Tag Archives: Aircraft Accident

14 August 1968

Sikorsky S-61L N300Y, Los Angeles Airways, at Disneyland Heliport, Anaheim, California. (Robert Boser)
Sikorsky S-61L N300Y, Los Angeles Airways, at Disneyland Heliport, Anaheim, California. (Robert Boser)

14 August 1968: At 10:28:15 a.m., Pacific Daylight Time, Los Angeles Airways Flight 417, a Sikorsky S-61L helicopter, departed Los Angles International Airport (LAX) on a regularly-scheduled passenger flight to Disneyland, Anaheim, California. On board were a crew of three and eighteen passengers. The aircraft commander, Captain Kenneth L. Waggoner, held an Airline Transport Pilot certificate and was type-rated in the Sikorsky S-55, S-58 and S-61L. He had a total of 5,877:23 flight hours, with 4,300:27 hours in the S-61L. Co-pilot F. Charles Fracker, Jr. had 1,661:18 flight hours, of which 634:18 were in the S-61L. Flight Attendant James A. Black had been employed with LAA for nearly ten years.

At approximately 10:35 a.m., while flying at an estimated altitude of 1,200–1,500 feet (370–460 meters) above the ground, one of the helicopter’s five main rotor blades separated from the aircraft which immediately went out of control, started to break up, and crashed in a recreational park in Compton. All twenty-one persons on board, including the 13-year-old grandson of the airlines’ founder and CEO, were killed.

The Sikorsky S-61 was registered N300Y.  It had been the prototype S-61L, serial number 61031. Los Angeles Airways was the first civil operator of the S-61, purchasing them at a cost of $650,000 each. As of the morning of 14 August 1968, 61031 had accumulated a total of 11,863.64 hours flight time on the airframe (TTAF). It flew an estimated 3.17 hours on the morning of the accident.

The Sikorsky S-61L was a civil variant of the United States Navy HSS-2 Sea King, and was the first helicopter specifically built for airline use. The prototype, N300Y, first flew 2 November 1961. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. Although HSS-2 fuselage is designed to allow landing on water, the S-61L is not amphibious, having standard fixed landing gear rather than the sponsons of the HSS-2 (and civil S-61N). The S-61L fuselage is 4 feet, 2 inches (1.270 meters) longer than that of the HSS-2. The S-61L is 72 feet, 7 inches (22.123 meters) long and 16 feet, 10 inches (5.131 meters) high, with rotors turning.

The main rotor has five blades and a diameter of 62 feet (18.898 meters). Each blade has a chord of 1 foot, 6.25 inches (0.464 meters). The tail rotor also has five blades and a diameter of 10 feet, 4 inches (3.149 meters). They each have a chord of 7–11/32 inches (0.187 meters). At 100% r.p.m., the main rotor turns 203 r.p.m. and the tail rotor, 1,244 r.p.m. The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right side.) The tail rotor turns clockwise, as seen from the left side. (The advancing blade is below.)

The S-61L was powered by two General Electric CT58-140-1 turboshaft engines, each of which was rated for 1,400 shaft horsepower for takeoff and maximum power of 1,500 shaft horsepower for 2½ minutes. The main transmission was rated for 2,300 horsepower, maximum.

The S-61 has a cruise speed of  166 miles per hour (267 kilometers per hour).  The service ceiling is 12,500 feet (3,810 meters). 61031 had a maximum takeoff weight (MTOW) of 19,000 pounds (8,618.3 kilograms).

Between 1958 and 1980, Sikorsky built 794 S-61 series helicopters. 13 were S-61Ls.

The National Transportation Safety Board investigation found that most of the helicopter was contained with a small area of Leuders Park. One main rotor blade, however, was located approximately 0.25 miles (0.40 kilometers) west of the main wreckage. This blade is referred to as the “yellow” blade. (The main rotor blades marked with colored paint for simplicity, red, black, white, yellow, and blue.) Analysis found that this blade’s spindle, where it attached to the main rotor hub assembly, had failed due to a fatigue fracture. It was believed that the fracture began in an area of substandard hardness which was present in the original ingot from which the part was forged, and that inadequate shot-peening of the part during the overhaul process further weakened the spindle.

Diagram of fractured main rotor spindle. (NTSB)
Diagram of fractured main rotor spindle. (NTSB)

Los Angeles Airways had experienced a similar accident only three months earlier which had resulted in the deaths of all 23 persons on board. (Flight 841, 22 May 1968). L.A. Airways never recovered from these accidents and ceased all operations by 1971.

© 2016, Bryan R. Swopes

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12 August 1985

Japan Air Lines’ Boeing 747-146SR, JA8119. (Robin787)

12 August 1985: The worst accident involving a single aircraft occurred when a Boeing 747 operated by Japan Air Lines crashed into a mountain in the Gunma Prefecture, killing 520 persons. There were just 4 survivors.

JAL Flight 123 was a Boeing 747-146SR, registration JA8119. It departed Tokyo International Airport enroute Osaka International Airport. There were 15 crewmembers, led by Captain Masami Takahama, with First Officer Yutaka Sasaki and Second Officer Hiroshi Fukuda. There were 509 passengers aboard.

Flight 123 lifted off at 6:12 p.m., 12 minutes behind schedule. 12 minutes after takeoff, as the 747 was at its cruising altitude, the fuselage rear pressure bulkhead suddenly failed, causing explosive decompression of the cabin. Cabin air then rushed into the unpressurized tail section. The resulting overpressure caused a failure of the APU bulkhead and the support structure for the vertical fin. The airliner’s vertical fin separated from the fuselage. All four of the 747’s hydraulic systems were ruptured. The hydraulic system was quickly depleted, leaving the crew unable to move any flight control surfaces.

JAL 123 following loss of its vertical fin.

Control of the airplane began to quickly deteriorate and the only control left was to vary the thrust on the four turbofan engines. The flight crew began an emergency descent and declared an emergency.

For the next 32 minutes, JA8119 flew in large uncontrolled arcs. The 747 rolled into banks as steep as 60°, and at one point, the nose pitched down into a dive reaching 18,000 feet per minute (91 meters per second). The crew was able to bring the 747 back to a nose-high attitude at about 5,000 feet (1,524 meters), but again lost control. At 6:56 p.m., JAL 123 disappeared from air traffic control radar.

Mount Takamagahara, 1,978.6 meters above Sea Level. (Σ64, via Wikipedia)

The airliner struck a ridge on 1,978.6 meter (6,491.5 feet) Mount Takamagahara at 340 knots (391 miles per hour, or 630 kilometers per hour), then impacted a second time at an elevation of 5,135 feet (1,565 meters). The aircraft was totally destroyed.

Investigation of the accident determined that the 747 had previously been damaged when its tail struck the runway during a landing, 2 June 1978. The rear pressure bulkhead had cracked as a result of the tail strike, but was repaired by a team of Boeing technicians. After the crash, it was discovered that the repair had not been correctly performed. Boeing engineers calculated that it could be expected to fail after 10,000 cycles. It was on the 12,219th cycle when the bulkhead failed.

Boeing 747-146SR JA8119 had accumulated a total of 25,030 flight hours by the time of the accident, on 18,835 flights.

Computer-generated image depicting the damage to JAL Flight 123. (Anynobody via Wikipedia)

© 2017, Bryan R. Swopes

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9 August 1896

Karl Wilhelm Otto Lilienthal. (NASM)

9 August 1896: Pioneering aviator Karl Wilhelm Otto Lilienthal was fatally injured when his glider stalled on his fourth flight of the day.

Flying at the Rhinow Hills, near Stölln in what is now northern Germany, he had been gliding as far as 820 feet (250 meters). The weather was windy. As he sailed off the slope, his glider suddenly pitched up. Lilienthal tried to correct the attitude by swinging back and fourth, but he had lost lift and the glider fell about 50 feet (15 meters) to the ground.

Seriously injured, he was taken to a doctor who determined that he had fractured the third cervical vertebra. He was then transported by train to Berlin where a very successful surgeon, Professor Ernst von Bergman, had a clinic.

Lilienthal died about 36 hours after his injury, 10 August 1896. Among his last words were, “Sacrifices must be made.”

His discoveries in controlled flight inspired the Wright Brothers to pursue aviation.  He is considered to be one of the most influential of the early pioneers of flight, and is known as The Father of Flight.

Otto Lilienthal flying one of his gliders.

© 2017, Bryan R. Swopes

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8 August 1957

Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)
Nikolay Arkadevich Korovin

8 August 1957: At Ramenskoye Airfield, Moscow, Russia, senior test pilot Lieutenant Colonel Nikolay Arkadevich Korovin (Коровин Николай Аркадьевич) was scheduled to take an experimental prototype interceptor to an altitude of 20,000 meters (65,617 feet).

The airplane was the Mikoyan-Gurevich Ye-50/3 (also known as the E-50/3). It was powered by an afterburning turbojet engine and a liquid-fueled rocket engine. This was the third prototype of the series.

The three Ye-50 prototypes were variants of the MiG 21. They were developed from the earlier MiG Ye-2, with a rocket engine installed. This was not merely a booster engine, but the aircraft carried sufficient fuel for as much as 20 minutes of rocket-assisted flight. A planned production interceptor, the Ye-50A, was designated MiG 23U. Only one of these was built.

Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)

The Ye-50/3 differed from Ye-50/2 with an increased fuel capacity and extended air intake with sharp leading edge. The Ye-50/3 was 4.85 meters (48.72 feet) long with a wingspan of 8.11 meters (21.61 feet). The aircraft had an empty weight of 5,920 kilograms (13,051 pounds), and maximum takeoff weight of 8,500 kilograms (18,739 pounds).

The Ye-50/3 was powered by an A.A. Mikulin AM-9E afterburning turbojet engine rated at 3,800 kilograms force ( pounds thrust) and a liquid-fueled Dushkin S-155 rocket engine. The S-155 used a hypergolic mixture of nitric acid and kerosene as fuel. It produced 1,300 kgf (2,866 pounds of thrust).

Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)

The Ye-50/3 had been completed in April 1957. Prior to 8 August, Ye-50/3 had made 10 test flights, 6 of which successfully used the rocket engine. It had a maximum speed of 2,460 kilometers per hour (1,529 miles per hour), or Mach 2.33. The service ceiling was 23,000 meters (75,460 feet. Its range was 475 kilometers (295 miles).

The Ye-50/3 was the only one of the three prototypes to be armed. It carried two Nudelman-Rikhter NR-30 30 mm autocannon.

Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)

Ramenskoye Airfield was very busy that day. Colonel Korovin’s launch was delayed by traffic on the runway. Finally, he took of at 12:50 p.m. and accelerated into a climb.

At 1:01 p.m., Colonel Korovin radioed that the aircraft was in a spin. 30 seconds later, he called that he was ejecting.

The Ye-50/3 crashed near the village of Radovitsy, approximately 100 kilometers (62 miles) southeast of Ramenskoye. The body of Colonel Korovin was located about 150 meters (164 yards) from the crash site, still in his ejection seat. The parachute had not opened, and the test pilot had been killed on impact.

The accident investigation found that during the delay to takeoff, the liquid oxidizer accumulated in the combustion chamber. This caught fire as the prototype took off. The rocket engine’s turbopump exploded. The explosion damaged the flight control system and the prototype caught fire. The fire burned away a portion of the airplane’s vertical fin. When it entered a spin, Colonel Korovin was unable to recover. It was found that he had removed his gloves and tried to manually pull the ejection seat parachute release cable, but to no avail.

On 9 September 1957, Lieutenant Colonel Korovin was posthumously named a Hero of the Soviet Union.

Cockpit of Mikoyan-Gurevich Ye-50/3. (Mikoyan Design Bureau via The Corner of the Sky)
Коровин Николай Аркадьевич

Nikolay Arkadevich Korovin was born 7 May 1920 at the village of Galanovo in the Votsk Autonomous Oblast (now, the Udmurt Republic). His family were peasants who worked on a collective farm. Korovin completed six grades of formal education.

In 1938 Korovin joined the Red Army. He received further education at a military school in Perm, a city in Russia near the Ural Mountains, graduating in 1939. The following year, he completed pilot training at the Stalingrad Military Aviation School.

From 1941 through 1944, Korovin served as a pilot instructor at Chkalovskaya (now Orenburg, Kazakhstan). In March 1944, he was assigned to combat operations, first with the 91st Guards Aviation Regiment (Ground Attack), and then the 92nd Guards. He fought on the second Ukrainian Front, and in Hungary, Checkoslavakia and Austria. He flew 66 combat missions in the Ilyushin Il-2 Штурмовик (Šturmovík) during the Great Patriotic War.

The Ilyushin Il-2 Šturmovík was the most-produced aircraft of the Second World War. (NASM)

Korovin remained in the Soviet Air Force following the War. He graduated from a senior officers tactical school at Taganrog, Rostov Oblast, in 1950, and then, in 1951, became a senior test pilot for the State Red Banner Scientific-Testing Institute for the Air Force (GK NII VVS). In 1955, Korovin flew government tests of the MiG 19.

During his military career, Lieutenant Colonel Nikolay Arkadevich Korovin was awarded the Order of Lenin, Order of the Red Banner, Order of the Patriotic War 1st Degree, and Order of the Red Star (two awards). His remains were buried at the military cemetery at Chkalovskaya.

© 2017, Bryan R. Swopes

 

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8 August 1955

8 August 1955: While being carried aloft by a Boeing B-29 Superfortress, the Bell X-1A was being readied for it’s next high-altitude supersonic flight by NACA test pilot Joe Walker. During the countdown, an internal explosion occurred. Walker was not injured and was able to get out. The X-1A was jettisoned. It crashed onto the desert floor and was destroyed.

A number of similar explosions had occurred in the X-1, D-558-II and the X-2. Several aircraft had been damaged or destroyed, and Bell Aircraft test pilot Skip Ziegler was killed when an X-2 exploded during a captive flight. A flight engineer aboard the B-29 mothership was also killed. The B-29 was able to land but was so heavily damaged that it never flew again.

Debris from the X-1A crash site was brought back to Edwards AFB for examination. It was discovered that a gasket material used in the rocket engine fuel systems was reacting with the fuel, resulting in the explosions. The problem was corrected and the mysterious explosions stopped.

Test pilot Joe Walker “horsing around” with the Bell X-1A, 1955. (NASA)

© 2015, Bryan R. Swopes

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