The World’s Deadliest Mid-Air Collision

Exactly 26 years ago today, the world’s deadliest mid-air collision occurred over the Indian village of Charkhi Dadri, killing 349 people. Involved in the collision was Saudi Arabia Airlines Flight SV763, a scheduled international flight from Delhi-Indira Gandhi International Airport (DEL) in India to King Abdulaziz International Airport (JED) with a stopover at Delhi International Airport. Dhahran (DHA) in Saudi Arabia. The aircraft used for the flight was a 14-year-old Saudi Arabian Airlines Boeing 747-168B with registration HZ-AIH.

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Captain Khalid Al-Shubaily, 45, was in charge of the flight, a veteran pilot with 9,837 flying hours. First Officer Nazir Khan and Flight Engineer Ahmed Edrees assisted the captain.


Kazakhstan Airlines Flight 1907

Kazakhstan Airlines Flight 1907 was a charter flight from Shymkent Airport (CIT) in Kazakhstan to Delhi-Indira Gandhi International Airport (DEL) in India. The aircraft used for the flight was a four-year-old Ilyushin Il-76TD registered UN-76435. Captain Alexander Cherepanov, 44, was in charge of the flight, a highly experienced pilot with 9,229 flying hours. First officer Ermek Dzhangirov, flight engineer Alexander Chuprov, navigator Zhahanbek Aripbaev and radio operator Egor Repp assisted the captain.

Kazakhstan Airlines Flight 1907 was descending to land in Delhi and contacted air traffic control (ATC) as it descended from 23,000ft to 18,000ft, 74 miles from the airport. The controller cleared the flight to descend and asked to be contacted when the aircraft was at 15,000 feet. At the same time, Saudi Arabia Airlines Flight SV763 took off from Delhi and was cleared to climb to 14,000ft.

The Kazakh aircraft failed to maintain its assigned altitude

Because the Kazakhstan Airlines flight was approaching from the opposite side, the controller told the Kazakh aircraft to hold 14,000 and await instructions. Shortly after, the Kazakh aircraft reported being at 15,000 feet 46 miles from the airport. The controller responded by saying: “Roger. Hold 150. Identified traffic at 12 p.m. Saudi Boeing 747 reciprocal, 14 miles. Report in sight.”

Cockpit of the Ilyushin Il-76TD

The Kazakhstan crew responded by questioning the distance, to which the controller replied: “Fourteen miles now, Roger 1907.” When no response followed, he warned again: “Traffic within 13 miles, level 140.”

For no apparent reason, Flight 1907 descended where it was supposed to be and collided with the Saudi Arabia Airlines Boeing 747. Both planes fell to the ground in flames.

Mid-air collision investigation and final report

The Lahoti Commission, headed by then Delhi High Court Judge Ramesh Chandra Lahoti, was in charge of the investigation. The air traffic control operator in charge of the flights was questioned, and the black boxes and cockpit voice recorders were sent to Moscow and London for decoding. The investigation concluded that the cause of the crash was the pilots of Kazakhstan Airlines Flight 1907 not following ATC instructions. Indian controllers also pointed out that Kazakh pilots sometimes confused their calculations because they used metric readings rather than feet and nautical miles.

The contributing factors to the accident were:

  • Poor understanding of English by the Kazakh pilot
  • Captain’s lack of piloting
  • The casual attitude of the crew in the performance of their duties
  • The absence of standard calls from any member of the crew

Following the mid-air collision, India’s Directorate General of Civil Aviation required all aircraft flying to and from India to be equipped with an on-board collision avoidance system.

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