ORIGINAL: John Palica
I know that with the big turbines that I work with at Pratt & Whitney, we pull an engine down after the fire bottles are discharged. It plugs up cooling passages and it's corrisive to the hot parts. I believe it's Halon.
I believe most aircraft turbine engines still use Halon 1211 due to the effectiveness. I do know some used dry chemical years ago in some cases, and that was really a maintenance intensive situation after a discharge. The big difference between a full size engine fire fighting scenario and a model turbine scenario is that in our circumstance, we are primarily fighting a small spot fire caused by, most likely, a pooling for fuel or small torch with low RPM so the flame hangs out in the local area possibly igniting other flammable materials on or within the model. We have to shoot at the engine itself, in the inlet area, etc. It's highly likely the CO2 (or whatever you are using) will get INSIDE the engine. Whereas in the full scale scenario a very focused and concentrated burst of halon goes to the outside of the engine case and the nacelle / accessories area with little chance of ingestion within the engine. So even while some dry powder has been used in the past with full scale, it never went "inside" the engine by design.
I have a feeling the "plugging up" of the engine thing on the full size stuff (after firing the halon) is due to the "squibb" or gunpowder blasting cap material as well as general metal shrapnel that gets inside the Halon direction plumbing as a by product of breaking the fire bottle seal to activate the halon gas, but I could be way off base too!
John, I have two extra aircraft cabin halon extinguishers, the 2.5 pound variety, decent size and pretty portable - if you can't find a reasonable CO2 extinguisher on the refurbished market let me know. I tried Ebay, I thought I might be able to get a decent deal but one guy's buddies kept out bidding me every time and the same extinguisher would go up again afterwards on a new listing so I said to heck with it and bought my refurbished and hydrostatic tested 10 pound CO2 bottle locally from a fire refurbishing company for $90 - no shipping, got it one day after I called. You can probably get them for 50 bucks somewhere but I never had any luck with that option that didn't involve phantom bidding on ebay or "wait and see what comes in over the next couple months" scenarios. Lots of nickels and dimes needed for the "extras", do you have your fuel station yet?
