Debbie et al,
The F-16 uses hydrazines as Aerozine-50 (50% monomethylhydrazine/50% un symmetrical dimethylhydrazine -- the latter a suspect, at least. carcinogen) as the fuel source for an auxilliary electrical generator component. T his is located somewhat beneath and aft of the command pilot's seat (but not in the actual cockpit; the pilot wears usually a CRU-60-P flight regulator w ith provides altitude-dependent varying amounts of oxygen and even CPAP at h igher altitudes with a very tight-fitting mask -- a true SAB device) in most F-16 models. The amount of hydrazines is small, to say the least. However, it is there, and small amounts are quite toxic, with t he potential to cause intractable seizures (to most anticonvulsants; there's a reason to use large doses of vitamin B-6; pyridoxine, intravenously just as we do for toxic mushroom poisoning and isoniazid poisoning, containi ng the same sorts of toxicants -- I'll explain the mechanisms if anyone is i nterested, but it happens) and quite significant methemoglobinemia and poten tial intravascular hemolysis. There's quite a bit of old NACA (NASA pe rcursor) and USAF literature on this (used to be used to fuel the liqui d stage of the Saturn-5 and other rockets and in certain liquid stage module s of various ICBMs ). Certain NASA "Shuttle" (STS) flights also used A erozine-50 as the hypergolic fuel and Nitrogen Tetroxide as the oxidizer. Gives one hades of a lot of power or thrust for the volume and weight (which translates into "drag" in the usual aeronautic equation): li fting about 1 pound into low earth orbit used to cost just about $US 17,000. 00 in terms of fuel expended.
When I used to take Flight Surgeon call at what used to be Carswell AFB in Fort Worth, TX where we were the receiving facility from General Dynamic s (just down the way) and civilian pilots brought the old F-16 "A" model ove r for USAF pilots to accept into the USAF inventory, we used to get called o ut to flight line to stand by for usually a flight of two with one experienc ing both electrical and hydraulic failure. The guy with the intact bir d led the other pilot in, and then us ol' flight surgeons had to stand way b ack in the flight line ambulance with binocs and advise the Incident Command er (usually the Fire Chief) about whether it was safe for them to approach t he aircraft. Usually turned out there was a failure of the hydraulics w hich shorted out some of the electrical power busses rather that a leak of h yrazines from the auxillary electrical generator (fluid dripped from about t he same place under the fusillage; the Aerozine-50 is colorless and most hyd raulic fluids have some color), but you sometimes had to call up a GD a eronautical engineer and go over the scematics and then perhaps ru n somebody in in Level A to check the pH (differences between even military s tandard hydraulic fluid and Aerozine-50, enough to almost always give the al l clear) ot get a sample, etc. Meanwhile, a busy runway on a SAC alert base with "gassed and cocked" B-52s sat there waiting for the ol' Soviet Be ar to start something. We tried our best, within safety parameters, to clear that runway ASAP.
So unless they've changed this component in later F-16 models (which I doubt ; from an engineering standpoint it was exceptionally weight/drag-effective) , then the concern might have been real.
Although, also, if an F-16 "augers in" and the military grade jet fuel ignit es, there won't be any hydrazine not thermally degraded left either. T hat's why the pilots have ejection seats, so they have a chance of not being incinerated as well. Of course, all us old pilots, military or civilian, th ink we have the "right stuff" to slap the bird back down, a bit bent or not. But there is a real time to chant the "Bail Out! Bail Out! Bail Out!" mantra and pull the release handles. Even Ol' Flight Surgeons were we ll-trained to do that.
I can give a more fully detailed lecture on the toxicity and mechanisms of t he hydrazines and the treatment or cite the literature if anyone is interest ed, but as Alphonse once said: "That's another story."
Alan H. Hall, M.D.
Maj, USAFR, MC, FS (Hon. Ret.)
Date: Tue, 14 Jun 2011 17:02:01 +0000
From: dmdecker**At_Symbol_Here**UCDAVIS.EDU< /a>
Subject: Re: [DCHAS-L] Chemical Safety Headlines =46rom Google (14 ar ticles)
Last week, (I think) I read one of these whe re an F-16 made an emergency landing (in Madison, WI) with hydrazine aboard. That seems incredibly strange to me. Would anyone in the collec tive have an idea of why an F-16 would be carrying hydrazine? I assume d it was in the crew compartment but the news story was typically sketchy. Hydrazine is an ingredient in liquid rocket propellant but this still d oesn=E2=80=99t make sense.
Debbie M. Decker, Campus Chemical Safety Off icer
Environmental Health and Safety
University of California, Davis1 Shields Ave.
Davis, CA 95616
(530)754-7964/(530)681-1799 (ce ll)
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