Maintenance Inspections
Teledyne Continental Motors, Inc.
TM
7-48
IOF-550 Permold Series Engine Maintenance Manual
1 April 2007
7-4.4. Engine Overspeed
Operating an engine beyond its capacity can damage the engine and result in subsequent
engine failure. IO-550 overspeed conditions have three levels of severity defined in the
table below:
Category Engine
Speed
CAT I
Up to 3000 RPM
CAT II
3000 – 3300 RPM
CAT III
Over 3300 RPM
NOTE: The rated RPM limit for aircraft equipped with digital
RPM measuring equipment may be established to include a +2%
variance for normal operations. Any operation beyond the rated
RPM limit plus the 2% variation must follow the inspection
criteria.
7-4.4.1. Category I Overspeed Inspection
If engine overspeed continues uncorrected for less than ten seconds, no action is required.
For more than 10 seconds, land the plane and proceed as follows:
Procedure
1.
Drain oil and inspect for debris. Remove the oil filter and inspect the filter element
for debris.
2.
Remove the rocker covers and inspect the following for damage or debris.
a.
Valves
b.
Springs
c.
Rocker arms
d.
Tappets
e.
Spring retainers
f.
Pushrods
3.
Inspect components using the service limits in Chapter 10, “Non-overhaul Removal
and Replacement” of this manual, repair and assemble the engine according to
instructions in this manual.
4.
Check accessory drives for excessive backlash.
5.
Repeat oil and filter change after five hours of accumulated flight.