NW_Pilot's Trans-Atlantic Flight -- All the scary details...

Back in my day (your day too - I think we are about the same age) a
little lambasting built character...

Now get out there and get your freakn' Instrument Rating!! ;-)

Jon Kraus
Mooney 201
4443H @ UMP

Jay Honeck wrote:

The fact is, you're always going to get flamed, no matter what you do.
You can't worry about it.

I agree. What's to worry about? Flames aren't fatal. They don't even
hurt. :-)


Well, as you know I am immune to flames, too -- but I often hear from
"lurkers" who say they don't post for fear of getting lambasted.

Not everyone is a thick-skinned as we are, and -- if we want GA to grow
-- we need to be welcoming everyone into this group with open arms, not
poison pens.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Mxsmanic" wrote in message
...
John Theune writes:

I'm a software engineer and I've dabbled a little in real time systems
and there are many things that can cause a system to reboot. It might
be a **** poor design or it might be something else.

It's always poor design, unless power is cut to the system.

Your absolutes are simply amazing.

In a previous article, Jim Logajan said:
wrote:
I agree that continuous rebooting is a bad idea.

Just FYI, NASA's Mars Spirit rover got itself into a continuous reboot
cycle too:

And even then they only way they fixed it was to figure out a way to stop
it rebooting long enough to listen to some commands.


--
Paul Tomblin http://xcski.com/blogs/pt/
Pity stayed his hand. "It's a pity I've run out of bullets", he thought.
-- Bored of the Rings

"Larry Dighera" wrote in message
...
Given the fact that the aux fuel system was a modification upon which
your safety depended, did you personally take the time to analyze its
intended operation from the schematic diagram and description of
system operation (not its use, but how it was engineered to operate)?
I believe you are intelligent enough to have done a reasonable job of
system analysis without benefit of specific training or an appropriate
college degree.

Yes, I looked at the system!


and so did the engineer that designed it and
wrote the instructions for it's usage! I would also assume so did the faa
inspector that approved the system description and usage instructions.
Once
you go changing the factory fuel system design you go from the engineered
description of the now modified fuel system.

If I understand your story correctly, the cause of the wing tank
venting was a result of the fuel return line pouring fuel that was
being feed from the separate aux tank fuel system into the wing
tank(s). Is that correct?

The aux tank was connected directly to the engine after the aircraft fuel
system, Not to the wing and the provided documentation and system
description mentioned nothing about the fuel return to the main tanks. The
description also stated that it was connected after the aircraft fuel
system.


They left out something very very important in the new systems
description!

Are you referring to the necessity to burn fuel from the wing tanks
before switching to the aux tank, so that there would be adequate room
in the wing tanks to hold the fuel being returned from the fuel
injection system?

Correct, They failed to mention this the description and instruction
provided!

therir instruction basicaly short and simple! Climb to altitude on both
tanks aircraft tanks once at altitude switch to ferry tank until specified
mark on aux tank near empty then switch back to aircraft fuel.

Now!! If the instructions stated to run on the left tank till near empty
then switch to the ferry tank and monitor the left tank fuel quantity and
return to aircraft fuel and switch ferry tank off when left tank was almost
full about 2 hours flight time this little problem would not have happened.
The Greenland CAA took a copy of the instructions and fuel system
description and copy of Cessna description of the problem and will be
contacting the ferry tank mfg and installer telling them to correct their
system instructions.


Can you provide the manufacturer's name and model number for the aux
fuel system installed in the aircraft you delivered?

The Ferry tank was Manufactured And Installed By Telford Aviation In Bangor,
Maine. In the future I will try and avoid this company or flying with this
company's installed equipment if at all possible and if I am to use them
(Not Likely) I will require them to provide a full schematic of the system
and talk with them more to support their documentation. Another thing that
****es me off when I called the company (telford) to help with the problem
they were rude and said there instruction were correct and that it was not
their problem! Cessna support and the weekend A&P in Greenland were the best
they had a solution with in a few hours after faxing the instructions to
them and are also writing a letter to Telford explaining the problem with
their instructions.


How large is the documentation of the aux fuel system? Is it possible
you could make a scanned copy available? In particular, I'd like to
see a schematic drawing of the system and the description of its
operation, and its operation use instructions, in that order.

No schematic was available only textual description of the fuel system and
its operation. All paperwork was given to new owner and there was no photo
copy machine available in Beirut at time of delivery for me to make a copy
for myself. The Greenland CAA made copies of all paperwork and said they
will forward me copies of all paperwork.

"Jose" wrote in message
...
I just went back and re-read the story and realized that this was not
truly a garmin problem. The modified fuel system caused the problem and
those additions are outside the design envelop of the garmin system.

I most strenuously disagree. Systems should be designed NOT to fail
catastrophically when outside their "intended use". The problem was =not=
caused by the modified fuel system, rather, the problem was caused by
unexpected sensor input. In this case the unexpected sensor input was
caused by the modified fuel system, but it could have come from any number
of reasons, and the whole point of aviation systems is that they be
robust.

Jose
--
"Never trust anything that can think for itself, if you can't see where it
keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

Don't think it was just one error causing the system to fail and reboot I
think it was multiple problems compounded by 1 problem. But still the system
should not reboot itself. When on the phone with Cessna engineering and
Garmin support they said they had a similar problem during stalls and slow
flight.

"Larry Dighera" wrote in message
...
On Mon, 2 Oct 2006 09:14:15 -0700, "NW_Pilot"
wrote in
:


Typically wing tanks are filled to the brim of the filler neck.
Presumably that leaves some air trapped in the tank. Without knowing
the exact placement of the fuel vent pipe intake within the tank, it
is difficult to confirm an over pressure condition in this case.
Absent knowledge of how Mr. Rhine came to his "over pressurizing"
conclusion, it is difficult to substantiate it as fact. Might not the
venting fuel have been merely excess fuel draining from the tank as it
was designed to do when the tank is over filled? After all,
presumably it is the same fuel pump operating in both the factory
designed fuel system and the aux fuel system.

The Aux system used it's own fuel pump and it was tied in after the
aircraft
fuel shut off valve.


So you're saying, that there was a new fuel selector valve placed in
the fuel line between the normal On/Off Cessna fuel selector valve and
the engine?

And the aux fuel system consisted of a fuel quantity indicator, the
aux fuel tank and vent, an additional fuel pump and electrical switch,
and a single fuel line leading from the aux fuel tank to the added
fuel selector valve?

The 172 SP has a fuel slector Valve L - B - R Plus A Fuel shut off Valve!

The Ferry Tank had a shut off valve fuel pump a hose that connected after
the aircraft fuel system shut off valve.

See Photo! Look by the aircraft fuel Selector You will see a Fuel Shut Off
Valve and The Fuel Pump with Switch.
http://www.alexisparkinn.com/photoga...rvivalGear.jpg

The aux tank was connected directly to the engine after the aircraft fuel
system, Not to the wing and the provided documentation and system
description mentioned nothing about the fuel return to the main tanks.

How would the fuel get to the main tanks in the first place? Is the
engine the only connection? (if so, with the fuel selector OFF that
should block fuel flow to the main tanks). Is there a vent line that
connects them?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

On 2 Oct 2006 10:45:20 -0700, "Jay Honeck" wrote
in . com:

I agree. What's to worry about? Flames aren't fatal. They don't even
hurt. :-)

Well, as you know I am immune to flames, too

We see few actual flames in this newsgroup. Most acrimonious
responses are more in the nature of heated discussion and
disagreements. Here's an example of what I consider a classic flame:

You know - they say that people with
I.Q.'s over 40-points apart are pretty
much unintelligible to each other.
That's just a random observation with no
ulterior meaning attached to it :P
As I read it, stupidity installed itself long
before you clocked three score and ten,
you are merely coming out, in bloom.
Let's pretend that you really are not an
obnoxious ignorant, cowardly, motor-mouthed
cretin exuding digital diarrhea as a pretext
to seeking a Life? About as topical as the
man who thinks its cool to jam garden gnomes
headlong up his ass to prove a qualified
opinion on de rigueur art decor, your puerile
attempt at self adulation is hilarious!
Unfortunately my having no respect for you
means your opinion of what I or anyone else
needs to respect means absolutely nothing.

Don't forget to **** yourself on your way
out, moron.

We don't see much in the way of that sort of "creative writing" in
this newsgroup (thankfully).

-- but I often hear from "lurkers" who say they don't post for fear of getting lambasted.

If the lurkers post USEFUL INFORMATION, that is correct and supported
by independent citations, they have nothing to fear. Otherwise, it
would appear that the 'flameage' is working.

Not everyone is a thick-skinned as we are, and -- if we want GA to grow
-- we need to be welcoming everyone into this group with open arms, not
poison pens.

Welcoming EVERYONE? You feel critical thinking* is misplaced? You
would recommend welcoming the likes of Mohammed Atta, AOL users, Ted
Kaczynski, Ted Bundy, John W. Hinckley, Jr, ...? Welcoming EVERYONE
could reduce Usenet to a the status of FidoNet. If you don't mean
'everyone,' don't use absolute language.

I have no tacit agenda to entice the timid to indulge in aviation.
If they are afraid of public response to their words, they are
probably much too fearful to become airmen.

Although you apparently believe Usenet was intended for kibitzing,
inane prattle, and chit chat, it is actually for the sharing of
INFORMATION.

This fellow put it well:

In my opinion, it is a very helpful (and in some instances quite
necessary) virtue to be able to take criticism even if it is
offensive or insulting. In fact, even the most offensive
criticism might (and hopefully does!) contain insights that are
valuable, and by disregarding the entire criticism, you are
throwing away that insight. You may not like it, but it sometimes
does pay to listen to a person that is not as friendly as you'd
like her to be.
-- Tobias Dussa

/rant

* http://en.wikipedia.org/wiki/Critical_thinking

When on the phone with Cessna engineering and
Garmin support they said they had a similar
problem during stalls and slow flight.

Sheesh, and they marketed it anyway?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

On Mon, 2 Oct 2006 11:47:43 -0700, "NW_Pilot"
wrote in
:

When on the phone with Cessna engineering and
Garmin support they said they had a similar problem
during stalls and slow flight.

So, the uncommanded FIS rebooting was a known issue, and both
manufactures chose to release their products for use? One would have
thought Cessna would have learned not to do that from their seat-rail
issue. I hope the premiums are paid current on their errors and
omissions insurance policies.