EOOW study UPDATED Exam Questions
and CORRECT Answers
What are the 5 events that take place in the Brayton cycle? - CORRECT ANSWER-✔✔
Intake, compression, combustion, expansion(power), exhaust
What does an increase in ambient air temp result in? - CORRECT ANSWER-✔✔ A decrease
in fuel economy and power output
What are the metering point? - CORRECT ANSWER-✔✔ Positions 2,3 & 5.4
What is position 2 in the GTM? - CORRECT ANSWER-✔✔ The compressor inlet which
measured values include T2- temperature at position 2 and Pt2 pressure total at position 2
What is position 3 in the GTM? - CORRECT ANSWER-✔✔ The compressor discharge
which measures the static pressure (ps3) expressed in psi (commonly referred to as CDP,
compressor discharge pressure)
What is position 5.4 in the GTM? - CORRECT ANSWER-✔✔ The inlet to the power turbine
which measured values are T5.4, power turbine inlet temp and Pt5.4, power turbine inlet
pressure expressed in psi
What is the LM 2500 GTM rated at? - CORRECT ANSWER-✔✔ Ambient temp: 100
degrees
Barometric pressure: 29.92 inches Hg
Relative humidity: 0%
Brake horsepower: 26,250
Fuel consumption: 0.42 LB/Hr/Hp
What 2 major assemblies does the LM 2500 consist of ? - CORRECT ANSWER-✔✔ The gas
generator and the power turbine
How many stages is the GTM compressor? - CORRECT ANSWER-✔✔ 16 stages
,What does the compressor stator assembly consist of? - CORRECT ANSWER-✔✔ One set
of inlet guide vanes (IGV) and 16 sets of stationary blades
What are the first six stages stator blading that can be moved called? - CORRECT
ANSWER-✔✔ Variable stator vanes (VsVs)
The VsVs adjusts as a function of what? - CORRECT ANSWER-✔✔ The compressor inlet
temp (CIT), Ngg, and compressor discharge pressure (CDP)
The VsVs minimize the chances of what? - CORRECT ANSWER-✔✔ A stall
The compressor rear frame houses what? - CORRECT ANSWER-✔✔ The combustor, HP
turbine, fuel manifold, 30 fuel nozzles, two spark ignitors, and costumer service bleed air
manifold
What type of combustor is in the GTM? - CORRECT ANSWER-✔✔ An annular type
combustor located inside the compressor rear frame
What percentage of air mixes with the fuel to burn in the combustor? - CORRECT
ANSWER-✔✔ 30%
What percentage of air is used for cooling, flame centering, and bleed air? - CORRECT
ANSWER-✔✔ 70%
Describe the HP Turbine - CORRECT ANSWER-✔✔ A high pressure, two stage, axial flow
turbine
What cools the HP turbine rotary assembly? - CORRECT ANSWER-✔✔ CDP air (16th stage
bleed air)
How are the gas generator and power turbine rotar shaft connected? - CORRECT ANSWER-
✔✔ Aerodynamically coupled
, What does the accessory gear box provide? - CORRECT ANSWER-✔✔ Mounting for and
drives the components needed to start and sustain engine operations
What are the mounted accessories included in the gear box? - CORRECT ANSWER-✔✔
FLAP, (fuel pump, lubo supply, air/oil separator, pneumatic starter)
Describe the power turbine - CORRECT ANSWER-✔✔ A six stage axial flow turbine
aerodynamically coupled to the gas generator, used to drive the main reduction gear via a
high speed flexible coupling shaft (HSFCS)
At what stages is bleed air extracted from the GTM? - CORRECT ANSWER-✔✔ 8th stage-
provides air for the bearing sump pressurization and cooling
9th stage- provides air to the power turbine balance chamber
13th stage- provides air to cool the 2nd stage HP turbine nozzles
16th stage- provides air to the gas generator balance chamber, HP turbine 1st and 2nd rotor
blade cooling, 1st stage HP turbine nozzle and costumer service bleed air system
What are symptoms of a stall in the GTM? - CORRECT ANSWER-✔✔ Higher than normal
or rapid rise in T5.4, decreasing or fail to increase Ngg, low frequency rumble or roar,
sluggish throttle response, higher than normal vibration, and lower than normal Pt5.4
What does the starting and motoring consist of? - CORRECT ANSWER-✔✔ A pneumatic
turbine starter and a start air valve
What does the starter air valve regulates start air to? - CORRECT ANSWER-✔✔ 35-41 psi
Prior to initiating the start command what checks to see if the start permissive are met ? -
CORRECT ANSWER-✔✔ The AN/UYK-44 computer in the SCU
What are the permissive that must be met prior to engine start? - CORRECT ANSWER-✔✔
1.MRG lube oil pressure greater than 13 psig
2.LM 2500 gas generator speed (Ngg) less than 3500 RPM
and CORRECT Answers
What are the 5 events that take place in the Brayton cycle? - CORRECT ANSWER-✔✔
Intake, compression, combustion, expansion(power), exhaust
What does an increase in ambient air temp result in? - CORRECT ANSWER-✔✔ A decrease
in fuel economy and power output
What are the metering point? - CORRECT ANSWER-✔✔ Positions 2,3 & 5.4
What is position 2 in the GTM? - CORRECT ANSWER-✔✔ The compressor inlet which
measured values include T2- temperature at position 2 and Pt2 pressure total at position 2
What is position 3 in the GTM? - CORRECT ANSWER-✔✔ The compressor discharge
which measures the static pressure (ps3) expressed in psi (commonly referred to as CDP,
compressor discharge pressure)
What is position 5.4 in the GTM? - CORRECT ANSWER-✔✔ The inlet to the power turbine
which measured values are T5.4, power turbine inlet temp and Pt5.4, power turbine inlet
pressure expressed in psi
What is the LM 2500 GTM rated at? - CORRECT ANSWER-✔✔ Ambient temp: 100
degrees
Barometric pressure: 29.92 inches Hg
Relative humidity: 0%
Brake horsepower: 26,250
Fuel consumption: 0.42 LB/Hr/Hp
What 2 major assemblies does the LM 2500 consist of ? - CORRECT ANSWER-✔✔ The gas
generator and the power turbine
How many stages is the GTM compressor? - CORRECT ANSWER-✔✔ 16 stages
,What does the compressor stator assembly consist of? - CORRECT ANSWER-✔✔ One set
of inlet guide vanes (IGV) and 16 sets of stationary blades
What are the first six stages stator blading that can be moved called? - CORRECT
ANSWER-✔✔ Variable stator vanes (VsVs)
The VsVs adjusts as a function of what? - CORRECT ANSWER-✔✔ The compressor inlet
temp (CIT), Ngg, and compressor discharge pressure (CDP)
The VsVs minimize the chances of what? - CORRECT ANSWER-✔✔ A stall
The compressor rear frame houses what? - CORRECT ANSWER-✔✔ The combustor, HP
turbine, fuel manifold, 30 fuel nozzles, two spark ignitors, and costumer service bleed air
manifold
What type of combustor is in the GTM? - CORRECT ANSWER-✔✔ An annular type
combustor located inside the compressor rear frame
What percentage of air mixes with the fuel to burn in the combustor? - CORRECT
ANSWER-✔✔ 30%
What percentage of air is used for cooling, flame centering, and bleed air? - CORRECT
ANSWER-✔✔ 70%
Describe the HP Turbine - CORRECT ANSWER-✔✔ A high pressure, two stage, axial flow
turbine
What cools the HP turbine rotary assembly? - CORRECT ANSWER-✔✔ CDP air (16th stage
bleed air)
How are the gas generator and power turbine rotar shaft connected? - CORRECT ANSWER-
✔✔ Aerodynamically coupled
, What does the accessory gear box provide? - CORRECT ANSWER-✔✔ Mounting for and
drives the components needed to start and sustain engine operations
What are the mounted accessories included in the gear box? - CORRECT ANSWER-✔✔
FLAP, (fuel pump, lubo supply, air/oil separator, pneumatic starter)
Describe the power turbine - CORRECT ANSWER-✔✔ A six stage axial flow turbine
aerodynamically coupled to the gas generator, used to drive the main reduction gear via a
high speed flexible coupling shaft (HSFCS)
At what stages is bleed air extracted from the GTM? - CORRECT ANSWER-✔✔ 8th stage-
provides air for the bearing sump pressurization and cooling
9th stage- provides air to the power turbine balance chamber
13th stage- provides air to cool the 2nd stage HP turbine nozzles
16th stage- provides air to the gas generator balance chamber, HP turbine 1st and 2nd rotor
blade cooling, 1st stage HP turbine nozzle and costumer service bleed air system
What are symptoms of a stall in the GTM? - CORRECT ANSWER-✔✔ Higher than normal
or rapid rise in T5.4, decreasing or fail to increase Ngg, low frequency rumble or roar,
sluggish throttle response, higher than normal vibration, and lower than normal Pt5.4
What does the starting and motoring consist of? - CORRECT ANSWER-✔✔ A pneumatic
turbine starter and a start air valve
What does the starter air valve regulates start air to? - CORRECT ANSWER-✔✔ 35-41 psi
Prior to initiating the start command what checks to see if the start permissive are met ? -
CORRECT ANSWER-✔✔ The AN/UYK-44 computer in the SCU
What are the permissive that must be met prior to engine start? - CORRECT ANSWER-✔✔
1.MRG lube oil pressure greater than 13 psig
2.LM 2500 gas generator speed (Ngg) less than 3500 RPM
