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ASN Wikibase Occurrence # 253952
Last updated: 9 June 2021
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Time:08:40 LT
Type:Silhouette image of generic B734 model; specific model in this crash may look slightly different
Boeing 737-401
Registration: YV3011
MSN: 23989/1716
Fatalities:Fatalities: 0 / Occupants: 139
Other fatalities:0
Aircraft damage: None
Location:near Tarapoto -   Peru
Phase: En route
Nature:Passenger - Scheduled
Departure airport:Lima-Jorge Chávez International Airport (LIM/SPJC)
Destination airport:Caracas-Simón Bolívar International Airport (CCS/SVMI)
Investigating agency: CIAA Peru
Avior flight 1521 suffered a loss of cabin pressure while en route at FL330. In coordination with Lima Control an emergency descent was initiated to FL190, which was the minimum area altitude over the Andes mountains.
The flight diverted to the nearest airport, Tarapoto.

Failure in the operation of the Outflow and Safety Relief valves of the aircraft pressurization system, due to absorption and blockage with the ISOLATION BLANKET (insulation covering the walls), unsealed for unknown reasons in the tail compartment of the aircraft, causing a sudden depressurization in flight.

Non-existence of procedures for continuous anti-drug inspections of the tail compartment of the aircraft, where both valves are installed, which could have caused the INSOLATION BLANKET not to be secured due to a probable non-application of the technical procedures of the manufacturer's manual, due to the short time available.



Accident investigation:
Investigating agency: CIAA Peru
Status: Investigation completed
Duration: 1 year and 4 months
Download report: Final report


Photo of YV3011 courtesy

Miami - International (KMIA / MIA)
5 March 2016; (c) Gerard Helmer

Revision history:

25-Apr-2021 16:55 harro Added

Corrections or additions? ... Edit this accident description