Aires Quickboost has released an easy replacement for the Hobby Boss 1/48 Kamov Ka-27 Helix kit that replaces the four kit seats with four resin seats with safety belts. There are no instructions but they are a simple replacement for the kit parts that use three parts to construct each seat. I am not aware if there are any other 1/48 kits of the Helix available that could use these seats, but they may be applicable on other 1/48 Russian helicopter kits with some modification.
Quickboost has molded the four seats perfectly in light grey resin with no apparent bubbles. The Quickboost seats are each supplied on their own resin sprue with a thin resin attachment to the part that will minimize any cleanup.