Aviat Aircraft Inc has released a Mandatory Service Bulletin which affects all Husky A-1C-180 & A-1C-200 aircraft. This Service Bulletin was released to verify proper operation of the Rapco fuel vent check valve P/N RA1798-00-1.
This Service Bulletin requires immediate action prior to next flight and prior to each flight thereafter.
http://aviataircraft.com/wp-content/uploads/2016/11/hsb33.pdf
