Engine-out procedures and eccentric forces on engine pylons

"Erik" wrote in message
...

I love the window seat, but dammit, I cannot look at the wing
ever. "Ok, if it didn't flex like that, it would be brittle
and snap. It's supposed to bounce, it's not supposed to break"

But nothing reassures me.


I find counting missing rivets and watching spinning rivets takes my mind
off the wing flex.

I love the window seat, but dammit, I cannot look at the wing
ever......

1971 - My very first airline ride -- Delta DC-9 Tampa to Atlanta
The wing looked very solid and very much "one with the airplane" --o--

30 minutes later - My second airline ride -- PanAm 747 Atlanta to LA
I coulda swore that the wings were flapping ~~o~~

I missed a lot of scenery :-)

TP

On May 23, 5:11 pm, Erik wrote:
BDS wrote:
"Bob Moore" wrote...

You should see what those pylons do in heavy turbulence!
The only stress is on the pilot who looks at them. :-)

My wife and I were on a flight a few years back in an A300 IIRC and we were
in seats that gave us a clear view of the engine on the left wing. I was
casually looking out at it when I noticed that it was oscillating back and
forth quite noticeably and considerably, and we were only in light chop at
the time. My first impression was HOLY #$%&! quickly followed by the
realization that since it hadn't come off yet it must be normal.

Judging by how much it was moving around you would have thought it was held
on with bungee cords.

BDS

I love the window seat, but dammit, I cannot look at the wing
ever. "Ok, if it didn't flex like that, it would be brittle
and snap. It's supposed to bounce, it's not supposed to break"

But nothing reassures me.-

Understandable. I'd feel the same way if I was you.


Bertie

Hide quoted text -

- Show quoted text -

Bob Moore writes:

You should see what those pylons do in heavy turbulence!
The only stress is on the pilot who looks at them. :-)

I've seen engine nacelles swaying merrily to and fro (along the wing axis) in
turbulence but I didn't know if twisting forces applied to the pylons would be
so easily tolerated.

As it is, modern pylons, so seemingly frail and so apparently inviting of very
concentrated stresses as they hold the engines way out in front of the wing,
always look like an invitation for trouble to me. But I suppose if they are
engineered properly they can hold, rather like that glass walkway that the
Havasupai recently built out over the Grand Canyon.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Mxsmanic wrote in
:

Bob Moore writes:

You should see what those pylons do in heavy turbulence!
The only stress is on the pilot who looks at them. :-)

I've seen engine nacelles swaying merrily to and fro (along the wing
axis) in turbulence but I didn't know if twisting forces applied to
the pylons would be so easily tolerated.

Fjukktard



Bertie

I.m wondering if the engineering on wings has changed a bit. I worked for
an airline carrier in the early 60's and we took deliver of the first
boeing 727 built. the company provied us with a very similar video. Its
showed a 727 straped into a cradel and the wings were bent up similar to
what this utube shows..
Difference:
i watched the wings pushed up to where both tips touched each other many
many many times
there was not a failur and i do not remeber exactly how many times but it
was in the dozens. I wonder what the difference is that this wing breaks
after only one raise
tom
"Bertie the Bunyip" wrote in message
.130...
Mxsmanic wrote in
:

Bob Moore writes:

You should see what those pylons do in heavy turbulence!
The only stress is on the pilot who looks at them. :-)

I've seen engine nacelles swaying merrily to and fro (along the wing
axis) in turbulence but I didn't know if twisting forces applied to
the pylons would be so easily tolerated.

Fjukktard



Bertie

On 24 May, 21:40, "tom laudato" tommyann wrote:
I.m wondering if the engineering on wings has changed a bit. I worked for
an airline carrier in the early 60's and we took deliver of the first
boeing 727 built. the company provied us with a very similar video. Its
showed a 727 straped into a cradel and the wings were bent up similar to
what this utube shows..
Difference:
i watched the wings pushed up to where both tips touched each other many
many many times
there was not a failur and i do not remeber exactly how many times but it
was in the dozens. I wonder what the difference is that this wing breaks
after only one raise

Nope, essentially the same up to the point where they're sticking
Carbon fiber spars in, but the certification standards are the same.

A wing pylon will happily accept a consideraable load in just about
any flight attitude, what it won't accept is s sudden high G load such
as extreme turbulence or an abrupt engine stoppage might cause.
you won't break a wing off too easily, though.

Bertie

Mxsmanic wrote in
:

Long ago it occurred to me that a twin-engine jet running with one
engine out might be putting tremendous eccentric stress on the plyon
and mounting of the running engine (meaning stress not aligned with
the normal thrust vector of the engine). Today it occurred to me that
this might not be true if the pilots adjust the attitude of the
aircraft so that it is flying straight forward. The adjustments would
create opposing forces that not only keep the aircraft in level flight
but also realign the stress on the running engine, as if there were
still two engines and symmetric forces on the pylons.

Does this make sense?

Nope, pretty much the same as everythign else you post.


Bertie