Service Bulletin #0017 - Potential Risk Of Shearing Of Control Stop Plate Rivets [Sling 4, Sling TSi]

[PhilipRueker]

This replaced the Safety Alert #0012.

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.

https://us18.campaign-archive.com/?u=69 ... a7a22171f8

[mikeblackburn]

#slingsupport

I did the inspection today. I can’t tell if the rivets are aluminium or stainless steel. I saw a video from Midwest Sky Sports on Facebook where they say the stainless ones are duller in color than the aluminium. They certainly don’t feel magnetic on my aircraft.

Any thoughts @andrewpitman?

[andrewpitman]

Hey Mike

Im not actually all that technically expert but my guess is those are aluminium, due to the tool mark on the lower one.

Ill get someone in technical to comment too though.

Cheers for now

Andrew
#slingsupport

[Sling Technical Official]

Hi guys

Yes Andrew you are correct, the rivet gun leaves noticeable mark on the head of an aluminium rivet.
The aluminium are generally a bit duller in color when compared to a stainless steel rivet.

I will share picture of a stainless steel rivet as an example shortly.

[Sling Technical Official]

Here is a picture of the torque tube with stainless steel rivets installed.