PROGNOSTICS SYSTEM - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General

A. The PHMU has the capability to monitor the following:

Oil debris
Vibrations
Anomaly detection.

** ON A/C NOT FOR ALL

2. Component Location

Prognostics System (PHMU) ** ON A/C NOT FOR ALL

Engine Indicating System (ODM) ** ON A/C NOT FOR ALL

The PHMU is installed to the fan case at the 2:30 o'clock position.

FIN	FUNCTIONAL DESIGNATION	ZONE	ATA REF
** ON A/C NOT FOR ALL
4609KS	PROGNOSTICS AND HEALTH MANAGEMENT UNIT	400	73-11-00
4074KS	SENSOR-OIL DEBRIS MONITORING	400	73-11-00

** ON A/C NOT FOR ALL

3. System Description

A. ODM

(1) The PHMU receives signals from the ODM, prepares the information and sends the applicable output to the EEC.

(2) The EEC then sends the information as maintenance messages to the aircraft/computer system.

(3) The ODM sensor is described in the AMM (Ref. AMM D/O 79-35-00-00).

B. Vibration Monitoring

(1) The PHMU receives signal analysis from engine accelerometers to assess the health of rotating and the mechanical components. The PHMU reports this information to the aircraft as maintenance messages and cockpit caution, status and warning messages if necessary.

C. Anomaly Detection

(1) The PHMU compares engine data to models of engine gaspath and subsystem parameters.

(2) The information is prepared by the PHMU and the applicable output is sent to the EEC. The EEC then sends this information to the aircraft computer as maintenance messages.

(3) The prepared ODM signal will enhance maintenance operations that provide an early indication of debris events which help the magnetic chip collector plug inspections that are required to troubleshoot.

(4) The prepared vibration signal will provide the applicable signal for cockpit indication during rotor imbalance. It will also provide additional vibration information for ground maintenance purposes.

(5) Processed signal information for anomaly detection is also used for ground maintenance purposes.

[Rev.10 from 2021] 2026.04.01 03:18:59 UTC