Upskill / Aerospace and Space / How gas-turbine engines work
How gas-turbine engines work
The Brayton cycle, intake to nozzle, turbofans, turboprops and turboshafts, bypass ratio, thrust and fuel burn, spools and engine systems, limits, certification and engine life. Part 1 of the Propulsion series.
By Aerospace Garage Desk · Basics · 45 minutes · 24 narrated pages
What you will be able to do
- ✓ Explain the gas-turbine (Brayton) cycle and calculate thrust and thrust specific fuel consumption from airflow, exit velocity and fuel flow.
- ✓ Describe what the intake, fan, compressors, combustor, turbines and nozzles do, and read pressure and temperature along the numbered engine stations.
- ✓ Compare turbojet, turbofan, turboprop and turboshaft engines and explain how bypass ratio affects fuel burn and noise.
- ✓ Describe spools, the accessory gearbox, fuel, oil, bleed air and the starting sequence, and recognise normal and abnormal starts.
- ✓ Summarise engine operating limits and the main CS-E and 14 CFR Part 33 certification tests, using the ValuJet Flight 597 investigation (NTSB/AAR-96/03) to explain blade containment and disc life limits.
- ✓ Explain flight cycles, life-limited parts and shop visits, and find the limiting part and the latest removal date for an engine.
Course content
Session 1 · The gas-turbine idea
1.1
- Squeeze, burn, expand: the Brayton cycle · free preview
- From pressure to thrust
- Pressure, temperature and the turbine limit
- Worked example: the thrust of an illustrative turbofan
Session 2 · Inside the engine: from intake to nozzle
1.2
- Intake and fan
- Compressors: many small steps
- Combustor, turbines and nozzle
- Worked example: reading a station table
Session 3 · Turbojet, turbofan, turboprop, turboshaft
1.3
- One core, four jobs
- Bypass ratio: fuel and noise
- Thrust and fuel burn in the real world
- Worked example: the business case for a lower-TSFC engine
Session 4 · Spools, gearbox and engine systems
1.4
- Spools: one, two or three shafts
- The accessory gearbox, fuel, oil and control
- Bleed air and starting
- Worked example: reading four starts
Session 5 · Limits and certification
1.5
- Living within the limits
- How an engine is certified
- Birds, rain, hail and ETOPS
- From the investigation file: ValuJet Flight 597
Session 6 · Engine life: cycles, life-limited parts and shop visits
1.6
- Counting cycles, not just hours
- Life-limited parts and their records
- The shop visit in outline
- Worked example: which part ends the engine's time on wing
Who this course is for
- Students and apprentices meeting turbofans, turboprops and turboshafts for the first time
- Planners, buyers and lessor staff who need cycles, life-limited parts and shop visits explained
- Pilots wanting to know what happens between intake and nozzle during a normal start
You need: No prior knowledge needed; simple arithmetic is used.
Upskill courses are for professional development and are not approved by any aviation authority. Learner Terms
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