Gross Weight

"Thomas Borchert" wrote in message
...
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)

That is NOT true. If you're insured, you're insured. Just as you're
insured driving your car even if you've got 3x the legal alchohol limit in
your system...

KB

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

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


As others have written, you are being a test pilot under those conditions.

Some a/c will fly better over gross than will others.

So far as the 15% overage for Alaska is concerned, my understanding is that
there is not a blanket endorsement for all a/c, but rather that overage is
governed by the verbiage in 14 CFR 91.323.

I do know that at least one manufacturer (Mooney) has some data for flying
an Ovation at more than the MGW. Someone I know who flew his Ovation
around the world contacted Mooney and was able to obtain some sort of
authorization allowing him to do so in order to carry extra fuel.
Performance figures were obviously different -- I believe they were
supplied also by Mooney.

Data point: My a/c was born in 1965. About ten years ago, when my shop
obtained some scales, I decided to perform a real weight and balance,
instead of merely relying on the adds/subtracts over the years of the
various modifications done to the a/c. Well, I lost 80 lbs of useful load.
What that meant is that I had been frequently over MGW.

Did it shorten the airframe life -- I dunno.

Did I have a problem with short field performance? I was never in a
critical situation.

Did I not meet book figures? No, I did not; but how many a/c do?

As to insurance coverage if you fly over MGW, instead of relying on
anecdotes here, I would read your insurance policy. I buy insurance in
part to protect me against my mistakes or oversights. If I had a policy
which required that I be in compliance with every single in order to be
covered, I'd find a different company. My policy is in effect unless I
charge any person or organization for the use of the aircraft, although I
may be reimbursed for operating expenses.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

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

That's putting it a bit strongly. As long as the CG issues are OK, the
effects of being reasonably over-weight are quite predictable in terms
of stall speed, take-off requirements etc. The structural issues won't
come into it as many aircraft have their max gross determined by other
things (eg. stall speed low enough for Part 23, or the need to
go-around at max gross with full flaps) and in any case, there's a
large safety margin in there. The fact is that assuming you're not on
the edge re DA or runway length, 5% overweight is going to be safe. It
isn't legal, but it will be safe. As to the arguement that breaking one
rule leads to breaking another, with respect, that is nonsense. That's
like saying speeding leads to murder...

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

That's putting it a bit strongly. As long as the CG issues are OK, the
effects of being reasonably over-weight are quite predictable in terms
of stall speed, take-off requirements etc. The structural issues won't
come into it as many aircraft have their max gross determined by other
things (eg. stall speed low enough for Part 23, or the need to
go-around at max gross with full flaps) and in any case, there's a
large safety margin in there. The fact is that assuming you're not on
the edge re DA or runway length, 5% overweight is going to be safe. It
isn't legal, but it will be safe. As to the arguement that breaking one
rule leads to breaking another, with respect, that is nonsense. That's
like saying speeding leads to murder...

Exactly.....and well put.

Fred

"Larry Dighera" wrote in message
...
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:
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"?


Everything makes a difference. On those occasions where I've flown over, the
weight has to be within reason, and the air needs to be cool if at all possible.
It's been my experience that balance is much more critical than weight.

In any case, you're entering uncharted waters. 45 lbs in a C-172 isn't going to
make any detectable difference.... 200 lbs is unflyable on the best of days.

Many years ago, I came out of the Bahamas in a Cherokee Six with six of us on
board plus all our crap. After I cleared customs in Ft. Pierce, FL, I taxied
over to get some lunch and fuel. I told them to fill the mains only. Later
after we'd eaten, I checked the mains to verify they were full and taxied out
for takeoff.

Jeez... what a pig it was. I averaged somewhere between 150 and 180 fpm climb
at best rate. I couldn't figure what was wrong until my eyes wandered across
the fuel guages... ALL four of them were full. That was an extra 34 gallons I
hadn't depended on with an already heavy aircraft on a hot day. I eventually
worked my way up to cooler air and burned off some fuel. And learned to check
*all* the tanks, not just the ones I ordered fueled.

If the aircraft had been out of balance, we'd have crashed for sure.



--
Mortimer Schnerd, RN

VE

Thanks for the comments. I am beginning to feel as if my initial post is
being interpreted as if I wanted to be "re-assured" that flying over gross
is okay. That is not what I meant to convey, nor is that ever my
intentions. I simply was having a discussion at work about weight in
aircraft, and it turned out to be a good discussion there, so I thought it
might be one here as well.

I know what is legal. And I also know that I never intend on flying over
gross. But, I would bet that there are alot of pilots out there that have
come up against the max weight, and struggled with this exact
decision......."I am only 25 lbs over the max.....will that be okay". Now,
if a pilot does that, and the plane fly's 'okay', then the next time, that
same pilot may say "well, it flew okay with 25 over, it will probably be
okay at 45 over....." and so on.

Fred


"Peter Duniho" wrote in message
...
"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

Watch the Focking Rats That Hang Around Here!! You may get an unexpected
call from the Fed's!!!

"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

Wasn't asking for advice, but I certainly agree with the "don't do it".

Fred

"Happy Dog" wrote in message
.. .
"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

Wow...that doesn't leave much flexibility for passengers. Why would someone
want an aircraft that you couldn't take anyone with you (other than
aerobatics of course)? I suppose if you used the aircraft for "commuting"
it might make sense.

Fred

"Cub Driver" wrote in message
...
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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