Tag Archives: Societé Anonyme Belge d’Exploitation de la Navigation Aérienne

18 September 1946

NOTE: After 8+ years and 1,524 published posts, This Day in Aviation is going to try something new today. TDiA was contacted by a regular reader with a suggestion for a new post. He was so knowledgeable about the incident, that rather than reinvent the wheel, I asked him to write the following article. I hope that you find it as interesting as I did. Please welcome our first guest author, Captain Sean M. Cross, United States Coast Guard (Retired), and now the President and COO of Helinet Aviation Services, Van Nuys, California. —Bryan

SABENA Douglas DC-4-1009 Skymaster OO-CBR, sister-ship of OO-CBG

18 September 1946: In the summer of 1946, SABENA (Societé Anonyme Belge d’Exploitation de la Navigation Aérienne, the national airline of Belgium) began twice-weekly flights from Brussels, Belgium, to New York City, with refueling stops at Shannon, Ireland, and Gander, Newfoundland, Canada. The airline operated brand-new four-engine Douglas DC-4 Skymasters on the route.

A little after 8:00 p.m., Tuesday, 17 September, OO-CBG departed Shannon for the overnight flight to Gander. The Douglas Skymaster was under the command Captain Jean Ester, a Belgian who had flown with the Royal Air Force during World War II. The co-pilot was Albert Drossaert; with Leopold Verstraeten, navigator; Paul Fassbender, flight engineer; and radio operator Jean Dutoict. There were two flight attendants , Jeanne Bruylant and Jean Rookx, and 37 passengers.

OO-CBG was due at Gander at 0720, Wednesday morning. At 0737, the flight reported by radio, estimating that it was 16 minutes out.

SABENA OO-CBG never arrived.

The Skymaster crashed during harsh weather 24 miles (39 kilometers) southwest of Gander. An inbound Transcontinental and Western Airlines (TWA) DC-4 located the crash site and remained overhead until a United States Coast Guard Consolidated PBY-5A Catalina flying boat, serial number 48314 (c/n 1506) from Air Detachment Argentia, arrived over the scene and confirmed that the wreckage was that of the missing SABENA airliner and that survivors were seen.

A PBY Catalina flies over the crash scene of SABENA’s Douglas DC-4. (National Naval Aviation Museum 1993.501.073.099)

The crash site was heavily wooded and the ground proved to be a very large bog. As the aircraft could not land, emergency aid supplies were dropped by parachute and plans were formulated to rescue the survivors.

A PBY-5A with a U.S. Army medical team from Fort McAndrew, Argentia, under the command of Captain Samuel Preston Martin III.M.D., U.S. Army, landed on Dead Wolf Pond, a lake about one and a half miles (2.4 kilometers) long, located five miles (8 kilometers) from the crash site.

With the assistance of experienced woodsman from Gander, Dr. Martin and his medical team began the hazardous trip down a river known as Dead Wolf Brook from the lake to an area near the crash site. Martin’s team then made their way by foot through the boggy area to the DC-4 and the survivors.

Dr. Martin determined that many of the severely injured would not survive the rugged overland trip upriver and that some other way had to be found to extract the survivors and rescuers.

Transiting Dead Wolf Brook. (U.S. Coast Guard)

The U.S. Coast Guard decided to use helicopters to carry out the survivors. The nearest  were located at the Coast Guard Air Stations, Brooklyn, New York, and Elizabeth City, North Carolina, in the United States. In fact, these were the only helicopters operating in the Coast Guard at the time.

Helicopters were just out of their infancy in 1946, moving into the adolescent stage—Igor Sikorsky had made the first helicopter flight just six years earlier. [See TDiA, 14 September 1939] However, the U.S. Coast Guard had pioneered helicopter development alongside Sikorsky as the military service responsible for the testing and evaluation of helicopters during the latter years of World War II. This would be their first large scale rescue which would prove the helicopter’s amazing capabilities.

A U.S. Coast Guard HNS-1 Hoverfly, 39051, flown by Lieutenant Stewart R. Graham transports one survivor from near the crashed airliner. (Igor I. Sikorsky Historical Archives)
Captain Richard L. Burke USCG

On 20 September 1946, two days after the airliner crashed, orders were received from the East Area Rescue Officer, Captain Richard L. Burke, U.S. Coast Guard, to prepare a Sikorsky R-4/HNS-1 helicopter for immediate shipment to Gander to take part in the rescue of survivors of a crashed Belgian airliner. Instructions were given by telephone to Lieutenant Alvin Nightingale Fisher, USCG, at Elizabeth City to begin disassembly of an HNS-1 for transport aboard a C-54 Skymaster (the military version of the Douglas DC-4). No details were available on the orders for Air Station Brooklyn, New York.

Lt.  Alvin N. Fisher, USCG

An Army Air Forces C-54 from Westover Field, near Springfield, Massachusetts, arrived at Elizabeth City at 9:25 p.m., local time, on the 20th. The disassembled fabric-covered HNS-1, serial number 39051, and its crew were loaded aboard and the transport departed at 11:25 p.m. for the 1,215 nautical mile (1,298 statute miles/2,250 kilometers) journey, landing at Gander at 8:55 a.m., the next morning. The helicopter was unloaded and assembly began at once.

While the helicopter was being reassembled, the pilots were taken to the scene of the crash by a PBY from Argentia, and plans were laid for flying the survivors out by helicopter. It was decided to drop lumber at the clearing nearest the crash for the purpose of constructing a small landing platform as the muskeg would not support the weight of the helicopter. A second platform was built on the edge of the lake approximately 7 miles (11 kilometers) from the clearing so that survivors could be transferred  at this point to PBYs and flown to Gander.

A Sikorsky HOS-1 approaches two PBYs on Gander Lake. (U.S. Coast Guard)

While the Elizabeth City Sikorsky HNS-1 was being prepared for flight, another helicopter, the metal-clad Sikorsky R-6/HOS-1, serial number 23470, a newer and more powerful machine, was also on the scene being readied. The HOS-1 from Air Station Brooklyn arrived at Gander some twenty minutes before the Elizabeth City machine and was reassembled and ready for flight before the HNS-1.

Coast Guard aviation machinist’s mates work on reassembling the Sikorsky HNS-1. (U.S. Coast Guard)

Chief Aviation Machinist’s Mates Oliver F. Berry, Leo Brzycki, and AAM1 Merwin Westerberg were the primary mechanics in charge of the disassembly and reassembly of the HNS-1, while Chief Aviation Machinist’s Mate Vanelli was the primary mechanic for the HOS-1. (Other personnel could not be identified.)

Aviation machinist’s mates work on the HOS-1 at Gander. (U.S. Coast Guard)

Taking the helicopters apart in order to airlift them on transport aircraft, then putting them back together on arrival at Gander was critical to the operation. After reassembly of the Elizabeth City and during the run-up prior to its test flight, someone approached too close to the turning rotors and the test pilot did an emergency shut down. This caused a pin to shear and it was dark before the trouble could be remedied.

The Brooklyn HOS-1 managed to evacuate 8 people before dark on the 21st, all of whom had to be carried by stretcher due to the severity of their injuries.

Ground personnel off-load an ambulatory survivor from HOS-1 23470
The next day, the 22nd, both helicopters were used to fly out the remaining survivors by making  repeated flights between the crash site and Gander Lake, a distance of about 12 miles (19 kilometers). The 18 survivors were placed in wire Stokes litters attached to the outside of the HNS-1 helicopter, and inside the hastily-modified HOS-1. One at a time they were flown to Wolf Lake where they were further stabilized by the U.S. Army medics. The survivors were then placed in inflatable life rafts and rowed out to a PBY-5A on the lake. They were taken aboard the amphibian and flown to Gander Airport where they were able to receive more extensive medical care.
A survivor in a Stokes litter is transferred to life raft to be rowed out to a waiting PBY-5A Catalina. (U.S. Coast Guard)

The helicopters and PBY-5As made numerous trips before all eighteen survivors were evacuated to Gander Airport. In addition, the helicopters withdrew the fourteen members of the Army’s ground rescue team, and several others. The following day, after all survivors had been flown out, the investigators and airline officials were flown in by helicopter. In all, the helicopters made forty flights into the clearing. Landings, both at the clearing and at the lake, were made on the wooden platforms, thus permitting maximum performance of the helicopters.

A U.S. Coast Guard Consolidated PBY-5A Catalina 48314 on Gander Lake with injured survivors of the SABENA crash. (National Naval Aviation Museum 1993.501.073.116)

The U.S. Coast Guard helicopter pilots were Commander Frank Anderson, Lieutenant Commander Stewart Graham, Lieutenant Walter Bolton and Lieutenant August Kleisch. Three of these four officers had begun their Coast Guard careers as enlisted men.

The aircrews received the U.S. Air Medal, while the government of Belgium presented the Chevalier (Knight) of the Order of Leopold to all for the rescue.

Lieutenant Commander Frank Arthur Erickson, U.S. Coast Guard, at the controls of a Sikorsky HNS-1, circa 1946. (Coast Guard Historian’s Office)
Captain Frank Arthur Erickson, United States Coast Guard. (6 November 1907–17 December 1978) Captain Erickson was designated Coast Guard Aviator No. 32 in 1935, and later, Coast Guard Helicopter Pilot No. 1. On 3 January 1944, then Commander Erickson carried out the first-ever helicopter life saving mission when he delivered plasma for the survivors of USS Turner (DD-648) from Battery Park, New York, to a hospital at Sandy Hook. This occurred during a severe snow storm. Captain Erickson is internationally recognized for his pioneering efforts of helicopter rescues, hydraulic hoist systems, and flight stabilization systems. Erickson Hall at the Aviation Training Center, Mobile, Alabama, where the Coast Guard aircraft flight simulators are located, was named in his honor. Captain Ericson graduated from the U.S. Coast Guard Academy in 1931 and was commissioned an ensign. He served until retirement in 1954.
Lieutenant Stewart R. Graham, USCG, in cockpit of Sikorsky HNS-1 near Gander, Newfoundland, September 1946. (U.S. Coast Guard)

Commander Stewart Ross (“Stew”) Graham, United States Coast Guard. (25 September 1917–13 August 2016) Commander Graham was designated Coast Guard Aviator No. 114 in 1942, and then Coast Guard Helicopter Pilot No. 2 in 1943. He was the leading pilot in pioneering Anti-Submarine Warfare tactics, and trained U.S. Navy pilots to conduct these critical missions. Commander Graham was awarded the Distinguished Flying Cross and two Air Medals. He was appointed Chevalier de l’Ordre de Léopold (Knight) by tPrince Charles, Regent of Belgium, for helicopter rescues.

August Kleisch

Lieutenant Commander August (“Gus”) Kleisch, United States Coast Guard. (2 October 1908–26 October 2003) Lieutenant Commander Kleisch was designated as an Enlisted Aviation Pilot in 1935, and after commissioning in 1942, Coast Guard Aviator No. 109. In 1943, at Coast Guard Air Station Brooklyn (located at Floyd Bennett Field, Brooklyn, New York, he qualified as Coast Guard Helicopter Pilot No. 5. In 1945, “Gus” Kleisch pioneered the first use of a training helicopter to rescue seven crewmembers of a Canadian PBY flying boat which had been forced down in a remote area of Labrador. He also delivered two medical officers to the scene. For his heroism and innovation, he was awarded the Distinguished Flying Cross by the U.S. Navy, and the Royal Canadian Air Force Cross by Prime Minister of Canada. He was appointed Chevalier de l’Ordre de Léopold (Knight) by Prince Charles, Regent of Belgium, for the rescue of the SABENA survivors. Lieutenant Commander Kleisch served in the United States Coast Guard from 1927 until he retired in 1959.

ACMM Oliver F. Berry USCG

Chief Machinist’s Mate Oliver Fuller Berry, United States Coast Guard. (8 March 1908–13 September 1991) ADC Berry was one of the world’s first helicopter maintenance specialists. A distinguished expert mechanic on original Coast Guard aircraft, he was a lead instructor at the very first United States military helicopter training unit. He contributed significantly to the 1946 SABENA crash rescue operation. Of exemplary character, extraordinary technical knowledge, exceptional planning talent, and superior leadership traits, his untiring quest for excellence established the ensuing high standards characterizing Coast Guard aviation maintenance. The Chief Oliver F. Berry Aviation Maintenance Award was established in Chief Berry’s honor, and he is the namesake of the Sentinel-class cutter USCGC Oliver Berry (WPC 1124).

Sikorsky XR-4C 41-18874 at the National Air and Space Museum. (NASM)
The Vought-Sikorsky VS-316A (which was designated XR-4 by the U.S. Army Air Corps and assigned serial number 41-18874), established the single main rotor/anti-torque tail rotor configuration. It was a two-place helicopter with side-by-side seating and dual flight controls. The fabric-covered three-blade main rotor was 38 feet (11.582 meters) in diameter and turned counter-clockwise as seen from above. (The advancing blade is on the helicopter’s right). The three-blade tail rotor was mounted to the right of the tail boom in a tractor configuration, and rotated clockwise when seen from the helicopter’s left side. (The advancing blade was below the axis of rotation.)
The XR-4 was 33 feet, 11.5 inches (10.351 meters) long and 12 feet, 5 inches (3.785 meters) high. It weighed 2,010 pounds (911.7 kilograms) empty and the maximum gross weight was 2,540 pounds (1,152.1 kilograms).
The VS-316A had originally been powered by a 499.8-cubic-inch-displacement (8.19 liter) air-cooled Warner Aircraft Corporation Scarab SS-50 (R-500-1) seven-cylinder radial engine, rated at 145 horsepower at 2,050 r.p.m. In the XR-4 configuration, the engine was upgraded to an air-cooled, direct-drive 555.298-cubic-inch-displacement (9.100 liter) Warner Super Scarab SS185 (R-550-3) seven-cylinder radial engine with a compression ration of 6.20:1. The R-550-3 was rated at 185 horsepower at 2,175 r.p.m. at Sea Level, and 200 horsepower at 2,475 r.p.m (five minute limit) for takeoff. The engine was placed backwards in the aircraft with the propeller shaft driving a short driveshaft through a clutch to a 90° gear box and the transmission. The R-550-3 weighed 344 pounds (156 kilograms).
The XR-4 was redesignated XR-4C. This would be the world’s first production helicopter. It is at the Steven F. Udvar-Hazy Center of the Smithsonian National Air and Space Museum.
U.S. Coast Guard Sikorsky HOS-1
Sikorsky designed the HOS-1(R-6) as a follow on to his fabric covered HNS-1 (R-4). While retaining the R-4’s rotor and transmission system, the R-6 had an all-metal fuselage. In October 1944 the first of three XHOS-1 were delivered to the US Navy and transferred to the US Coast Guard Air Station Brooklyn, Floyd Bennett Field, for test and evaluation. One of these crashed.
The Navy then acquired 36 HOS-1 (R-6A) from the Army Air Force which were purchased by the Coast Guard between January 1945 and January 1946. Of these, two were destroyed in crashes (no fatalities), and the majority of the remaining helicopters were returned to the Navy or disposed of with the closing of the helicopter training school.
On 18 June 1946 CDR Erickson was moved to the Coast Guard Elizabeth City air station. His downsized Helicopter Test and Development Unit consisted of a small group of dedicated personnel, one hangar, one HNS and two HOS helicopters. This was the thread that kept the Coast Guard helicopter program alive.
General characteristics
Crew: one
Capacity: one observer
Length: 47 ft 11 in (14.61 m)
Gross weight: 2,600 lb (1,179 kg)
Powerplant: 1 × Franklin O-405-9 piston, 240 hp (180 kW)
Main rotor diameter: 38 ft 0 in (11.58 m)
Maximum speed: 100 mph (160 km/h, 87 kn) – this new aircraft could attain 100 mph compared with 82 mph by the earlier design.
Service ceiling: 10,000 ft (3,000 m)
© 2020, Sean M. Cross

1 September 1953

Sabena Sikorsky S-55 OO-SHA (Sabena)

1 September 1953: The Societé Anonyme Belge d’Exploitation de la Navigation Aérienne (SABENA) began scheduled international passenger service flying the Sikorsky S-55, a commercial variant of the military H-19 Chickasaw. It carried 8 passengers.

SABENA advertisement

For just over three years, since 21 August 1950, SABENA flew mail from Brussels to Antwerp, Liege, and Turnhout using the Bell Model 47D-1.

The Sikorsky Aircraft Corporation S-55 was flown by two pilots in a cockpit placed above the passenger/cargo compartment. The most significant design feature was moving the engine from directly under the main rotor mast to a position at the front of the helicopter. Installed at an angle, the engine turned a drive shaft to the main transmission. The engine placement provided space for a large passenger/cargo compartment. The aircraft was constructed primarily of aluminum and magnesium, with all-metal main and tail rotor blades.

Cutaway drawing of the Sikorsky S-55/H-19/HO4S/HRS. Note the rearward-facing, angled placement of the radial engine.(Sikorsky Historical Archives)

The main rotor consisted of three fully-articulated blades built of hollow aluminum spars, with aluminum ribs. Spaces within the blade were filled with an aluminum honeycomb. The blades were covered with aluminum sheet. The hollow spars were filled with nitrogen pressurized to 10 p.s.i. An indicator at the blade root would change color if nitrogen was released, giving pilots and mechanics an indication that the spar had developed a crack or was otherwise compromised. The main rotor turned counter-clockwise as seen from above. (The advancing blade is on the helicopter’s right.) Flapping hinges were offset from the main rotor axis, giving greater control response and effectiveness. 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 helicopter’s fuselage was 42 feet, 2 inches (12.852 meters). The main rotor had a diameter of 53 feet (16.154 meters) and tail rotor diameter was 8 feet, 8 inches (2.642 meters), giving the helicopter an overall length with all blades turning of 62 feet, 2 inches (18.948 meters). It was 13 feet, 4 inches (4.064 meters) high. The landing gear tread was 11 feet (3.353 meters). The S-55 had an empty weight of 4,785 pounds (2,173 kilograms) and maximum takeoff weight of 7,200 pounds (3,271 kilograms). Fuel capacity was 185 gallons (698 liters).

The S-55’s large clam shell doors provided excellent access to the engine.

The S-55 commercial helicopter and H-19/HO4S and HRS military variants used an air-cooled, supercharged 1,301.868-cubic-inch (21.334 liter) Wright Aeronautical Division 871C7BA1 Cyclone 7 (R-1300-3) 7-cylinder radial engine with a compression ratio of 6.2:1. The R-1300-3 was also a direct-drive engine, but was rated at 700 horsepower at 2,400 r.p.m., Normal Power, and 800 horsepower at 2,600 r.p.m. for Take-Off. The engine incorporated a large cooling fan to circulate air around the cylinders. The R-1300-3 was 49.68 inches (1.261 meters) long, 50.45 inches (1.281 meters) in diameter, and weighed 1,080 pounds (490 kilograms).

SABENA Sikorsky S-55 OO-SHF. (Mike Hooks/Avia Deja Vu)

© 2018, Bryan R. Swopes

15 February 1961, 09:05 UTC

Boeing 707-329 OO-SJB, Sabena Flight 548. (© Guy Van de Merckt)
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)
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.)
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.
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 (MMO) of 0.887 Mach above 25,000 feet (7,620 meters). At 24,900 feet (7,590 meters), its maximum indicated airspeed (VMO) 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.

© 2021, Bryan R. Swopes