Charkhi Dadri – Deadliest Mid-Air Collision
Date of Incident: November 12, 1996
Location: Charkhi Dadri, Haryana, India
🧭 What Happened
Two aircraft — Saudia Flight 763 and Kazakhstan Airlines Flight 1907 — collided mid-air over the village of Charkhi Dadri, killing all 349 people onboard. The crash remains the deadliest mid-air collision in aviation history. The tragedy was caused by a breakdown in communication, poor radar infrastructure, and a failure to maintain assigned altitudes.
✈️ Aircraft Details
Saudia Flight 763: Boeing 747-168B (HZ-AIH)
Kazakhstan Flight 1907: Ilyushin Il-76TD (UN-76435)
Departure: SV763 from Delhi (DEL) to Jeddah via Dhahran; KZ1907 from Chimkent (CIT) to Delhi
Fatalities: 312 (SV763) + 37 (KZ1907)
Survivors: 0
🔍 Key Factors
The Kazakh crew descended below their assigned altitude of 15,000 ft, entering the same airspace as the ascending Saudi 747 at 14,000 ft. Language barriers, reliance on a radio operator, and outdated radar systems contributed to the failure to prevent the collision.
📆 Timeline of Events
- 13:02 UTC – SV763 departs Delhi
- 13:04 UTC – KZ1907 contacts Delhi ATC, descending from FL230
- 13:05 UTC – KZ1907 cleared to descend to FL150
- 13:06 UTC – SV763 cleared to climb to FL140
- 13:08 UTC – SV763 reports reaching FL140
- 13:09 UTC – KZ1907 reports reaching FL150 (actually at 16,348 ft and descending)
- 13:10 UTC – Collision occurs at ~14,000 ft
🎙️ Cockpit Voice & Flight Data
“Maintain one five zero.” — ATC to Kazakh crew
“Now looking 1907.” — Kazakh radio operator
The CVR revealed the Kazakh crew misunderstood altitude instructions and relied solely on a radio operator for ATC communication. The Saudi crew recited the Shahada moments before impact. Both CVRs were recovered and analyzed.
⚙️ Aircraft Systems & Failures
- Primary radar used — no altitude verification
- No TCAS (Traffic Collision Avoidance System) installed
- Language barrier and metric/imperial unit confusion
- Kazakh aircraft descended below assigned level
🛡️ Aftermath and Reforms
- India mandated TCAS-II on all commercial aircraft by 1998
- Secondary radar installed at major airports
- Air corridors separated for inbound and outbound traffic
- CRM and English proficiency training enforced globally