The Mother of Invention

Some of the busiest flying fields here in San Diego county aren't
airports. Although you can see them from the air or on Google's
satellite shots, most of them don't even exist, according to the
aviation bureaucracy. A couple of them are paved but the others are
dirt, sod, gravel, or a dry lake bed. One is just a section of seldom
traveled road. The ones that are paved usually appear on your air-nav
charts but most of them aren't on any map, their location known only
to airmen or to near-by home owners, if there are any. Which can lead
to some funny situations.

I'd promised to help a friend put some new tires on his
notso-ultralight, hangared under an oak tree about two hours from the
shop. As I loaded the tools into my bus I realized that while I'd
flown into the place a time or two, I didn't know how to get there by
road. Even though I knew the location of the airfield it wasn't
shown on any of the maps I checked. I finally had to call the fellow.

The next day, following the directions I'd penciled onto my Thomas
Bros., I got there a bit ahead of him, parked near his bird, poured
myself a cuppa thermos coffee. Folks were flying but the strip was
well away from the tie-downs. Next door, a couple of guys were working
on blue & white pusher. Pretty. Nowadays there's so many different
ultralights I can't tell one from another. My friend arrives and we
set up a work-station. I don't like doing maintenance on dirt so we
put down a tarp then some cardboard.

He's using six-inch Azusa wheels with juice brakes from that fellow
in Oregon. We get the brake's caliper out of the way, removed the
wheel and were taking it apart when the neighbors wander over to ask if
we might have some spare wire. They're trying to ring-out a wiring
problem using a digital VOM as a continuity tester but the leads are
too short to reach from the engine to the panel.

There's some jumpers somewhere in my kit but I don't want to go dig
them out. Hand them my flashlight. Then have to show them how it
works. Unwrap the wires from around the flashlight, unclip the
alligator clips and you've got a continuity tester about ten feet
long.

We're starting on the other wheel when the neighbors fire up their
engine, the electrical problem apparently solved. A little later they
shut it down, bring back my flashlight and we chat for a while before
they go off to fly. I re-wind the wires, roll the big o-ring over them
to keep them in place.

It's a little past noon when we finish the job, clean up and put the
tools away. We've been keeping an eye on the wind because the strip
is sorta east & west, the wind wasn't and my fee is a bit of free
flight time. The wind has picked up but my friend decides we're good
to go so we evict the mice, pull the wing covers and go flying. We
buzz over to another field about twenty minutes away where the wind is
pretty much right down the middle of the strip. After bouncing the
wheels a few times we decide the new tires are working okay and take
the bird back home.

After slipping on the wing covers and doing the paper-work we discuss
getting some covers for the wheels, probably a good idea and sure to
please the little brown and white field mice that are becoming
something of a problem. Then my friend asks:

"How's that flashlight-thing work?"

I dig it out, take it apart and show him the piece of double-sided
circuit board that fits under the batteries, down on top of the
bed-spring. It has got to be the world's cheapest flashlight - - one
of those one-piece jobbies where you unscrew the lens and drop the
batteries down the hole. To turn it into a continuity tester you
thread a couple of wires through a hole you drill in the bottom. One
wire is about two feet long, the other about eight. One wire is
soldered to the bed-spring side of the circuit board, the other is lead
though a small hole in the center of the circuit board and soldered to
the top side. Turn the flashlight on, nothing happens. Unless you
connect the two wires. Put a pair of alligator clips on the wires,
wind the wires around the flashlight and you've always got a
continuity tester handy.

"I've never seen that," he sez.

"That's because you've never been caught without a continuity
tester," I laugh, and tell him about the neat little sign in VA-214's
electrical shop at Moffet Field, back when they were still flying
Spads: 'Mothers are a Necessary Invention.' He doesn't get it
but smiles anyway. Back then we used a couple of pieces of shim brass
separated by a circle of tarred cardboard from an ammo can, the usual
flashlight being a one-cell jobbie salvaged from an over-age May West.

-R.S.Hoover

There's some jumpers somewhere in my kit but I don't want to go dig
them out. Hand them my flashlight. Then have to show them how it
works. Unwrap the wires from around the flashlight, unclip the
alligator clips and you've got a continuity tester about ten feet
long.


I once had a fuel seep somewhere in a 150. Could smell it in the
cockpit, but couldn't find it. Checked all the lines from the tanks,
through the valve, to the firewall, and all the primer lines. Even in a
simple airplane there are a lot of connections.
Air out the airplane. Close the doors. Come back in the
morning, cockpit stinks of avgas. Look all over the systems again;
still nothing.
We have stethoscopes to find funny clicks and knocks and whines.
We have signal tracers and continuity testers and ohmmeters to find bad
electrical connections. We can get ultrasonic air leak detectors to
find microscopic pressure leaks. I have (or had) nothing to find that
tiny fuel seep.
I took some old pitot-static tubing, which is just translucent
polyethylene tubing. Old tubing is better because it has no odor
anymore. I took a bit of 1/16" rubber diaphragm material (a chunk of
old inner tube would work) and formed a funnel, the small end being
tight around the poly tube and the other having about 1 1/4" diameter.
The funnel was about 2 1/2" long. Stapled the diaphragm material
together at the overlap; don't have to get fussy. Duct tape held the
funnel to the tubing. With a pair of scissors, I cut the end of the
funnel so that it fit around my nose with a good seal so that when I
sucked in, the air had to come through the tube.
Now maybe I can nail that tiny seep. Sniffed all the same
fittings I had looked at before, and when I got to the primer inlet
line fitting at the firewall, I had no doubt as to the source of my
leak. IIRC it was the line cracked at the base of the flare, just
enough to allow the gravity head to force a tiny bit of fuel through.
There was never any stain; the fuel was blue and so was the anodized
aluminum fitting, and the leak was never big enough to drip. If it had
broken right off in flight we'd have had a big problem.
I've since used that sniffer to find other leaks. If the cockpit
of a Cessna single smells, the leak could be in either wing or at any
one of about 25 connections, drain points or valve gaskets. Cessnas
aren't known for their airtight cockpits.
I've even found bad electrical crimp connections with it.
Sniffing an almost-inaccessible heat-darkened crimp connector will
tell you if the burn is recent or old. Sticking the tube into an
alternator could identify burned windings.
If you're a smoker, this tool might not work for you..

Dan

Good tip - I will try it. Most Cessna owners have likely had similar
problems.

David Johnson

Do you get a high from sniffing the AV gas? Back before Nam and after
Korea, I worked on B-36s and the fuel cell repair group would drain the
fuel tanks and air them out with blowers and then crawl thru a small access
panel and reseal leaks from the inside. (You could stand up vertically near
the wing root) Even with the draining and air out stuff one large guy got
high off the fumes and set down on the gear box (inside the tank) and pulled
out a cigarette and a lighter. A very small guy picked him up and pushed
him thru the small access panel hole. It was normal for those guys to get
out of the tank with a buzz on.

--
stuart Fields
Experimental Helo magazine
P. O. Box 1585
Inyokern, CA 93527
(760) 377-4478 ph
(760) 408-9747 publication cell
"Dave" wrote in message
oups.com...
Good tip - I will try it. Most Cessna owners have likely had similar
problems.

David Johnson

On 13 Nov 2006 15:18:11 -0800, wrote:

snip
I've even found bad electrical crimp connections with it.
Sniffing an almost-inaccessible heat-darkened crimp connector will
tell you if the burn is recent or old. Sticking the tube into an
alternator could identify burned windings.
If you're a smoker, this tool might not work for you..

Guess it depends on what you stick in the tube? It sounds like the
ultimate inhalation machine...Which reminds me...

A couple of days ago I was rudely awakened in the middle of my night
by a low flying helicopter. You do have to realize the middle of my
night is around noon.

At any rate a low flying helicopter gets my attention due to the top
antennas being at 130 feet and I've seen the search choppers at tree
top level. Usually at night they will put a car on the corner with a
spot light on the antennas. OTOH any time anything fly's over I have
to run out and see what it is/was.

No, I don't live next a jail, or prison. The county farm is about a
half mile from here and once in a while a resident has been known to
wander away. The weather up here just isn't conclusive to spending the
night outside unless you've spent a small fortune at Gander Mountain
first.

Sooo... The deputies were going door to door asking people to check
any places said wander may have crawled in to get warm. Well... The
stopped at one place that hadn't been expecting them. I guess the
haze was a tad thick inside and after their vision had cleared a bit
they found four pounds of "happy weed" all packaged up. I don't know
if they aired the house out or just stood there inhailing deeply until
the air was clear.


When going up the tower I usually check the corn fields within a
half mile to mile to see if anything is "sticking up" above the corn.
They like to put it in the farmer's corn fields to hide it, but that
stuff grows 10 to 12 feet tall (or more) so about harvest time it
becomes quite visible.

BTW a farmer about a half mile SE of here discovered said wanderer (in
good shape) when he was pulling some hay bales out of the barn.


Dan
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Stuart & Kathryn Fields wrote:
Do you get a high from sniffing the AV gas? Back before Nam and after
Korea, I worked on B-36s and the fuel cell repair group would drain the
fuel tanks and air them out with blowers and then crawl thru a small access
panel and reseal leaks from the inside. (You could stand up vertically near
the wing root) Even with the draining and air out stuff one large guy got
high off the fumes and set down on the gear box (inside the tank) and pulled
out a cigarette and a lighter. A very small guy picked him up and pushed
him thru the small access panel hole. It was normal for those guys to get
out of the tank with a buzz on.

You don't sniff it long enough to get any sort of buzz. As
soon as you find the leak you'll get a one-second whiff, and that's it.
I think we absorb more avgas fumes when fuelling on a still day. And
you'd also absorb more using the normal methods of finding a leak in
the cabin: much time breathing fumes while trying to find the loose or
cracked fitting.
The idea of climbing into a large fuel tank sure doesn't
appeal to me. Seems to me that guys who do that shouldn't be allowed to
have lighters or matches on them, huh?

Dan

"Stuart & Kathryn Fields" wrote in message
news
Do you get a high from sniffing the AV gas? Back before Nam and after Korea,
I worked on B-36s and the fuel cell repair group would drain the fuel tanks
and air them out with blowers and then crawl thru a small access panel and
reseal leaks from the inside. (You could stand up vertically near the wing
root) Even with the draining and air out stuff one large guy got high off the
fumes and set down on the gear box (inside the tank) and pulled out a
cigarette and a lighter. A very small guy picked him up and pushed him thru
the small access panel hole. It was normal for those guys to get out of the
tank with a buzz on.

Today's standards would never let that happen. They at a minimum would have
respirators with activated charcoal elements, and possibly forced (positive
pressure) fresh air masks.
--
Jim in NC

On Nov 15, 5:46 am, wrote:
Stuart & Kathryn Fields wrote:

The idea of climbing into a large fuel tank sure doesn't
appeal to me. Seems to me that guys who do that shouldn't be allowed to
have lighters or matches on them, huh?

Dan

The Defence Dept in AUS is having trouble with RAAF veterans who
climbed into the internal tanks on the F-111 fleet. The chemicals in
the tank sealants combined with the lack of protective clothing seem to
have been the issue. The planes are still flying and I presume they
have a current solution to protect the mechanics, but the 'Pig' has
been in service for over 30 years now - that is a lot of sick mechanics!

wrote:
There's some jumpers somewhere in my kit but I don't want to go dig
them out. Hand them my flashlight. Then have to show them how it
works. Unwrap the wires from around the flashlight, unclip the
alligator clips and you've got a continuity tester about ten feet
long.


I once had a fuel seep somewhere in a 150. Could smell it in the
cockpit, but couldn't find it. Checked all the lines from the tanks,
through the valve, to the firewall, and all the primer lines. Even in a
simple airplane there are a lot of connections.
Air out the airplane. Close the doors. Come back in the
morning, cockpit stinks of avgas. Look all over the systems again;
still nothing.
We have stethoscopes to find funny clicks and knocks and whines.
We have signal tracers and continuity testers and ohmmeters to find bad
electrical connections. We can get ultrasonic air leak detectors to
find microscopic pressure leaks. I have (or had) nothing to find that
tiny fuel seep.
I took some old pitot-static tubing, which is just translucent
polyethylene tubing. Old tubing is better because it has no odor
anymore. I took a bit of 1/16" rubber diaphragm material (a chunk of
old inner tube would work) and formed a funnel, the small end being
tight around the poly tube and the other having about 1 1/4" diameter.
The funnel was about 2 1/2" long. Stapled the diaphragm material
together at the overlap; don't have to get fussy. Duct tape held the
funnel to the tubing. With a pair of scissors, I cut the end of the
funnel so that it fit around my nose with a good seal so that when I
sucked in, the air had to come through the tube.
Now maybe I can nail that tiny seep. Sniffed all the same
fittings I had looked at before, and when I got to the primer inlet
line fitting at the firewall, I had no doubt as to the source of my
leak. IIRC it was the line cracked at the base of the flare, just
enough to allow the gravity head to force a tiny bit of fuel through.
There was never any stain; the fuel was blue and so was the anodized
aluminum fitting, and the leak was never big enough to drip. If it had
broken right off in flight we'd have had a big problem.
I've since used that sniffer to find other leaks. If the cockpit
of a Cessna single smells, the leak could be in either wing or at any
one of about 25 connections, drain points or valve gaskets. Cessnas
aren't known for their airtight cockpits.
I've even found bad electrical crimp connections with it.
Sniffing an almost-inaccessible heat-darkened crimp connector will
tell you if the burn is recent or old. Sticking the tube into an
alternator could identify burned windings.
If you're a smoker, this tool might not work for you..

Dan



You've invented the "Smellescope" from Futurama a thousand years early!

If you need both hands free do you staple the rubber funnel to your nose
or use the duct tape?

Nyuk nyuk nyuk...

VERY clever actually.

John

Stuart & Kathryn Fields wrote:
Do you get a high from sniffing the AV gas? Back before Nam and after
Korea, I worked on B-36s and the fuel cell repair group would drain the
fuel tanks and air them out with blowers and then crawl thru a small access
panel and reseal leaks from the inside. (You could stand up vertically near
the wing root) Even with the draining and air out stuff one large guy got
high off the fumes and set down on the gear box (inside the tank) and pulled
out a cigarette and a lighter. A very small guy picked him up and pushed
him thru the small access panel hole. It was normal for those guys to get
out of the tank with a buzz on.


It should never have been normal for them to get into the tank
without an air-supply respirator.

--

FF