Gross Weight

"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

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

Peter Duniho wrote:
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.

As I was reading this I was enjoying a nice mental image of "rescuing
the damsel in distress"... until I got to the part about "50 or 100
pounds overweight". Doh!

-R

"Rob" wrote in message
ups.com...
As I was reading this I was enjoying a nice mental image of "rescuing
the damsel in distress"... until I got to the part about "50 or 100
pounds overweight". Doh!

What's the problem? There are dozens of ways that still works. A six-foot
goddess could add a lot of weight, while still being quite the "damsel".
If you're 50 pounds overweight, you might have only been 50 or 100 pounds
below max weight in the first place (depending on height, 150 pounds could
be a weight still well within societal norms of beauty, and certainly
weights between 100 and 150 are). Or, to be quite frank about it, you might
find that a person can be plump and yet still quite the damsel.

Personally, I favor the "six foot goddess" scenario, but please feel free to
choose your own.

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

In article ,
"Hotel 179" wrote:

If you are flying in Alaska, the regs allow a 15% fudge factor if you are
below a certain weight.

Not true. The 15% increase is for specific airplanes with approval.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

"Dale" wrote in message
...
In article ,
"Hotel 179" wrote:

If you are flying in Alaska, the regs allow a 15% fudge factor if you are
below a certain weight.

Not true. The 15% increase is for specific airplanes with approval.

--
Dale L. Falk
-------------------------------------------reply---------------------------------------

A very general statement about a hypothetical situation should have
read"...below a certain weight in a specific aircraft with approval."

I didn't cite the regulation because it was just a what-if about 40 pounds
in a C172. I stand corrected.

Stephen
Foley, Alabama

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

email (put Cubdriver in subject line)

Warbird's Forum: www.warbirdforum.com
Piper Cub Forum: www.pipercubforum.com
the blog: www.danford.net
In Search of Lost Time: www.readingproust.com

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

email (put Cubdriver in subject line)

Warbird's Forum: www.warbirdforum.com
Piper Cub Forum: www.pipercubforum.com
the blog: www.danford.net
In Search of Lost Time: www.readingproust.com

"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