BOEING 707 circa 1970 - Engine Starting Guide
Introduction
The engine starting procedure is based on that of the real aircraft, and is explained in this HTML file. Since the Boeing 707 lacks an APU, initial starting requires the aircraft to be hooked up to a power unit on the ground. Diagrams are included to make this starting guide easier to use:
Starting the engines using the Ground Power Unit
On a Boeing 707, the engines are normally started in the order 3-4-2-1. The starting procedure for is as follows:
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1. Check that Batteries are Switched On (Flight Engineer Panel) - this is needed to call the Attendant. |
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2. After checking Parking Brake On, call the Attendant to connect the Ground Power Unit (Overhead Panel) - this will provide a supply of electricity for all the aircraft's instruments, many of which are incapable of operating on battery power alone. |
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3. Connect GPU power (Flight Engineer Panel) - check GPU electrical power is connected, then switch the GPU power ON. |
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4. Set the Essential Power Switch to EXT (Flight Engineer Panel) - this allows the ground power unit to supply electricity to the aircraft. |
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5. Call the Attendant to start the compressed air supply (Overhead Panel) - compressed air is needed to start jet engines. |
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6. Check compressed air is available (Flight Engineer Panel) - at least 40 psi duct pressure is needed for starting engines |
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7. Open the Start Air Valve (Overhead Panel) - this allows air from the ground power unit to reach the engine starters (on the Overhead panel) |
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8. Set the Engine 3 Start Control to GND (Overhead Panel) - This opens the flow of compressed air to the engine - you should see the N2 RPM begin to rise. |
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9. Move the Engine 3 Start lever to START (Pedestal) - Once the N2 RPM reaches 15%, move the start lever (below the throttle) to START. This supplies fuel to the engine. |
Once the engine is started, the start control moves to OFF, and the start lever moves to IDLE. Steps 8 and 9 may now be repeated for engine 4,2 and 1. Once the procedure is completed, the Start Air Valve on the Overhead panel should be closed, the Essential Power Switch should be set to receive power from a running engine, and the attendant called again to disconnect the Ground Power Unit.
Cross-bleed Starting
Once one engine is started using the ground power unit, it is possible to use this engine to supply compressed air for starting other engines via a bleed or turbocompressor. The rest of the procedure for starting is the same as for starting using a ground power unit.
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1. Check Engine Bleed is on, or Turbocompressor is running (Flight Engineer panel) - This is needed to supply compressed air to the engine starter. |
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2. Check Electricity is Available (Flight Engineer panel) - set the Essential Power switch to obtain power from the already-running engine. |
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3. Open the Start Air Valve (Overhead Panel) - this allows air from the ground power unit to reach the engine starters |
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4. Set the Engine Start Control to GND (Overhead Panel) - This opens the flow of compressed air to the engine - you should see the N2 RPM begin to rise. |
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5. Move the Start lever to START (Pedestal) - Once the N2 RPM reaches 15%, move the start lever (below the throttle) to START. This supplies fuel to the engine. |
Windmill Starting
If an engine fails in flight, this procedure is used to restart the engine. Unlike modern high-bypass turbofans, the JT3D is relatively easy to spin, and windmill starting is therefore possible at any airspeed above 120 KIAS.
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1. Set the Engine Start Control to FLT |
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2. Move the Start lever to START |