Accident An-22 in Panagarh

An-22 with serial number 9340205 and serial number 02-05 was released by the Tashkent Aviation Plant in 1969 and then transferred to the Ministry of Defense . The aircraft received registration number CCCP-09305 and was sent to the 81st military transport aviation regiment (based at the Severny airfield in the Ivanovo region ) ^[1] .

The crew had the following composition ^[2] :

• Commander 1 ae - military pilot of the 1st class lieutenant colonel Skok Nikolay Stepanovich;
• Navigator 1 ae - military navigator of the 1st class Major Osintsev Valentin Vladimirovich;
• Assistant to the commander of the ship - Captain Shandrakov Nikolay Viktorovich;
• On-board engineer of the instructor ship - Captain Vasileutsky Vladimir Mikhailovich;
• Senior on-board technician in aviation equipment-instructor - Captain Nikolay Martynov;
• The chief of communications of the squadron, senior air radio operator - senior lieutenant Androshchuk Joseph Emelyanovich;
• Airborne equipment technician of the service group - Lieutenant Kravtsov Gennady Dmitrievich
• Senior engineer for the operation of aircraft and aircraft engines - Major Startsev Veniamin Andreevich;
• Senior Aviation Technician of the ship - Senior Lieutenant Parabin Pyotr Feoktistovich;
• Senior Radio Equipment Technician - Senior Lieutenant Godonyuk Vladimir Tikhonovich;
• Senior Technician in Instrumentation and Electronic Automation - Senior Lieutenant Kananykhin Vladimir Grigoryevich.

On November 12, 1970, the East Bengal coast was hit by a cyclone of Bhol , which became the most destructive cyclone in history (up to half a million dead). The territory of East Pakistan was particularly affected. To provide humanitarian assistance, the 81st VTAP was given a special task in December to transport goods for flood victims, for which 4 crews were involved. On December 19, the crew of Lieutenant Colonel Skok on An-22 with tail number 09305 delivered cargo to Dhaka and is now returning to India (according to some reports, to Delhi ^[3] ). On board, there were 11 crew members and 6 passengers (including an interpreter). But after 43 minutes from the departure at 10:08 UTC, when the plane flew at an altitude of 6250 meters (echelon 205) at a heading of 270 °, all 4 engines suddenly stopped. Because of the leaking cargo compartment, it was impossible to go into it and through the windows to inspect the power plants. In addition, horizon indicators, speed indicators and radio communications have failed. The crew tried several times to start the second engine (left internal), but this failed. Then the third engine (right inner) was started, this time successfully. However, the flight engineer then reported that the engine did not respond to the movement of the throttle , which indicated a break in the cable wires for engine control, while with a special mechanism the engine operating mode was automatically set to 64% ^{[2] [4]} .

Because of the passengers on board, the crew could not use the parachutes to leave the plane. Also, at first it was decided to make an emergency landing on the surface of the Indian Ocean , but then the crew decided to follow to the nearest airfield - Panagarh . It turned out to be impossible to connect the third engine generator to the onboard power supply, and the battery charge quickly ran out. The pressure in the booster hydraulic system dropped, which made it impossible to control the wing mechanization . Also, in the process of descent to the airfield, a fire broke out in the engines, including in the third one, therefore it was switched off at an altitude of 1000 meters, after which Antey turned into a steep decline. The speed at that moment was about 400 km / h, while the usual one was supposed to be 240-250 km / h, but the pilots could not extinguish it in this situation. In the process of alignment, a right roll arose. At 10:18 UTC in flight configuration (with flaps and landing gear retracted), the An-22 at a height of about a meter rushed for about 2200 meters almost over the entire strip, after which the right plane crashed into the ground and began to collapse. An uncontrolled plane crashed to the ground, completely collapsed and burned down. All 17 people on board died ^{[2] [4]} .

The crash of board 09305 occurred just five months after the crash of board 09303 in the Atlantic Ocean , so all An-22 flights were suspended. Flight recorders of the aircraft were found, but it turned out that the parametric recorder did not record in the last flight, but the voice recorder was correct. Also, thirty kilometers from the crash site, a twin propeller bushing was found, which separated from the second power plant. On this hub were three front screw blades, while all of the rear screw blades were torn off. Later, all four rear propeller blades were found. When one of the front screw blades separated, the rear screw underwent an unbalancing moment, the force of which reached fifty tons, which led to the separation of all the blades on the rear screw. After examining the fracture of the initially separated blade, the investigators immediately found three foci of fatigue cracks, which gradually merged into one large crack, the area of ​​which was about 35% of the blade section. These foci arose from knife cuts with a depth of 0.3 mm, which appeared at the manufacturing stage, when one of the workers used a shoe knife rather than a plastic knife to cut the flake on the butt of the screw, while applying excessive force, which led to the appearance of cuts. Further, from elastic loads, the crack expanded by another 30% of the cross-sectional area of ​​the blade, after which the blade separated. A torn blade was also found and traces of paint from the aircraft body were found on it. This testified to the fact that after separation, the blade broke through the fuselage and tore off all communications leading to the engines, which led to a halt of the latter, as well as a wing fire. A study of the propellers of the remaining propellers of the An-22 aircraft showed that another thirteen of them also had incisions and signs of fatigue cracks ^[5] .

On January 7, 1971, a commission of the USSR Ministry of Aviation Industry concluded that the cause of the disaster was the fatigue fracture of the front propeller blade of the second power plant ^[5] . Based on the results of the investigation, they adjusted the manufacturing process of the screws, tightened the output control and introduced periodic inspection by the factory representatives of the blades in operation. After that, during the entire operation of the AV-90 propellers, their destruction during flights did not occur. Also in 1973, on the An-22 aircraft, a new spaced-out wiring of engine control cables began to be used. To determine the characteristics of reduction, stability and controllability of An-22 aircraft during landing with three and four failed engines, 25 flights were performed on CCCP-56391 (currently UR-64460). Based on the results of these flights, appropriate changes were made to the crew instructions. In February 1971, the Anteyev flights were resumed ^[2] .

• The catastrophe of the An-22 in the Atlantic - according to the MAP commission, occurred for the same reason
• EMB 120 crash near Carrollton