Gross Weight

"Mike Granby" wrote in message
oups.com...

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

That's putting it a bit strongly.

No, it's putting it quite accurately.

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 effects of flight at any weight are quite predictable in terms of stall
speed, take-off requirements etc. And yet, during certification, the
airplane is required to be *tested* at in a variety of configurations by a
*test pilot* to demonstrate the actual performance.

Just because one can predict the performance, that doesn't change the fact
that a person flying an airplane in an untested (as far as they know)
configuration is a "test pilot".

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)

Very few single-engined airplanes have a stall speed at the maximum allowed
value (noting, of course, that the "maximum allowed value" isn't really so
much a hard limit, but rather one that a manufacturer is required to meet in
order to avoid other things). It's true that max gross weight may be
affected by things other than structural issues, but there is no way to know
whether this is true without consulting the manufacturer (which I doubt the
theoretical over-gross pilot is going to do), and I can think of at least
one common airplane for which structural issues DO limit the maximum landing
weight (which is lower than the maximum takeoff weight for that airplane).

and in any case, there's a
large safety margin in there.

The reason for that safety margin is for normal, legal weight operations.
It's not so you can operate over the legal limits. Operate over the legal
weight, and you've just abandoned your "large safety margin".

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.

It *might* be safe. You are still a test pilot when flying over the legal
weight, which is the comment to which you replied.

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...

That's a matter of opinion, I guess. I personally believe that if we had
better enforcement of the little laws, we wouldn't have so many people
disregarding the more important ones. Looking the other way when it comes
to speeding (and similar) simply teaches people disregard for rules. Each
person winds up setting their own limits, rather than respecting the limits
society claims to have made. And yes, in some cases, those limits go way
beyond just speeding.

Obviously each individual who speeds doesn't wind up a murderer, but general
disregard for the rules does certainly lead to other negative behavior.

Pete