NIFE ENGINES EXAM REPORTED
QUESTIONS WITH CORRECT
ANSWERS
Workings of a Turboshaft - Answer- Similar to a turboprop except all energy not used to
drive the compressor is converted to shaft horsepower
Pascal's Law - Answer- Pressure applied to a confined liquid is transmitted equally in all
directions without loss of pressure and acts with equal force on all surfaces
Pressure - Answer- Force per unit area.
Workings of Hydraulics - Answer- If input and output area are the same, then the force
and distance displaced will be the same.
If they are different, the force will vary based on F1=A1*F2/A2. This is based on the
basic pressure equation P=F/A. The displacement will be inversely proportional
Power Control System - Answer- Supplies fluid pressure to the flight controls only
Utility Control System - Answer- Supplies fluid pressure to the utility systems as well as
the flight controls
Ex. Landing gear, wing fold, wheel brakes
Reservoir Functions - Answer- S torage space for hydraulic fluid
H eat dissipation
A eration
F oreign matter trapping
T hermal expansion
Non-Pressurized Reservoirs - Answer- Vented to ambient air
Balances reservoir pressure with atmospheric
Located in pressurized compartment
Pressurized Reservoirs - Answer- Designed for high altitude operation
Pressurized by bleed air from compressor or by hydraulic system pressure
Pressurization ensures positive fluid flow for any aircraft attitude
Types of Pumps - Answer- Hand pumps: backup hydraulic system, provides alternative
hydraulic power, mainly used for emergency systems
,Variable displacement pump: regulates fluid volume delivery in accordance with system
flow
Constant displacement pump: delivers constant fluid output for any rotational speed,
delivers steady flow regardless of system pressure, must incorporate a pressure
regulator/unloader valve
Pressure Regulator/Unloader Valve - Answer- Maintains a set pressure by diverting
excess pump flow back to reservoir
Check Valve - Answer- Allows free flow of hydraulic fluid from pumps but prevents back
flow of system pressure
Accumulator Functions - Answer- S hock absorber
E mergency pressure use
A ssist peak operations
M aintain pressure during shutdown
Filters - Answer- Ensure delivery of contaminant free hydraulic fluid by preventing dust,
grit, and undesirable impurities from entering the system
Relief Valve - Answer- safety valve installed to prevent pressure to build up to the point
where a seal might burst or a damage may occur
Pressure Gauges - Answer- Indicate the amount of pressure in the hydraulic system
Pressure Switches - Answer- Used to indicate a hydraulic pressure drop that falls below
allowable limits
Hydraulic Fuses - Answer- Safety devices that detect ruptures, failed fittings, or other
leak producing failures/damage
Prevents loss of fluids while allowing rest of system to remain in operation
Selector Control Valves - Answer- Redirects fluid flow for system operation
Changing the direction reverses the flow changing the direction of fluid flow to the
actuator
Actuators - Answer- Convert fluid under pressure to linear or reciprocating mechanical
motion
Direct Current (DC) - Answer- Electric current that flows in only one direction
System components are usually heavy and are not as reliable
, Alternating Current (AC) - Answer- A flow of electric charge that reverses its direction
System components are lightweight, simple, and reliable
Generator - Answer- A machine that converts mechanical energy into electrical energy
AC generator commonly referred to as an alternator
AC generator simply referred to as a generator
Constant Speed Drive (CSD) - Answer- Linkage used to ensure a constant input RPM in
a generator through the use of hydro mechanical linkage
Ensures steady voltage output to equipment
Used on turbojets and turbofans
Inverter - Answer- A device that converts DC to AC
Used on an AC system as a backup if AC generator fails
Transformer Rectifier (TR) - Answer- Electrical device that transforms AC to DC
Sources of DC Electrical Energy - Answer- DC generator, TR, and battery
Bus - Answer- Provides the medium or path between the energy source and their
respective electrical load
Common distribution point for electricity
Essential Bus - Answer- Routes power required for flight safety
DC essential bus powers the battery
Primary Bus - Answer- Routes power to equipment devoted to aircraft's intended
mission
Monitor or Secondary Bus - Answer- Routes power to convenience circuits
Starter Bus - Answer- Routes power to start the aircraft engines
Powered by external DC power, the internal battery, or APU
Switches - Answer- Provide manual control of power
QUESTIONS WITH CORRECT
ANSWERS
Workings of a Turboshaft - Answer- Similar to a turboprop except all energy not used to
drive the compressor is converted to shaft horsepower
Pascal's Law - Answer- Pressure applied to a confined liquid is transmitted equally in all
directions without loss of pressure and acts with equal force on all surfaces
Pressure - Answer- Force per unit area.
Workings of Hydraulics - Answer- If input and output area are the same, then the force
and distance displaced will be the same.
If they are different, the force will vary based on F1=A1*F2/A2. This is based on the
basic pressure equation P=F/A. The displacement will be inversely proportional
Power Control System - Answer- Supplies fluid pressure to the flight controls only
Utility Control System - Answer- Supplies fluid pressure to the utility systems as well as
the flight controls
Ex. Landing gear, wing fold, wheel brakes
Reservoir Functions - Answer- S torage space for hydraulic fluid
H eat dissipation
A eration
F oreign matter trapping
T hermal expansion
Non-Pressurized Reservoirs - Answer- Vented to ambient air
Balances reservoir pressure with atmospheric
Located in pressurized compartment
Pressurized Reservoirs - Answer- Designed for high altitude operation
Pressurized by bleed air from compressor or by hydraulic system pressure
Pressurization ensures positive fluid flow for any aircraft attitude
Types of Pumps - Answer- Hand pumps: backup hydraulic system, provides alternative
hydraulic power, mainly used for emergency systems
,Variable displacement pump: regulates fluid volume delivery in accordance with system
flow
Constant displacement pump: delivers constant fluid output for any rotational speed,
delivers steady flow regardless of system pressure, must incorporate a pressure
regulator/unloader valve
Pressure Regulator/Unloader Valve - Answer- Maintains a set pressure by diverting
excess pump flow back to reservoir
Check Valve - Answer- Allows free flow of hydraulic fluid from pumps but prevents back
flow of system pressure
Accumulator Functions - Answer- S hock absorber
E mergency pressure use
A ssist peak operations
M aintain pressure during shutdown
Filters - Answer- Ensure delivery of contaminant free hydraulic fluid by preventing dust,
grit, and undesirable impurities from entering the system
Relief Valve - Answer- safety valve installed to prevent pressure to build up to the point
where a seal might burst or a damage may occur
Pressure Gauges - Answer- Indicate the amount of pressure in the hydraulic system
Pressure Switches - Answer- Used to indicate a hydraulic pressure drop that falls below
allowable limits
Hydraulic Fuses - Answer- Safety devices that detect ruptures, failed fittings, or other
leak producing failures/damage
Prevents loss of fluids while allowing rest of system to remain in operation
Selector Control Valves - Answer- Redirects fluid flow for system operation
Changing the direction reverses the flow changing the direction of fluid flow to the
actuator
Actuators - Answer- Convert fluid under pressure to linear or reciprocating mechanical
motion
Direct Current (DC) - Answer- Electric current that flows in only one direction
System components are usually heavy and are not as reliable
, Alternating Current (AC) - Answer- A flow of electric charge that reverses its direction
System components are lightweight, simple, and reliable
Generator - Answer- A machine that converts mechanical energy into electrical energy
AC generator commonly referred to as an alternator
AC generator simply referred to as a generator
Constant Speed Drive (CSD) - Answer- Linkage used to ensure a constant input RPM in
a generator through the use of hydro mechanical linkage
Ensures steady voltage output to equipment
Used on turbojets and turbofans
Inverter - Answer- A device that converts DC to AC
Used on an AC system as a backup if AC generator fails
Transformer Rectifier (TR) - Answer- Electrical device that transforms AC to DC
Sources of DC Electrical Energy - Answer- DC generator, TR, and battery
Bus - Answer- Provides the medium or path between the energy source and their
respective electrical load
Common distribution point for electricity
Essential Bus - Answer- Routes power required for flight safety
DC essential bus powers the battery
Primary Bus - Answer- Routes power to equipment devoted to aircraft's intended
mission
Monitor or Secondary Bus - Answer- Routes power to convenience circuits
Starter Bus - Answer- Routes power to start the aircraft engines
Powered by external DC power, the internal battery, or APU
Switches - Answer- Provide manual control of power
