The Fire Warning/Extinguishing System is included with the Pratt & Whitney F100-PW-220/229 engine integration to the F-15E. Engine integration is illustrated by a cutaway drawing below.

To prevent fire in one engine to reach the other engine, the two engine bays are divided by massive titanium firewalls (5). The Fire Warning/Extinguishing System consists of cockpit controls, various warning/caution lights, a fire extinguisher bottle and fire sensors located in the engines and AMAD compartments.

The container of fire extinguishing material is located between the firewalls (4). This is a 'one-shot' bottle, it can empty its gaseous content to the appropriate engine/ AMAD only once. The extinguishing gas is non-toxic, non-corrosive and will not damage aircraft components.

Electrical power is required to operate the Fire Warning/Extinguishing System. It is linked into the Jet Fuel Starter (JFS) (15), Airframe Mounted Accessory Drives (AMADs) and engines. During JFS operation, before the emergency generator comes on-line, only the AMAD system is operative.

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Pilot Controls

The Fire Warning/Extinguishing System is controlled from a dash-mounted panel in the top left side of the front cockpit (see illustration below).

The system features three illuminated pushbuttons, one for each engine and one for AMAD. The rear cockpit has lights only for the two engines. In case of engine/ AMAD fire or afterburner/engine overheat occurs, the appropriate pushbutton illuminates and a "fire sensor" caution appears on the caution display on the MPD/ MPCD while the master caution light and engine caution light illuminates as well. In the meantime the pilot gets appropriate audio warning from ' Bitching Betty' as well. The voice warning will state the cause of problem, pauses and repeates it again. Possible audio warning messages are the following:

• "Warning, overtemp left"
• "Warning, overtemp right"
• "Warning, engine fire left"
• "Warning, engine fire right"
• "Warning, AMAD fire"
• "Warning, AB burn thru right"
• "Warning, AB burn thru right"

Overheat occurs when temperature in the afterburner or in the engine's turbine section exceeds design limits. These limits are 1,000 and 1,107 Celsius FTIT (Fan Turbine Inlet Temperature) for PW-220 and PW-229 engines, respectively.

Pushing the button illuminated (after lifting a spring loaded metal guard) immediately removes power from the appropriate engine, shuts off bleed air, removes fuel flow from the engine and arms the extinguisher for discharge. After button push the engine decelerates but may continue running at sub-idle rpm for up to 120 seconds until the fuel is consumed downstream of the airframe mounted fuel shutoff valve. Pushing the AMAD button (guarded too by a spring loaded metal cover) will not prevent normal JFS operation.

When arm is selected, the black-yellow stripes around the discharge switch become visible. The fire light buttons must be pressed again to dearm the extinguisher and restore the selected system to normal operation. Once armed (the appropriate pushbuttons pushed) it can be discharged by a switch located above the pushbuttons (see illustration above). The switch is spring loaded to the middle, normal position. Extinguisher gas discharge cannot be initiated from the rear cockpit.

A test feature (to test the system without actually discharging the extinguisher gas) is also included. Switching to test mode the three fire warning lights illuminate (only the AMAD light illuminates during JFS operation) indicating the fire sensors are operational. Rear cockpit lights are also illuminated. Each fire light consists of four quarters (see illustration above), each of them capable of illuminate independently. The top two quarters of the AMAD light are associated with the AMAD fire sensor loop, while the two bottom quarters with the JFS fire sensor loop. In case of the engine fire lights, the top two quarters are associated with the forward transponder loop, the bottom two quarters with the aft transponder loop. If any of the quarter-pair are not illuminate, this means there is a problem with their corresponding sensor loops.

Note that from aircraft serial number 87-0201 and up the front cockpit warning/extinguisher panel contains left and right "afterburner burnthru" warning lights.

Sources

• F-15E Flight Manual TO 1F-15E-1 (courtesy of eFlightManuals.com)

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