Chapter 8 PowerPlant Installation PDF

Chapter 8: PowerPlant Installation Introduction  Powerplant Installation  Engine on Aircraft Configuration  Nacelle Configuration  Engine Accessibility  Engine Firewall  Engine Pylon  Engine Mounts  Engines Drains Mast  Throttle System...

Chapter 8: PowerPlant Installation Introduction  Powerplant Installation  Engine on Aircraft Configuration  Nacelle Configuration  Engine Accessibility  Engine Firewall  Engine Pylon  Engine Mounts  Engines Drains Mast  Throttle System 2 PowerPlant Installation 3 Engine on Aircraft Configuration - Mounted Pod Installation 4 Engine on Aircraft Configuration - Tail And Wing-mounted Pod Installation 5 Engine on Aircraft Configuration - Wing-mounted Pod Installation 6 Nacelle Configuration 7 Nacelle Configuration The position of the power plant must not affect the efficiency of the air intake, and the exhaust gases must be discharge clear of the aircraft and its control surfaces. Nacelles are streamlined enclosures used on multi-engine aircraft primarily to house the core engine. It provide a smooth aerodynamic airflow with min drag and as well as to protect the components mounted on the core engine from physical damage from outside sources. The nacelle consists on skin cowlings, structural members, firewall and the engine mounts. For turbofan it consists of inlet cowl, fan cowl, thrust reverser cowl and the trailing edge fairing. 8 Nacelle Configuration - Inlet Cowl 9 Nacelle Configuration - Fan Cowl Panels 10 Nacelle Configuration - Thrust Reverser Cowl The thrust reversal fairings provides a smooth fairing for the engine and controls fan exhaust for forward and reverse thrust. 11 Nacelle Configuration - Exhaust Sleeve and Plug Purpose: The turbine exhaust components provide a smooth exit path for the turbine exhaust gas. 12 Engine Accessibility 13 Engine Accessibility - Opening The Thrust Reverser 14 Engine Accessibility - Cowling Access Panels 15 Pylon 16 Pylon 17 Pylon Pylon transmit loads produced by the engine and also other loads such as side, vertical, gyroscopic and moment load induced on the engine. It also serve to house the services such as fuel, hydraulics, electrics and the engine related controls. Ideally, pylons are designed to allow easy accessibility for inspection and maintenance. 18 Firewall - Pylon 19 Firewall - Pylon The engine and the wing section must be isolated from to prevent any potential engine fire from spreading to the fuel stored in the wing tank. Firewall must be constructed in such a way that no hazardous quantity of air, fluid, or flame can pass from the compartment to other portions of the aircraft. 20 Firewall - Engine 21 Engine Mount 22 Engine Mount - Loading The mounts serve to transfer the load occurring on the engine on the pylon and subsequently transferred to the aircraft wing. The usual loads that occur on an engine are the vertical, side, thrust and the gyroscopic loads. The forward mount is designed to handle thrust, while other load are designed to be transferred through both mounts. 23 Engine Mount - Gyroscopic Force 24 Engine Mount - Front Mount The front mount is designed to resist all translational and rotational forces and moments. 25 Engine Mount - Rear Mount The rear mount is designed to transmit engine torque load, vertical loads and side loads to the aircraft pylon. As well as allowing any thermal growth on the engine by allowing it to move axially. 26 Engine Mount - Front And Rear Mount For An Aircraft Engine 27 Engine Mount - Front And Rear Mount For An L1011 Aircraft Engine 28 Engine Mount - Vibration Isolators The function of the vibration isolators is to be mechanically isolate the APU or the engine from the aircraft structure to minimize the two-way transmission of vibration and shocks between the aircraft and the engine. 29 Engine Drain Mast 30 Engine Drain Mast *T900 Training Notes 31 Engine Drain Mast 32 Engine Drain Mast Leaks from the accessories and the oil breather are drained overboard via a drain mast. Some of the typical components whose leaks can be connected to the drain mast are:  The gearbox breather (vent)  The hydraulic pump  The fuel pump/Hydro-mechanical metering unit (HMU) assembly  The pneumatic starter  The Integrated Drive Generator (IDG)  The Variable Stator Vane (VSV) actuators  The oil tank scupper  The front pylon structure  The fuel drain tank 33 Throttle System *T900 Training Notes 34 Throttle System – Fuel Control Unit The control lever is mechanically connected to the engine fuel control unit (FCU) where it acts along a graduated angular sector. Control *Turbomeca Training notes 35 Throttle System - Auto Throttle System The auto-throttle system is under the command of an auto throttle computer. Automatic corrections of the selected power lever are effected mechanically by the auto-throttle servomotor, which drives the thrust control system, which simultaneously drives the power lever and the FCU. Auto throttle systems automatically optimizes the thrust that is delivered by the engine depending on the flight level, flight phase, environmental conditions etc. 36 Recap  The general working principle of a pylon  Describe about the loading on both mounts  The components that leak substances to the engine drain mast  Component that is used to absorb vibration  Describe about the Auto Throttle System 37