GTM Parameters Flashcards
What are the parameters of the GTM compressor?
16 stage, 16:1 axial flow annular type
1 Stage inlet guide vane (IGV)
6 stages variable stator vanes (VSV)
Bleed Air Regulating Valves Set point
75 Psig
What does 8th stage bleed air provide?
Sump pressurization and cooling
GG balance and piston air
What does 9th stage bleed air provide?
Mid frame strut cooling
PT Turbine Fwd Seal Pressurization
PT Balance piston cavity Press
What does 13th stage bleed air provide?
Cooling 2nd Stage HP Turbine Nozzles
What does 16th stage bleed air Provide?
Cooling 1st stage HP Turbine nozzles
Note: ship service -start , pairie anti-icing, masker. Ngg of 7500 rpms required to produce usable pressure for ships service.
Discharge static pressure rated?
250 Pisa max
How many stages in the HP turbine?
Two stage
How many stages in the gas generator?
16 stages
What is the idle speed of the GTM?
5000 rpm +/- 100rpm
What is the overspeed alarm point?
9700rpm, if exceeds 10,122 rpms, then the engine must be overhauled
Windmilling limits
100 rpms for 2 weeks
>1000 rpms w/ scavenge oil temp <300F
GG High vibration alarm set point
4 MILS (NGG >4850)
GG high vib trip
7mils, ( NGG >4850)
How long can the engine be operated with the PT break engaged?
14 mins @ idle
How many stages in the power turbine?
6 stages
What is idle speed of the power turbine?
1600-2200 rpms
What is the PT speed high alarm set point?
3852 rpms
What is the overspeed trip for GTM?
3960 +- 40 rpm ( if 4585 rpms exceeded, PT must be overhauled)
When is speed limiting active?
3672 rpm
PT high vibes set point?
7 MILS (NGG > 4850)
PT High vibe trip point
10 MILS (NGG >4850)
Idle T5.4
1000 F
Hight T5.4
1600F
High T5.4 trip
1625 F
What bearing is in A sump?
3 roller
What bearing is in B sump?
4 roller and 4 ball
What bearing is in C sump?
5 roller 6 ball
What bearing is in D sump?
7 ball 7 roller
What type of fuel?
F-76, F-44 in emergencies
Fuel pump rating is at?
78 GPM
Fuel filter rating?
46-76 microns
DP alarm set point for fuel filter
27 psid (7 psi at idle)
What is the Bypass valve set point.
30-40 psid
How many nozzles are in the LM2500?
30 dual office, swirl atomizer with internal flow divider
When does the flow divider open?
Opens at 330 -350 psi
What is the flame out trip?
< 400F T5.4 and > 50 Psig FMP
What is the idle FMP?
230 - 350 psi. (80-160 psi at ignition)
How much fuel does the Purge Valve Use?
Approx 3 GAL
Ignition Exciter Voltage
20,000 Volts
Start Air Pressure
35-45 PSI
Motor Pressure
20-22 PSI
Max Temp for starter system
200F
Starter CutOut
NGG 4500+/- 200 RPM