Fuel level senders

[Adrian Tuddenham]

Yep, caused by the battery being compromised. All that acid spilling on
all that metal, plus the electochemical energy stored in there getting
out due to shorts, etc.

Not always. Spillage of brake/clutch fluid onto a hot engine manifold
has been identified as a cause of an increase in car fires in some
models. After the older soldered-on metal brake fluid reservoirs were
replaced by plastic 'plug in' ones, a relatively minor shunt could
dislodge the reservoir and spray fluid all over the engine compartment.

I have securely tied mine onto the metal body of the master cylinder.

 

[Rich The Newsgroup Wacko]

But engine compartment fires happen regularly.

Last weekend, in my neighborhood, we had a drunken teenager hit a
wall, partially ejected through the windshield (no seat belt).

The car burst into flames and the teenager was burned to death,
because no one could get close enough to pull him out in time.

Darwin Strikes Again! >:->

Cheers!
Rich

 

[Jim Thompson]

Not always. Spillage of brake/clutch fluid onto a hot engine manifold
has been identified as a cause of an increase in car fires in some
models. After the older soldered-on metal brake fluid reservoirs were
replaced by plastic 'plug in' ones, a relatively minor shunt could
dislodge the reservoir and spray fluid all over the engine compartment.

I have securely tied mine onto the metal body of the master cylinder.

I always thought those fluids had high flash points. Then I sprung a
pinhole leak in a power steering hose and had a fire going on the
exhaust manifold that rivaled a furnace burner ;-)

...Jim Thompson

 

[Franc Zabkar]

<snip>

I got a kick out of this, at the bottom of the page:
------------------
** HISTORICAL FOOTNOTE: Aluminum was originally named "alumium" by Sir
Humphry Davy, who later changed it to "aluminum" (perhaps in an attempt to
make it more Latinized since alumen is Latin for alum, the aluminum
compound that the name is derived from). The British (and allied English
speakers) shortly thereafter changed the name once more, this time to
"aluminium" so that it would again match the pattern of most other
elements (helium, sodium, etc.), while the North Americans eventually
decided to keep the second, slightly more traditional name. I predict that
North Americans will adopt the more regular "-ium" spelling by the year
2050, prompting the British to start calling it "alumininium". At that
point debate can begin on changing "platinum" to "platinium"

Genuine tin foil hats are made from stannum. In any case, plumbum
would be better for keeping out the harmful radiation. Argentum and
aurum may not work as well, but the sort of people who would wear them
wouldn't be seen dead in aluminium apparel.


- Franc Zabkar

 

[Paul Hovnanian P.E.]

Those fuel pumps actually use the fuel to help cool them ! The commutator area is
sealed however !

Not necessarily. I've seen fuel pumps with commutators immersed in the
fuel. They work just fine.

Actually the problem lies not so much with the FQIS itself but wiring ageing
problems in old jets.

I've seen pics of arc-over between cables in airframes and it's no joke. The
presumption is that something arced over to the FQIS and that provided sufficient
ignition energy.

Sufficient energy for what? The mixture in a fuel tank is too rich to
ignite, particularly on a hot day.
The fuel's vapor pressure would be quite high. Upon takeoff, the
decreasing atmospheric pressure would drive the vapors out of the tank,
replaced by pure fuel vapor from the warm fuel.

I doubt that the full truth will ever some out.

Probably not. Its just interesting to note the things they overlook.

 

[Paul Hovnanian P.E.]

It might have been. I was doing some work for Sperry/Honeywell Flight
Systems at the time, and I was told that the armature hit the stator
on "a" pump, due to no (fuel) lubrication.

Doubtful. The center tank was, for all practical purposes, empty. Why
would a pump be running in there?

 

[Paul Hovnanian P.E.]

Except in Hollywood !

Or with a cellular phone. ;-)

 

[Paul Hovnanian P.E.]

I always thought those fluids had high flash points. Then I sprung a
pinhole leak in a power steering hose and had a fire going on the
exhaust manifold that rivaled a furnace burner ;-)

An oil leak will start a pretty good fire too.

 

[Ken Taylor]

Genuine tin foil hats are made from stannum. In any case, plumbum
would be better for keeping out the harmful radiation. Argentum and
aurum may not work as well, but the sort of people who would wear them
wouldn't be seen dead in aluminium apparel.


- Franc Zabkar
--

Hang on, wouldn't they be stannum hats then? And would Argentum hats be used
in the Falkland Islands by the British?

Ken
(I've got such an aura about me that I wear an aurum hat to protect others!)

 

[Pooh Bear]

sealed however !

Not necessarily. I've seen fuel pumps with commutators immersed in the
fuel. They work just fine.

I can see that could be true. The ones Boeing used on the 747 did have isolated
commutator compartments though IIRC.

ignition energy.

Sufficient energy for what? The mixture in a fuel tank is too rich to
ignite, particularly on a hot day.

Ahh - but that has always been the presumed wisdom.

Events have shown otherwise. A couple of 737s have 'blown up' on the ground due to fuel
tank explosions.

The fuel's vapor pressure would be quite high. Upon takeoff, the
decreasing atmospheric pressure would drive the vapors out of the tank,
replaced by pure fuel vapor from the warm fuel.

That's the perceived wisdom for sure.

But here's the snag.

The centre tank on TWA 800 was almost empty. There was some elaborate modelling to
illustrate how its potential for ignition varied with altitude too.

Probably not. Its just interesting to note the things they overlook.

aircraft lost on the ground due to fuel tank explosions too.

It's interesting to note that there is now an economical fuel tank inerting system being
developed.

Graham

 

[Rich The Newsgroup Wacko]

Genuine tin foil hats are made from stannum. In any case, plumbum
would be better for keeping out the harmful radiation. Argentum and
aurum may not work as well,

Well, now you're getting into the area of, "Define, 'work'". I think
an aurum and argentum hat might be very becoming, in the right circles.
Heavens knows, they're (argentum and aurum) quite popular amongst
electronics aficionadi, albeit not necessarily as headgear.

but the sort of people who would wear them
wouldn't be seen dead in aluminium apparel.

Amen!

 

[Paul Hovnanian P.E.]

I can see that could be true. The ones Boeing used on the 747 did have isolated
commutator compartments though IIRC.

The fuel pumps on a 747 are 120V 3 phase (400Hz). There are no
commutators.

Ahh - but that has always been the presumed wisdom.

Events have shown otherwise. A couple of 737s have 'blown up' on the ground due to fuel
tank explosions.

What was the primary failure in each case?

That's the perceived wisdom for sure.

But here's the snag.

The centre tank on TWA 800 was almost empty. There was some elaborate modelling to
illustrate how its potential for ignition varied with altitude too.

Why elaborate? Probably because the simple explaination didn't get them
the right answer.

It's interesting to note that there is now an economical fuel tank inerting system being
developed.

I see that this whole issue has been placed on a back burner now that
the US airlines are in financial trouble. It will be interesting to see
if they ever go through with it.

 

[Adrian Tuddenham]

I always thought those fluids had high flash points. Then I sprung a
pinhole leak in a power steering hose and had a fire going on the
exhaust manifold that rivaled a furnace burner ;-)

I was told about this by a local Fire Officer.

They were packing up the fire engine after dealing with some minor
incident when two cars collided nearby. The bump was only a minor one
with little damage, but one car immediately burst into flames.

They promptly lifted the bonnet (hood) and extinguished the fire, but
to their amazement there was no petrol leak. Instead they found the
part-melted brake fluid reservoir dangling by its sensor leads above the
exhaust manifold.

Then they went back through the records and found a number of similar
incidents where the fire might have had the same cause.

His advice to me was to securely tie on the brake fluid reservoir with
something like a nylon ratchet strap - I actually use waxed nylon loom
lacing cord. (Remember how to lace wiring looms, do they still teach
that?)

 

[Pooh Bear]

What was the primary failure in each case?

You'd have to read the detailed accident report no doubt.

It's been shown that it's incorrect to assume that vapour in the tanks is not flammable though.

http://seattlepi.nwsource.com/business/18352_boeing12.shtml

Found with a quick gooogle gives the overview.

Graham

 

[Pooh Bear]

Doubtful. The center tank was, for all practical purposes, empty. Why
would a pump be running in there?

The flight crew don't always turn off all the pumps you might expect them to.

I'm fairly certain the scavenge pump was running ( possibly an oversight ? ).

Graham

 

[Pooh Bear]

In frontal crashes.


Yep. All of his buddies are whining and moaning now, but they didn't
think enough of him to stop him from leaving the party in a totally
inebriated state :-(

The cops are saying his estimated impact velocity was 70MPH. This was
in the heavily curved area of Ray Road in Ahwatukee Foothills (for
those of you who know the area).

Just out of curiosity I looked tor a map and found one with Ray Road marked. I don't recall a scale but
I'd guess by British standards it's quite a gentle curve ( does an almost 180 IIRC ).

If you can point me to a more detailed map I'd be interested to see.

The map was a realtor's btw. I was intruiged to see how many houses seem to be single storey there.

Graham

 

[Jim Thompson]

Just out of curiosity I looked tor a map and found one with Ray Road marked. I don't recall a scale but
I'd guess by British standards it's quite a gentle curve ( does an almost 180 IIRC ).

If you can point me to a more detailed map I'd be interested to see.

Just back-and-forth-and-back-and-forth... just enough to put a drunk
to sleep, see...

Newsgroups: alt.binaries.schematics.electronic
Subject: Accident Discussion, From S.E.D - AccidentSite.pdf (1/2)
Message-ID: <[email protected]>

and add 70+ MPH to it, and you have disaster.

The map was a realtor's btw. I was intruiged to see how many houses seem to be single storey there.

Graham

I live about 2.5 miles west of where Ray and Chandler Blvd merge.

As for single story dwellings, most here are single story, except the
lower-priced homes, where the land/lot premium dominates the cost. My
home is 3650 sq-ft single-level.

...Jim Thompson

 

[keith]

I always thought those fluids had high flash points. Then I sprung a
pinhole leak in a power steering hose and had a fire going on the
exhaust manifold that rivaled a furnace burner ;-)

I know of a case where a bar patron came out at closing and tried to start
his car. The carb caught on fire, so the (volunteer) fire department was
called out to put it out. No problem, they used a CO2 extinguisher and it
knocked it right out. No foul. The second time the guy started the car
the carb cought on fire again. The firemen put it out once again. The
third time the fireman grabbed the "wrong" extinguisher and loaded the
carb with powder. He then said "oops", finished the paperwork, and went
home and back to bed.

 

[Anno Siegel]

[...]
That is, the fuel concentration is above the Upper Explosive Limit

Right, and the limits are pretty narrow as well. I remember playing
with a cork gun, a piece of steel tube with a spark plug at one end
and a cork at the other. Three drops of petrol popped the cork 20m
high. Two or four drops did nothing.

Ohhh... I want one. How long is the tube?

Anno

 

[Rich The Newsgroup Wacko]

<crossposted, because I just _had_ to share this - - watch your followups!>

[...]
That is, the fuel concentration is above the Upper Explosive Limit

Right, and the limits are pretty narrow as well. I remember playing
with a cork gun, a piece of steel tube with a spark plug at one end and
a cork at the other. Three drops of petrol popped the cork 20m high.
Two or four drops did nothing.

Ohhh... I want one. How long is the tube?

I once soldered together six coffee cans to make a popgun. IOW, it's
as long as you make it. We fueled it with lighter fluid, and, it seems
that I've learned WAY too late, we were loading it with way, way too
rich of a mixture. It just barely blew the plastic thing off the top.

Heck, you can make a neat pop with a little flour and a candle, if
you follow the instructions. >:->
--
Cheers!
Rich
------
"Attracted by repeated newspaper advertisements, and realizing that his
waist had gone both East and West despite his daily racquetball, a young
executive appeared at a local health resort. Looking over the several
weight loss plans offered, he selected one guaranteed to reduce his
weight by two pounds per day. After a light breakfast, and a almost
non-existent lunch, he was escorted to a large room, where a young,
attractive woman told him that "if he caught her, he could have her".
After an hour of hard running, he finally gave up; and weighing himself,
was comforted to realize that he had lost just under three pounds.
Returning the next week, he chose the plan that was to reduce his weight
by four pounds per session. After following the same regimen, he was
again escorted to a large room, but after two hours of running, he
caught the young woman. Weight loss, just over four pounds. Returning
the following week, he chose to lose eight pounds in a single day. He
was shown to the largest room he'd seen, by far, where he was confronted
by an extremely muscular, burly man, who looked him square in the eye, flung
his towel into a corner, and snarled, "You know the rules. Start running!""