Your opinion on this landing

On May 10, 3:20 pm, Matt Whiting wrote:
Paul Tomblin wrote:
In a previous article, Erik said:
Sheista wrote:
http://www.thepollspace.com/polls.php?pollid=1359



I know this already, but it always amazes me to see
the wing holding up the plane. It's propped off of
the ground on the one wing. I know this happens in
the air, it's just neat to see how strong the wings
actually are.

In the air, the load is distributed along the length of the wing, rather
than just on the wing tip. So this wing is taking more torque than a wing
in the air.

Only if you consider an air load of 1G. I'd have to do that calculation
to be sure, but I'm fairly confident that 4G in the air is more moment
at the wing root than is 1G at the tip.

Matt- Hide quoted text -

- Show quoted text -

I'm not sure how actual aircraft engineers do it but when I got my
engineering degree that isn't how we would do it. Looking at the
moment at the root seems to imply that the entire length of the wing
is of equal strength and the forces are focused on the root. In fact
the wing is not designed to be equal strength throughout, each section
of the wing is only as strong as it needs to be. Therefore, the chance
of failure (at least ideally) is about equal anywhere along the wing
(root, mid section, tip, etc). There may be practical frabrication
reasons why you would have one section of a wing "over engineered",
but in general, that would not be an engineer's goal.

When I was an engineering student we would look at each spar's forces
as a continous function using calc. That way we could use dx to see
the force on any infinite small section of each spar. Looking at the
max force at any dx we could reduce weight (i.e. strength) if one
section was stronger than necessary. The strength at that section
would be designed to meet the requirement of the force expected. I.e.
we wouldn't make the entire wing the same strength if the forces were
not the same throughout.

-Robert

each section
of the wing is only as strong as it needs to be. Therefore, the chance
of failure (at least ideally) is about equal anywhere along the wing

In fact, there's a video somewhere showing a stress test on a wing; the
entire wing fails pretty much at the same time.

Jose
--
Quantum Mechanics is like this: God =does= play dice with the universe,
except there's no God, and there's no dice. And maybe there's no universe.
for Email, make the obvious change in the address.

Erik writes:

I know this already, but it always amazes me to see
the wing holding up the plane. It's propped off of
the ground on the one wing. [...]

As Paul wrote, the loading is different here. But what may be helping
here is that a lot of the force seems to be compressive along the wing
spar(s).

- FChE

Sheista wrote:
http://www.thepollspace.com/polls.php?pollid=1359




There was no landing shown. Parking and landing aren't the same.

Matt

On May 10, 2:47 pm, Sheista wrote:
http://www.thepollspace.com/polls.php?pollid=1359



It wasn't a good one.

Bertie

On May 10, 6:47 am, Sheista wrote:
http://www.thepollspace.com/polls.php?pollid=1359



Certainly couldn't have happened with the energy of a landing with so
little damage. Looks like the line guy may have been pushing it back
and went just a bit too far back. BTW: When on the Kitty Hawk it was
always amazing to me that none of the A-7's ever got pushed off the
deck. They would push them damn close to the edge, often with the
pilot still in it.

-Robert

"Sheista" wrote in message
ups.com...
http://www.thepollspace.com/polls.php?pollid=1359




Any landing you can walk away from is a good landing.

Any landing you can taxi away from is a great landing.

I would say this was a good but not great landing.

Danny Deger
www.dannydeger.net

In article ,
"Danny Deger" wrote:

"Sheista" wrote in message
ups.com...
http://www.thepollspace.com/polls.php?pollid=1359




Any landing you can walk away from is a good landing.

Any landing you can taxi away from is a great landing.

I would say this was a good but not great landing.

Danny Deger
www.dannydeger.net

As I understand it, it was not a landing accident at all! Apparently,
somebody either forgot to set the parking brake or forgot to chock the
plane and it rolled backwards, down the slope, through the fence and
into the waterway.

Orval Fairbairn wrote:
In article ,
"Danny Deger" wrote:

"Sheista" wrote in message
ups.com...
http://www.thepollspace.com/polls.php?pollid=1359



Any landing you can walk away from is a good landing.

Any landing you can taxi away from is a great landing.

I would say this was a good but not great landing.

Danny Deger
www.dannydeger.net

As I understand it, it was not a landing accident at all! Apparently,
somebody either forgot to set the parking brake or forgot to chock the
plane and it rolled backwards, down the slope, through the fence and
into the waterway.



My understanding as well.
DH

"Orval Fairbairn" wrote in message
news
As I understand it, it was not a landing accident at all! Apparently,
somebody either forgot to set the parking brake or forgot to chock the
plane and it rolled backwards, down the slope, through the fence and
into the waterway.

Reminds me of a time I couldn't get a C-172 to track straight down the
taxiway. Kept pulling to the left, and I thought it was the wicked gusting
crosswind we were having.

About the time the wheels left the planet I realized the parking brake was
partially engaged It was the first time I'd ever encountered a situation
where the previous renter had engaged the parking brake...not enough that it
was obvious by the position of the handle, but enough that it caught on the
wheel with the best shoe (Number of Checklist Items = Number of Checklist
Items + 1)

I confessed to the FBO but they weren't worried about the brakes; it was
scheduled for its 100-hour very soon, still had positive braking on both
wheels, and the brake pads were due for replacement anyway. Whew...

-c