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T-38 engine model designation
What are the 7 parts of the engine, in order
- Front frame
- main frame
What is the function of the front frame section?
Admit air into compressor section and direct airflow into the first stage compressor at proper angle
What is the function of the compressor section?
Supply large masses of compressed air into the combustion section.
What is the function of the main frame section?
Primary structural component and divergent diffuser passage for compressed air entering combustion section
What is the function of the combustion section?
To add fuel to the compressed air and ignite it
What is the function of the turbine section?
Extract energy from the high-velocity airstream to drive compressor and engine accessories
What is the function of the exhaust section?
Smooths out airflow leaving turbine and entering tailpipe, contains AB fuel and lighting components and T5 sensor
What is the function of the afterburner section?
augment thrust of main engine 5-40% at a cost of twice the fuel consumption per pound of thrust
What is the function of the variable area exhaust nozzle?
Provides an efficient exit passage that opens and closes to optimize engine efficiency and control EGT
What is the purpose of the variable geometry system?
Inlet guide vanes direct incoming air to the optimum AOA
What are the operating characteristics of the variable geometry system?
At low RPM, bleed valve opens to allow compressed air escape the 3rd-5th stages of the compressor
What is the purpose of the engine anti-ice system?
To prevent ice build-up on the inlet vanes and bullet nose of the engine
What are the operating characteristics of the engine anti-ice system?
Directs 8th stage compressor air; automatically comes on with right AC failure
What is the purpose of the engine accessories?
Converts engine power into usable power for aircraft systems
What are the operating characteristics of the engine accessories?
Divided into 2 sections - airframe accessories and airframe mounted gearbox. Driven by a power takeoff (PTO) from engine compressor drive shaft
What is the purpose of the fire detection system?
Warn the pilot of a high-temperature condition in the engine bay
What are the operating characteristics of the fire detection system?
- Cannot be dimmed
- independent for L and R
- operates on DC power
- sensors are pneumatically operated through inert gas
- can respond to average or highly localized temps
What is unique about the tachometer?
Only independently operated indicator in the whole jet
What are the three failure modes of the tachometer?
- broken wire (0%)
- sheared oil pump shaft
- EED failure (FAIL)
What are the AC-powered instruments?
- hydraulic pressure
- engine tachometer
- fuel flow
- fuel quantity
- oxygen quantity
- oil px
What are the engine-oil restrictions for zero-g and neg-g flight?
10 seconds and 30 seconds
What are the DC-powered instruments?
- nozzle, EED, EGT, flaps
What purpose of the inlet guide vanes serve?
Reduce possibility of compressor stalls
How will anti-ice be affected with an AC power failure?
fully effective (automatic) above 80% RPM
What atmospheric conditions should you use anti-ice?
Temp near or below 32*, visible moisture or high humidity
What is the primary advantage of afterburners in engine design?
High thrust for low weight
Name 3 properties of the T5 system and nozzles
- Nozzles close until 97%
- T5 operates nozzles to maintain 630-650 EGT in MAX
- T5 system's purpose maintain EGT within limits
What are two ways you can observe the T5 system working?
- Observe EGT between 630 and 650
- check nozzles open while advancing throttle from 97% to MIL
What is the T5 electrical source?
Independent AC alternator