TM 55-2840-241-23
CHAPTER 12
SPECIAL INSPECTIONS
Section I. ENGINE HOT END
12-1. Scope.
12-1 and 12-2 list the various overtemperature conditions
for starting and power transients and the maintenance
This section presents special instructions to be per-
action required for each.
formed on the turbine when the engine has experienced
operation beyond allowable temperature limits. Tables
Table 12-1. Overtemperature During Start
Temperature range
Time
Maintenance action
810-927°C (1490-1700°F)
Over 10 seconds
Inspect turbine.*
Over 927-999°C (1700-1830°F)
Anytime
Inspect Turbine.*
Over 999°C (1830°F)
Anytime
Remove engine for depot
maintenance or overhaul.
NOTE
1. Refer to item 6, table 4-1 when start temperature
consistently exceeds 843° C (1550° F).
2. The time-at-temperature limits are not additive
and may be repeated without restrictions.
*Refer to Turbine Overtemperature Inspection paragraph 12-2.
Table 12-2. Overtemperature During Power Transients
Temperature range
Time
Maintenance action
810-843° C (1490-1550° F)
Over 6 seconds
Inspect turbine*
843-927° C (1550-1700° F)
Anytime
Inspect turbine*
Over 927° C (1700° F)
Anytime
Remove engine for depot
maintenance or overhaul.
NOTE
The time-at-temperature limits are not additive and
may be repeated without restrictions.
*Refer to Turbine Overtemperatures Inspection paragraph 12-2.
12-2. Turbine Overtemperature Inspection.
NOTE
NOTE
This inspection may be performed with the engine in-
Removal of the first-stage turbine nozzle from the
stalled in the airframe.
turbine is not authorized.
a. Remove the combustion section. (Refer to para-
b. Inspect the first-stage turbine nozzle and shield as
graph 3-21.)
outlined in table 12-3. (See figure 12-1.)
Change 10
12-1
