b737gearboy

Tuesday December 18 4:18 PM ET
Pilots of United Jet 'Wrestle' Aircraft to Ground
WASHINGTON (Reuters) - Pilots had to ``wrestle'' a United Airlines jetliner to the ground last week after an apparent rudder malfunction during a flight to Chicago, authorities said on Tuesday.

Federal investigators said Flight 578 from St. Louis was at 9,000 feet on Dec. 13 when the nose of the Boeing 737-300 swung to the right. After disconnecting the auto pilot and a rudder control device, the crew struggled hard to regain control of the plane.

One official said the pilots had to ``wrestle'' the aircraft to a safe landing at O'Hare airport in Chicago. After landing, the crew said they heard a bang after the rudder swung to the left and then right.

None of the 93 passengers aboard were hurt.

National Transportation Safety Board (news - web sites) investigators are analyzing the plane's flight data recorder for clues. One regulatory official said the problem was reported to authorities as an uncommanded rudder movement.

Investigators determined that rudder malfunctions were the likely cause of two fatal 737 crashes in 1991 and 1994. Those disasters prompted Boeing to replace certain parts in all 737 rudder systems.

Last month, the Federal Aviation Administration (news - web sites) proposed the industry outfit its fleet of 2,000 U.S.-registered 737s with new rudder control systems over a five-year period at a cost of $364 million.

United is a unit of UAL Corp.

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GO BUCKEYES!!!! NATIONAL CHAMPS!! O----H----I----O

Steven De Lisser

I've always believed that this is one of the reasons why American carriers have chosen Airbus products over Beoing (other than obvious costs savings). Afterall, why would United and USAir need to have both the 737 in all of its incarnations and the A320 and A319.

It's very apparent that another crash or two and the loss of more innocent lives will have to occur before something is actually done.

Waiting and relying on the FAA to mandate a fix when the problem is obvious and in need of immediate repair is typical FAA, big business, cost analysis b u l l s h i t . No different from the Sept 11 airport security fiasco.

And by the way, armed guards in airports amount to a hill of beans.

Steve

Scott

Steven, how could a typically bright guy make such a flawed hypothesis????? UA ordered the narrow-body Airbus family for lots of reasons, NOT due to rudder difficulties. And now we see Airbus scrutinized for THEIR rudder encounters. Composites may be at fault, and Airbus is one of the largest purveyors of these advanced materials. Just wait to see how much is utilized in the A-380! We may eventually see tougher inspection standards in the aftermath of much research. At least Boeing and the FAA give pilots much guidance to react to uncommanded rudder inputs. Ain't no emergency or abnormal checklist to help when the vertical fin seperates.

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Fly the Friendly Skies of United

uniTED takes wing Feb 12, 2004

Tony Sepanski

Before you all sharpen your pitchforks and go on a witch hunt for 737's, read this:

Forgotten brush may have caused 737 rudder glitch

By Steve Miletich
Seattle Times business reporter

A wire brush left under the cockpit floor of a United Airlines Boeing 737 may have led to a rudder problem the pilots encountered last week as the plane was descending into Chicago.

The discovery of the brush is part of the National Transportation Safety Board's investigation into the occurrence, said Paul Schlamm, a board spokesman. But no conclusions have been made as investigators continue to examine what happened, he said.

The Air Line Pilots Association, which also is looking into the matter, believes the brush jammed the rudder cables, said John Mazor, a spokesman for the union. The brush was apparently left by a mechanic, Mazor said. "That could happen on any airplane," Mazor said, adding that this case doesn't appear to be related to 737 rudder problems that the safety board linked to two air crashes in the early 1990s. Those problems can be caused by a jam in the power-control unit that provides hydraulic movement in the rudder.

United spokesman Chris Brathwaite confirmed that a brush had been foundunder the cockpit. "We don't know if it contributed to the event," he said.
The airline is cooperating with the safety board in the inquiry, Brathwaite said.

The rudder is the flap on the vertical tail of the aircraft. Moving the rudder left or right causes the plane to turn left or right. The pilots flying United Flight 578 from St. Louis to Chicago's O'Hare International Airport last Thursday reported the plane's nose suddenly swung to the left and right as the aircraft descended to about 9,000 feet, the Federal Aviation Administration (FAA) said.

The pilots disconnected the autopilot, and the plane then banked sharply, prompting them to apply pressure on the rudder pedals to level the wings and regain control, the FAA said.

After the plane touched down, the agency said, the pilots reported the rudderswung left and then fully to the right, accompanied by a bang. The plane completed the landing safely.

The occurrence renewed questions about the rudders on 737s, which were the subject of a proposed order by the FAA last month requiring airlines, beginning in 2003, to install new rudder-control systems on 737s, the world's most popular jetliner.

Boeing announced in September that it would teach pilots how to handle jammed rudders and would begin installing new rudder systems on 737s in
2003. The FAA's proposal would give the airlines five years to install the new systems.

Under the retrofitting, every 737's rudder would have two control valves instead of one, in case one valve failed.

Several years ago, an upgraded rudder servo valve was installed on 737s to prevent rudder malfunctions.

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I recommend reading the investigation notes, or where that may be unpractical, perhaps MacArthur Jobs' excellent summary in "Air Disaster vol. 3". He points out that in over 15,000 man-hours of testing, NO ONE was able to get the rudder to duplicate what they say caused the rudder malfunctions. It did happen in test circumstances completely outside conditions that would ever occur in the 'real' world, however. This was enough for Boeing and FAA to institute training and re-design and implement them.

The fact is, no one ever could have anticipated the rudder doing what it did, and no one has ever been able to get it to duplicate what they say happened.

b737gearboy

Scott,
You make some good points above. I don't want to get into an Airbus vs. Boeing discussion, however to say Boeing gave any type of guidance is not entirely accurate. My employer, soon to be former, lost a 737 in Pittsburgh due to a rudder hard over. Boeing fought tooth and nail claiming that the accident was due to pilot error reacting to wake turbulence. After extensive research, partly in a US Airways 737, the FAA was able to conclude the accident was NOT caused by wake turbulence. My employer had several pilots from the training department work with Boeing and the FAA in hopes of finding some resolution. When I was on the 737 I had the good fortune of taking a checkride with one of these gentlemen and learned quite a bit about Boeing's lack of cooperation. It took several other non-fatal rudder hard overs and pressure from the FAA before Boeing budged. In fact, there was a press release quoting an unamed former FAA rep that said "the airplane should have NEVER been certified". As a true red-blooded American I have always cheered for Boeing and still do but I find their attitude most disturbing.
Happy Holidays

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GO BUCKEYES!!!! NATIONAL CHAMPS!! O----H----I----O

b737gearboy

*** Forgotten brush may have caused 737 rudder glitch

Seattle Times -- A wire brush left under the cockpit
floor of a United Airlines Boeing 737 may have led to
a rudder problem the pilots encountered last week as the
plane was descending into Chicago. The discovery of the
brush is part of the National Transportation Safety
Board's investigation into the occurrence, said Paul
Schlamm, a board spokesman. Several years ago, an
upgraded rudder servo valve was installed on 737s to
prevent rudder malfunctions.
http://airlinebiz.com/wire/12202001#MAIN (See Full Story!)

__________________
GO BUCKEYES!!!! NATIONAL CHAMPS!! O----H----I----O

Scott

Well stated, Gearboy! While my reference to Boeings' cooperation is based on current directives, I didn't realize how difficult it was to bring the "horse to the water". I seem to remember their bias towards crew error as the USAirways investigation unfolded. The only rational reference to crew error was that the autopilot was not immediately disconnected. This is of course armchair quarterbacking and now required following much simulator testing. During unusual-attitude training I've experienced deliberate recovery utilizing the cws mode with autopilot engaged - it isn't pretty! As the saying goes: our procedures are frequently written in blood.
Happy and safe holidays to you and yours.

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Fly the Friendly Skies of United

uniTED takes wing Feb 12, 2004

IFTNFS

So if the 737 is supposedly such an unsafe aircraft, why is it that Southwest has been using them for over 30 years as the ONLY aircraft type in their fleet (minus the 727s that were leased briefly) and we never hear about uncommanded rudder deflection on a Southwest flight? Do they not happen, or do we just not hear about it?

Rick

b737gearboy

Make whatever conclusions you want to but I don't think it is an UNSAFE airplane. I don't know if WN has had a rudder hardover or not. The incidence of a rudder hardover is very rare for how many 737's are flying and how many hours they fly. Scott do you have any numbers? I believe all 737's have been retro-fitted with Digital Rudder Pressure Reducers. These RPR's reduce full rudder deflection limits after takeoff (at least 1200 agl as I recall) and do so untill somewhere on final(700agl stands out). In the simulator they are able to demonstrate a rudder hardover with and without RPR. Suffice it to say the RPR makes it a MUCH easier situation to handle, without it a rudder hardover is VERY nasty to say the least. My concern about the rudder hardover is what if you got it when the RPR is ineffective like right after takeoff or on a very short final.

__________________
GO BUCKEYES!!!! NATIONAL CHAMPS!! O----H----I----O

pi737

Rick,

USAir and one of it's predecessors,Piedmont, flew the 737 for about 26 years before they had a rudder hardover. It is a rare occurence and maybe Southwest has never had one. I have about 9,000 hours in the -200, -300, and -400, and think they are great aircraft.

As a new 737 F/O in 1987 I was flying with a very senior captain. We were cruising along and I had my feet on the rudder pedals. He looked over and said "Son, you better get your feet off of those rudder pedals. If we have a hardover it will break your leg." I didn't know what he was talking about, and was too embarrassed to ask. After Flt. 427 in Pittsburgh I wished I had.

Gearboy-Sorry to hear that you are one of Steve and Rakesh's extended vacation club members. Good luck to you.


Tony

Steven De Lisser

Hey Scott. Smart people have dumb thoughts - I am allowed.

I remember when those series of crashes occured (USAir, United) and it was a big deal back then. The crashes startled everyone in the aviation community because of the severity of each incident, the investigators inabilty to get a definitive answer as to what exactly transpired (pre-wake tests with the USAir 737) and involving such a reliable, well made aircraft. Some experts at the time felt the FAA and Boeing were slow to respond and trying to sweep the problem under the table because of the economic consequences. And it was around this time, or just before, UA and USAir began placing large orders to replace/compliment their 737 fleets and I remember wondering if the crashes had anything, at all, to do with their decisions.

At the very least, I find it hard to believe such a thing was never mentioned at the negotiating table.

Steven

Tony Sepanski

What is frustrating about Boeing's position is the front that any major corporation is forced to put up when a situation like this occurs: litigation. Corporate 'counsel' demands the company make absolutely no admission of any responsibility for fear of it being used against them in future lawsuits. The affect of law departments and our litigious society have driven situations like this to absurd proportions.

I wonder how much faster a solution would have been arrived at without the spectre of a multi-hundred-million dollar lawsuit hanging over their heads (I'm not advocating the release from any responsbility by the parties involved, but the lawsuits and awards have reached preposterous proportions).

Travelin' Man

Hey - As great as Boeing is as a company, they are just another Fortune 500 mega firm that is full of MBA and lawyers. These pricks take the fun out of anything. There was nothing fun about the previos 737 accidents, but it would have been nice to have Boeing fess up to the mistakes, pay a settlement and go on with life. This lawyer crap just strings it out and makes for bad reputations. For once it would be nice to have a company step up to the plate and do the honorable thing. But in a litigous economic system, that will never happen.