Brazil Plane Crash...?

Question

The Brazil plane that crashed was an Airbus. The inital report on CNN said that it ran right off the runway without stopping and crashed into a building. they also stated it had been raining.

Now I took an aircraft safety class during my undergrad degree and one entire day the professor spend speaking about the problems with the Airbus system and listing crashes with the "why's" and "how's". A few were like this, where the plane came into land and never stopped. Reason? Airbus system gives the final say to to the computer and not the pilots. When the planes land, because of the water on the runway, the computer doesnt register the correct amount of friction associated with a landing and never initiated the braking system.

Anyone think that's what happened here too????

They keep stating that it was b/c the runway was short... but how many other planes of that size land there daily and have no problem???

Anyone???

Jim: YES! I'm more Astronautics option then Aeronautics option in engineering, so thanks for filling in the detailed info I didnt put up.

Answer 1

Many modern airliners have safety features built into certain systems that actually work against you in some circumstances. (Unless otherwise noted the systems described are for the Dornier 328 Jet).

The first system is the brakes. When I was undergoing training years ago in light aircraft you would frequently see a brand new tire with a flat spot on it caused by a pilot landing with his feet on the brakes. The same pedal that operates the rudder in the air operates the brakes on the ground (brakes are operated with toe pressure - rudder is operated with heel pressure). In order to prevent this our brakes do not work AT ALL after landing until the airplane has sensed that it is on the ground or the wheels have spun up to 30 knots.

The 2nd system we'll talk about is ground spoilers. These are panels on top of the wing that pop up after landing to reduce the lift of the wing to make the brakes more effective. Needless to say it is a very bad thing for these devices to deploy during flight so certain safeguards were put in place to prevent this. The spoilers on my plane will not deploy unless the throttles are back near idle, the landing gear is down, the aircraft senses weight on wheels and the wheels have spun up to 45 knots.

The final system we'll talk about is thrust reversers. These allow thrust from the jets to be directed forward to help the plane stop. Again, this is something you definitely don't want activating in flight. My plane doesn't have this feature so I'll speak in general terms. The safeguards are usually similar to what I described above. The airplane needs to know it's on the ground either through "weight-on-wheels" logic or wheel spin up logic or both.

None of these are really unsafe but they can bite you if you get sloppy when landing on a wet or icy runway. The problem usually begins by flying the final approach a little too quickly. This causes the airplane to land farther down the runway. The second trap you can fall into is if you try to make a nice smooth landing. By holding the plane off to "grease it on" you eat up still more runway and when the airplane does get on the ground it has touched down so softly that it takes longer for the "weight-on-wheels" sensors to detect that it's actually on the ground and for the wheels to spin up.

I read about an accident where all three of these factors came into play. The airplane landed quite far down an icy runway and, after it landed, neither brakes, spoilers, or reverse was available to help it stop and it ran off the end of the runway.

The safeguards I mentioned are not difficult to work around. Quite simply, when operating from shorter runways you fly the correct approach speed, touch down quickly and firmly, and then apply max braking and reverse.

Just a note: I am not saying this is what happened in the Brazilian crash.

Answer 2

Airbus is notorious for limiting the pilot's countability over the plane. How ever, the situation you described is in my opinion not realistic. I don't have an A320 type rating, so I am a bit unfamiliar with the systems, but I would guess that the flight crew used auto brake. This is a device that pilots can use to select there requested amount of braking. And at any one time the pilot can stomp on the brakes manually.I don't think anyone would design a braking system that in the most crucial set of circumstances of it's use( Short runway, wet and contaminated surface, high landing speed) would simply not work. That is too unheard of. (even for the French{Joking guys})

As to your question about why hasn't it happened before, A number of things can happen.
-Excessive approach speeds,
-Delay of arming and using crucial systems( Speedbrakes Reduce airflow over the wings and make the brakes more effective, Reversers, redirect the thrust forwward)
-Wet surface
-A wind component
-Wind shear
-Crew error
and any other things.

Also in this case, the failur to groove the runway meant that braking action was poor. Grooving would have increased the braking Action significintally.

It is to early for speculation. The Brazilian authorities will publish a report in a year or so. We can only then know the whole story. But I really don't think that your professor was right in criticizing Airbus Aircraft and there systems (and I don't even like them my self) They have proven that they are reliable.

Answer 3

That is a good theory about the brakes. From my understanding, this runway had recently been repaved and had not had the grooves put into it. Grooves will greatly improve your braking performance (assuming the brakes are activated). IF there were no grooves, then the water would have been standing in puddles and the plane would have hydroplaned easily sending it off the end of the runway. They could have also came in a little too fast and that coupled with the wet conditions would have caused this. Similar to the Southwest incident in California a few years back and the one in Chicago last winter.

But as always, it is too early in the investigation to really know what went wrong.

Answer 4

Just heard on the NBC news this morning, that from eyewitness reports , when the plane landed, they say the plane started to skid and then the pilot tried to take off again. If that is true, then the pilot and the plane would not have been braking at all. The pilot just did not have enough time or runway to get back airborne it looks like now.

Answer 5

Actually 2 smaller aircrafts skidded off that same runway Monday I believe. However they were not damaged or anything.

It is just a short runway combined with a wet surface.

Maybe it was a pilot error. Maybe the pilot forgot to put the thrust reversers on or not high enough.

But the braking system you stated does not seem like it would be real. I do not have a rating for this plane or for any plane for that matter. But I do read alot! And not being able to take a plane off auto-pilot / auto-braking seems wrong.

Answer 6

No No No No. Listen up folks. It will take the investigators, probably our NTSB and FAA included, a year or more to determine the cause of the accident. Almost everything you read or hear on the news WILL BE INCORRECT. They rarely get it right especially in the first few days. That runway is no shorter than almost every runway at La Guardia or Reagan national airports. Not to mention Burbank. Pay little or no attention to what you are reading, hearing or watching. Especially here.

Answer 7

Oh perhaps via fact... there is greater evidence proving that some thing different than A airplane crashed into the Pentagon. The Pentagon isn't precisely a hotspot for the conventional public to be putting out (to make certain issues like a airplane crash). What evidence that replaced into uncovered replaced into immediately taken by ability of secret provider (and has by no ability been released. why?) the element is, you may not eliminate video clips that individuals have recorded of the commerce center towers and attempt to assert it by no ability got here approximately on the grounds that is impossible. Neither are you able to try this with what got here approximately in Brazil (to my information). whilst there are not a great form of people finding, and what evidence is taken away, they'd extraordinarily lots say even though they want. I actually have a great number of hyperlinks with evidence against what they say got here approximately and different government suitable matters. Edit: If there have been plenty products of the airplane, why ought to they not discover all the jet engines which may be scientifically impossible to vaporize? analyze the evidence of that crash to the evidence of different 757 jet crashes, there is only a fragment of a crash on the pentagon. There are not even any indicators of the airplane scratching the exterior of the floor or leaving a path. the guy the government claims flew into the pentagon is in certainty an unexperienced pilot who his instructors stated ought to fly with an regularly occurring capacity point AT terrific and that the manuevers made by ability of him have been almost impossible(what they declare) extremely by ability of somebody together with his capacity point. (Kinda humorous how they by no ability chanced on any bodies in Pennsylvania related to flight ninety 3. What? extremely?) Ya. Watch the video clips.

Answer 8

most plane wrecks were caused by pilot error in the past...but bad parts and repair problems are causing more...that being said i just pulled the fuse from my ABS brakes on my pickup truck because the sensor went bad twice and was telling the brakes to go on when i was driving...very bad.

Answer 9

hi, the info was interesting,i didn't know that's how the braking system worked.sounds to me that your right

Answer 10

Good comments, make sense.