What happened
During a night departure from runway 27 at Bombay-Santa Cruz Airport, an aircraft was climbing through 2,400 feet when the captain communicated a New Year's greeting to air traffic control. After receiving clearance to climb to 8,000 feet, the pilot began a right-hand turn as prescribed by departure protocols. As the aircraft leveled off, the captain observed that his Attitude Director Indicator (ADI) indicated a continuous right bank. Although the co-pilot believed his own ADI was accurate and the flight engineer noted a discrepancy between the captain's instrument and the third ADI, the captain initiated a left turn to correct what he perceived as an incorrect aircraft attitude.
This maneuver caused the plane to bank left at 40 degrees before reaching an extreme angle of 108 degrees, resulting in a total loss of control. The aircraft entered a steep dive from approximately 2,000 feet and struck the Arabian Sea. The impact caused the airframe to disintegrate, resulting in 213 fatalities. Debris was located in shallow waters roughly 3 km from the coast.
Findings
Investigations determined that the accident resulted from irrational control inputs by the captain, who was unaware of the true aircraft attitude due to a malfunctioning ADI. The crew failed to use secondary instruments, such as the Standby Horizon Indicator, to verify the aircraft's position. Additionally, the co-pilot did not sufficiently monitor the flight instruments or intervene to assist the captain in determining the correct orientation during the flight.