RedeyeAV8r

Hey LivininginMEM.

Sure One can always Hope! I hope that I win the powerBall on a weekly basis.
Still hoping on that one!

alvrb211

Seems like you are getting off on a tangent here. The Comet was the first jet transport in the world. Every aircraft manufacturer the world over learned from it. And, far fewer people lost their lives compared with the 737 crashes decades later. And, you'll core lock any turbofan if you operate it incorrectly due to the differing "specific heat capacities" of the engine materials!

By far the worst repeated design flaw I can think of was in the case of the US Navy warships during WW2. Hundreds were built and hundreds snapped in two as a result of poor design. "Thousands" lost their lives because of a simple design flaw.

You simply can't down play the 737 accidents. No other Jet transport in the world has a rudder system like it and that's a good thing!

As I stated before, "many" (not all) JAR 21 certification standards are more stringent. And, I'm not talking about mere isle width or exit location either!

JAR-25 deals with large Aircraft and the JAA/FAA harmonisation under the JAA Board and Associate body of ECAC fosters cooperation between member states.

This statement leads me to believe you are unfamiliar with the unusual 737 rudder design and resultant fatal crashes.




Al

FamilyATM

In an Airbus product if you ice over the pitot tubes with no associated ecam faults the ADC's will accept the erroneuos information. The airspeed will decay, the pitch trim will kick off, the auto-pilot will disengage and the rudder will go into the "low speed" mode. With no rudder inputs from the pilot the yaw dampener will begin to make larger and larger inputs unless a/c speed is reduce. I know this to be a fact because it happened to me in 2006 at FL310. At first Airbus said no way that that could happen and that we had to induce these failures. Thanks to a few hard charging mx types they found some melted pitot heat relays that shut off the pitot heat but did not produce any ecam warnings. I am not saying this is what happened here, just my past experience. My thoughts and prayers go out to those that are suffering at this time and that the FDR and CVR are recovered.

iceman49

Family, which Airbus product was it? Thx.

ZDub

Simmilar disclaimer, simmilar pedigree. Concur. Take a look at the vert attach points on AA 587, they appear shorn in a nearly identical manner. In fact, the NTSB concluded nearly verbatum what you did.

Sniper

Interesting situation you experienced there, 'FamilyATM'. I too am curious what specific Airbus did this.

My understanding is the accident aircraft degraded to 'Alternate Law'. As such, what's supposed to happen is you lose some yaw damp authority, and lose all yaw damp authority if there is a triple ADR (Air Data Reference) failure. This may have been the situation Air France encountered.

Without the FDR, its hard to say what happened here. Even with the FDR, there's only so much that can be known. Maybe the answer to this is in the 'Enders Report'.

PilotFrog

A side note, but has anyone noticed that on the volume control of the BBC video stream you can take it to 11!. I just thought that was quite creative.

LivingInMEM

I will answer this on this thread because a memory of that chapter will help us keep this mishap (and the response to it) in perspective. As qouted in this article: (Clear Agreement Elusive On Fixing 737's Rudders - The New York Times): " The unforgivable sin in aviation is not killing a planeload of passengers -- it is killing two planeloads because of the same cause. That is one reason the Valujet crash last May near Miami was such a crisis for the aviation agency; it was not the first time that hazardous material had burned in a cargo compartment with no smoke detectors or fire suppression system. The tragedy of the Pittsburgh crash will seem worse if investigators eventually conclude that the one in Colorado, three years earlier, had the same cause.
If both crashes were caused by a rudder problem, the odds of another rudder malfunction is, quite literally, about one in a million. There are about 1,100 Boeing 737's in service in this country and 1,600 abroad, and the airlines worldwide have about 75 million hours of experience flying them over the last 30 years, the manufacturer says. Since the 737 makes mostly short flights, that comes out to about 75 million flights."

What we are hearing, and are going to hear, is that the Airbus has quite the safety record and that the aircraft was designed to meet or exceed all applicable requirements. That is all a smokescreen to deflect attention and blame - there will be a huge fight to avoid the finger pointing and the safety of subsequent flights will be compromised.

I am quite familiar with the history of the 737 rudder system. It consisted of one PCU that was served simultaneously by two hydraulic systems. While no "smoking gun" was ever found in the wreckage that confirmed a rudder hardover or reversal, it was shown that a rudder reversal "could" occur with a misalignment of guide springs/etc that could allow an actuator to extend too far and allow hydraulic fluid to travel down an unintended path. Overall, there were two crashes and several other incidents that were most likely attributable to the rudder - but the lack of a clear "direct link" allowed the FAA and Boeing wiggle room to avoid immediate action. Specifically, the FAA was wary of grounding up to 1600 airframes (worldwide) and several carriers that were flying the fleet exclusively. Eventually, the FAA agreed to a generous timeline for retrofit after Boeing finalized a re-design.

The crime was not that the engineers overlooked a potential single-point failure - there is no evidence that they were aware that the concentric dual servo valve's spring, spring guide, and end cap could be forced out of alignment and allow the hydraulic reversal when the system was designed. They felt they had designed the required redundancy into the system and the regulations at the time clearly allowed such a system. In a similar fashion, JAR's allowed Airbus to avoid the use of traditional cotter pins and crown nuts in lieu of a proprietary spring locking system. Amongst the A300/310 mechanics that I know, there is unanimous opinion that it is a very common occurrence to find these connectors securing flight control surfaces and actuators to have de-torqued. The regulations don't force traditional methods to be used, they look for equivalent levels of safety that don't always work in the real world over the long haul.

There is no literature from the NTSB calling for any sanctions against the original designers or changes to the certification process - they focused on getting the newly discovered fault fixed. For that reason - I am hesitant to call the design "unusually poor", but I am willing to call the reaction by the FAA and manufacturers "unusually poor". It is in this reference that I will be looking at the Airbus, JAA, and FAA response to this latest accident.

FamilyATM

It was an A310. With no ecam faults the ADC's believed all data inputs so the aircraft thought it was flying at 120kts at FL290 when we were actually at 260kts.

Phantom Flyer

Thanks LivinginMem for the information. Well stated and interesting.

G'Day Mate