Service difficulty report · Thrust Button

Difficulty date
May 9, 2026
Submitted
May 9, 2026
Operation
General aviation
Engine
Lyc IO540*
Part
Thrust Button
Part number
SL12892
Part serial
250923000028574
Condition
Faulted
Location
Cylinders
Stage of operation
IN
How discovered
V
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DURING MAJOR OVERHAUL INSTALLED SUPERIOR ROCKER SHAFT THRUST BUTTONS P/N SL12893.INFORMATION THAT WE RECEIVED STATED THAT FAULTY THRUST BUTTONS WILLFLOAT IN WATER AND GOOD PARTS WILL SINK. WE PERFORMED THIS TEST ON EVERY LOT NUMBER IN OURINVENTORY AND FOUND SEVERAL LOT NUMBER BATCHES THAT FLOAT. WE THEN CONTACTED ANY CUSTOMERSWITH THE SUSPECT LOT NUMBER THRUST BUTTONS INSTALLED IN THEIR ENGINES TO INFORM THEM OFOUR FINDINGS AND TO REMOVE THE PARTS FROM SERVICE. SUSPECT LOT NUMBERS IN OUR INVENTORYWERE QUARANTINED. DEFECTIVE SUPERIOR THRUST BUTTONS WERE REMOVED AND REPLACED WITH LYCOMING THRUST BUTTONS P/N LW-12893. DEFECTIVE PARTS WERE REMOVED BEFORE ENGINE WAS TEST RUN.