Powerplant Ch. 6 Flashcards
What are the engines on the G280?
Honeywell HTF7250 turbofan engines
How many pounds of thrust do the engines provide?
7,240lbs of max continuous thrust
The engine is an ________
Integrated Power Plant System (IPPS)
What does the Integrated Power Plant System include?
Air inlet, engine cowling, accessory gear drive, and TR
The engine is a ____ bypass ratio (BPR), ___ spool, __-____ turbofan engine
4.2
Two
Co-rotating
The inner spool contains the large diameter fan stage at the forward end that is driven by _____
Three turbine stages at the aft end
What is the inner spool referred to as? Why?
The Low Pressure or LP turbine
The 3 turbine stages at the aft end of the engine, that drive the large diameter fan at the forward end of the engine, are located within the larger diameter and cooler section of the engine exhaust where gases expand
What does the outer spool rotate freely around? What is it termed?
Inner spool
The high pressure or HP turbine
What does the HP turbine consist of?
Four stage axial and single stage centrifugal compressor driven by a two stage HP turbine
What is each spool supported by?
Roller/Thrust bearings, they are lubricated by a recirculating oil system
How many spray nozzles are located in the combustion chamber? How many igniter plugs?
16
2
What are engine control and monitoring functions executed by?
Full Authority Digital Electronic Control (FADEC)
What are the different sections of the Honeywell HTF7250?
Air Inlet
Compressor
Combustion
Turbine
Exhaust
Bypass
Accessory Drives
How is the exhaust noise suppressed?
The exhaust duct is formed by a convergent duct that mixes turbine exhaust with LP fan air
Rotational engine force is used to provide the mechanical drive for aircraft system components via an ___ and __________
LP and HP accessory gearbox
What does the HP gearbox power?
- 28VDC generator
- Hydromechanical unit (Includes fuel pump)
- Oil pump
- Hydraulic pump
- PMA - Permanent magnet alternator
What does the start system consist of?
An Air Turbine Starter (ATS) and an ATS control valve
How is engine rotation started? Where could that come from?
Supplying air to an engine mounted Air Turbine Starter
APU Bleed Air
Cross engine bleed air (one engine to another)
Ground air cart
How is the engine ignition system activated?
Automatically by the FADEC or manually by a cockpit switch
How is the ignition system powered?
By the emergency buses during start, or by an engine mounted PMA when engines are running
What systems does the engine consist of?
Full Authority Digital Electronic Control (FADEC)
Engine fuel system
Engine oil system
Thrust control system
Autothrottle system
Indication
Thrust reverser system
What is the primary control unit of the FADEC? What does it do?
Electronic control units (ECU)
Commands engine thrust in relation to the power position set on the throttle quadrant
When does Automatic Performance Reserve (APR) become Manual Performance Reserve (MPR)?
Press the APR switch on the center pedestal and setting takeoff power manually
What controls the amount of fuel being delivered to the spray nozzles?
The fuel metering unit by the electronic control unit
While the reverse doors are in transit, what icon is displayed in the respective N1 scale?
White “REV”
When does the green “REV” icon display in the respective N1 Scale?
When the doors are fully deployed, accompanied by an audible click in the TQA
When is max reverse thrust available?
Above 85 knots
What percent of reverse thrust is available from 85-65 knots?
68%
When must reversers be at Idle?
40 knots
When will normal thrust reverser operation occur?
Landing gear down & locked
Aircraft is weight on wheels or wheel spin is greater than or equal to 45kts
Engine thrust levers selected to “reverse idle” or at a position further back on the throttle
When would you abort an engine start?
No N2 rotation
N2 fails to reach idle speed within engine start time limitations
No N1 rotation by 25% N2
Light-off does not occur within 30 seconds of start initiation
N1 or N2 stops accelerating to idle (hung start)
No positive indication of oil pressure by 30% N2
ITT rises rapidly through max start limit of 650 up to 40% N2
Any unusual noise or vibration
ATS Valve Fails to close
*L starter on CAS
*R starter on CAS
*switching fuel control to off after removing all bleed air sources to the ATS
