Another Airbus Down

[willtel]

There is another Airbus down, an A310 went down in Yemen with 150 on board.

http://www.cnn.com/2009/WORLD/meast/06/29/yemen.plane.crash/index.html

Originally Posted by CNN

A Yemeni airliner with 150 people aboard has crashed in the Indian Ocean off the island nation of Comoros, an aviation official in Yemen's capital said Tuesday.

An Airbus 310 like the one pictured has crashed while on the way to the capital of Comoros.

The aircraft, from the national airline Yemenia, was en route to Comoros when it crashed about an hour from its destination, an airline official said. There was no immediate news of the fate of those on board.

The Airbus A310 was en route from Yemen's capital Sanaa to Moroni, the capital of Comoros, and most of the passengers were Comoran, an official at Sanaa's international airport said. Moroni is about 2,900 kilometers (1,800 miles) south of Yemen, off the east coast of Africa.

"We don't know if there are any survivors among the 150 people on the plane," Comoros Vice President Idi Nadhoim told Reuters.

[artplumber]

That sounds like terrorism may be a real possibility.

[pwd72s]

Originally Posted by artplumber

That sounds like terrorism may be a real possibility.

A sad commentary of our time...that we need to consider this whenever a passenger jet crashes.

[Joeaksa]

Yemen is a snakes den of terrorism. Until they clean their act up there, there is not enough money in the world to get most sane people to go there.

[Tishabet]

I thought it crashed while trying to land in bad weather? I think that's what they said on the radio.

[Deschodt]

Before anyone jumps on Airbus again, that plane was barred from French airspace because it was way below maintenance standards... It tried to land in bad weather, 50 mph crosswinds, could not, went around and splashed in the ocean during the attempt at another landing...

Amazingly a little girl survived and was plucked out of the water ! Sounds more like poor flying/bad maintenance combo than terrorism !

[Zef]

This company A/C was on the EU black list....!

[fingpilot]

Have flown here as well. Runway was a one-way in and out. Meaning approach and land from the north onto a rwy that parallel skirts a beach with a volcano at the south end of the runway. Miss the approach, and it is an E-ticket ride for the pax. The winds (on an island) are always blowing, and it was not unusual for there to be a 10 knot tailwind at both ends of the runway, meaning that even if you swung clear of the volcano and made a pass at landing from the south, you'd still be in these swirling winds all the way to touchdown. Coral pavement on runway shredded the tires (not necessarily because of the heavy braking), the mechs could always tell if I'd landed in French Polynesia or the Cosmoros Islands.

A nightmare at night, or in bad weather (very common).

Story is they missed the first approach, at night, in bad weather, and splashed short of the island on second approach. Black Hole Syndrome is suspected. BTDT, it is a nasty place. Top it off with the fact that departure and destination are both insurgent/terrorist meccas (pardon the pun), and it is a recepie for disaster.

Am always sorry to hear of the loss of life, but I doubt this was an airplane problem.

[flatbutt]

Fair enough fingpilot, as always good info well presented. But as an emotional person I'm still glad my son is flying Boeing next month.

[Vipergrün]

I don't recall the last Boeing I flew on, but last week flew to Munich and back on an Airbus A340. Is it just me or do these planes seem to have a lot of weave and flex in turbulence? At times the plane seemed to 'snake' thru the air. Ok, perhaps a bit extreme, but....

[t6dpilot]

Weave and flex eh? According to what I have read, the Airbus A300 series aircraft are manufactured using 25% composite materials. This used to be just for non-structural areas, but are being used for structural areas now - vertical stabilizer and wing attachment box are two examples. They are being used because they are lighter and can create a smoother surface - better fuel efficiency and airflow. Yes, I know that composites have been used to great success for years in the experimental category aircraft. Actually, they have revolutionized the aircraft industry to a large degree. But I believe that their use in commercial airliner is relatively new.

I recently received a white paper of sorts that described this in detail and related their use as being faults (vertical stabilizer) in several high profile Airbus crashes. And this includes being a possible failure point in the AF447 crash recently. Not sure that I should post it here, so will hold off for the time being. I would love to hear from Fingpilot, MFFAF, and others who are extremely knowledgeable in this industry. I always enjoy and respect your very informative and well thought out posts.

[Zef]

Originally Posted by flatbutt

Fair enough fingpilot, as always good info well presented. But as an emotional person I'm still glad my son is flying Boeing next month.

??????????? look like you're very emotional...!

[fingpilot]

Originally Posted by Vipergrün

I don't recall the last Boeing I flew on, but last week flew to Munich and back on an Airbus A340. Is it just me or do these planes seem to have a lot of weave and flex in turbulence? At times the plane seemed to 'snake' thru the air. Ok, perhaps a bit extreme, but....

Funny you should say that. I grew up in an F4-D. The only thing that flexed on that was your own glutes anytime the thing was within a foot of the deck. Short, solid, multi camber wings, even shorter anhedral tail, extendable nosegear strut and extendable tailhook.

Mach 1.5 180-degree turn radius? If you were young and stupid, and could do the constant 7 G's... turn radius was 6 miles. Miles. Nothing vibrated or 'swayed' during that turn except your heart and the cuffs around your lower regions.

I rode to Tahiti not too long ago on an A340-300. LAX to NTAA, 10+ hours. Thru the Intertropical Convergence Zone, across the equator, thru lots of tops and turbulence. I was right over the rear of the wing.

My impression was exactly as yours. Sway and waddle. The wings are so slender and flexible (a good thang) and the fuselage so long, it seemed to flex it's way thru the turbulence the entire time. While it made a comfortable ride, it was disconcerting at first, seeing all 4 engines each describing their own unique arc as they flexed at the end of their pylons differently from the rest of the wing. I am used to the relative stiffness of a whale and while the 747-400's will do some of that (when heavy and high), it is several orders of magnitude more obvious in the A340.

This from a guy normally upfront, and not aware of these cabin perceptions. Being up at the tip of the arrow means you don't feel anywhere near the movement like in back.

Not a criticism of the bird, mind you, just a similar experience as yours. Yes, as a pax, I did sleep some of the way, and nothing I saw or felt would keep me from doing it again.

[jeffgrant]

Some of the scariest flights I've ever been on have been at the back end of an old-school stretch DC-8.

You could watch the aisle snake while you were flying.

The engineer in me tells me that some flexibility is a good thing, but damn was it unsettling to watch it happen.

[MFAFF]

All of these long fuselaged planes have similar characteristics...

The 747 isn't really a long fuselaged plane....the width to length ratio is 'good' in terms of it providing a decent 'stiffness' or resistance to longitudinal bending.

So the A330/340, the DC-10-6x (even the first extended 707s) all have relatively bendy fuselages. Now some flexing is inherently beneficial (all of the wings flex of a reason) in structural terms but in terms of pax comfort and 'impression' its a different matter.

The A330/340 structures, being newer and 'optimised' to a greater extent than the DC-8 have a greater flex...as the design can be simulated and modelled prior to manufacture to maximise the fatigue relief benefits with the minimum weights etc. I'm not certain the greater use of composites is related, they tend to be 'stiffer' as opposed to metals...but it might be simply a relative displacement of flex...ie certain areas are stiffer so the more flexible areas move 'more'.

Its been a long time since I flew behind the wing as it were....recent flights on a 777 and A380 were very interesting...the 777 has a 'stiffer' ride.. much more high frequency, low amplitude disturbances.. like in a 911, which when on an overnight flight makes for poor pax comfort (relatively).. whereas the 380 (double decker remember; on the upper deck) was much smoother and the ride much more comfortable... like a 928.

Mind you looking back to the wing the 380 wing was flexing far more than the 777 wings.. perhaps therein lies the answer. From memory the 747 wing was also far more rigid...

I think the long fuselaged a/c (especially those with a long moment arm behind the wing.. the distance from wing to rear stabs) are more likely to be prone to Dutch roll...hence the ventral fin on early 707s unless the vertical stab is 'over sized'...not saying this is an issue but it may be the a/c, espescially the active Airbuses may be working harder to counteract this...hence a bit of tail wagging.

It is interesting to see how the perception of A vs B is so pronounced...with B being viewed as 'safer' yet the accidents stats and reasons tends to suggest 'equality' in terms of a/c issues/piloting/WX and others....

The investiagtion into the AF flight will provide interesting reasons for airframe failure... because regardless of the reason it did fail. On a side note however a 767 was also suffered loss of reliable airspeed data in severe turbulence. The needed to reduce height and even with this did not regain reliable airspeed data.
This tends to support a pitot issue rather than inherent FBW concept issue...

Hohum...we shall see...