More cracks in scarebus wings

[Tupac]

Ok, you go up to 30k feet and start traveling at  500mph carrying nothing and then you tell us how you experienced no stress from the temp/pressure/speed change.

I'm saying that any part of the wing is critical. I think what you just said would support that.

[Golfer]

Pretty snazzy now that the Jeppesen private pilot kit books talk about heavy aircraft aeronautical engineering.

I just did some Wiki-Math and the A380s wing loading at Max Takeoff Weight is actually less than but very close to the 747-400.  It's about twice as much as a Lear 45 and roughly 10x as a 172.  It's not just the weight that matters, it's how it's distributed and how it's attached.

[Golfer]

FWIW my favorite line in one of these articles came from an Airbus engineer:

"these cracks were unexpected, but they happened exactly as expected."

That's just a synopsis but it's worthy of a WTF.

[Tupac]

Pretty snazzy now that the Jeppesen private pilot kit books talk about heavy aircraft aeronautical engineering.

I just did some Wiki-Math and the A380s wing loading at Max Takeoff Weight is actually less than but very close to the 747-400.  It's about twice as much as a Lear 45 and roughly 10x as a 172.  It's not just the weight that matters, it's how it's distributed and how it's attached.

I'm studying for the commercial  

This is the reaction that makes me very happy http://mobile.reuters.com/article/idUSL6E8CK11P20120120?irpc=932

[nrshida]

How do you remove a thread from your "Show new replies to your posts" listing?

[Tupac]

How do you remove a thread from your "Show new replies to your posts" listing?

It will Peter out shortly - I don't know if there is a way to remove it

[icepac]

Now not to knock Cirrus or Diamond they both make an incredibly fine product and I have no doubt some of them will be flying a long ways down the road, but they aren't subject to the incredible weights that the A380 incurs. I just hope the 787 doesn't run into problems.


I've never flown in a Boeing that sounds like it had someone's bowling ball collection rolling around under the floor. I shouldn't have said "If it ain't Boeing I ain't going" because I will gladly fly any Beech, Cessna, Cirrus, Diamond, Fairchild, Aeronca, American Champion, Piper, Rockwell, Bellanca, Flight Design, Grumman, Jabiru, Lancair, etc

What about the ones with wooden spars?

[Tupac]

What about the ones with wooden spars?

I think I covered that in an earlier post - I am a big fan of Bellanca. When I'm around at boerne I help my friend build a starduster 2 which has an aluminum fueselage and wood wings.

[Tupac]

:Potstir:

[colmbo]

Did you read the entire article? One of the Aussies said he wouldn't put his family on one. My patriotism has nothing to do with it. As a pilot and someone with a little bit of common sense I wouldn't fly in one. The immense loads that wing is bearing boggle my mind, and I wouldn't want one weakened by cracks. I like my airplanes aluminum, thank you.

Crawl around through your airplane.  You WILL find cracks.  In the 172 the horizontal will probably have the most cracks.  You're not one of those guys that sits on the stab to swing the nose around are you?  If so, check even closer.  The very last bulkhead at the bottom where the tiedown ring is - - another likely spot for cracks.  Wing skins around the flap hinge attachments, and ribs where the flap hinges attach.  Skin on the flaps, especially along trailing edge, is another likely spot.  You have manual flaps?  Check around the brackets attaching the flap cable pullets to the bulkheads, especially the one forward of the flap handle (particular favorite of mine, really nice when it fails on a go around giving you  jammed asymmetric flaps).  Engine cowling always has cracks around attachment points.

[Tupac]

I actually have cracks in the trailing edge that I am fixing next week at annual with one of those trailing edge cuffs

[PR3D4TOR]

...in the wing. If it is not critical why is there enough load on it to crack it?

“Critical” has a different meaning in engineering terms. Engineers design redundancies in structures for this exact reason. There’s a whole list of parts on an airplane that the FAA will let you take off without, or at least without them being functional. Airliners are massively over-engineered. Twin jets have to be able to take off, land, and if they’re ETOPS fly for a hell of a long time on one engine. So arguably the second engine isn't even “critical”… although I’m not seriously suggesting that.
 
The Aviation Week article says: “Each wing has around 2,000 L-shaped brackets (30-40 per rib, with 60 ribs per wing), so the failure of one bracket is not seen as a safety issue.” These are the parts that distribute the aerodynamic loads from the wing skin to the rib/spar assembly. Essentially they’re secondary load bearing structure. If you have enough of them fail, you could potentially lose a wing skin section but the probability of that is exceedingly low owing to the shear number of brackets. I wouldn't start worrying till you hear stories of cracked wing spars or other primary structure.

[PR3D4TOR]

FWIW my favorite line in one of these articles came from an Airbus engineer:

"these cracks were unexpected, but they happened exactly as expected."

That's just a synopsis but it's worthy of a WTF.

Engineers design parts to fail in a predictable manner. They didn't expect the part to fail, but when it did it did so in the way they predicted.

[Zeagle]

That's okay, they'll fix it. A lot of airplanes had problems that made them dangerous, it does not mean that they will never be safe. I'm sure you know about the problem the 172 had when the seats would slide back on take off causing a crash, yet you still fly one. That's because FAA issued an AD for it (as far as I remember) and now the seats attach differently.

That actually happened to me down low and pulling a few g's in a 152. Luckily I am 6ft tall so it was just an inconvenience. And, we were briefed that it could happen. In the 172 it would have been a bit more serious but still recoverable. I think more folks have wrecked 172's on takeoff due to an open door than the seats sliding back though.

As far as the 380 goes, they almost lost one already. Not interested in flying on them.

[mthrockmor]

What's the B-52 made of? They are flying strong, and should be for another 20 years.

Boo