Sure there is. An Aviation Week article covered this a number of years ago, after the AA crash in NY.

IIRC, Boeing's statement was that they designed to exceed the FAA requirements for the vert stab/rudder strength.

Which they have to do because in many cases, the JAR 21 certification process is more stringent than the FAA!

AL

This is also an interesting read
 

See this link

Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data

Also,go to the bottom of the article and access the email comments.

CC

So alvrb211, what is the mishap rate of the 737 - even before the rudder redesign? You can quote the overall mishap rate or the rate of rudder failures alone. What is the mishap rate that distinguishes whether it is just poor design or unusually poor design? Given the rate of failure of the rudder with respect to operating hours or cycles worldwide, I don't think I would call the design either of those two terms.

Engineers are human - they aren't God and they don't have crystal balls. Believe it or not, there are conditions which may result in the real world (extreme temperature conditions, quick transitions between those extreme temperatures, temperature differentials between circulating hydraulic fluids and cold-soaked fuselage components, unforecast wear, extreme stresses to materials in all axes, etc) that may exceed the expectations of the engineers given the number of cycles that these aircraft are flown.

If I were to label anything "unusually poor", it would be the resistance to the admission that the rudders may have been a factor. There are factions that don't place enough priority on the safety of the aircraft and personnel, but the engineers are not who I would include in that group.

PS - what is with all of the posts in the various threads lately where people just throw out their jaded unsupported opinions and see no need to back up their statements with evidence?

Please cite an example of why you believe this to be true - specifically, I would expect that you are referring to the certification of the fuselage structure and the vertical stab.

Hey, this is APC. Facts aren't required here and are seldom used. :)

Not to play Boeing vs Airbus....But didn't Boeing add additional Rudder Hardover Protection....especially in the low speed portion of flight (ie approach - different degrees of rudder travel were restricted depending of aircraft airspeed). Following the Colorado Springs and Pittsburgh accidents, there has been little to do with Rudder Hardovers reports that I have read in regard to Boeing products....anyboby else have any other info??

Redeye, one can hope, can't they? Otherwise, I might as well be listening to my neighbors discuss these details.

If you are familiar with the 737 rudder, you'll know that the design is very unusual. Secondly, it was proven to have been the cause of multiple fatal crashes. I'd say it was unusually poor! Even after the modification, it's a very unusual system which lacks redundancy!

I'm familiar with many areas where the FAA certification requirements are not as strict as those under JAR-21.

I'm not sure why you would "expect" that I'm referring to the mere fuselage and vertical stab. There's a lot more to certification than a fuselage and vertical stab. As I mentioned before, JAR-21 deals specifically with the "Certfication Procedures for Aircraft, Products, and Related parts".

I think at this stage it's fair to say that rudder design was the root cause of multiple fatal crashes of the Boeing 737. I'm certainly not going to pass judgement on the A330 at this early stage.

Al

Alvrb211,

How about the design of the engines that allow them to core-lock after a compressor stall/flameout - ala Pinnacle 3701? How about the design of the cargo doors or lack of slat lockout devices (hydraulic fluid loss) on the original DC-10's? What about the design of the Comet fuselage structure? The mishap rate caused by all of those failures was higher than that of the 737, given the number of 737's flying around the world. Is every design deficiency "unusually poor"?

I could keep going. Throughout history, advances have been made in aircraft design. Had the manufacturers maintained the status quo, we wouldn't be flying any of these aircraft that we do today. There are many successful designs that we accept as commonplace now that were "unusual" at the time. If the 737 rudder controls were designed to the existing safety standard and tested to the level consistent with the norm at the time, I don't think I'd characterize it as "unusually poor".

Given how you feel about the 737 rudder design, how do you feel about the use of composite materials in structural areas? If I were to call either one unusual, I'd go with the composite materials as their introduction is a more drastic change from tradition than Boeing's rudder design. If the use of composites or the failure of the vert stab is attributable in this mishap, then I would suppose that those two types of failures would have caused more deaths than the 737 rudder has. What about Airbus's use of brake-by-wire? How many runway over-runs has that caused? This is a complex and dynamic environment that we operate in, and I wouldn't go so far to say that every failure is a result of "unusually poor" design.

As I said before, don't confuse the reaction or lack of reaction after the fact to the quality of the original design. The action that bordered on negligence was the resistance to the admission that the rudder control may have been a factor, mostly for political reasons. To place all of the blame on the design (the "unusually poor" design as you refer to it) relieves the people who are actually responsible for the subsequent losses of life of their true burden. Their will always be deficiencies in design, the real world is too complex to be perfect and there is no true way to eliminate ALL single points of failure. In the real world, it's the response that matters.

As to why I would think that you are stating that JAR standards are greater with respect to the vert stab in particular, refer to post #4. In that, you clearly are relating JAR standards to the Airbus design philosophy concerning the vert stab. In this case, I really don't care about the differences between the two concerning EMF, or aisle-width, or emergency exit design, etc.