Daily Archives: March 27, 2023

27 March 1977

A recent photograph looking west-northwest (300° Magnetic) along Runway 30 at Los Rodeos Airport (TFN), Tenerife, Canary Islands. (© Claudio)

27 March 1977: The deadliest accident in the history of aviation occurred when two Boeing 747 airliners collided on the runway on the island of Tenerife in the Canary Islands. 583 people died.

A terrorist incident at Gran Canaria International Airport (LPA) on the island of Gran Canaria resulted in the airport being closed for flight operations. This forced many trans-Atlantic airliners to divert to the smaller Los Rodeos Airport (TFN) on Tenerife. The ramp and taxiways at Los Rodeos were congested and refuelers were overwhelmed by the increased traffic, which led to many delays.

A Pan American World Airways Boeing 747-121, N750PA, similar to N736PA. (Michael Gilliand via Wikipedia)

Los Rodeos Airport has only one runway, Runway 12/30, with a parallel taxiway and four short taxiways joining the two.

Pan American World Airways’ Flight 1736, a Boeing 747-121, FAA registration number N736PA, named Clipper Victor ¹ was ready for takeoff with 380 passengers and crew, but had to “back taxi” on Runway 12 (“One-Two”) because the parallel taxiway was jammed with airplanes. The airliner proceeded east-southeast, intending to exit the runway to the parallel taxiway after passing by the congestion around the terminal.

Also on the runway was Koninklijke Luchtvaart Maatschappij (KLM) Flight 4805, a Boeing 747-206B, PH-BUF, named Rijn (“Rhine”). The KLM jumbo jet had 248 passengers and crew members on board. Flight 4805 had back-taxied for the entire length of Runway 12, then made a 180° turn to align itself with Runway 30, the “active” runway.

KLM Royal Dutch Airways’ Boeing 747-206B PH-BUF, Rijn. (clipperarctic via Wikipedia)

Weather at the time of the accident was IFR, with low clouds and fog. Visibility on the runway was restricted to about 1,000 feet (305 meters). Takeoff rules required a minimum of 2,300 feet (701 meters). What happened next was a misunderstanding between the air traffic controllers and the crew of both airliners.

The control tower instructed KLM 4805 to taxi into position on Runway 30 (“Three-Zero”) for takeoff, and to hold there for release. The Pan Am airliner was told to taxi off the runway and to report when clear. The tower controllers could not see either airliner because of the fog, and their flight crews could not see each other.

The aircraft commander of the Dutch airliner, that company’s Chief Pilot and Chief Flight Instructor, Captain Jacob Veldhuyzen Van Zanten, apparently misunderstood what was occurring and radioed to the tower that he was taking off. He then accelerated.

The crew in the Pan Am airliner heard the KLM pilot report that he was taking off, immediately turned left and ran the engines up to full throttle in order to try to get off the runway. With the KLM 747 accelerating through the fog, its flight crew belatedly realized that the other airliner was still ahead of them. Too late to stop, they applied full power and pulled the nose up trying to takeoff. The tail of their airplane actually dragged over sixty feet (18 meters) on the runway because its extreme nose up angle.

Computer-generated illustration of the moment of impact as KLM Flight 4805 hits Pan Am Flight 1736 on the runway at Tenerife. (PBS Nova)

KLM 4805 lifted off about 300 feet (91 meters) from Pan Am 1736, and because of the high angle of attack, its nose wheel actually passed over American airliner’s fuselage, but the rest of the Dutch airplane hit at 140 knots (259 kilometers per hour). Clipper Victor was ripped in half, caught fire and exploded. Rijn crashed about 250 yards (229 meters) down the runway, and it also caught fire and exploded.

All 248 people aboard the Royal Dutch Airlines airplane were killed. Miraculously, there were 61 survivors from the Pan Am Clipper, including the co-pilot, but the remaining 335 died.

Two Boeing 747 airliners collided on the runway at Tenerife, 27 March 1977. (Unattributed)

The 747-100 series was the first version of the Boeing 747 to be built. It was operated by a flight crew of three and was designed to carry 366 to 452 passengers. It is 231 feet, 10.2 inches (70.668 meters) long with a wingspan of 195 feet, 8 inches (59.639 meters) and overall height of 63 feet, 5 inches (19.329 meters). The interior cabin width is 20 feet (6.096 meters), giving it the name “wide body.” Its empty weight is 370,816 pounds (168,199 kilograms) and the Maximum Takeoff Weight (MTOW) is 735,000 pounds (333,390 kilograms).

The 747-100 is powered by four Pratt & Whitney JT9D-7A high-bypass ratio turbofan engines. The JT9D is a two-spool, axial-flow turbofan engine with a single-stage fan section, 14-stage compressor (11 high- and 3 low-pressure stages) and 6-stage turbine (2 high- and 4 low-pressure stages). The engine is rated at 46,950 pounds of thrust (208.844 kilonewtons), or 48,570 pounds (216.050 kilonewtons) with water injection (2½-minute limit). This engine has a maximum diameter of 7 feet, 11.6 inches (2.428 meters), is 12 feet, 10.2 inches (3.917 meters) long and weighs 8,850 pounds (4,014 kilograms).

The 747-100 has a cruise speed of 0.84 Mach (555 miles per hour, 893 kilometers per hour) at 35,000 feet (10,668 meters). The maximum certificated operating speed is 0.92 Mach. The airliner’s maximum range is 6,100 miles (9,817 kilometers).

The Boeing 747 has been in production for 48 years. More than 1,520 have been delivered to date. 205 of these were the 747-100 series. The U.S. Air Force has selected the Boeing 747-8 as the next presidential transport aircraft.

¹ Pan American World Airways’ Boeing 747 Clipper Victor was the very first Boeing 747 in service. It made its first commercial passenger flight, New York to London, 22 January 1970. Another airliner, Clipper Young America, was scheduled to  make that flight but suffered mechanical problems shortly before departure. Clipper Victor was substituted, but Pan Am changed the airliner’s name to Clipper Young America. On 2 August 1970, N736PA was hijacked to Cuba, and afterwards, to avoid the negative publicity, the name of the 747 was changed back to Clipper Victor.

© 2019, Bryan R. Swopes

27 March 1968

Yuri Gagarin photographed shortly before his death in 1968. (RSC Energia)

27 March 1968: Colonel Yuri Alekseevich Gagarin, Pilot-Cosmonaut of the Soviet Union,  was killed in the crash of a Mikoyan-Gurevich MiG-15UTI two-place trainer near the village of Novoselova, Vladamir Oblast, Russia.

Colonel Vladimir Sergeyevich Seregin, Hero of the Soviet Union.

Colonel Gagarin was on a routine training flight with an instructor, Colonel-Engineer Vladimir Sergeyevich Seregin. (Seregin was the commanding officer of the cosmonauts’ training regiment at the Cosmonaut Training Center.) The weather was poor, with rain, snow, wind and low clouds. His last reported altitude was 4,200 meters (13,780 feet).

A Sukhoi Su-15 on test flight inadvertently passed very close to the MiG at supersonic speed. The Sukhoi’s test had been planned for 10,000 meters (32,808 feet), but the pilot actually was flying much lower, passing through clouds, and the interceptor came within an estimated 15–20 meters (49–66 feet) of the trainer. Its wake vortices put Gagarin’s airplane into a spin from which he and Seregin were unable to recover. 55 seconds after Gagarin’s last radio transmission, the MiG-15 crashed. Both men were killed.

Colonel Yuri Alekseyevich Gagarin, Soviet Air Forces. (9 March 1934 – 27 March 1968)

Yuriy Alekseyevich Gagarin (Юрий Алексеевич Гагарин) was born at Klushino, a village in Smolensk Oblast, Russian Soviet Federative Socialist Republic, 9 March 1934. He was the third of four children of Alexey Ivanovich Gagarin and Anna Timofeyevna Gagarina. The family, workers on a collective farm, were displaced by the German invasion of 1941.

Gagarin was drafted by the Soviet Army in 1955 and was sent to flight school. Gagarin received a commission as a lieutenant in the Soviet Air Force in 1957 and was promoted to senior lieutenant two years later.

Lieutenant Gagarin was one of nineteen pilots selected for the space program in 1960. This was further reduced to six cosmonaut candidates. Gagarin and Gherman Titov were the final Two candidates for the first manned space launch, with Gagarin being chosen.

Yuri Gagarin before launch. (RIA Novosti)

Yuri Gagarin was the first human to fly into space when he orbited Earth aboard Vostok I, 12 April 1961. The spacecraft was a spherical Vostok 3KA-3 capsule carried aloft by a Vostok-K rocket. Gagarin made one orbit of the Earth and began reentry over Africa. As the spacecraft was descending through 7,000 meters (20,966 feet), he ejected from the capsule and parachuted to the ground, landing near Engels, Saratov Oblast, at 0805 UTC.

Gagarin statue, London.
Gagarin statue, London.

© 2019, Bryan R. Swopes

27 March 1966

Test pilot Jack L. Zimmerman with the record-setting Hughes YOH-6A Light Observation Helicopter, 62-4213. (FAI)

27 March 1966: At Edwards Air Force Base in the high desert of southern California, Hughes Aircraft Company test pilot Jack Louis Zimmerman flew the third prototype YOH-6A Light Observation Helicopter, 62-4213, to set six Fédération Aéronautique Internationale (FAI) World Record for Altitude and Time-to-Climb. The records were set in two sub-classes, based on the helicopter’s take-off weight. Fifty-three years later, one of these records still stands.

Hughes YOH-6A 62-4213 at Edwards Air Force Base, 1966. (FAI)

Zimmerman took the YOH-6A from the surface to a height of 3,000 meters (9,843 feet) in 4 minutes, 1.5 seconds ;¹ and to 6,000 meters (19,685 feet) in 7 minutes, 12 seconds.² The helicopter reached an altitude in level flight of 8,061 meters (26,447 feet).³  9921 remains the current record for helicopters in Sub-Class E-1b, with a takeoff weight of 500–1,000 kilograms (1,102–2,205pounds).

Beginning with a takeoff weight between 1,000–1,750 kilograms (2,205–3,858 pounds) (Sub-Class E-1c), Zimmerman took the “loach” to a height 3,000 meters (9,843 feet) in 5 minutes, 37 seconds.⁴ The helicopter reached an altitude of 5,503 meters (16,578 feet), without payload.⁵

[The field elevation of Edwards Air Force Base (EDW) is 2,210 feet (704 meters) above Sea Level. If the time-to-altitude flights had been made at nearby NAS Point Mugu (NTD) on the southern California coast, which has a field elevation 13 feet (4 meters), the times might have been significantly reduced. The air temperature at Edwards, though, was much colder.]

One day earlier, 26 March, Allison Engine Company test pilot Jack Schweibold flew the same YOH-6A  to set three Fédération Aéronautique Internationale (FAI) World Records for Distance Over a Closed Circuit Without Landing of 2,800.20 kilometers (1,739.96 miles).⁶ One week earlier, 20 March, Jack Zimmerman had set a Fédération Aéronautique Internationale (FAI) World Record for Distance Over a Closed Circuit Without Landing of 1,700.12 kilometers (1,056.41 miles).⁷ Fifty-three years later, these four World Records still stand.

The Hughes Model 369 was built in response to a U.S. Army requirement for a Light Observation Helicopter (“L.O.H.”). It was designated YOH-6A, and the first aircraft received U.S. Army serial number 62-4211. It competed with prototypes from Bell Helicopter Company (YOH-4) and Fairchild-Hiller (YOH-5). All three aircraft were powered by a lightweight Allison Engine Company turboshaft engine. The YOH-6A won the three-way competition and was ordered into production as the OH-6A Cayuse. It was nicknamed “loach,” an acronym for L.O.H.

The third prototype YOH-6A, 62-4213, testing the XM-7 twin M60 7.62 weapons system. (U.S. Army)

The YOH-6A was a two-place light helicopter, flown by a single pilot. It had a four-bladed, articulated main rotor which turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) Stacks of thin stainless steel “straps” fastened the rotor blades to the hub and were flexible enough to allow for flapping and feathering. Hydraulic dampers controlled lead-lag. Originally, there were blade cuffs around the main rotor blade roots in an attempt to reduce aerodynamic drag, but these were soon discarded. A two-bladed semi-rigid tail rotor was mounted on the left side of the tail boom. Seen from the left, the tail-rotor rotates counter-clockwise. (The advancing blade is above the axis of rotation.)

The YOH-6A was powered by a T63-A-5 turboshaft engine (Allison Model 250-C10) mounted behind the cabin at a 45° angle. The engine was rated at 212 shaft horsepower at 52,142 r.p.m. (102% N1) and 693 °C. turbine outlet temperature for maximum continuous power, and 250 shaft horsepower at 738 °C., 5-minute limit, for takeoff. Production OH-6A helicopters used the slightly more powerful T63-A-5A (250-C10A) engine.

The Hughes Tool Company Aircraft Division built 1,420 OH-6A Cayuse helicopters for the U.S. Army. The helicopter remains in production as AH-6C and MH-6 military helicopters, and the MD500E and MD530F civil aircraft.

Hughes YOH-6A 62-4213 is in the collection of the United States Army Aviation Museum, Fort Rucker, Alabama.

U.S. Army Hughes YOH-6A prototype 62-4213 at Le Bourget, circa 1965.

¹ FAI Record File Number 9922

² FAI Record File Number 9923

³ FAI Record File Numbers 9920 and 9921

⁴ FAI Record File Number 771

⁵ FAI Record File Number 772

⁶ FAI Record File Numbers 786, 787 and 11656.

⁷ FAI Record File Number 762.

© 2017 Bryan R. Swopes

27 March 1942

North American Aviation B-25B Mitchell 40-2291 at Eglin Field, Florida, March 1942. (U.S. Air Force)

27 March 1942: After three weeks of intensive training at Eglin Field, Florida, twenty-two North American Aviation B-25B Mitchell twin-engine medium bombers of the 34th Bombardment Squadron (Medium), 17th Bombardment Group (Medium), U.S. Army Air Force, under the command of Lieutenant Colonel James Harold Doolittle, completed a two-day, low-level, transcontinental flight, and arrived at the Sacramento Air Depot, McClellan Field, California, for final modifications, repairs and maintenance before an upcoming secret mission: The Halsey-Doolittle Raid.

The B-25 had made its first flight 19 October 1940 with test pilot Vance Breese and engineer Roy Ferren in the cockpit. It was a mid-wing airplane with twin vertical tails and retractable tricycle landing gear. The first 8–10 production airplanes were built with a constant dihedral wing. Testing at Wright Field showed that the airplane had a slight tendency to “Dutch roll” so all B-25s after those were built with a “cranked” wing, using dihedral for the inner wing and anhedral in the wing outboard of the engines. This gave it the bomber’s characteristic “gull wing” appearance. The two vertical stabilizers were also increased in size.

A 34th Bombardment Squadron B-25B Mitchell bomber at Mid-Continent Airlines, Minneapolis, Minnesota, for modifications, January–February 1942. (U.S. Air Force)

The B-25B Mitchell was operated by a crew of five: two pilots, a navigator, bombardier and radio operator/gunner.  It was 53 feet, 0 inch (16.154 meters) long with a wingspan of 67 feet, 7.7 inches (20.617 meters) and overall height of 15 feet, 9 inches (4.801 meters). The The B-25B had an empty weight of 20,000 pounds (9,072 kilograms) and the maximum gross weight was 28,460 pounds (12,909 kilograms).

The B-25B was powered by two air-cooled, supercharged, 2,603.737-cubic-inch-displacement (42.668 liter) Wright Aeronautical Division Cyclone 14 GR2600B665 (R-2600-9) two-row 14-cylinder radial engines with a compression ratio of 6.9:1. The engines had a Normal Power rating of 1,500 horsepower at 2,400 r.p.m., and 1,700 horsepower at 2,600 r.p.m. for takeoff, burning 100-octane gasoline. These engines (also commonly called “Twin Cyclone”) drove three-bladed Hamilton Standard Hydromatic variable-pitch propellers through 16:9 gear reduction. The R-2600-9 was 5 feet, 3.1 inches (1.603 meters) long and 4 feet, 6.26 inches (1.378 meters) in diameter. It weighed 1,980 pounds (898 kilograms).

“On a low level training mission early in 1942 B-25 40-2297 would be airplane number 14 for the Doolittle Raid on Tokyo — This image was taken before the modification to the troublesome ventral turret. Pilot Major J.A. Hilger, Co-Pilot 2nd Lt. Jack A. Sims, Navigator 2nd Lt. James H. Macie, Jr., Bombardier S/Sgt. Jacob Eierman, Engineer/Gunner S/Sgt. Edwin V. Bain” —HISTORYNET

The medium bomber had a maximum speed of 322 miles per hour (518 kilometers per hour) at 15,000 feet (4,572 meters) and a service ceiling of 30,000 feet (9,144 meters).

It could carry a 3,000 pound (1,361 kilograms) bomb load 2,000 miles (3,219 kilometers). Defensive armament consisted of a single Browning M2 .30-caliber machine gun mounted in the nose, two Browning M2 .50-caliber machine guns in a power dorsal turret, and two more .50s in a retractable ventral turret. (The lower turrets were removed from all of the Doolittle B-25s.)

North American Aviation, Inc., built 9,816 B-25s at Inglewood, California, and Kansas City, Kansas. 120 of these were B-25Bs.

North American Aviation B-25 Mitchell medium bombers being assembled at the Kansas City bomber plant, October 1942. (Alfred T. Palmer, Office of War Information)

© 2017, Bryan R. Swopes

Victoria Cross, 2nd Lieutenant Alan Arnett McLeod, Royal Air Force

Lieutenant Alan Arnett McLeod, VC, No. 2 Squadron, Royal Flying Corps Canada (RFCC) (Royal Canadian Air Force)

Air Ministry,

1st May, 1918

     His Majesty the KING has been graciously pleased to award the Victoria Cross to the undermentioned Officers of the Royal Air Force, for services displaying outstanding bravery:—                                                                          

___________

     2nd Lt Alan Arnett McLeod, Royal Air Force

Whilst flying with his observer (Lt. A. W. Hammond, M.C.), attacking hostile formations by bombs and machine-gun fire, he was assailed at a height of 5,000 feet by eight enemy triplanes, which dived at him from all directions, firing from the r front guns. By skilful [sic] maneuvering he enabled his observer to fire bursts at each machine in turn, shooting three of them down out of control. By this time Lt McLeod had received five wounds, and whilst continuing the engagement a bullet penetrated his petrol tank and set the machine on fire.

He then climbed out on to the left bottom plane, controlling his machine from the side of the fuselage, and by side-slipping steeply kept the flames to one side, thus enabling the observer to continue firing until the ground was reached.

The observer had been wounded six times when the machine crashed in “No Man’s Land,” and 2nd Lt McLeod, notwithstanding his own wounds, dragged him away from the burning wreckage at great personal risk from heavy machine-gun fire from the enemy’s lines. This very gallant pilot was again wounded by a bomb whilst engaged in this act of rescue, but he persevered until he had placed Lt. Hammond in comparative safety, before falling himself from exhaustion and loss of blood.

The London Gazette, Number 30663, Wednesday, 1 May 1918, at Pages 5287 and 5288

“Second Lieutenant Alan McLeod and Lieutenant Arthur Hammond, Mcleod’s observer, relax outside quarters at their airfield in France just before the action that earned McLeod a Victoria Cross and Hammond a Bar to his Military Cross.” (Royal Canadian Air Force)

Alan Arnett McCleod was born 20 April 1899 in the village of Stonewall, Selkirk, Manitoba, Dominion of Canada. He was the first of two children of Alexander Neil McLeod, M.D., a physician, and Margaret Lillian Arnett McLeod.

Private Alan Arnett McLeod, Royal Flying Corps Canada, 1917. (Royal Canadian Air Force)

After previously being turned away due to his age, Alan McLeod joined the Royal Flying Corps Canada (R.F.C.C.) 20 April 1917—his 18th birthday. He was sent to the University of Toronto for military training, then to Long Branch and Camp Borden for flight training. He was commissioned a Temporary 2nd Lieutenant (on probation), 19 August 1917.

On 20 August 1917, 2nd Lieutenant McLeod boarded the Canadian Pacific passenger liner S.S. Metagama and sailed to Bantry Bay, Ireland. For the next four months McLeod continued to train as a pilot in the Royal Air Force. He then joined No. 2 Squadron on the Western Front.

Following the action of 27 March 1918, Lieutenant McLeod spent a long period of time recovering from his wounds. It was decided to send him home to Canada. On 20 September 1918, he sailed from Southhampton aboard the Cunard liner R.M S. Aquitania. The ship arrived at the Port of New York, 27 September. Lieutenant McLeod then traveled to his home in Stonewall.

2nd Lieutenant Alan A. McLeod, V.C., sailed home from Europe aboard R.M.S. Aquitania, 20–27 September 1918.

On 29 October 1918, Lieutenant McLeod was admitted to Winnipeg General Hospital in Winnipeg, Manitoba, diagnosed with the Spanish Flu, then a worldwide epidemic.

2nd Lieutenant Alan Arnett McCleod, V.C., Royal Air Force, died 6 November 1918. He was just 18 years old.

Armstrong Whitworth F.K.8 (Library and Archives of Canada)

The Armstrong Whitworth F.K.8 was a been designed by Dutch engineer Frederick Koolhoven. It was a single-engine, two-place, two-bay biplane. The F.K.8 was 30 feet, 8 inches (9.347 meters long). Both upper and lower wings had a span of 43 feet, 0 inches (13.106 meters), and chord of 6 feet, 6 inches (1.981 meters). The upper wing area was 270 square feet (25.1 square meters), and the lower, 254 square feet (23.6 square meters). The vertical gap between the wings was 5 feet, 11 inches (1.803 meters) and the lower wing was staggered 1 foot, 7½ inches (0.495 meters) behind the upper. Both the upper and lower wings had an angle of incidence of  2¼°, no sweep, and 4° dihedral.

The F.K.8 had an empty weight of 1,720 pounds (780 kilograms), and gross weight of 3,000 pounds (1,361 pounds).

The F.K.8 was powered by a water-cooled, normally-aspirated 13.937 liter (850.481-cubic-inch-displacement) Beardmore Aero Engine, Ltd., 160-h.p. inline six-cylinder engine with a compression ratio of 4.85:1. The engine was direct drive, and although it was identified as “160 h.p.”, it actually produced 154 horsepower at 1,400 r.p.m. The engine was 57 inches (1.148 meters) long, 19.9 inches (0.505 meters) wide and 31.9 inches (0.810 meters) high. It weighed 545 pounds (247 kilograms).

The airplane had a maximum speed of 102 miles per hour (164 kilometers per hour) at Sea Level, and 98 miles per hour (158 kilometers per hour) at 10,000 feet (3,048 meters). It could climb to 10,000 feet in 20 minutes. Its ceiling was 20,000 feet (6,096 meters). It carried fuel for 3.75 hours of flight.

The F.K.8 was armed with two machine guns, and carried a wireless apparatus.

Armstong Whitworth F.K.8. © IWM (Q 68122)

© 2019, Bryan R. Swopes