LEFT: B737-600 NG Fire Suppression Panel installed to center pedestal. The lights test illuminates the annunciators (click to enlarge).
This is the third fire panel I have owned. The first was from a Boeing 737-300 which was converted in a rudimentary way to operate with very limited functionality in Flight Simulator. The second unit was from a B737-600 NG; but, the conversion was an ‘intermediate’ design with the relays and interface card located outside the unit within the now defunct Interface Master Module (IMM). Both these panels were sold and replaced with the current 600 NG series panel.
I am not going to document the functions and conditions of use for the fire panel as this has been documented very well in other literature. For an excellent review, read the Fire Protection Systems Summary published by Smart Cockpit.
LEFT: B737-600 NG series Fire Suppression Panel light plate, fire handles, annunciators and installed interface card and relays (click to enlarge).
Before going further, it should be noted that the Fire Suppression Panel is known by a number of names: fire protection panel, fire control panel and fire handles are some of the more common names used to describe the unit.
'Plug and Fly' Conversion
LEFT: Panel with outer casing removed showing installation of Phidget and and relays. Ferrules are used for easier connection of wires to the Phidget card. Green tape has been applied to the red lenses to protect them whilst work is in progress (click to enlarge).
Rather than rewire the internals of the unit and connect to interface cards mounted outside of the unit, it was decided to remove the electronic boards from the panel and install the appropriate interface card and relays inside the unit. To provide 5 and 28 volt power to illuminate the annunciators and backlighting, the unit uses dedicated OEM (Original Equipment Manufacture) Canon plugs to connect to the power supplies. Connection of the unit to the computer is by a single USB cable. The end product is, excusing the pun - ‘plug and fly’.
Miniaturization has advantages and the release of a smaller Phidget 0/16/16 interface card allowed this card to be installed inside the unit alongside three standard relay cards. The relays are needed to activate the on/off function that enables the fire handles to be pulled and turned.
LEFT: Rear of panel showing integration of OEM Canon plugs to supply power to the unit (5 and 28 volts). The USB cable (not shown) connects above the middle Canon plug (click to enlarge).
The benefit of having the interface card and relays installed within the panel rather than outside cannot be underestimated. As any serious cockpit builder will attend, a full simulator carries with it the liability of many wires running behind panels and walls to power the simulator and provide functionality. Minimizing the number of wires can only make the simulator building process easier and more neater, and converting the fire handles in this manner has followed through with this philosophy.
Complete Functionality including Push To Test
The functionality of the unit is only as good as the flight avionics suite it is configured to operate with, and complete functionality has been enabled using ProSim737.
One of the positives when using an OEM Fire Suppression Panel is the ability to use the push to test function for each annunciator. Depressing any of the annunciators will test the functionality and cause the 28 volt bulb to illuminate. This is in addition to using the lights test toggle located on the Main Instrument Panel (MIP) which illuminates all annunciators simultaneously.
At the end of this post is a short video demonstrating several functions of the unit.
The conversion of this panel was not done by myself. Rather, it was converted by a gentleman who is debating converting OEM units and selling these units commercially; as such, I will not document how the conversion was accomplished as this would provide an unfair disadvantage to the person concerned.
Differences - OEM verses Reproduction
There are several reproduction fire suppression panels currently available, and those manufactured by Flight Deck Solutions and CP Flight (Fly Engravity) are very good; however, pale in comparison to a genuine panel. Certainly, purchasing a panel that works out of the box has its benefits; however the purchase cost of a reproduction panel is only marginally less that using a converted OEM panel.
By far the most important difference between an OEM panel and a reproduction unit is build quality. An OEM panel is exceptionally robust, the annunciators illuminate to the correct light intensity with the correct colour balance, and the tension when pulling and turning the handles is correct with longevity assured. I have read of a number of users of reproduction units that have broken the handles from overzealous use; this is almost impossible to do when using a real panel. Furthermore, there are differences between reproduction annunciators and OEM annunciators, the most obvious difference being the individual push to test functionality of the OEM units.
Fire Suppression Panels are not difficult to find; a search of e-bay usually reveals a few units for sale. However, many of the units for sale are the older panels used in the classic B737 airframes.
LEFT: B737-200 Fire Suppression Panel. The differences between the older 200 and 300 series and the NG style is self evident; however the basic functionality is similar.
Although the functionality between the older and newer units is almost identical, the similarity ends there. The Next Generation panels have a different light plate and include additional annunciators configured in a different layout to the older classic units.
The video demonstrates the following:
- Backlighting off to on (barely seen due to daylight video-shooting conditions)
- Push To Test from the MIP (lights test)
- Push To Test for individual annunciators
- Fault and overhead fire test
- Switch tests; and,
- A basic scenario with an engine 1 fire.
NOTE: The video demonstrates one of two possible methods of deactivating the fire bell. The usual method is for the flight crew to disable the bell warning by depressing the Fire Warning Cutout annunciator located beside the six packs on the Main Instrument Panel (MIP). An alterative method is to depress the bell cutout bar located on the Fire Suppression Panel.