Status:	Final
Date:	27 JUN 2010
Time:	15:45
Type:	Antonov 2R
Operator:	?
Registration:	RA-62631
C/n / msn:	1G178-23
First flight:	1978
Total airframe hrs:	3208
Engines:	1 PZL Kalisz (Shvetsov) ASz-62IR
Crew:	Fatalities: 0 / Occupants: 2
Passengers:	Fatalities: 0 / Occupants: 1
Total:	Fatalities: 0 / Occupants: 3
Airplane damage:	Written off
Airplane fate:	Written off (damaged beyond repair)
Location:	near Voznesenskoye, Nizhny Novgorod Region (Russia)
Phase:	En route (ENR)
Nature:	Survey/research
Departure airport:	?
Destination airport:	?

Narrative:


CONCLUSION:
The accident without casualties concerning AN-2 aircraft RA-62631 was the result of a forced landing on the water surface due unstable operation of the engine with the loss of power which resuloted from the re-enrichment of the fuel-air mixture because of jamming of the needle valve of the left float chamber of the carburetor.
The most probable reason for jamming of the needle valve of the left float chamber is its clogging by foreign particles that resulted from failure to comply with section 2.02.01.20 of the rules of maintenance of the AN-2 while performing 100-hour maintenance works due to lack of RTO requirements for mandatory compliance.

Sources: