What happened
On 14 June 2020, an Airbus A3/20-271N, registration VT-IJT, was operating a chartered flight from Dammam, Saudi Arabia, to Cochin, India. During the descent phase, the aircraft encountered significant changes in wind conditions, transitioning from a headwind to a tailwind. This shift, combined with the aircraft's descent profile, caused the rate of descent to accelerate sharply, reaching approximately 6,600 feet per minute.
As the aircraft's flight path steepened, the pilot disengaged the autopilot to manually intervene. During this period of manual flight, the aircraft experienced sudden vertical load variations and pitch changes. The resulting abrupt movements caused a cabin crew member to fall near a lavatory, resulting in a serious injury (a fractured left leg). The aircraft eventually stabilized and landed safely at Cochin International Airport.
The investigation
AAIB India examined the Digital Flight Data Recorder (DFDR) and Cockpit Voice Recorder (CVR) to reconstruct the flight dynamics. The investigation focused on the aircraft's descent profile, the impact of wind gusts, and the crew's manual handling of the aircraft. Investigators analyzed the flight control inputs, noting that the pilot applied significant nose-up and nose-down side stick deflections to manage transient airspeed excursions that approached the maximum operating speed (VMO). The investigation also reviewed the serviceability of the Airbus A320-271N and the medical circumstances of the injured crew member.
Findings
- The aircraft's rate of descent increased significantly as it transitioned through various flight levels.
- A sudden change in wind direction, from headwind to tailwind, contributed to transient airspeed increases.
- The pilot's manual inputs to arrest the high rate of descent and manage speed excursions caused abrupt aircraft behavior that led to the cabin crew member's fall.
- The seat belt sign was not illuminated at the time of the incident, and a lavatory door was not properly latched.
- All required airworthiness directives and maintenance requirements for the aircraft were up to date.