Operational Alert: 159
Date: August 19, 2005
Subject: Installation of Slip Joint Springless Type Muffler
Compliance: Mandatory
Models Affected: All RANS pusher aircraft (S-12, S-12XL, S-12S, S-14, S-18)
using ROTAX 912 or 912S engines
with the Slip Joint Springless type Muffler.

Installation of the Slip Joint Springless type Muffler for RANS pusher kit planes needs special
attention to pre-load binding. The muffler canister should be installed to NOT move when
pushed against by hand.

The procedure is a follows:
 
1. Set exhaust pipes so the muffler canister moves up and down freely. Rotate pipes until the canister
is not moving freely. Do not over bind the pipes in the slip joint; adjust each a little until canister stops
movement. Be sure the canister is safety wired to the engine.

2. Check for movement after a flight and adjust as required.

3. Always included an inspection of muffler integrity and freedom of movement in each pre-flight.

4. Pipes may wear if there is excessive movement and will become thin at the pipe openings. A section
of pipe may separate and enter the prop. Inspect these areas carefully for wear prior to each flight.

Thank you for your attention to this matter.
Hopefully we have not inconvenienced you to any great degree.

Fly safe.