Objective 2d Engine Configuration

Objective 2d.
Given applicable TOs, Identify facts about the Engine
Configuration with a minimum accuracy of 80%

Technical orders

1C­17A­2­71GS­00­1

1C­17a­2­24GS­00­1

Safety!

Corrosion Identification/control

Foreign Object Damage prevention

Engine Configuration

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Engine
Configuration

•F117 engine is a dual spool, axial flow, high bypass ratio turbofan engine

•Dual spool means two compressors

•Axial flow means the air entering the engine flows along the long axis of engine

•High bypass means the engine produces two airlfows

•Primary airflow (core)

•Secondary airflow (fan)

•F117 engine can produce 41,700 lbs. of thrust at takeoff

•Data plate on Engine lists the amount of thrust produced at 40,900

•Core F117 engine weighs 7160 lbs.

•Engine weighs 10,300 lbs. with QEC

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Engine Configuration cont..

The F117 engine has seven major modules

1.

N1 or Low Pressure Compressor (LPC)

2.

N2 or High Pressure Compressor (HPC)

3.

Diffuser and Combustion Chamber

4. High Pressure Turbine

5.

Low Pressure Turbine

6. Exhaust Case

7.

Gearbox Assembly

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Low Pressure
Compressor (N1)

•

5 Stages of Compression

•

A stage of compression is made
up of a rotational assembly and a
stationary assembly also known
as a blade and a stator

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

High Pressure
Compressor (N2)

•

12 Stages of
Compression

•

17 total stages
of compression

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Diffuser &
Combustion
Chamber

•

Annular Type combustion
chamber

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

High Pressure
Turbine (HPT)

•

Two Stages in HPT

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Low Pressure Turbine (LPT)

•

Five Stages in LPT

•

Seven Stages total in Turbine

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Exhaust Case

•

Has 15 Struts used to straighten airflow

•

11 struts are used for instrumentation

•

Top 4 struts are hollow

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Exhaust Case Cont..

 Out of the 11 Instrumentation struts

 5 struts have pressure sensing provisions

 These struts provide P4.9 readings to EEC

 P4.9 is used to calculate Engine Pressure Ratio
(EPR)

 6 struts house T4.9 thermocouples

 Used to detect Exhaust Gas Temperature (EGT)

 EGT is displayed on MFD & Standby Engine Display
(SED) in flight deck

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Gearbox Assembly

 Provides power to drive the
engine and aircraft accessories

 Starting on the front left of the
gearbox and working left to right the
following components are on the
gearbox:

1.Primary Hydraulic Pump

2.Gearbox Scavenge Pump

3.Pneumatic Starter

4.Secondary Hydraulic Pump

5.EEC Alternator or Permanent
Magnet Alternator (PMA)

6.Deoiler

7.Fuel Pump

8.Angle Gearbox

9.Integrated Drive Generator (IDG)

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Primary Hydraulic Pump

 Produces hydraulic pressure for
brakes, flight controls, thrust
reversers, etc.

 Hydraulic System Controller (HSC) 1
& 2 located in avionics bay, monitors
and controls the hydraulic system

 A Switch light on the Hydraulic
Control Panel allows technician to
turn pump on/off

 Produces 3800­4200 psi

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Gearbox Scavenge Pump

 Engine Lube and Scavenge Pump is attached to Gearbox Scavenge Pump

 L&S pump scavenges oil from main gearbox and sends it back to oil tank
located at 8 o’clock position

 L&S Pump lubricates and scavenges the five main engine bearings

Gearbox Scavenge Pump

Lube and Scavenge Pump

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Pneumatic Starter

 Provides initial rotation of the engine (N2 compressor)

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Secondary Hydraulic Pump

 Works just like the Primary
Pump

 If the Primary Pump drops
below 3800 psi the
secondary pump will
automatically turn on

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

EEC Alternator/Permanent Magnet
Alternator (PMA)

(PMA) powers the EEC.

The PMA also converts the rotation of the N2 into an electrical signal interpreted by the EEC as N2
rotation.

N2 is displayed on the MFD expanded engine page and the SED.

There is one “blue” and one “green” wire cannon plug connection on the PMA. Blue and green wire
cannon plug connections indicate these wires are connected to the EEC and only the EEC.

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

EEC Alternator/Permanent Magnet
Alternator (PMA) cont..

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Deoiler

 Separates the air from the oil system

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Fuel Pump

Pressurizes the Fuel System

The Fuel Control (FCU) is attached to the fuel pump. The FCU meters fuel for combustion

The FCU also routes servo fuel pressure for actuation of EEC controlled fuel actuated engine
components

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Fuel Pump cont..

Fuel Pump

Fuel Control

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Angle Gearbox

 Converts the vertical shaft power of the tower shaft to
horizontal shaft power for the gearbox

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

AETC Training Use Only. Do Not Use for the Operation, Troubleshooting, or Maintenance of Operational Weapon
Systems

AETC Training Use Only. Do Not Use for the Operation, Troubleshooting, or Maintenance of Operational Weapon
Systems

Integrated Drive Generator (IDG)

 It produces 115/200 Volts
Alternating Current (VAC),
3­phase, 400hz power.

 The IDG is a constant speed
drive and generator
combined into one assembly.

 The GCUs monitor and
control the IDGs like the EEC
monitors and controls the
engine.

 The GCUs report fault data to
Auxiliary Power Unit (APU)
External Power Control Unit
(EPCU) or Bus Power Control
Unit (BPCU) located in the
flight station.

 The IDG has its own oil
system and cooling circuit.

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Engine Bearings

 The F117 Engine has 5
bearings

 Bearings support axial
and radial loads

 Number 1 &3 bearings
are thrust bearings

 Number 2, 4 &5 are
roller bearings

 Use the acronym
B.R.B.R.R

 To remember which
bearings are Ball and
which are Roller

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Engine Mounts

 The F117 has two engine mounts.

 The forward engine mount and the aft engine mount.

 Each mount has four bolts that connect the engine mount to
the aircraft pylon.

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems

Objective 2d.
Given applicable TOs, Identify facts about the Engine
Configuration with a minimum accuracy of 80%

For AETC Training Use only. Do not use for the operation, troubleshooting, or maintenance of operational weapon systems