misdrilled hole on on tubular aluminum spar question

"Orval Fairbairn" wrote in message
news
In article ,
jerry wass wrote:

patrick mitchel wrote:

There's a discussion on a ul ng about a guy that built a strut braced
light
plane and in a fit of overkill (apparently ) decided to add a (non
plans)
jury strut. He drilled a hole (3/16") on the bottom of the tubular alum
spar. Then realized he may have made a mistake. Whats the outcome and
is
there a fix without putting in a new spar. Just curious (and I didn't
do
it!!) Pat


snip

The strut is in tension and at an angle to the spar which puts a compression
load on the spar. Aerodynamic forces between the strut and the root tend to
lift the wing, which increases the compression on the bottom of the spar
between the strut and root (supported at both ends).The moment applied at
the strut from the outboard portion of the wing tends to put the top in
compression, the bottom in tension. The net result (tension or compression)
depends on the details of the geometry - how far out is the strut and what
kind of angle is it at.

In any case, I would want to put a doubler over the hole...

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Capt. Geoffrey Thorpe wrote:
"Orval Fairbairn" wrote in message
news
In article ,
jerry wass wrote:


patrick mitchel wrote:


There's a discussion on a ul ng about a guy that built a strut braced
light
plane and in a fit of overkill (apparently ) decided to add a (non
plans)
jury strut. He drilled a hole (3/16") on the bottom of the tubular alum
spar. Then realized he may have made a mistake. Whats the outcome and
is
there a fix without putting in a new spar. Just curious (and I didn't
do
it!!) Pat



snip

The strut is in tension and at an angle to the spar which puts a compression
load on the spar. Aerodynamic forces between the strut and the root tend to
lift the wing, which increases the compression on the bottom of the spar
between the strut and root (supported at both ends).The moment applied at
the strut from the outboard portion of the wing tends to put the top in
compression, the bottom in tension. The net result (tension or compression)
depends on the details of the geometry - how far out is the strut and what
kind of angle is it at.

In any case, I would want to put a doubler over the hole...

You're SO RIGHT --I forgot to tack on the overhanging portion of the
wing---Jetty

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.