I bent it, to be sure.

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Boac
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I bent it, to be sure.

#1 Post by Boac » Tue Mar 10, 2020 10:30 am

Whoops! http://avherald.com/h?article=4d449dfc&opt=0

Anyone want any scrap metal? Paddy McGuinness has some in Shannon town. :))

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Re: I bent it, to be sure.

#2 Post by llondel » Tue Mar 10, 2020 2:56 pm

Was it counted as one landing or two?

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Re: I bent it, to be sure.

#3 Post by Boac » Tue Mar 10, 2020 3:51 pm

I guess if you average out the 'g' it was ok.

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Re: I bent it, to be sure.

#4 Post by TheGreenGoblin » Wed Mar 11, 2020 10:12 am

More crinkles than a crinkle cut crisp. Career threatening crisp mind.
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Re: I bent it, to be sure.

#5 Post by OFSO » Wed Mar 11, 2020 5:07 pm

Ripples ?

An article at The Aviationist addresses one of the least well known but apparently common facts about large airplanes—the skin does not always sit still and it isn't meant to. As the article explains the skin of large aircraft such as the B-52 Stratofortress buckles in flight, rippling with the high speed flow of air over the surface of the aircraft. Although slightly alarming, it’s perfectly safe.

Recently, the site shared a photo of the moment an engine on a B-52H Stratofortress sent a shower of sparks flying. The photo was a rare closeup of the forward fuselage, between the cockpit and the wing. The photo showed not only the aircraft’s markings but a definite pattern of vertical ripples across the skin of the airplane, giving it a papery or plastic-y appearance.
The ripples are a regular thing, but most people would never know it. The B-52 is 159 feet long, and many photographers prefer to take photos of the entire aircraft. What’s more, photos of the big bomber flying are usually taken from another aircraft, making smaller details harder to spot. The photographer responsible for The Aviationist’s shot was zoomed in on the front of the airplane as it departed Leoš Janáček Airport, in Ostrava in the Czech Republic.
All aircraft have relatively lightweight metal skins, a function of trying to keep an aircraft as light as possible. The thin metal skins are subject to compressive and pressure loads during flight. This causes the rippling effect in the metal. The rippling does not harm the aircraft nor apparently alter its performance in flight. The buckles are particularly visible on the B-52 bomber, which has a large, long, slab-sided fuselage.

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Re: I bent it, to be sure.

#6 Post by TheGreenGoblin » Wed Mar 11, 2020 5:48 pm

Airframes are designed to expand and contract due to pressurisation, heating, cooling and so on. Fuselages can twist, bend, and even ripple within certain tolerances too of course but such motions should never become divergent and the airframe should revert to its original shape. The aircraft in the photo has clearly been overstressed and bent resulting in a crease in the skin.

Control surfaces that bend or ripple can facilitate flutter which is bad news... Where the oscillations become harmonic or divergent mid air break up is a very big risk!

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Re: I bent it, to be sure.

#7 Post by TheGreenGoblin » Wed Mar 11, 2020 5:57 pm

There is that aircraft certification test video that shows how one can go too far...



https://www.fss.aero/accident-reports/l ... rt_key=169
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Re: I bent it, to be sure.

#8 Post by TheGreenGoblin » Wed Mar 11, 2020 6:34 pm

Accident occurred Friday, March 28, 2008 in Monterrey, Mexico
Aircraft: British Aerospace 800A, registration: N167DD
Injuries: 2 Uninjured.


The two hot rods flying this decided to roll the aircraft...

[attachment=0]image001.jpg[/attachment]
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Re: I bent it, to be sure.

#9 Post by TheGreenGoblin » Wed Mar 11, 2020 8:17 pm

How tough is the 747... bend it like Beckham!

https://en.wikipedia.org/wiki/China_Airlines_Flight_006
There were two serious injuries on board: a fracture and laceration of a foot, and an acute back strain requiring two days of hospitalization. The aircraft was significantly damaged by the excessive G-forces. The wings were permanently bent upwards by 2 inches (5 cm), the inboard main landing gear lost two actuator doors, and the two inboard main gear struts were left dangling. Most affected was the tail, where large outer parts of the horizontal stabilizer had been ripped off. The entire left outboard elevator had been lost along with its actuator, which had been powered by the hydraulic system that ruptured and drained.
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Re: I bent it, to be sure.

#10 Post by barkingmad » Fri Apr 17, 2020 7:52 am

https://www.rt.com/news/486070-canada-p ... y-landing/

This guy obviously didn’t appear to bend it!!
Strange “critical malfunction” where the engine is still running and appeared to be supplying energy for the final approach E M?

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Re: I bent it, to be sure.

#11 Post by TheGreenGoblin » Fri Apr 17, 2020 1:49 pm

barkingmad wrote:
Fri Apr 17, 2020 7:52 am
https://www.rt.com/news/486070-canada-p ... y-landing/

This guy obviously didn’t appear to bend it!!
Strange “critical malfunction” where the engine is still running and appeared to be supplying energy for the final approach E M?
Partial loss of power? The engine seemed to be smoking on his approach. Lucky to get away with it. No damage done...

Once had an electrical fire in the cockpit of a Grumman Cougar, the heat was enough make me think very seriously of putting down on a road but, fortunately, the airfield was close enough to make it back, shaken and slightly singed...
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Re: I bent it, to be sure.

#12 Post by AtomKraft » Sat Apr 18, 2020 8:44 am

Flutter?


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Re: I bent it, to be sure.

#13 Post by TheGreenGoblin » Sat Apr 18, 2020 10:23 am

An old school friend owns a skydiving school and is also a very good stick and rudder guy and a gyrocopter instructor and examiner to boot. Anyway he had just disgorged four eager meat bombs when when the Cessna 210 began to shudder violently and then the yoke jammed solid, fortunately in a basically neutral position with the aircraft heading towards the coast. He told me he would have abandoned the aircraft if he had had a parachute on, which he didn't, so instead he dialed up Cape Town International and declared a Mayday and was given vectors for a long final to runway 19 at FACT. He then gingerly managed to turn, in a still juddering aircraft, using rudder alone, and line up, noticing the parade of emergency vehicles parked near the runway in expectation of his almost certain crash but he defied the odds and pulled off a greaser much to everybody's astonishment.

The aircraft was written off however, both wing spars having been twisted at the roots due to flutter caused by loose rigging in the ailerons arising from poor maintenance! I have a photograph of the aircraft somewhere and I will see if I can fish it out and post it here. He was very lucky not to have shed both wings...

This is taken from an aircraft over the location of where the onset of flutter began... (the photo of the aircraft I have has the smiling protagonist next to it so I shall refrain from posting it)
Scene of the flutter.JPG
Though you remain
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"To be alive
You must have somewhere
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Your destination remains
Elusive."

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