Volume 4 AIRCRAFT EQUIPMENT AND OPERATIONAL AUTHORIZATIONS
chapter 14 GENERAL OPERATING AND FLIGHT RULESMAINTENANCE ISSUES
Section 11 Testing of Powerplants After Overhaul
4-1601 GENERAL. This section provides guidance
to ensure that powerplant overhaul facilities accomplish the testing of powerplants
after overhaul per the maintenance procedures recommended by the engine manufacturer.
A. Manufacturer Recommended Procedures. Powerplant
manufacturers are very specific in their recommended procedures for powerplant
testing after overhaul. This testing is required to run‑in new parts,
check powerplant performance, and check the quality of the work performed during
overhaul. The procedures to be followed in overhaul testing of a powerplant
vary by make and model, but are clearly outlined in the manufacturer’s manual.
B. Practices Acceptable to the Administrator.
Title 14 of the Code of Federal Regulations (14 CFR) part 43, § 43.13
requires that each person performing maintenance must use methods, techniques,
and practices acceptable to the Administrator. If special equipment or test
apparatus is recommended by the powerplant manufacturer, that equipment or apparatus
(or an equivalent acceptable to the Administrator) must be used.
C. Certificated Repair Stations. Title 14 CFR
part 145, § 145.109
requires repair stations to possess the equipment, tools and materials required
to perform maintenance in accordance with part 43,
to include § 43.13.
Repair stations performing powerplant tests required by § 43.2
after overhaul must ensure the methods, techniques and practices prescribed
in the current manufacturer’s maintenance manual, or instructions for continued
airworthiness (ICA) prescribed by the manufacturer, or other methods, techniques
and practices acceptable to the Administrator, are used. The testing may be
performed by the repair station itself or may be accomplished by an outside
maintenance organization, as allowed by § 145.217.
The repair station will be responsible for the final acceptance of the tested
engine if the maintenance organization performing the test did not issue an
approval for return to service per § 43.9.
D. Outside Agencies Performing Overhaul Testing. A certificated
repair station may utilize an outside maintenance organization to perform the
required testing after overhaul provided:
agency that is to perform the test has the information necessary to complete
the test properly;
powerplant records will be maintained per § 145.219;
until the required test procedures have been completed by a person authorized
43.7, the powerplant has not been tested and is not considered airworthy;
person authorized by § 43.7
is responsible for the final acceptance of the tested powerplant.
E. Powerplant Overhaul Testing Environment.
1) Turbine Engine Testing. Since the performance
of a turbine engine is greatly affected by the surrounding atmospheric conditions,
most turbine engine manufacturers recommend that powerplant testing after overhaul
be accomplished in the controlled conditions of a test facility/cell equipped
as outlined in the manufacturer’s overhaul manual.
2) Reciprocating Engine Testing. The manufacturers
of reciprocating engines allow the airframe to be considered a suitable test
stand for the running‑in of overhauled engines, provided the following
requirements are observed:
test club is used in place of a flight propeller;
suitable cooling shroud or scoop is used to gather and direct cooling air over
cylinder head temperature pickup is installed on each cylinder to monitor individual
cylinder temperature; and
necessary calibrated gauges are installed independent of the aircraft gauges.
3) Additional Testing Methods. When other
methods for testing come to the attention of aviation safety inspectors (ASIs),
the methods should be evaluated to determine if they are equivalent to the previously
stated requirements. When noncompliance with § 43.13
is evident, corrective action must be initiated to correct any discrepancies.
NOTE: When performing an engine overhaul, especially
if it includes any kind of engine modification, all of the work must be accomplished
in accordance with approved data.
RESERVED. Paragraphs 4‑1602 through 4‑1620.