Bad fuel gauges?

On 2008-02-24, Andy Hawkins wrote:
And if you've left the fuel cap off in your pre flight, and your fuel has
gradually been ****ing all over the wing, how will you know?

By the blue streaks back from the cap along the top of the wing?

Yeah, this kinda leaves 172 drivers out in the cold...
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
http://www.hercules-390.org (Yes, that's me!)
Buy Hercules stuff at http://www.cafepress.com/hercules-390

On 2008-02-24, wrote:
Until you came along, this was an interesting, civil discussion in
which people who disagreed were genuinely trying to understand the
reasons for the differences in their points of view.

Pot, kettle, black. Not once in this discussion have you shown the slightest
interest in dealing with the reality of the large number of aircraft in the
GA fleet having gauges that are unusable in flight beyond "they'r all
illegal!".
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
http://www.hercules-390.org (Yes, that's me!)
Buy Hercules stuff at http://www.cafepress.com/hercules-390

On Feb 23, 10:19*pm, Jay Maynard
wrote:
On 2008-02-24, wrote:
Pot, kettle, black. Not once in this discussion have you shown the slightest
interest in dealing with the reality of the large number of aircraft in the
GA fleet having gauges that are unusable in flight beyond "they'r all
illegal!".

No, I haven't just proclaimed that. Rather, I've explained in detail
why I think the gauges ARE useful, in a particular way, if they're
anything like the dozens of planes I've rented in various places. And
I've explained in detail why I think they're illegal otherwise, citing
specific regulations. (There may or may not be a "reality" that
illegal planes are common--but that doesn't change whether they're
illegal.) And CJ and I and others have given reasons that fuel gauges
are desirable for safety as well as legality.

You may disagree with the reasons we've put forth, and that's fine.
But we have in fact been explaining ourselves, and responding
constructively and politely to opposing explanations.

In article
,
says...


Hi all,
A recurring theme seems to be that one should should not rely in fuel
gauges. I can understand that from a safety point of view (I always
dip the tank before start), but I get the feeling that they are
considered just plain inaccurate. Why is that, every car I've driven
has a fuel gauge that seems accurate. Am I missing something?


What kind of car do you drive?
I've never yet driven a car with an accurate fuel gauge. Usually they go
down very slowly for the first half, then much more quickly - exactly the
opposite of the response you would want if your life were to depend on
it.

Fuel gauges in small airplanes often have problems, and should not be
relied upon. There are better methods for soiuynd fuel management.

This said, thje later-generation (post GARA) airplanes have made huge
strides in this respect, and I definitely have a much higher level of
copnfidence in the gauges of a 172-R or a 182-S than the older models.

In article ,
wrote:

A leak may be a very infrequent event, but
aviation safety is about being prepared for unlikely problems, rather
than unnecessarily relying on the gamble that it will never happen to
you.

But aviation safety is not about being prepared for every single problem
no matter how unlikely. Aviation safety is about reducing the residual
risk to an acceptable level. These levels are defined in AC 23.1309
and AC 25.1309.


The Part 91 airworthiness regs (which pilots are required to know
before being allowed to solo) mandate a gauge that indicates the fuel
level in each tank. No specific accuracy is mandated, either in Part
91 or in the aircraft-certification regs in Part 23. So it becomes a
matter of common sense: a working fuel gauge has to be accurate enough
to serve its intended purpose, which (in familiar light GA planes
anyway) is to provide a rough cross-check of the consumption
calculations, to warn of a leak or other problem.

You've just added an "intended purpose" with the claim that the gauge
is there to warn of a leak, etc. The reg states the intended purpose,
that is, to indicate the fuel level. If a aircraft manufacturer wants to
add another intended purpose, then it is allowed to do that. In that
case, it would also be obligated to include that in the Failure Hazard Analysis.

--
Bob Noel
(goodness, please trim replies!!!)

In article ,
Andy Hawkins wrote:

And if you've left the fuel cap off in your pre flight, and your fuel has
gradually been ****ing all over the wing, how will you know?

In a low wing Piper, you look over and see the fuel flowing out of the hole.
You don't need a gauge to detect that hazard. (Perhaps this is another
advantage of flying a cherokee)

--
Bob Noel
(goodness, please trim replies!!!)

On Sun, 24 Feb 2008 07:18:25 -0500, Bob Noel
wrote:

In article ,
Andy Hawkins wrote:

And if you've left the fuel cap off in your pre flight, and your fuel has
gradually been ****ing all over the wing, how will you know?

In a low wing Piper, you look over and see the fuel flowing out of the hole.
You don't need a gauge to detect that hazard. (Perhaps this is another
advantage of flying a cherokee)

And at night?

--

"Peter Clark" wrote in message
news
On Sun, 24 Feb 2008 07:18:25 -0500, Bob Noel
wrote:

In article ,
Andy Hawkins wrote:

And if you've left the fuel cap off in your pre flight, and your fuel
has
gradually been ****ing all over the wing, how will you know?

In a low wing Piper, you look over and see the fuel flowing out of the
hole.
You don't need a gauge to detect that hazard. (Perhaps this is another
advantage of flying a cherokee)

And at night?

Your 2 D-cell or equivalent flashlight?

--
*H. Allen Smith*
WACO - We are all here, because we are not all there.

On 2008-02-23 16:03:52 -0800, "Bob Gardner" said:

Look at the Pilot's Handbook of Aeronautical Knowledge, too.

FUEL GAUGES

The fuel quantity gauges indicate the amount of fuel measured by a
sensing unit in each fuel tank and is displayed in gallons or pounds.
Aircraft certification rules only require accuracy in fuel gauges when
they read "empty." Any reading other than "empty" should be verified.
Do not depend solely on the accuracy of the fuel quantity gauges.
Always visually check the fuel level in each tank during the preflight
inspection, and then compare it with the corresponding fuel quantity
indication.

Bob Gardner

So that is where people keep coming up with that stupid myth! This is a
serious error in the Pilot's Handbook of Aeronautical Knowledge.



--
Waddling Eagle
World Famous Flight Instructor

On 2008-02-23 18:41:51 -0800, "RST Engineering" said:


If an airplane does not have accurate fuel gauges then it is not
airworthy. Knowingly climbing into an aircraft that you know has
inaccurate fuel gauges is both dangerous and illegal. That is why you
check them during preflight. From FAR 91.205:

Horse****.




(a) General. Except as provided in paragraphs (c)(3) and (e) of this
section, no person may operate a powered civil aircraft with a standard
category U.S. airworthiness certificate

...
(9) Fuel gauge indicating the quantity of fuel in each tank.


To what precision and accuracy and where defined? More than half but less
than full? More than empty but less than a gallon? More than ten gallons
and less than 11? Cite accuracy regs, please.

Jim

I have had this issue come up in a ramp check. The inspector insisted
that the plane was not airworthy because the gauges read half full and
the tanks were full.

If there is a regulation specifying the tolerances for accuracy, I am
unaware of it. However, the regulations do specify that you must have
fuel gauges indicating the quantity of fuel in each tank and that the
gauges must be calibrated so that "0" means 0 usable fuel. I guess it
depends on how far you think you can get away with it if you are ramp
checked.
--
Waddling Eagle
World Famous Flight Instructor