Mild Aerobatics

Jay Honeck wrote:

Well, to my (admittedly un-trained) eye, there doesn't appear to be
enough "there" there...

Each 10,000# engine on the B-707 was attached with three (3)
bolts the size of your small finger! Never lost one.


At OSH several of us were examining "Aluminum Overcast" (the EAA B-17 that
is being re-built after a landing gear collapse), and we all shuddered after
looking at the engine-less nacelles and noting that those huge radial
engines were attached to the firewall with what appeared to be bicycle
parts...

In fact, the bolt holding my rear sprocket on my bicycle is BIGGER than the
bolts holding the motor mounts to the nacelle!

:-)

Jay, Jay, Jay ... don't confuse size with strength. :-)


Matt

Jose wrote:

Well, to my (admittedly un-trained) eye, there doesn't appear to be
enough "there" there...


In all fairness, the struts don't have to support the whole load of the
wing. There is also some strength in the wing spar itself.

Really? Most Cessnas I've seen don't have any way to develop any
significant moment about the wing attack points, so the struts DO have
to support the whole load of the wing. The spar is there simply to
transfer the air loads to the strut and wing attach points (compression
generally, or tension if pulling negative G.


Matt

Jose wrote:

I'm guessing there were used in double shear


Whazzat?

Jose

It is when a bolt has two shear planes, which means the bolt passes
through three pieces of metal, with one being on either side of a middle
member. Hard to draw in ASCII, but I'll try:

X's represent the metal being fastened, O's represent the bolt

Single shear:
O
XXXXXXOXX
XXOXXXXXXX
O

Double shear:
O
XXXXXXOXX
XXOXXXXXXX
XXXXXXOXX
O


You can probably Google "double shear" and find much better diagrams and
explanations.

Matt

Jose wrote:

In all fairness, the struts don't have to support the whole load of
the wing. There is also some strength in the wing spar itself.


Not like you'd think. Pull the strut out from under a Cessna and the
wing falls to the ground faster than you can get out from under it.


Hmmm. Good to know. I always thought the strut was more for when the
wing is supporting the aircraft. Is the support set up so that if the
bolts fail on the ground, the wing will fall, or is there a little notch
that would hold it in place.

The wingtip will go right to the ground. There are two bolts that hold
the wing to the fuselage, and they really aren't all the big. These two
attach points are basically like a door hinge, their strength is fore
and aft, not up and down. The strut handles the up and down part.

Newps wrote:
These two attach points are basically like a door hinge,
their strength is fore and aft,

Tension and compression?

not up and down. The strut handles the up and down part.

Shear?

On Sun, 14 Aug 2005 17:45:36 -0600, Newps wrote:



Jose wrote:
Well, to my (admittedly un-trained) eye, there doesn't appear to be
enough "there" there...


In all fairness, the struts don't have to support the whole load of the
wing. There is also some strength in the wing spar itself.

Not like you'd think. Pull the strut out from under a Cessna and the
wing falls to the ground faster than you can get out from under it.

I'll never pre-flight a 210 again.

Thanks for the info.

Mike Weller

On Fri, 12 Aug 2005 17:15:42 GMT, "Mortimer Schnerd, RN"
wrote:

wrote:
Bryan, can't you learn those maneuvers without getting a commercial
ticket?


Of course you can but why bother? The maneuvers are and of themselves are
pretty useless. You might as well get credit for learning them.

One of the best things about flying is that you never stop learning.

I mean that in the kindest way.

Mike Weller

Jay Honeck wrote:

rambunctious thing we ever do are "Up-Downs" (as the kids call them), which
is a firm pull up with a steady push-over at the top that induces negative
Gs in the back seat.

As others have sait: If there's no dirt floating around, you don't even
hit zero G, let alone negatives. I think you should go and take some
real acro lessons. (Actually, I think every pilot should!) It's fun and
it definitely makes you a better pilot. And you'll learn something about
the flight envelope. If I recollect correctly, your average spam can is
certified for something like +5.3 and -2.5 G at Va. Ask your acro
instructor to demonstrate those loads. You'll be surprized! (Not sure
whether you'll like it.)

Stefan

john smith wrote:

Newps wrote:

These two attach points are basically like a door hinge,
their strength is fore and aft,


Tension and compression?

not up and down. The strut handles the up and down part.


Shear?

Just the opposite. The wing attach bolts are loaded in shear and the
strut in tension (primarily) or compression (negative G).


Matt

Mike Weller wrote:

On Sun, 14 Aug 2005 17:45:36 -0600, Newps wrote:



Jose wrote:

Well, to my (admittedly un-trained) eye, there doesn't appear to be
enough "there" there...


In all fairness, the struts don't have to support the whole load of the
wing. There is also some strength in the wing spar itself.

Not like you'd think. Pull the strut out from under a Cessna and the
wing falls to the ground faster than you can get out from under it.


I'll never pre-flight a 210 again.

Thanks for the info.

I've never read the preflight checklist for a 210, but the 150-182
series doesn't include removing the wing strut as a preflight checklist
item! :-)

Matt