TM 55-2840-231-23
Section VI. TROUBLESHOOTING
1-66
Troubleshooting procedures
1-67
1-47. GENERAL.
The troubleshooting procedures in this section are presented as a guide for locating and correcting malfunc-
tions. Use of these procedures will reduce delays and maintenance down-time and will minimize unnecessary re-
placement of engine components. Two basic assumptions have been made in preparing these procedures;(1) the
correct operating procedures have been followed and (2) the problem is caused by a single failure or malfunction.
The trouble as reported by the flight crew is the main point of the problem. Obtain as much information as
possible from the flight crew and their report. In many cases. this information will define the problem completely;
however, the malfunction should be confirmed by a ground run, providing there is no danger of possible engine
damage occuring.
The probable cause lists the components which might cause the malfunction. The cockpit indications can
often give a clue as to which of these components is causing the problem.
Caution must be exercised to avoid troubleshooting difficulties caused by false cockpit indications. In most
cases, a false indication can be detected by checking it against other indications. For example, a TOT indication
system malfunction should be suspected if TOT is high, low, or fluctuating with no change in fuel flow or torque.
It is not possible to list troubleshooting difficulties caused by false cockpit indications. In most cases, a false
indication can be detected by checking it against other indications. For example, a TOT indication system mal-
function should be suspected if TOT is high, low, or fluctuating with no change in fuel flow or torque.
The troubleshooting procedures are given in logic diagrams. The logic diagrams are organized by specific
symptoms and contain the steps required to locate the fault.
The logic diagram lists the action to be taken to correct the fault.
Preserve the engine before removing it from aircraft.
The following is an outline of procedures to follow when troubleshooting.
If possible, confirm the reported fault with a ground test run.
Troubleshoot according to the symptoms listed in the Symptom Index. Table 1-8.
Confirm fault has been fixed with a maintenance operation check.
Change 13
1-66.1/(1-66.2 blank)
