United Airlines jet landed after losing primary flight instruments

In the nose shot you can see the emergency ram-air-turbine is deployed. Also It looks like they only had the use of one spoiler panel on each wing combined with loss of anti-skid and a short runway. Kudos to the crew.

Dave

 

It's that little prop that is hanging out at about the 4:00 position. It runs a small generator that provides emergency power (and not much of it), to the airplane when the main power bus is down.

 

A computer controlled airplane with no electrical power... Just another reason I don't fly Airbus aircraft. This was a lot closer to being a disaster than the skin ripping open on the Boeing that is being hyped as a near disaster (that it wasn't).

This was a fairly new airplane. You have to ask yourself "what's going to happen when these things get old???". With a Boeing you have to contend with fatigue, but that's a managable situation. You inspect for it and you fix the cracks when they happen. What do you do when the computers and electrics fail in flight? You don't just stop and reboot like you do on your home computer or your car.

I have a feeling we are just seeing the beginning of these kinds of issues.

 

What a ridiculously alarmist post. (and you complain about the media!)

You have no idea what caused it.

Yet you've already determined it is systemic to the entire line, irreparable and will get worse with age.

Then you make a ridiculous statement about computers that can't be rebooted in planes. Do you think Boeing doesn't use computers?

And you base your alarmist rant on a 'feeling.' Well good for you. I prefer facts myself.
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Edit: Before you answer you might want to read this thread http://www.ferrarichat.com/forum/showthread.php?t=303700

 

When it comes to the design and certification of flight critical software I do know a thing or two, and have been an aerospace engineer and program manager for over 35 years. I have stood before an FAA type certification board, and managed the FAA certification of flight critical software. This is key knowledge and experience in this field and it directly applies to the topic at hand. Since I don't believe, by your comments that you have this experience, I strongly suggest that you learn something about the process and what it takes to produce aircraft that are flightworthy and safe before you make a comment like that. The subject of what happened here comes back to the aircraft electrical systems, software and its ability to function in less than perfect conditions.

No we don't know what caused the failure of the power bus, or the smoke in the cockpit, but we do know exactly what happened when there was an electrical problem. The aircraft computers shut down and all of the screens went blank. That is not supposed to happen. That is the problem here, a relatively simple short turned out the lights. Obviously you don't know much about Airbus aircraft and how reliant they are on the flight computer systems, so you don't understand how critical this event was. Here is a link to the ABC news story on this, and the pilot had to do a PAR approach down to 600 ft with minimal instruments. He did a great job, but this just as easily could have ended very badly.

http://abcnews.go.com/Travel/united-flight-emergency-landing/story?id=13295085

I was being facetious about rebooting the computer in flight, I fully understand how these systems work and what you can and can’t do, but was making the point that the failure of a software system in an aircraft is a lot more consequential than a software failure in a car or a laptop. Sorry if it went over your head. More importantly to your comment, Boeing aircraft have computers and those computers run the autopilot and there are several computers that control aspects of the aircraft. However, the Boeing commercial aircraft are not primarily controlled by the computers and fly by wire systems like the Airbus family of aircraft are and that is a key difference that makes Airbus aircraft uniquely susceptible to software problems. Again, obviously you don’t have any experience in this field or you would understand these differences. They are real and very important.

Airbus has poor record when it comes to software redundancy, and robust software design. There have been NUMEROUS situations where Airbus aircraft have crashed or have had very near disastrous results due to failure of the system software. This recent incident is yet another example of an Airbus aircraft losing key systems when their software or computer systems fail. From the first crash of an Airbus at the Paris airshow in June of 1988 to the recent Airbus 380 near disaster in Singapore and including the loss of Air France 477, there is a consistent thread of system failures that the aircraft software could not cope with.

As I noted, this was a relatively new airplane. What's going to happen as these planes get old? Multiple system failures that result from a single short circuit are not the type of robust design that is flight worthy and do not meet FAA airworthiness standards. Ok, you can have a circuit failure, but to bring down the entire flight display system on this aircraft due to a short circuit is not acceptable, and this isn't supposed to be able to happen in anything less than the most dire circumstance. Threre are suposed to be redundant power systems and display systems, and this type of failure should never happen. The fact that it did is yet another example of poor engineering at Airbus.

The FAA criterion uses statistical probability of multiple failures to calculate the reliability of the system. Unfortunately software systems don't work like mechanical systems and data failures can very quickly cascade through a system and bring the whole system down. When that happens, as it did yet again the other day, the Airbus systems quickly throw up their hands and shut down. To work properly through this type of failure is the essence of robust software design. It isn't that it works on a sunny day; it's that it works when more than two or three things go wrong. Airbus aircraft have consistently demonstrated that they can't cope with multiple system failures that seem to occur with regularity on their aircraft.

Well, as I noted above, I know a lot more about these types of systems than lay people do, and IMO these aircraft aren’t sufficiently safe for me to fly in them. That is my personal choice, but it is an INFORMED choice, not based in any way on “feeling”. Perhaps if you were more informed you might feel differently.

I am most familiar with the thread you noted and I am not a big fan of the "all electric aircraft" concept. When the 787 is part of the fleet and IF it has problems and incidents like Airbus continues to have on a regular basis I will be just as hard on them. Right now I don't know what criteria Boeing uses for its software and system design, and until that is clear I prefer not to comment on their design and the safety aspects of it. As you noted it is better to comment on facts, and since I have no facts on the Boeing 787 I won’t comment. The 787 is much more like Airbus aircraft, so that is not a good thing. It's not an issue until they are in service. Right now there is a world of difference between the Airbus aircraft and the Boeing built aircraft that are flying in commercial service.

Let me also be clear. EVERYBODY has problems. It isn't that you have a problem; it's how you respond and change your design and systems to insure that the problems that you find don't come back and kill people later. The more I learn about the software on the Airbus aircraft, I find that they "meet the FAA requirements". As I have said in other posts previously, that's not necessarily safe.

Sorry for the long post, but this is just another example of the inability of these aircraft to cope with multiple system failures and is why IMHO they aren’t safe and why I don’t fly them.

 

Well I would think someone with your background would be a little less reckless with your posts.

ie: You admit we don't know the cause but then say "That is the problem here, a relatively simple short turned out the lights. "

Oh? How do you know it was a "relatively simple short?"

You don't. Yet you paddle on like you do. As I said, Reckless.

 

He postulated a theory based on his experience and knowledge, both of which appear to be extensive. That's not reckless.

 

Yes, that's true, I was perhaps a bit rash. We don't know how extensive the electrical problem was. Still I have a really hard time trying to figure out how they lost all of the displays and that is very serious failure on this aircraft. We will learn more as time goes on, and, it seems, the more we learn the less confidence I have in these aircraft.

 

First, I don't know for certain they lost all displays. (Perhaps the media was this accurate and detailed later but I have not seen it...)

But here is my problem with your posts... Here's just one snippet of one post:

Now let's count the unfounded assumptions:

You don't know it was a short. And you don't know it was a single failure but other than that, you're dead on the target. And I'm pretty sure the plane met FAA airworthiness standards.

You know that it was a problem with a circuit and not a wire? Or a component? Again, you know it is a short? (do you know what a short is?) How do you know it was not a dire circumstance? There was smoke. An on-board fire could easily cause multiple systems to fail. And who says the failure had to start as electrical at all? Granted a fire that took out instrumentation strongly points to electrical... but we don't know that yet. The (very similar) Boeing problem was FOD.

You go back and forth blaming the software and this mythical short? Which is it? You apparently think if you make enough unfounded assumptions it will sound credible. To people with real engineering backgrounds it sounds likes voodoo.

There are redundant power and display systems! We can tell from the pix the ram-air turbine was deployed. We don't know for sure they lost all displays and if they did we don't know why redundant systems also failed.

Further they reported smoke well before they lost instrumentation. That basically defines a Cascading failure. http://en.wikipedia.org/wiki/Cascading_failure Yet you keep stating with authority that this was caused by a single point failure. http://en.wikipedia.org/wiki/Single_point_of_failure We don't know much about this incident but we pretty well know that's wrong.

A completely moronic assumption based on a complete lack of knowledge of the incident.

 

I love the Airbus vs. Boeing arguments. For the record I am type rated in the A320 Series and fly them for a living.

Solofast... To my knowledge there has never been an Airbus crash caused by an electrical problem. You apparently have a lot of experience and knowledge, but perhaps not as much as you think about Airbus aircraft. The Paris crash was caused by the pilot not understanding what phase of flight the aircraft was in and therefore what he was attempting to demonstrate (alpha floor and recovery) did not happen and it was too late for him to recover once he figured it out. The crash had nothing to do with fly by wire systems and there was no malfunction. The plane did exactly what it was should have done, the pilot did not understand what it was doing. Further, we do not know the cause of the Air France crash, and any conclusions are pure speculation. The A320 has been flying since the late 1980s with a tremendous saftey record. Your concern with Airbus products is misplaced.

I can think of three structural failures on 737s - Aloha and two with Southwest. In addition Boeing had serious problems with 737 yaw dampers. Lots of dead people caused by Boeing aircraft stuctural and mechanical failures, so the whole Boeing is better or safer is a joke. There have been 320s crash but none that I am aware of due the concerns you express, moreover, I am unaware of any deaths on an A320 anywhere due to structural failure or mechanical failure - although I might not know every accident.

I find that most people that are afraid to fly on an Airbus do not understand it. That is fine, but they are typically concerned because there is "computer" flying it and that makes people concerned. However, the statistics just don't support your fear. Additionally, the computers on the bus do a lot to protect passengers where every other aircraft do not. If those regional pilots in Buffalo were flying an Airbus they would not have stalled and there would not have been a crash and tragedy.

As for systems knowledge - the RAT would give the Captain his PFD so he would have instruments in a total electrical failure until 125 knots on most aircraft. They would have lost both PFDs and MFDs immediately after a total electrical failure (but still would have the standby instruments) until the RAT pressurized the BLUE HYD system which in turn spins the generator to power the emergency electrical configuration. And even if the RAT did not work in a total electrical failure, you have batteries which supply limited power to the aircraft systems for about 30 minutes. So to say that there are no redundant electrical or display systems is incorrect.

 

I reread your post and found this gem...

Only not one of those incidents involved software.

In Paris the pilot flew it into the ground. Air France 477 the jury is still out on and in Singapore a freaking Rolls-Royce engine exploded. And the A380 had enough redundant systems it managed to circle for two hours dumping fuel.

On what planet are these software issues? (much less a "consistent thread") You're clueless.

OK I'll stand down. The fact you're just making stuff up is now abundantly clear.

cya

 

I have no problem flying Airbus. I flew on the A380 and I don't think a more awesome commercial aircraft exists in the world.

For those that think Boeing is perfect or better, let me remind you of the 747 crash in Japan from a blown out bulkhead caused by a poor repair.

http://en.wikipedia.org/wiki/Japan_Airlines_Flight_123

It can happen to anyone.

And, for those concerned about using Carbon Fibre, Boeing is the leader in this, not Airbus. The new Dreamliner has the first CF fuselage.

 

Not exactly 100% accurate as the Airbus had 2 technical bulletins issued prior to the crash yet the pilots did not know of the issues as Air France did not make them available to the pilots.

http://www.airdisaster.com/investigations/af296/af296.shtml

 

Not exactly 100% accurate as just because there were technical bulletins on the aircraft that does not mean that was the cause. There are thousands of technical bulletins issued per year but you don't see planes falling out the sky. Correlation does not imply causation. http://en.wikipedia.org/wiki/Correlation_does_not_imply_causation

The cause was determined to be pilot error. http://aviation-safety.net/database/record.php?id=19880626-0

 

I would like to clarify something on the 747 bulkhead repair on the JAL 747. The airplane was subjected to a heavy tail strike that damaged the lower part of the 48 section pressure bulkhead. Boeing initially insisted that a new bulkhead be installed in that airplane and the airline refused and insisted that it be repaired IN THE AIRPLANE instead of spending the money to remove it and to replace it. Boeing then designed a repair that replaced the lower half of the dome skin with very adequate doublers and triplers at the splice area. The mechanics, FOUR OF WHICH WERE JAPANESE, found it too difficult to assemble the intricate layers of the splice elements and CUT them in half so that they could assemble them from the upper and lower halves of the new part. Thus negating the purpose of the entire design to beef up the spliced area. After gooping everything up with sealant, it was impossible for the inspector to see what had been done.
Even then the airplane flew many cycles before it failed.

 

Going back to the original topic...I find it interesting that the emergency chutes were deployed front/rear, but the overwing exits were not used.

 

The Captain at the Paris Airshow was attempting to demonstrate the aircraft entering into what is called "Alpha Floor" in which the airplane adjusts pitch to ride a stall and then the aircraft would go into "Toga Lock" where full power is automatically applied and the airplane would climb and recover from a stall. What the pilot did not understand about the systems is that when the airplane is close to the ground with the gear down, the automatic stall recovery system is inhibited because the plane thinks you are trying to land. So the airplane just rode the stall and didn't recover and by the time the pilot realized it he was almost into the trees. He put the power to the jet but it was too late. If you watch the video you can hear the engines spool at the last second as it goes into the trees.

And I am 100% accurate. The altimeter setting if wrong would cause the airplane to think it is landing mode (below 50 feet) and if it was not crosschecked it would be pilot error. As for the engine acceleration - the airplane would have gone to full power on its own had it not been in landing mode, and the pilot being late or a non responsive power application was secondary to the fact that the pilot was way too late to recover once he realized the airplane was not doing what he though it should do.

The report doesn't explain why the airplane was in the situation but that is the reason it crashed.

 

Others have noted that software was an issue in the Paris airshow incident. The aircraft wasn't following his commands for whatever reason. He may have had an altimeter mis-set, but that shouldn't cause the aircraft to crash.

Here is an an additional incident where software was directly involved in crash of an Airbus. I'll comment on some others in later post. There is a consistent thread of software being involved in Airbus aircraft crashes, and I'm not making this up.

Crash: Air New Zealand A320 near Perpignan on Nov 27th 2008
In this crash the AOA sensors were failed (frozen), and the pilots didn’t know it, and that let the airplane stall. But there is more to it than that. The pilots initiated a recovery by adding power and pushing the stick forward. Both of which are the correct action on the part of the pilots. What happened next is a prime example of why I believe that these aircraft aren’t safe. I’m quoting here directly from the accident report:

What happened here is that the control system stopped working in its normal mode and left the aircraft at the last trim position commanded (full nose up trim). The pilots didn’t notice it because the aircraft is supposed to automatically trim back down when the control system is operating correctly. That didn’t happen because the control system had checked out because it couldn’t agree on how fast the aircraft was flying (more to come on this issue in future posts). While you can blame the pilots for not noticing that the trim was full nose up and not coming down, the real problem is why did the autotrim feature stop working. It stopped working because the airspeed sensors didn’t agree on what the speed was. When this control system doesn’t have enough information it throws up its hands and shuts down. I have a problem with that because the aircraft is supposed to do things consistently. Moreover, the pilot recognized he was stalling and for whatever reason, even if he wasn’t supposed to be able to stall the airplane and it did (because of the AOA sensors being failed), he did the right thing. He pushed the nose down and added power T/O power. If you are commanding nose down, the elevator should push the nose down and not just do nothing because the automatic trim function was no longer operative. To be safe aircraft have to respond the same way, all the time. In these aircraft there is a big difference in what works and what doesn’t depending on what mode the computer is in. The software was directly involved in this crash and was really the key to why the aircraft crashed. Had the software not failed and stopped working, the autotrim would have prevented the secondary stall and they would have flown out of it. You can blame the pilots all you want, but rolling in nose down trim isn't part of the normal stall recovery procedure in any airplane I've flown. You get the nose down first, add power, start recovery and THEN you worry about trim. These guys didn't get that chance.

There was much discussion in the accident report centering on the AOA sensors that allowed the airplane to stall in the first place. That to me was not the reason the aircraft crashed. It crashed because it didn’t respond to the stall recovery initiated by the pilot, and a secondary stall occurred that wasn’t recoverable. The secondary stall was a result of the aircraft not being trimmed correctly, despite the correct main control inputs from the pilot. Big aircraft aren't like little aircraft in that the elevator isn't directly connected to the yoke, but if you push the stick forward the damn nose ought to come down. In this case it didn't and those people are dead because of it.

Thats one case that is documented where software was part of the problem. More to come.

 

I can't speak to how difficult such a landing is without instruments or limited control, but from the Audio tapes, it sounded like the crew knew exactly what they had to do to land safely. Well done.

 

Are you just trolling now? Nobody noted this because you're just making stuff up...

You're either trolling just to get attention, or you're nutty as a bed bug.... I don't worry anout airbus nearly as much as I worry you might really be telling the truth about working in the aviation industry. THAT scares me.

 

No comment on the Air New Zealand crash????

I'm surprised that you don't have a sarcastic comment on that one two, or is it a bit too compelling. Please oh wise one, tell me where I have made an horrible error in that analysis.

 

No, I answered from my phone and did not even read past the first paragraph... But I won't bother. You're clearly delusional and there is no point following you down another rabbit hole.

You weren't the guy flying the Piper huh?