BOEING 707-420 - 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. In the simulation, this ground power unit is available whenever the aircraft is stationary. 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:

| 1. Hook-up Power from the Ground Power Unit - the ground power unit provides electricity, plus the compressed air required for engine starting (on the Flight Engineer panel).
| 2. Set the Essential Power Switch to EXT - this allows the ground power unit to supply electricity to the aircraft.
| 3. Open the Start Air Valve - this allows air from the ground power unit to reach the engine starters (on the Overhead panel)
| 4. Set the Engine 3 Start Control to GND - This opens the flow of compressed air to the engine - you should see the N2 RPM begin to rise.
| 5. Move the Engine 3 Start lever to START (on the 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 4 and 5 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 Ground Power Unit should be disconnected.

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.

| 1. Check Engine Bleed is on, or Turbocompressor is running - This is needed to supply compressed air to the engine starter. (check on the Flight Engineer panel)
| 2. Check Electricity is Available - set the Essential Power switch to obtain power from the already-running engine.
| 3. Open the Start Air Valve - this allows air from the ground power unit to reach the engine starters
| 4. Set the Engine Start Control to GND - This opens the flow of compressed air to the engine - you should see the N2 RPM begin to rise.
| 5. Move the Start lever to START - 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.

| 1. Set the Engine Start Control to FLT
| 2. Move the Start lever to START

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