Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
NE-07-54
September 24, 2007
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) alerts you,
owners, operators, and certificated repair facilities of Microturbo TRS
18 series turbojet engines, of an Airworthiness Directive (AD) issued
by the Direction General de l’aviation Civile (DGAC), which is the
aviation authority for France. The DGAC AD, No. F-2005-180, dated
November 23, 2005, references
Microturbo service bulletin, 046-72-01, dated November 3, 2005, that
defines the recommended maintenance practices for these engines. These
engines are installed on, but not limited to, BD-5J airplanes.
Background
The Federal Aviation Administration issued type certificate, No.
E13CE, to Ames Industrial Corporation for the TRS 18-046 engine model
on May 25, 1976, and type certificate, No. E27NE, to Microturbo, S.A.
(Microturbo) for the TRS 18-1-202 engine model on December 4, 1987.
Microturbo, Inc. of Grand Prairie, Texas, is the successor to Ames
Industrial Corporation and can provide information related to the TRS
18-046 and TRS 18-1-202 engine models. Certain other TRS 18 series
engine models produced are not FAA certificated but use some of the
same parts used in the certificated models.
The DGAC issued AD No. F-2005-180, dated November 23, 2005, because
they and Microturbo have been mostly unable to obtain information about
the airworthiness of these engines and because unapproved parts or
modifications might have been installed. A copy of DGAC AD No.
F-2005-180 is attached to this SAIB.
The FAA Engine Certification Office has no data to suggest the
certificated Microturbo TRS 18 series engines operating in the United
States are not airworthy. However, because of the concern stated in
DGAC AD No. F-2005-180, and a possible lack of contact between
Microturbo and operators of these engines, we are providing the
recommendations in this SAIB.
DGAC AD No. F-2005-180 calls particular attention to the safety
significance of the life-limited, high-energy rotating components
installed in Microturbo TRS 18 series engines. You are required to
comply with the published life limit of 2,500 hours that applies to the
impellers and turbine wheels installed in the FAA certificated
Microturbo TRS 18 series engine models as stated in FAR 91.403 (c). You
should also be aware that these two life-limited components might be
exposed to more severe operating conditions if they are installed in
engines that are not FAA certificated. An uncontained engine failure
could occur before reaching the 2,500 hour life limit if a used
impeller or turbine wheel from a more severe engine application is
installed in a certificated engine.
In addition, owners and operators of Microturbo TRS 18 series engines
should be aware that Microturbo recommends scheduled maintenance
actions between engine overhauls, and engine overhauls every 600 hours
time-in-service.
Recommendations
We strongly recommend you comply with the published impeller and
turbine wheel life limits and be aware of the operating history of used
parts that could be installed as replacements for these components. We
also recommend you remain aware that the installation of unapproved
parts or modifications might result in an engine that is not airworthy.
In addition, we recommend you obtain and comply with Microturbo service
bulletin No. 046-72-01, which provides more detailed information about
Microturbo TRS 18 series turbojet engine maintenance.
For Further Information Contact
Richard Woldan, Aerospace Engineer, FAA Engine Certification
Office, ANE-140, 12 New England Executive Park, Burlington, MA 01803;
phone: 781-238-7136; fax: 781-238-7199; email: richard.woldan@faa.gov.
For Related Service Information Contact
Microturbo, Inc., Attn: Jim Dalton, 2709 Forum Drive, Grand
Prairie, TX 75052; phone: 972-606-8155; email:
jim.dalton@microturbo.com.