Air show 787

[island911]

Originally Posted by Scott Douglas

And therein lies the problem, they broke.
Unlike the B-52 example where they deformed.
Composites aren't very forgiving when pushed past the limit. It's catastrophic failure.

My understanding of the test facility is that they always deflect to full break. The B52 is a Long-ass wing. - huge strain to UTS failure.

Of course you are right about the composite wing, and strain to failure. But the loading will be ridiculously high, compared to say the B52.

[BigInJapan]

Originally Posted by vash

Serious?

Question. From a ground guy. As a pilot, is there a huge difference when you fly an empty jumbo jet versus one bringing back a load of tourist from Disney world? I mean loaded heavy.


Typos and bad grammar sponsored by iPhone!

I'm assuming that your question is about the flight characteristics/dynamics of an empty airplane vs an airplane at max gross:

Yes...

Stall speed (the most important flight characteristic in regard to low speed maneuvers) goes up because of multiple factors. The airplane must fly at a different AOA throughout the flight envelope to develop the same lift needed for flight (level flight for instance). This changes the angle of incidence and thus changes the speeds necessary to maintain flight without stall.

The 87 would not be able to depart vertically, as it did in the video, at max gross without stalling much sooner.

Ian

[Neilk]

Originally Posted by island911

My understanding of the test facility is that they always deflect to full break. The B52 is a Long-ass wing. - huge strain to UTS failure.

Of course you are right about the composite wing, and strain to failure. But the loading will be ridiculously high, compared to say the B52.

From what I have read, Boeing passed their target limits on the 787 wing by a couple of percentage points but did not go all the way to breaking them. Apparently breaking them would have sent carbon fiber shards through out the building and would not have netted them any more meaningful information.

[Sarc]

Originally Posted by Jeff Higgins

Your video is real. First one is computer generated.

Negative.

Originally Posted by J P Stein

Eddie Allen did a slow roll over the Gold Cup race on Lake Washington in a 707 back in the 50s. Rumor has it that it sold a lot of airplanes.

He practiced that far away from prying eyes. A 1G roll would not spill a drop of water from a full to the brim glass.....but it looked damn impresive. The CEO of Boeing was at the race (along with a half million other folks) & about **** a brick.

Wasn't it this the guy that did the roll in the 707?

[450knotOffice]

Originally Posted by Scott Douglas

And therein lies the problem, they broke.
Unlike the B-52 example where they deformed.
Composites aren't very forgiving when pushed past the limit. It's catastrophic failure.

Actually, that's not indicative of a problem at all. In fact, the video he speaks of is an FAA Certification test of a wing's ultimate strength. In other words, how far will it go past it's designed ultimate strength, which is itself WELL beyond the ultimate load that wing will ever see in its life. The test is designed to take a wing to its breaking point. That's the planned (and achieved) end of the test. Engineers then study the data to determine the wing's ultimate strength.

By the way, I am HIGHLY doubtful that the B52 wings were able to be pulled up so high that they ultimately touched tips. Not only that, a wing's strength test only involves ONE sacrificial bare wing in a test rig designed to apply a measured, controlled (and massive) force to the wing, across the entire span. So, I call that statement to be nothing more than urban legend, unless someone shows a video or picture of it.

[450knotOffice]

And it was "Tex" Johnson who barrel rolled the B707 over Lake Washington, and yes, The President of Boeing was horrified to see that, but Tex kept his job.

[David]

I rode in one from LA to Houston a few months ago. It was neat but I didn't notice the pressure difference or higher humidity or whatever else it's supposed to be better at.

I was amused by the guy in the window seat being unable to figure out the window dimming feature. I played with it before he got there and while not real intuitive, it wasn't rocket science. Once again, some people shouldn't be allowed to use tools.

[Seahawk]

Originally Posted by vash

Serious?

Question. From a ground guy. As a pilot, is there a huge difference when you fly an empty jumbo jet versus one bringing back a load of tourist from Disney world? I mean loaded heavy.

Absolutely. There is a tried and true saying in aviation: "High, Hot and Heavy".

Meaning, an aircraft landing at Denver in the summer when it is 90 degrees in the shade with a full boat of peeps and their luggage is a whole different experience than squeaking an empty jet on at SeaTac in January.

Every tactical flight I have flown we ran the numbers that impact aircraft performance: Temperature, humidity, weight, actual engine performance and any drag inducing external equipment (missiles, gun pods, etc.).

Everything matters.

The largest aircraft I have piloted was a USN P-3. I probably have ten hours in the co-pilot seat and four landings, all during post maintenance flights.

The thing I find impressive about honking big aircraft around is just how much control input/deflection is required to make it look so smooth. I really enjoyed watching the pros at work (I think)

[BE911SC]

Originally Posted by BigInJapan

Looks like an incredibly skilled pilot/crew who know the machine very well. Didn't look dangerous to me.

Ian

This. (Spoken as a 15,000-hour USAF and airline pilot.)

And: Eddie Allen was a Boeing test pilot on the WWII B-29 bomber. Died when his B-29 crashed on landing at Boeing Field during the development program.

[BE911SC]

Airbus lobbied the authorities at Farnborough to have the 787 guys tone down their aerial demo because the Airbus can't do a touch-and-go without trying to kill its pilots.

Farnborough Air Show bans thrilling maneuver as Airbus and Boeing jets aim to impress | Boeing Blog | Seattle Times

[BE911SC]

Originally Posted by Sarc

Negative.



Wasn't it this the guy that did the roll in the 707?

Tex rolled it and sold it. A true legend.

[jyl]

Can the pilot/engineer types discuss the wingtips on the 787? They are different than what I see on other airliners. Is the sharp and slightly upswept shape - sort of like a claw - better than the tall winglets common today?

[Don Plumley]

Great interview with Tex:



"You know that. I know that. Let's don't do it anymore."

[450knotOffice]

Originally Posted by BE911SC

Airbus lobbied the authorities at Farnborough to have the 787 guys tone down their aerial demo because the Airbus can't do a touch-and-go without trying to kill its pilots.

Farnborough Air Show bans thrilling maneuver as Airbus and Boeing jets aim to impress | Boeing Blog | Seattle Times

Sorry, but you're mistaken about the Airbus. The Airbus most certainly CAN do a Touch and Go. It's called a Rejected Landing, and is in our manual as a normal maneuver, to be used as needed.

Apply TOGA thrust and select go around flaps while rotating to the go around attitude. Ground spoilers retract automatically if at least one thrust lever is advanced more than 20 degrees (not much).

[BE911SC]

Okay, but my opinion makes for a better story than your facts.

(I should run for office.)

[Scott R]

The opened with this video at our division staff meeting today at Boeing. We're pretty proud of it.

[rick-l]

Any aero guys out there?

See the spoiler near the wing tip deployed in those high bank angle turns. Does that unload the skinny wing tip?

[J P Stein]

I stand corrected, it was Tex Johnson who did the roll.
Eddie Allen augered into a meat packing packing plant while testing a B-29.
The engines on the B-29 claimed him and a bunch of others.

My memory ain't what it used to be...nor is anything else.

[gordner]

They all break them, it is required. That wing vastly out performs the B52 wing structurally, not breaking is not all there is to it. Composites fail progressively, not all at once like metals. They regain their original shape better after deformation and they weigh a lot less.

[island911]

"Composites fail progressively, not all at once like metals."

say wuhaa...?