NOTE – THIS SERVICE BULLETIN REPLACES SAFETY ALERT #0012 IN ITS ENTIRETY
RELEASE DATE: 2020/07/01
EFFECTIVE DATE: 2020/07/01
SUBJECT: Potential risk of shearing of control stop plate rivets
MODELS AFFECTED: Sling 4 and Sling 4 TSi aircraft
COMPLIANCE TIME: At the next MPI (Mandatory Periodic Inspection)
LABOUR TIME: Inspection only: 2 hours
Inspection and repair: 6 hours
DESCRIPTION: The Service Bulletin provides the instructions for the inspection, and if required, repair of the elevator control torque tube for Sling 4 and Sling 4 TSi aircraft. Internal quality checks have shown that elevator control stop plates in some aircraft may have been installed with aluminium 3.2 x 8 mm domed rivets instead of stainless steel 3.2 x 8 mm domed rivets. These aluminium rivets shear at lower control stick loads compared to the stainless-steel rivets, so it must be ensured that stainless steel rivets are installed.
This Service Bulletin requires that inspections be carried out on all flying aircraft as well as kit-built aircraft still under construction prior to first flight.