Procedure for calculating weight and balance

TxSrv writes:

What's the default position in my 1972 American AA-5
Traveler? No mention of it in the Pilot Operating Handbook.

I know.

--
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Mxsmanic wrote:
TxSrv writes:

What's the default position in my 1972 American AA-5
Traveler? No mention of it in the Pilot Operating Handbook.

I know.

You know what? It's "default position," or that this odd
and irrelevant piece of information is not in the POH?

F--

TxSrv writes:

You know what? It's "default position," or that this odd
and irrelevant piece of information is not in the POH?

I know that it's not in the POH.

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Mxsmanic wrote:

I know that it's not in the POH.

Then you may have read my plane's POH, but certainly have
never flown one. Else you'd know how trim works and why
there's no "default position."

F--

see
http://www.faa.gov/library/manuals/a...A-S-8083-1.pdf
W&B handbook
and
http://www.faa.gov/library/manuals/a...lane_handbook/
and
http://www.faa.gov/library/manuals/a...a/ac90-89a.pdf
am. flight testing


"TxSrv" wrote in message
. ..
| Mxsmanic wrote:
|
| I know that it's not in the POH.
|
| Then you may have read my plane's POH, but certainly have
| never flown one. Else you'd know how trim works and why
| there's no "default position."
|
| F--

TxSrv wrote:

Then you may have read my plane's POH, but certainly have
never flown one. Else you'd know how trim works and why
there's no "default position."

Okay, now that I've made the mistake of reading this discussion, you've got
me curious: How does your plane's trim work? It's obviously not a trim tab.
And how can there be no neutral/default position of the elevator or the
trim device?

Anno v. Heimburg writes:

Okay, now that I've made the mistake of reading this discussion, you've got
me curious: How does your plane's trim work? It's obviously not a trim tab.
And how can there be no neutral/default position of the elevator or the
trim device?

The neutral position of a trim tab is the position in which it does
not intefere with the flow of air over the control surface, and thus
does not deflect the control surface in either direction.

There is no default position of a trim tab, as it is set as
appropriate for circumstances, which vary widely. In my use of the
term, I was thinking of trim positions that compensate for specific
power and pitch configurations and the like, excluding those that
compensate solely for a poorly balanced payload or fuel load.

In other words, I make a distinction between trim used to maintain the
aircraft in a specific, normal flight configuration, and trim used to
keep the nose from pitching violently upward because there's so much
junk loaded in the back of the aircraft (or violently forward because
the pilot and copilot are heavy and there's no ballast behind them).

As I understand it, the manufacturer's CG envelope is designed to
ensure adequate remaining control authority for any CG within the
envelope. I'm not sure how they determine what is adequate, however,
so I still worry. Which is why I'd like the most neutral CG possible,
that is, the one that has the least tendency to induce pitch or roll
movements.

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Mxsmanic wrote:

The neutral position of a trim tab is the position in which it does
not intefere with the flow of air over the control surface....

A trim tab does not necessarily "interfere" with the flow of
air over a control surface. You need to read Hoerner's books.

F--

Anno,

And how can there be no neutral/default position of the elevator or the
trim device?


Ok, you got me curious. No default position in all Cessnas I have flown.
Not in the Bo. Nor in the Tobago. Not in the Cirrus nor the DA-40 or the
-20. Nor any other plane I can remember INCLUDING the big airliners in
MSFS. WTF are you talking about?

There's a marking for take-off, alright. But that'S not what we're
talking about.

--
Thomas Borchert (EDDH)

Thomas Borchert wrote:

Ok, you got me curious. No default position in all Cessnas I have flown.
Not in the Bo. Nor in the Tobago. Not in the Cirrus nor the DA-40 or the
-20. Nor any other plane I can remember INCLUDING the big airliners in
MSFS.

The position where the control surfaces align with the stabilizer, that is,
no deflection upwards or downwards. At least that's what I interpreted the
expression to mean. I freely admit I'm clueless, though.

NB that I'm not saying that this position is necessarily marked anywhere,
nor that it is relevant to actually flying the plane.