Lycoming IO-390-D Series Maintenance Manual page 74

NOTICE: Refer to the engine specifications in Appendix A of the IO-390-D Series Engine
(2) If an engine is operated at overspeed for more than 3 seconds, identify the category of
percent of overspeed based on the three categories of overspeed shown in Table 1. Refer
to the latest revision of Service Bulletin No. SB-369 for additional details.
Overspeed Category
Engine overspeed less
than 5% in excess of
maximum rated rpm for
more than 3 seconds
Engine overspeed
between 5% and 10%
in excess of maximum
rated engine rpm for
more than 3 seconds.
Engine overspeed more
than 10% in excess of
maximum rated engine
rpm for any duration
05-50
Page 48
Installation and Operation Manual for rated engine speed.
All incidents of engine overspeed must be recorded in the engine logbook along
with any corrective action identified herein.
Overspeed Values for IO-390-D Series Engines
rpm
2701 a. Identify and correct the cause of the overspeed.
to b. In the engine logbook, record the overspeed incident and any
2834 inspections and corrective action.
2835 a. Identify and correct the cause of the overspeed.
b. Complete the "Cylinder Overspeed Inspection" procedure in this
to
2970 chapter.
c. Refer to Chapter 12-10:
(1) Drain the lubricating system.
(2) Remove the suction screen and oil filter.
(3) Examine the suction screen and oil filter element for metal
contamination. If any unexplained metal accumulation is found,
identify and correct the cause before putting the engine back into
service.
d. Complete the "Valve Train Overspeed Inspection" procedure in this
chapter.
e. Complete the "EIS Overspeed Inspection" or "Magneto Overspeed
Inspection" in this chapter.
f. In the engine logbook, record the overspeed incident and any
inspection and corrective action.
a. Remove the engine from the aircraft. Refer to the "Engine Removal"
2971 or
more procedure in Chapter 72-00.
for any b. It is recommended the engine be sent to Lycoming Engines for
length customized evaluation. Include a description of the overspeed
of time incident, amount of overspeed, and duration.
c. In the engine logbook, record the overspeed incident and any
inspections and corrective action.
OR
Refer to Chapter 72-05 and the latest revision of Service Bulletin No.
SB-240 to:
• Disassemble the engine
• Complete an inspection of the engine
• Replace any parts that are damaged or not in compliance
• Replace any parts that must be replaced at overhaul or upon removal
IO-390-D Series Engine Maintenance Manual
IO-390-D Series Engine Maintenance Manual
Table 1
Corrective Action
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March 2020