The FAA has announced a new AD on Superior Cylinders. Superior informed the
FAA that they had omitted a critical heat treating step in the
manufacturing of the cylinders, and that there are 9 reports of cylinder
heads coming off of the cylinder barrels in the affected lot.

Excerpts from the AD's preliminary announcement are below. Basically if you
have the bad cylinders installed, you have to 150 hours TT on the cylinder
to remove them from service. If over 150, you have to ferry it to a repair
station.

==========================
2007-04-19 Superior Air Parts, Inc.

Unsafe Condition

(d) This AD results from the discovery of nine separated SAP
cylinder assemblies installed in TCM 470, 520, and 550 series
reciprocating engines and one separated SAP cylinder assembly
installed in LE 320, 360, and 540 series reciprocating engines. We
are issuing this AD to prevent cylinder separation that can lead to
engine failure, a possible engine compartment fire, and damage to
the airplane.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or
develop on other TCM 470, 520, and 550; LE 320, 360, and 540; AL 540,
and SAP 360 series reciprocating engines of the same type design with
SAP cast cylinder assemblies that have as original equipment, or have
been overhauled or repaired using SAP part numbers listed in the table
above. For that reason, we are issuing this AD to prevent cylinder
separation which can lead to engine failure, a possible engine
compartment fire, and damage to the airplane. This AD requires removing
from service installed SAP cast cylinder assemblies listed in the table
above, no later than 150 hours total TIS to preclude cylinder head
fatigue failure and separation at the head-to-barrel threaded
interface.

Determining Which Cast Cylinder Assemblies Are Installed

(f) If aircraft engine records do not list the P/N of the
cylinder installed during engine overhaul or repair, visually
inspect the cylinders. The affected SAP cylinder head flanges are
marked: SA47000L-A1, SA47000L-A20P, SA47000S-A1, SA47000S-A20P,
SA47000S-A21P, SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P,
SA52000-A23P, SA55000-A1, or SA55000-A20P or SL32000W-A1, SL32000W-
A20P, SL32000W-A21P, SL32000WH-A1, SL32000WH-A20P, SL32006W-A1,
SL32006W-A20P, SL32006W-A21P, SL36000TW-A1, SL36000TW-A20P,
SL36000TW-A21P, SL36000TW-A22P, SL36000W-A1, SL36000W-A20P,
SL36000W-A21P, SL36006W-A1, SL36006W-A20P, or SL36006W-A21P.

Related Information

(l) Superior Air Parts, Inc. Mandatory Service Bulletin B06-01,
Rev. E, dated January 24, 2007, contains information related to the
subject of this AD.
(m) Contact Jurgen Priester, Aerospace Engineer, Special
Certification Office, FAA, Rotorcraft Directorate, Southwest
Regional Headquarters, 2601 Meacham Blvd., Fort Worth, Texas 76137;
e-mail: jurgen.priester@faa.gov; telephone (817) 222-5159; fax (817)
222-5785 for more information about this AD.

The full text is here:
http://a257.g.akamaitech.net/7/257/2...07/E7-2985.htm

==============
Further research has indicated that the cylinders in question were
manufactured between April and November 2005.

http://www.superiorairparts.com/sb0601/

The Service Bulletin says that the cylinders in question were manufactured
between April and November of 2005, so if you have OLDER Superior
cylinders, they are not included in this AD and recall.

If you have any ANY Superior cylinders installed since April of 2005, you
may be affected by this AD and recall. Get thee to thy Log books or to thy
plane to inspect the numbers on the cylinders!

Bob Steward, A&P IA
Birmingham, AL