airport, France. (Alain Durand/Wikipedia)

The the 707-320 International-series had an operating empty weight of 142,600 pounds (64,682 kilograms). Its maximum take off weight (MTOW) was 312,000 pounds (141,521 kilograms). When OO-SJB departed New York, its total weight was 119,500 kilograms (263,452 pounds), well below MTOW. It carried 50,000 kilograms (110,231 pounds) of JP-1 fuel.

OO-SJB was powered by four Pratt & Whitney Turbo Wasp JT4A engines. These were two-spool, axial-flow turbojet engine with a 15-stage compressor (8 low-, 7 high-pressure stages) and 3-stage turbine (1 high- and 2 low-pressure stages). The –12 was rated at 14,900 pounds of thrust (66.279 kilonewtons), maximum continuous power, and 17,500 pounds of thrust (77.844 kilonewtons) at 9,355 r.p.m. (N₂) for takeoff. The engine was 12 feet, 0.1 inches (3.660 meters) long, 3 feet, 6.5 inches (1.080 meters) in diameter, and weighed 4,895 pounds (2,220 kilograms).

The 707-329 had a maximum operating speed (M_MO) of 0.887 Mach above 25,000 feet (7,620 meters). At 24,900 feet (7,590 meters), its maximum indicated airspeed (V_MO) was 378 knots (435 miles per hour/700 kilometers per hour). At MTOW, the 707-329 required 10,840 feet (3,304 meters) of runway for takeoff. It had a range of 4,298 miles (6,917 kilometers).

The Boeing 707 was in production from 1958 to 1979. 1,010 were built.

The cover of the 13 February 1961 edition of Sports Illustrated. (SI) — The cover of the 13 February 1961 edition of *Sports Illustrated*. (SI)

According to the accident investigation report, following this overhaul, which took place from 11 January to 9 February 1961,

1) The pilot noted that during the first test flight on 9 February 1962 the trim button had to be pushed harder than normal. A second test flight was made to confirm the fault, after which the pilot noted “abnormal response of the stabilizer particularly after trimming nose down; slight nose up impulses give no result.”

2) The second incident was observed during the same flight. The pilot noted: “At the beginning of the flight there was a strong tendency of the aircraft to roll to the right. In level flight, the two left wing spoilers are 1 inch out.

“After descent, speed brakes out, at the moment of their retraction there was a marked roll to the right – it did not recur afterwards.

“At the end of the flight, the tendency to roll to the right was considerably diminished.”

—ICAO Circular 69-AN/61, Page 44, Column 2

In response to the stabilzer trim concern, maintenance replaced the stabilizer trim motor. It functioned normally during ground tests. As to the roll issue, an inspection following the flight did not reveal anything abnormal.

15 February 1946

February 15, 2025Aviation1, 2, 3, 36326, 4, 45-873, Douglas Aircraft Company, Douglas XC-112A, Douglas YC-112A, First Flight, Hollywood-Burbank Airport, Mercer Airlines Inc., Mercer Flight 901, N901MA, Pratt & Whitney Double Wasp CA15, Prototype, Van Nuys AirportBryan Swopes

Douglas XC-112A Liftmaster 45-873 (U.S. Air Force) — Douglas XC-112A 45-873 (W. T. Larkins Collection/Wikipedia)

15 February 1946: First flight of Douglas XC-112A (s/n 36326) 45-873.

In 1944, the U.S. Army Air Corps had requested a faster, higher-flying variant of the Douglas C-54E Skymaster, with a pressurized cabin. Douglas Aircraft Company developed the XC-112A in response. It was completed 11 February 1946 and made its first flight 4 days later. With the end of World War II, military requirements were scaled back and no orders for the type were placed.

Douglas saw a need for a new post-war civil airliner to compete with the Lockheed L-049 Constellation. Based on the XC-112A, the prototype Douglas DC-6 was built and made its first flight four months later, 29 June 1946.

Prototype Douglas DC-6 civil transport. (Century of Flight)

The Air Force ordered the twenty-sixth production Douglas DC-6 as a presidential transport, designated VC-118, The Independence. Beginning in 1951, the Air Force ordered a variant of the DC-6A as a the C-118A Liftmaster military transport and MC-118A medical transport. The U.S. Navy ordered it as the R6D-1.

The Douglas DC-6 was flown by a pilot, co-pilot, flight engineer and a navigator on longer flights. It was designed to carry between 48 and 68 passengers, depending on variant.

The DC-6 was 100 feet, 7 inches (30.658 meters) long with a wingspan of 117 feet, 6 inches (35.814 meters) and overall height of 28 feet, 5 inches (8.612 meters). The aircraft had an empty weight of 55,567 pounds (25,205 kilograms) and maximum takeoff weight of 97,200 pounds (44,090 kilograms).

The initial production DC-6 was powered by four 2,804.4-cubic-inch-displacement (45.956 liter), air-cooled, supercharged Pratt & Whitney Double Wasp CA15 two-row, 18 cylinder radial engines with a compression ratio of 6.75:1. The CA15 had a Normal Power rating of 1,800 h.p. at 2,600 r.p.m. at 6,000 feet (1,829 meters), 1,600 horsepower at 16,000 feet (4,877 meters), and 2,400 h.p. at 2,800 r.p.m with water injection for take off. The engines drove three-bladed Hamilton Standard Hydromatic 43E60 constant-speed propellers with a 15 foot, 2 inch (4.623 meter) diameter through a 0.450:1 gear reduction. The Double Wasp CA15 was 6 feet, 4.39 inches (1.940 meters) long, 4 feet, 4.80 inches (1.341 meters) in diameter, and weighed 2,330 pounds (1,057 kilograms).

The Douglas DC-6 had a cruise speed of 311 miles per hour (501 kilometers per hour) and range of 4,584 miles (7,377 kilometers).

XC-112A 45-873 was redesignated YC-112A and was retained by the Air Force before being transferred to the Civil Aeronautics Administration at Oklahoma City, where it was used as a ground trainer. 36326 was sold at auction as surplus equipment, and was purchased by Conner Airlines, Inc. Miami, Florida and received its first civil registration, N6166G, 1 August 1956. The YC-112A was certified in the transport category, 20 August 1956.

Conner Airlines sold 36326 to Compañia Ecuatoriana de Aviación (CEA), an Ecuadorian airline. Registered HC-ADJ, Ecuatoriana operated 36326 for several years.

It was next re-registered N6166G, 1 August 1962, owned by ASA International. A few months later, 1 May 1963, 36326 was registered to Trabajeros Aereos del Sahara SA (TASSA) a Spanish charter company specializing in the support of oil drilling operations in the Sahara, registered EC-AUC.

XC-112A was operated as a DC-6, EC-AUC, by TASSA Air Charter, seen here at London Gatwick, 29 August 1964. (RuthAS) — The XC-112A was operated as EC-AUC by TASSA Air Charter, seen here at London Gatwick, 29 August 1964. (RuthAS)

In 1965, with a private owner, 36326 was once again re-registered N6166G. Just two weeks after that, 1 June 1965, 36326 was registered to TransAir Canada as CF-TAX.

Two years later, 13 June 1967, Mercer Airlines bought 36326. This time the airplane was registered N901MA. Mercer was a charter company which also operated a Douglas C-47 and Douglas DC-4.

N901MA at Hollywood-Burbank Airport (Bureau d'Archives des Accidents d'Avion) — N901MA at Hollywood-Burbank Airport (Bureau d’Archives des Accidents d’Avion)

A Las Vegas, Nevada, hotel chartered Mercer Airlines to fly a group of passengers from Ontario International Airport (ONT), Ontario, California, to McCarran International Airport (LAS). On 8 February 1976, 36326, operating as Mercer Flight 901, was preparing to fly from Hollywood-Burbank Airport (BUR) where it was based, to ONT. The airliner had a flight crew of three: Captain James R. Seccombe, First Officer Jack R. Finger, Flight Engineer Arthur M. Bankers. There were two flight attendants in the passenger cabin, along with another Mercer employee.

Weather at BUR was reported as 1,000 feet (305 meters) scattered, 7,000 feet (2,134 meters) overcast, with visibility 4 miles (6.4 kilometers) in light rain and fog. The air temperature was 56 °F. (13.3 °C.), the wind was 180° at 4 knots (2 meters per second).

At 10:35 a.m. PST (18:35 UTC), Flight 901 was cleared for a rolling takeoff on Burbank’s Runway 15. While on takeoff roll, Flight Engineer Bankers observed a warning light for engine #3 (inboard, starboard wing). He called out a warning to the Captain, however, the takeoff continued.

Immediately after takeoff, a propeller blade on #3 failed. The intense vibration from the unbalanced propeller tore the #3 engine off of the airplane’s wing, and it fell on to the runway below.

The thrown blade passed through the lower fuselage, cut through hydraulic and pneumatic lines and electrical cables and then struck the #2 engine (inboard, port wing), further damaging the airplane’s electrical components and putting a large hole in that engine’s forward accessory drive case. The engine rapidly lost lubricating oil.

Flight 901 declared an emergency and requested to land on Runway 07, which was approved by the Burbank control tower, though they were informed that debris from the engine was on the runway at the intersection of 15/33 and 07/25. The airplane circled to the right to line up for Runway 07.

Just prior to touchdown, warning lights indicated that the propeller on the #2 engine had reversed. (In fact, it had not.) Captain Seccombe announced that they would only reverse #1 and #4 (the outboard engines, port and starboard wings) to slow 36326 after landing, and the airplane touched down very close to the approach end of the runway.

Because of the damage to the airplane’s systems, the outboard propellers would not reverse to slow the airplane and the service and emergency brakes also had failed. N901MA was in danger of running off the east end of the 6,055 foot (1,846 meters) runway, across the busy Hollywood Way and on into the city beyond.

The flight crew applied full power on the remaining three engines and again took off. The landing gear would not retract. The electrical systems failed. The #2 engine lost oil pressure and began to slow.

The DC-6 circled to the right again and headed toward Van Nuys Airport (VNY), 6.9 miles (11.1 kilometers) west of Hollywood-Burbank Airport. They informed Burbank tower that they would be landing on Van Nuys Runway 34L which was 8,000 feet (2,438 meters) long. Because of the emergency, the crew remained on Burbank’s radio frequency. The #2 engine then stopped but the propeller could not be feathered.

Bob Hope Burbank irport is at the right edge of this image, and Van Nuys Airport is at the left. Woodly Golf Course is just south of VNY. (Google Earth image) — Hollywood-Burbank Airport (BUR) is at the right edge of this image, and Van Nuys Airport is at the left. Woodley Lakes Golf Course is just south of VNY. (Google Earth image)

Van Nuys weather was reported as 600 feet (183 meters) scattered, 10,000 feet (3,048 meters) overcast, with visibility 10 miles (16.1 kilometers) in light rain, temperature 55 °F. (12.8 °C.). The airliner was flying in and out of the clouds and the crew was on instruments. [1045: “Special, 1,200 scattered, 10,000 feet overcast, visibility—10 miles, rainshowers, wind—130° at 4 kn, altimeter setting—29.93 in.”]

Because of the drag of the unfeathered engine #2 propeller and the extended landing gear, the Flight 901 was unable to maintain altitude with the two remaining engines. The airplane was not able to reach the runway at VNY.

A forced landing was made on a golf course just south of the airport. The airplane touched down about 1 mile south of the threshold of Runway 34L on the main landing gear and bounced three times. At 10:44:55, the nose then struck the foundation of a partially constructed building, crushing the cockpit. All three flight crew members were killed by the impact.

N901MA-2 — Douglas YC-112A serial number 36326, N901MA, shortly after crash landing at Woodley Golf Course, Van Nuys, California, 8 February 1976. (Bureau d’Archives des Accidents d’Avions)

Both flight attendants were trapped under their damaged seats but were able to free themselves. They and the passenger were able to escape from the wreck with minor injuries.

Los Angeles City Fire Department firefighters attempted to rescue the crew by cutting into the fuselage. Even though the area around the airplane had been covered with fire-retardant foam, at about 20 minutes after the crash, sparks from the power saw ignited gasoline fumes. Fire erupted around the airplane. Ten firefighters were burned, three severely. N901MA was destroyed.

"Feb. 8, 1976: Firemen scatter after saw ignites gas fumes at crash site of DC-6 in Van Nuys. Three trapped crew members of Mercer Enterprises DC-6 charter plane died. Ten firemen were injured." (Boris Yaro/Los Angeles Times) — “Feb. 8, 1976: Firemen scatter after saw ignites gas fumes at crash site of DC-6 in Van Nuys. Three trapped crew members of Mercer Enterprises DC-6 charter plane died. Ten firemen were injured.” (Boris Yaro/Los Angeles Times)

At the time of the accident, YC-112A 36326 was just three days short of the 30th anniversary of its completion at Douglas. It had flown a total of 10,280.4 hours. It was powered by three Pratt & Whitney R-2800-83 AMS, and one R-2800-CA18 Double Wasp engines. All four engines drove three-bladed Curtiss-Wright Type C632-S constant-speed propellers. The failed propeller had been overhauled then installed on N901MA 85 hours prior to the 8 February flight.

The National Transportation Safety Board investigated the accident. It was found that a fatigue fracture in the leading edge of the propeller blade had caused the failure. Though the propeller had recently been overhauled, it was discovered that the most recent procedures had not been followed. This required that the rubber deicing boots be stripped so that a magnetic inspection could be made of the blade’s entire surface. Because this had not been done, the crack in the hollow steel blade was not found.

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