Mailing List lml@lancaironline.net Message #26558
From: Jim Auman <jimauman@comcast.net>
Sender: Marvin Kaye <marv@lancaironline.net>
Subject: Re: [LML] Re: Halon fire extinquishers - Certain Pre-Preg Burn Characteristics!
Date: Thu, 11 Nov 2004 18:51:34 -0500
To: <lml@lancaironline.net>
I have interjected a point or two below that need clarification.
 
The nose gear fold and resultant fire was due to PIO unrelated to the gear switch scenario (although true, in a previous incident years before without fire.)  Damage from that earlier incident was the usual gear up stuff.
 
Jim Auman
 
jimauman@comcast.net
----- Original Message -----
Sent: Thursday, November 11, 2004 9:33 AM
Subject: [LML] Re: Halon fire extinquishers - Certain Pre-Preg Burn Characteristics!

In a message dated 11/11/2004 8:10:37 AM Central Standard Time, lorn@dynacomm.ws writes:
Now that I think about it, I don't think that you should lean the plane
at all. If I have a fire at startup, my engine may be able to suck the
fire into itself if left running. I can't think of a better place to
put the fuel than into the engine. Am I missing something?
Lorn, Et Al,
 
Assuming the fire is from an oil or fuel leak in the engine compartment, most of us would not be sucking the fire into the engine because of fancy air induction systems, ram air, etc.  Now, my old Skymaster could possibly do that because the air intake (thru a filter) sat in the upper cooling plenum -- that is the induction air was being taken from inside the cowling.
 
If the engine was running, I guess a better sequence would be to turn off the fuel supply valve but leave the mixture rich so that most of the fuel in the lines, gascolater and pump  could be burned inside the engine rather than in the engine compartment.
 
BTW, yesterday I saw a Lancair 235/320 restoration project that left me with my jaw hanging.  Here is the setup - The gear switch was an ordinary toggle switch set at the bottom of the left side of the panel - low enough to be exposed to a knee or bad hand movement (bad idea).
 
JLA         Howdy! This is Jim.  I need to interject some light to this detail.  The switch location was the culprit to a previous incident that resulted in the "gear up" at a high desert episode in ground effect.  But no fire on that incident.
 
JLA  The second incident that did this ship in was PIO by the pilot insisting that he get this bird on the runway and not go around as would have been prudent.
 
Instead the nose gear overcenter link gave out after about the third PIO and said "I'm outa here" and broke allowing the nose gear to fold.  The rest is pretty much as stated....
 
Thanks for visiting and appreciating the restoration!......JLA.
 
  Upon landing and rollout, the nose gear was retracted (probably thru the switch going up) and as the nose/bottom cowl was scraping along, a fuel line was broken open and an engine compartment fire ensued.  At some point, the fuel was shut off and the pilot successfully exited the airplane.  The fire burned the spinner, the right side of the cowl, the right edge of the upper deck/header tank, the right fwd canopy was burned and plexiglas deformed, the right fwd fuselage skin burnt, the right fwd upper stub wing skin burned and bubbled and there was some minor fire damage behind the right side of the panel.  I do not know how the fire was put out and, with respect to the airframe, the damage was only to the outer skin and a singeing of the outside of the foam core.
 
The most interesting part.  Almost none of the fiberglass was consumed by the fire, but the epoxy was.  That is, all of the components that suffered flames were as though at some heat level the epoxy was liquefied and then joined the fire but the glass fabric did not burn.  In fact, the fabric, sans epoxy, looks and feels normal except that it is black.  Of course, some edges here and there were burned away.
 
The spinner itself is basically a bowl of floppy fabric!  Parts of the cowl show the coarse and fine glass fabric and the glass mat material that was used in its construction.  The next time I visit this project, I will try to get some pictures. 
 
Interesting, Huh?
 
Scott Krueger AKA Grayhawk
N92EX IO320 Aurora, IL (KARR)

Some Assembly Required
Using Common Hand Tools.
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