1996 Charkhi Dadri mid-air collision

The 1996 Charkhi Dadri mid-air collision occurred on Tuesday, November 12, 1996 when Saudi Arabian Airlines Flight 763 (SVA 763), a Boeing 747-168B en route from New Delhi, India, to Dhahran, Saudi Arabia, collided in mid-air with Kazakhstan Airlines Flight 1907 (KZA 1907), an Ilyushin Il-76 en route from Shymkent, Kazakhstan, to New Delhi, over the village of Charkhi Dadri, Haryana, India. All 349 people on board both flights were killed, making it the deadliest mid-air collision in the history of aviation.

History and cause
Flight SVA 763 departed Delhi at 6:32 PM local time. Flight KZA 1907 was, at the same time, descending to land at Delhi. Both flights were controlled by approach controller VK Dutta. The crew of flight 763 consisted of Captain Khalid Al Shubaily, First Officer Nazir Khan, and Flight Engineer Evris Arabia. On Flight KZA 1907, Gennadi Cherepanov served as the pilot and Igor Repp served as the radio operator.

Flight KZA 1907 was cleared to descend to 15,000 feet (4,600 m) when 74 miles (119 km) from the airport while Flight SVA 763, travelling on the same airway as Flight KZA 1907 but in the opposite direction, was cleared to climb to 14,000 feet (4,300 m). About eight minutes later, around 6:40 PM, Flight KZA 1907 reported having reached its assigned altitude of 15,000 feet (4,600 m) but it was actually lower, at 14,500 feet (4,400 m), and still descending. At this time, Dutta advised the flight, "Identified traffic 12 o'clock, reciprocal Saudia Boeing 747, 10 miles (16 km). Report in sight."

When the controller called Flight KZA 1907 again, he received no reply. He warned of the other flight's distance, but it was too late—the two aircraft had collided. The tail of KZA 1907 sliced through the left wing of SVA 763. Flight SVA 763 had lost its horizontal stabilizer in its left wing and as a result, went into spiral motion towards the ground with fire trailing from the wing. The aircraft disintegrated under the stress before the wreckage hit the ground at almost 1135 kilometres per hour. The fuselage of Flight KZA 1907 remained structurally intact as it went in a steady but rapid and uncontrolled descent until it crashed in a field. Rescuers discovered four critically injured passengers from the IL-76 but all died soon afterward. In the end, all 312 people on board Flight SVA 763 and all 37 people on Flight KZA 1907 perished.

Capt. Timothy J. Place, a pilot for the United States Air Force, was the sole eyewitness to the event. He was making an initial approach in a Lockheed C-141B Starlifter when he saw "the cloud suddenly flash into bright red".

The wreckage of the Saudia aircraft impacted in Bhiwani District, Haryana, near Dhani. The Kazakhstani aircraft wreckage hit Rohtak District, Haryana, near Birohar.

Saudi Arabian Airlines Flight 763
An article in The New York Times on 14 November stated that 215 Indians who boarded the flight worked in Saudi Arabia. Many of the Indians worked or planned to work in blue collar jobs as house maids, drivers, and cooks. The article also stated that 40 Nepalis and 3 Americans boarded the Saudi flight.

According to a 13 November 1996 New York Times article, the passenger manifest included 17 people of other nationalities, including nine Nepalis, three Pakistanis, two Americans, one Bangladeshi, one Briton, and one Saudi.

Twelve of the crew members, including five anti-terrorism officials, were Saudi citizens.

Kazakhstan Airlines Flight 1907
A company from Kazakhstan chartered the flight, and the passenger manifest mostly included ethnic Russian Kazakhstani citizens planning to go shopping in India.

Thirteen Kazakhstani traders boarded the flight.

Crash investigation and report
The crash was investigated by the Lahoti Commission, headed by then-Delhi High Court judge Ramesh Chandra Lahoti. Depositions were taken from the Air Traffic Controllers Guild and the two airlines. The flight data recorders were decoded by Kazakhstani Airlines and Saudia under supervision of air crash investigators in Moscow and Farnborough, Hampshire, England, respectively.

The commission determined that the accident had been the fault of the Kazakhstani Il-76 commander, who (according to FDR evidence) had descended from the assigned altitude of 15,000 feet (4,600 m) to 14,500 feet (4,400 m) and subsequently 14,000 feet (4,300 m) and even below that. The report ascribed the cause of this serious breach in operating procedure to the lack of English language skills on the part of the Kazakhstani aircraft pilots; they were relying entirely on their radio operator for communications with the ATC who in turn did not have his own flight instrumentation but had to look over the pilots' shoulders for a reading. Kazakhstani officials stated that the aircraft had descended while their pilots were fighting turbulence inside a bank of cumulus clouds. Also, a few seconds from impact, the Kazakhstani plane climbed slightly and the two planes collided. This was due to the fact that only then did the radio operator of Kazakhstani 1907 discover that they did not fly at 15000 ft. Had the Kazakhstani pilots not climbed slightly, it is likely that they would have passed under the Saudi plane. He asked the pilot to do so and the captain gave orders for full throttle and the plane climbed, only to hit the oncoming Saudi plane. The tail of the Kazakhstani plane clipped the left wing of the Saudi jet, severing both parts off their respective planes. The recorder of the Saudi plane revealed the pilots reciting the prayer that they had to, according to Islamic law, when they face death. The counsel for the ATC Guild denied the presence of turbulence, quoting meteorological reports, but did state that the collision occurred inside a cloud. This was substantiated by the affidavit of Capt. Place, who was the commander of the aforementioned Lockheed C-141B Starlifter which was flying into New Delhi at the time of the crash. The members of his crew would file similar affidavits. The ultimate cause was held to be the failure of Kazakhstan Airlines Flight 1907's pilot to follow ATC instructions, whether due to cloud turbulence or due to communication problems.

Indira Gandhi International Airport did not have secondary surveillance radar, which produces exact readings of aircraft altitudes by reading transponder signals; instead the airport had outdated primary radar, which only produced readings of distance. In addition, the civilian airspace around New Delhi had one corridor for departures and arrivals. Most areas separate departures and arrivals into separate corridors. The airspace had one civilian corridor because much of the airspace was taken by the Indian Air Force. Due to the crash, the air-crash investigation report recommended changes to air-traffic procedures and infrastructure in New Delhi's air-space: Separation of in-bound and out-bound aircraft through the creation of 'air corridors', installation of a secondary air-traffic control radar for aircraft altitude data, mandatory collision avoidance equipment on commercial aircraft operating in Indian airspace and reduction of the airspace over New Delhi which was formerly under exclusive control of the Indian Air Force.

The Civil Aviation Authorities in India made it mandatory for all aircraft flying in and out of India to be equipped with an ACAS (Airborne Collision Avoidance System). This was the first time in the world that ACAS was mandatory.

Disaster in popular media

 * Miditech, a company based in Gurgaon, Haryana, produced a documentary about the disaster called Head On!, aired on the National Geographic Channel.


 * The disaster was again the subject of an episode in the documentary series Mayday on March 2, 2009 entitled "Crash Course", in a wide-screen format with sophisticated computer animations on National Geographic Channel.