Engine Synchronization System

STUDENT GUIDE FOR T-1A AIRCRAFT SYSTEMS

CHAPTER THREE

311. ENGINE SYNCHRONIZATION SYSTEM

The engine synchronization system provides synchronization to either the fan or turbine

Revolutions per Minute (RPM) of both engines by electrically matching the RPMs. The left

throttle operates as the master and the right throttle serves as the slave. A control box determines

the error difference of the right slave and the left master RPM input and generates a command

signal input to the EFC. The EFC then sends a signal to the torque motor in the HMU to adjust

the fuel flow schedule of the right engine to synchronize the RPMs. The synchronization

actuators have a limited range of approximately 1.5% fan or turbine RPM.

312. THROTTLES

The throttles are provided for thrust setting adjustment and fuel cutoff for the respective engine.

313. ENGINE INSTRUMENTS

Ten engine instruments using gauge displays with needle pointers are arranged in two adjacent

vertical rows on the center instrument panel. The left side represents the Number 1 engine; the

right side represents the Number 2 engine.

N1 (Fan RPM Indicator)

These indicators display percentage of engine fan speed from 0-110% RPM. The information is

provided in both digital and analogue format. The indicators receive RPM information from the

respective N1 speed sensor.

Inter-Turbine Temperature Indicator

These indicators display Inter-Turbine Temperature (ITT) and provide an average readout of the

ITT through six thermocouples. The numerical readings are interpreted in degrees Celsius (C)

times 100.

N2 (Turbine RPM Indicator)

These indicators display percentage of turbine speeds from 0-110% RPM. The information is

provided in both digital and analog format. They receive RPM information from the respective

N2 speed sensor installed on the accessory gearbox. The sensor reads off of the oil pump drive

gear.

Fuel Flow Indicators

The gauges indicate fuel flow in pounds per hour times 100.

Oil Pressure and Temperature Indicators

These gauges have a dual arc scale: one for oil pressure and one for oil temperature. The oil

pressure arc has a numerical range from 0-15 (x10), and indicates the pressure on the delivery

ENGINES

3-5