Serious incident Airbus A320-251N VT-TNE, 07 Feb 2018
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ASN Wikibase Occurrence # 205989
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Time:20:31 LT
Type:Silhouette image of generic A20N model; specific model in this crash may look slightly different    
Airbus A320-251N
Registration: VT-TNE
MSN: 7733
Fatalities:Fatalities: 0 / Occupants: 152
Other fatalities:0
Aircraft damage: None
Category:Serious incident
Location:67NM NE of Mumbai -   India
Phase: En route
Nature:Passenger - Scheduled
Departure airport:Delhi-Indira Gandhi International Airport (DEL/VIDP)
Destination airport:Pune-Lohegaon Airport (PNQ/VAPO)
Investigating agency: AAIB India
Confidence Rating: Accident investigation report completed and information captured
Vistara flight UK997, an Airbus A320neo, and Air India flight AI631, an Airbus A319, were involved in an airprox incident northeast of Mumbai, India.
UK997 was cleared to descend to FL290 towards the destination Pune, but continued to descend to FL270 when at the same time AI631 was climbing to the same altitude after departure from Mumbai-Chhatrapati Shivaji International Airport. Both flights followed the respective TCAS resolution advisories (RAs) and continued to their destinations.
The minimum separation between both aircraft was zero feet vertically and less than 2 NM horizontally.

Cause Leading to Incident
(a) The controller took over the navigation of the aircraft by issuing direct routing.
(b) Controller failed to identify the mismatch of the level assigned and level entered by the crew.
(c) Flight crew entered the wrong level and descended below the cleared level i.e. FL270, which was pre-assumed by the crew.


Accident investigation:
Investigating agency: AAIB India
Status: Investigation completed
Download report: Final report


Revision history:

11-Feb-2018 12:21 harro Added
15-Feb-2018 20:46 harro Updated [Source, Narrative]
15-Feb-2018 20:46 harro Updated [Location]
13-Jul-2018 19:10 harro Updated [Narrative]
09-Apr-2023 17:29 harro Updated [Narrative, Accident report]

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