Engine Control System Flashcards
Type of Engine
T700-GE-401C
Horse Power
1662 SHP Continuous
1800 SHP 30 min
1940 SHP 2.5 minutes
Dimensions
Length, MR Diameter, TR Diameter, Wheel Base, Height, Width, Ground Clearance
Length Overall- 64' 10" Main Rotor Diameter- 53' 8" Tail Rotor Diameter- 11' Wheel Base- 29' Height- 17' Width- 7' 9" Ground Clearance- 1' 7"
Flow of Air Through Engine
Inlet (5th stage bleed air via engine AI/SB valve)
Swirl (Imparts Rotation)
IPS (Throws Particles Outward)
Collection Scroll (Particles Collected)
Scroll Vanes (Contained in collections scroll)
Deswirl (removes rotation)
Compressor (smooth, particle free air)
Ng Turbine
- Two Stages
- Drives Compressor and AGB
Np Turbine
- Two Stages
- Np Shaft is inside Ng Shaft
- Connects to High Speed Shaft, which connects to input module
Engine Air Used For Combustion
30%, remaining used for
- 1) T2 (Compressor Inlet Temperature Air)
- 2) P3 (Compressor Discharge Pressure Air)
- 3) Combustor and Turbine Cooling
- 4) Engine Oil Seal Pressurization
Major Components of Engine
HMU, ODV, DECU, Alternator, and Fuel Flow Valves
Basic Operation
- Maintain Constant Np/Nr
- Interaction of DECU and HMU
- HMU provides Gas Generator control while DECU trims HMU down to meet demands of Np, ultimately reducing pilot workload
Load Demand Spindle
- HMU responds quickly to collective position via load demand spindle
Inputs to HMU (5)
- Collective via LDS
- PCL via PAS
- Variable Stator Vanes and AI/SB valve positioning is controlled in response to T2, P3, and Ng
1) Fuel Shutoff
2) Automatic Acceleration to Ground Idle
3) Set up to Max permissible Ng
4) Fuel Priming
5) DECU Lockout
HMU Operation
- Basic Gas-Gen power control with no input from Torque Motor Servo
- Fuel Enters through Pump, routed to metering valve
- LVDT provides feedback to DECU to prevent hunting
Ng Ovespeed Valve
110 +- 2%
HMU provides higher then required power for 2 reasons:
1) Fail Safe to High Power
2) Power Available with One Engine Inop (OEI)
HMU Functions (6)
1) Ng Governing
2) Ng Overspeed Protection
3) Flame-out/Compressor Stall Protection
4) Acceleration Limiting
5) Automatic Fuel Scheduling For Engine Start
6) Rapid Engine Response through Collective Compensation