Gross Weight

Here is a topic that was of discussion at work today:

How much is too much over gross weight? For example.....the 172 has a gross
weight of 2300 lbs, but what if you are 2345 at time of takeoff.....is that
too much over, even if you are going to be burning enough fuel before your
first scheduled stop to be under weight for landing?

What about airframe age, prop age...etc? Does it make a difference on
decision to "carry a little extra"?

I know that when I was receiving training, my instructor once had me bring 2
male adults with me to a lesson. That put 4 male adults in a 172 with full
fuel. I don't recall the specific weight we were at, but we were over
weight. The airport we flying out of had 8000' of runway, and my instructor
had me doing pattern work. The aircraft was very clumsy, and made me really
work at flying it. I didn't like that feeling at all! It was a good
training day.

Anyway, it was a good discussion between a few of us at work, so I thought
it might make a good topic here.

Fred

You'll never convince the FAA that anything over gross is legitimate (unless
you are in Alaska). If you have an accident/incident, your insurer will not
be impressed either. Your instructor was a dork to let you break the rules
during an instructional flight (duh!). Not the best way to train safe
pilots.

Bob Gardner

"Fred Choate" wrote in message
...
Here is a topic that was of discussion at work today:

How much is too much over gross weight? For example.....the 172 has a
gross weight of 2300 lbs, but what if you are 2345 at time of
takeoff.....is that too much over, even if you are going to be burning
enough fuel before your first scheduled stop to be under weight for
landing?

What about airframe age, prop age...etc? Does it make a difference on
decision to "carry a little extra"?

I know that when I was receiving training, my instructor once had me bring
2 male adults with me to a lesson. That put 4 male adults in a 172 with
full fuel. I don't recall the specific weight we were at, but we were
over weight. The airport we flying out of had 8000' of runway, and my
instructor had me doing pattern work. The aircraft was very clumsy, and
made me really work at flying it. I didn't like that feeling at all! It
was a good training day.

Anyway, it was a good discussion between a few of us at work, so I thought
it might make a good topic here.

Fred

You are right Bob.....I agree. But I was hoping for discussion on the
topic, not whether my old instructor did a good or a bad thing..... (But
I do agree with you about my old instructor. That lesson should not have
been flown, but on the upside, I did learn from it)

I chatted with an instructor down at my FBO after my discussion at work, and
his spin was "once you go over the max weight, you are essentially a test
pilot". I hadn't heard that one before, and will remember it.

Fred


"Bob Gardner" wrote in message
...
You'll never convince the FAA that anything over gross is legitimate
(unless you are in Alaska). If you have an accident/incident, your insurer
will not be impressed either. Your instructor was a dork to let you break
the rules during an instructional flight (duh!). Not the best way to train
safe pilots.

Bob Gardner

"Fred Choate" wrote in message
...
Here is a topic that was of discussion at work today:

How much is too much over gross weight? For example.....the 172 has a
gross weight of 2300 lbs, but what if you are 2345 at time of
takeoff.....is that too much over, even if you are going to be burning
enough fuel before your first scheduled stop to be under weight for
landing?

What about airframe age, prop age...etc? Does it make a difference on
decision to "carry a little extra"?

I know that when I was receiving training, my instructor once had me
bring 2 male adults with me to a lesson. That put 4 male adults in a 172
with full fuel. I don't recall the specific weight we were at, but we
were over weight. The airport we flying out of had 8000' of runway, and
my instructor had me doing pattern work. The aircraft was very clumsy,
and made me really work at flying it. I didn't like that feeling at all!
It was a good training day.

Anyway, it was a good discussion between a few of us at work, so I
thought it might make a good topic here.

Fred

On Thu, 7 Jul 2005 21:23:42 -0700, "Fred Choate"
wrote in
::

How much is too much over gross weight?

Too much for what? Too much to prevent the aircraft from getting off
the ground in the available runway length? Too much to make the
aircraft uncontrollable? Too much to overstress the airframe and do
permanent damage to it? Too much to get by the inspector conducting
the ramp check? Too much to negatively impress those who are aware
that you are willing to betray their trust? ...

If you don't load the aircraft by the book, it won't fly by the book.

But the most serious aspect of your question has to do with attitude.
If one rule can be broken, how many more can be broken? It's a
slippery slope. Don't go there, least you find the answer to your
question.

Airmen have a responsibility to their passengers and those over whom
they aviate. If you yield to social pressure, and permit it to coerce
you into violating regulations, you haven't learned one of the hardest
lessons an airman must. When something goes wrong, those who coerced
you will not defend you; they will condemn you for not adhering to
regulations even if that didn't cause the problem. Rather, show
others that you are a safe, responsible airman who respects the trust
placed in him by those who expect you to be prudent and wise. Be an
asset to the ranks of your fellow airman. Please...

"Fred Choate" wrote in message
...
Here is a topic that was of discussion at work today:

How much is too much over gross weight? For example.....the 172 has a
gross weight of 2300 lbs, but what if you are 2345 at time of
takeoff.....is that too much over, even if you are going to be burning
enough fuel before your first scheduled stop to be under weight for
landing?

The "...you are a test pilot" phrase applies to many situations, including
going over gross weight.

Assuming a non-emergency situation, you fly the airplane by the book. That
means, even one pound over max gross is too much.

Let's say after landing at a remote airport, you stumbled upon an
organized-crime pot growing operation, along with a kidnap victim they kept.
Just as you are untying the victim, you are discovered. You and the victim
run to the plane, but just as you are getting ready to take off, having
narrowly escaped your pursuers, you realize that with your additional
passenger, you may be as much as 50 or 100 pounds overweight.

Do you at that point shut down the airplane, get out and let yourselves be
tied up again by the mobsters? I sure hope not!

There may be moments when being a test pilot is appropriate. In those
moments, you should be aware of the effects of the extra weight. To some
extent, if you've ever flown the airplane at max gross as well as at lower
weights, you already have an idea of the change in performance.

The 2% overage you describe will produce a noticeable reduction in
performance, but probably nothing that even an average pilot can't
accomodate (assuming you're not cutting things too close already). A 10%
overage is likely to create significant problems; one can prepare for them
(and many pilots have, for the purpose of ferrying airplanes long distances
for example), but should attempt only after calculating exactly what the new
performance figures will be, and with adequate planning for the flight
itself (assuming the drug runners aren't chasing you, that is...in that
case, I suppose you can just play it off the cuff ).

None of that implies that over-gross operations, even by a small margin, are
to be taken lightly. When ferry pilots operate over-gross, they do so with
a special exception granted by the FAA. This isn't a normal operation, and
the fact that some pilots do it doesn't mean it can be done safely by any
other random pilot (and certainly doesn't mean it can be done legally).

Even ignoring the safety issues, I agree it was entirely irresponsible for
your instructor to teach you to fly over gross. And make no mistake, he was
*teaching* you to do that. It only makes it worse that he taught it very
poorly, not even bothering to address the actual performance issues related
to flying over-gross (other than to let you suffer through them).

I don't know what kind of discussion you were expecting, but IMHO for
standard operations, there is simply no amount of excess weight above max
gross that is reasonable.

Pete

"Fred Choate" wrote in message
...
Here is a topic that was of discussion at work today:

How much is too much over gross weight?

-----------------------------------------------------reply----------------------------------------

The weights were determined at some point by the manufacturer's testing
process and then presented to the government for approval. The statement
regarding test pilot is absolutely spelled out in the regs. The
manufacturer has to employ those folks to wring it out and their findings
are dumped into the formula which spits out that magic number.

If you are flying in Alaska, the regs allow a 15% fudge factor if you are
below a certain weight. Don't forget to factor in "and balance". You can
push the performance envelope but not the CG. Extra weight will make things
happen more slowly than you are accustomed to experiencing, i.e. take-off
rolls will be longer, climb rate decreased, control inputs
exagerated......of course, you already know this because you had an
instructor with the mind-set to expose you to this situation in a training
environment. Good for him.

Your candid discussion of this weight issue shows a regard for safety and a
desire to enter into a dialogue about a topic that is probably of interest
to many folks on the board.

Now, talk among yourself.....

Stephen
Foley, Alabama

Fred,

"once you go over the max weight, you are essentially a test
pilot".


As Bob pointed out, you are also illegal and not covered by insurance.


--
Thomas Borchert (EDDH)

Larry,

It's a
slippery slope.


I really like how you put that aspect.

--
Thomas Borchert (EDDH)

"Fred Choate" wrote in

How much is too much over gross weight? For example.....the 172 has a
gross weight of 2300 lbs, but what if you are 2345 at time of takeoff.

If you're asking for advice, don't do it. But, 172? 45 lbs? Non-issue.
It's been done so many times by so many people that you don't have to worry.
Lots of 172 drivers here. Ask them what's an uncomfortable over-gross
figure. All of them. Again the advice; don't do it.

moo

On Thu, 7 Jul 2005 21:23:42 -0700, "Fred Choate"
wrote:

I know that when I was receiving training, my instructor once had me bring 2
male adults with me to a lesson. That put 4 male adults in a 172 with full
fuel. I don't recall the specific weight we were at, but we were over
weight.

The Taylorcraft (Sport?) that's supposed to go into manufacture would
likely be overweight with TWO adult American males on board.



-- all the best, Dan Ford

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