Showing posts with label Boeing 737 Incidents. Show all posts
Showing posts with label Boeing 737 Incidents. Show all posts

Thursday, January 1, 2009

Continental Airlines Crash Update - The Spin Doctors Take Over

The latest from the Continental Airlines B-737 accident at Denver is the claim that a sudden gust of wind caused the aircraft to swerve off the runway. So, a pilot with 11,000 hours of flying time and a very experienced first officer couldn’t do a successful crosswind take-off in one of the simplest of all airliners? Not!!!

These same spin doctors said the B-737 accident at Colorado Springs in 1991 was caused by a sudden, theretofore never heard of, wind shear in the form of a rotor that rolled down the mountainside, followed the aircraft around the traffic pattern and rolled it over, killing 25 people.

The spin doctors were out in full force again when USAir’s B-737 rolled over and dived to the ground, killing 133 more people near Pittsburgh in 1994. Then they said that wake turbulence (a wind gust from a preceding aircraft) miles away rolled the aircraft up into a ball.

Following that, it was a faulty connection to a pilot’s altitude indicator that rolled a B-737 into the ground in Panama, though the broken wire had nothing to do with that instrument’s function, it was later learned.
Oh, and of course, it was a pilot’s suicide that caused another 737, this time in Indonesia, to roll in from altitude, killing all aboard. The co-pilot on that one was either in the lavatory or reading the paper, I guess.
Here’s the deal. The current National Transportation Safety Board (NTSB) is more incompetent, or politically too sensitive, than the NTSB that existed in 1991 to 1994. The government needs to throw out all the party participants like the airline, pilots’ union and manufacturers and bring back some of the investigators who reluctantly accepted my findings, and those of other experts, and concluded correctly that the rudder is the problem. While the rudder may be blameless on this one, a sudden gust of wind sure in hell wasn’t the reason for this crash either.

Arthur Alan Wolk
January 1, 2009

Monday, December 22, 2008

Continental 737 Crash at Denver–Better Look at the Rudder

Yet another Boeing 737 crashes, but this time no one was killed. The flight crew masterfully rejected a takeoff that went wrong. Loud noises were heard that were reminiscent of the sounds identified just before domestic flights on United 585 and USAir 427 rolled over and dived to the ground, killing a total of 152 people in 1991 and 1994 respectively, and overseas airlines COPA 201 and SilkAir 185 crashed, taking the lives of another 151 people in 1992 and 1997.

If I were the NTSB investigator in charge, I would pull the rudder actuator and take some SEM photographs to see if the actuator bears a resemblance to the three other actuators that showed witness marks of jamming.

In my opinion, the Boeing 737 still does not have a reliably redundant rudder control system, and even after hundreds of deaths, the FAA allowed Boeing to build an entirely new generation of B-737’s with a single rudder actuator when all of its other aircraft have at least two.

Noises heard on earlier cockpit voice recorders were the death sounds of an aircraft about to go out of control. These sounds are generated by the hydraulic system telegraphing its agonizing inability to control the rudder. At speeds below 190 knots, the rudder will cause a rapid roll of the aircraft that cannot be stopped before tragedy occurs.

While redesigned after the accidents of the 1990’s, the rudder control system still has no true redundancy. If the flight crew of this aircraft sensed that they were about to lose directional control, they saved themselves and all their passengers from certain death.

The airplane is trashed and some people were hurt, but everyone will ultimately go home to their families this Christmas. Congratulations to a “heads up” Continental crew.

Arthur Alan Wolk
December 22, 2008

Thursday, August 23, 2007

Air China Boeing 737 Exploding Center Fuel Tank – It’s Déjà vu of TWA 800

An Air China Boeing 737 Next Generation airliner recently pulled up to the gate, caught fire, and moments after the passengers deplaned through emergency exits, the center fuel tank exploded and destroyed the aircraft.

Had the explosion occurred just minutes before, all 152 passengers would most likely have been killed. The TWA 800 explosion brought home a well-known fatal flaw in transport category aircraft – large fuel tanks harbor fuel vapors that can explode and kill people. The problem has been well known for 45 years. The military long ago addressed it by putting fire suppression safeguards in large aircraft fuel tanks. Nitrogen inerting of the fuel tank is the preferred method and is effective, although passing cabin air through the tanks to lean the air and purge fuel molecules is another method.

Nitrogen inerting systems are supposed to be installed in new aircraft but either the system didn’t work, the aircraft didn’t have one, or other factors that need further investigation allowed an explosion to occur. The bottom line is simple. FAA predictions that center fuel tank explosions would be unlikely, with only four predicted over the next fifty years are obviously bogus, like all other FAA predictions. Inerting the fuel tanks of all transport category airplanes is vital unless we are prepared to assume the human and economic costs of hundreds dead.

Today, new fuel tank inerting systems that manufacture their own nitrogen from air weigh only a few hundred pounds. They can be retrofitted and eliminate this problem that has already taken a thousand lives. When technology is available to prevent death in aviation, it is immoral to allow bureaucratic inaction and industry stonewalling to assume this risk flight after flight. The FAA needs to act now!

Arthur Alan Wolk
August 2007

Tuesday, October 23, 2001

THE FAA STILL DOESN'T GET IT -- THE BOEING 737 STILL NEEDS A RELIABLY REDUNDANT RUDDER

In the face of sweeping NTSB Safety Recommendations with respect to modifying the Boeing 737 rudder system with one that is reliably redundant, the FAA's response is, "We need to get to the Board about what that [term] means." That's scary!

The dictionary defines reliable as "consistent and dependable". That same dictionary defines redundant as "exceeding what is usual or necessary and supplied as a backup". In other words, what the 737 rudder system needs, according to the NTSB, is a consistently dependent duplicate system or backup.

Statements made by the FAA in response to the Safety Recommendation are frightening. For example, the 737 is the only air carrier airplane that was designed with a single panel rudder controlled by a single actuator. The FAA said, "You want to hesitate about changing something such as the rudder system on an airplane.... What scares us regulators is the possibility of introducing an unintended safety risk." In the face of two and possibly three airplanes that have rolled on their backs and crashed, killing hundreds of people, the FAA is scared about fixing the airplane, it complains.

What is even more scary, is the FAA's comment that, "In this 737 PCU it takes two jams internally to get hardover." What's frightening about it is that it demonstrates that thirty years after the 737 certification, and eight years after United 585 came crashing into the ground in Colorado Springs, the FAA still doesn't know that it only takes one jam in the rudder servo valve to cause a reversal or hardover, which can't be controlled by the flight crew.

Either the FAA can't read, write or understand plain English, or it doesn't understand hydraulics, or perhaps it simply doesn't want to understand it because it would look so guilty for the unnecessary loss of life that it alone allowed to happen by ignoring its certification responsibilities.

Part 25 of the Federal Aviation Regulations required then and requires now that there be a redundant control system for the rudder, and that other flight controls be able to overcome a single failure in the rudder control system. Neither was true with the Boeing 737, and the FAA ignored it in certification, ignored it when problems cropped up in the field and before there was a fatality, and still ignored it after there were multiple fatalities.

Indeed, even after there were two and possibly three 737 crashes due to rudder control system failures, the FAA certificated an entirely new generation of Boeing 737s with a single rudder actuator design. There is a point below which incompetence becomes inexcusable. We've reached that point.
The old adage "Close enough for government work" should no longer be the standard to which the FAA aspires. Shame on the FAA!

Tuesday, March 23, 1999

Attorney Specializing in Aviation: NTSB Investigation of the Boeing 737 Took Longer Than it Did to Conceive, Design, Certify, Produce And Field the Aircraft

 

In response to the NTSB's March 23, 1999, hearings on the USAir 427 accident, Attorney Arthur Alan Wolk, who has focused his efforts in the field of air crash litigation, issued the following opinion:

The National Transportation Safety Board, which is about to announce its long awaited conclusions on the causes of the crash of USAir 427, which occurred on September 8, 1994, and United 585, which occurred on March 3, 1991, took longer to complete its investigation of these two accidents than it did for Boeing to conceive, design, certify, produce, and field the Boeing 737.

Not only did it take too long, but from statements issued by both the NTSB and the Federal Aviation Administration, it is clear that both of those agencies of government still don't have a clue either about why the rudder of the Boeing 737 has a mind of its own or the means to fix it. In short, eight years after 25 people were killed in United 585, five years after 132 people were killed in USAir 427, and six years after more than 100 people were killed in Copa 201, the Boeing 737 still is not fixed.

The FAA, in the face of pending recommendations that a dual rudder actuating system be installed in all existing Boeing 737s to prevent the single actuator causing a crash, has said, "There is no data to suggest planes with dual power control units are less prone to an in-flight upset than the 737." It also pointed out that a 737 "is equipped with a standby rudder system that serves a similar purpose." This statement demonstrates that the Federal Aviation Administration, the agency of government responsible for ensuring the safety of flight and for certifying the Boeing 737, still doesn't understand how the rudder control system of that aircraft works. The standby rudder actuator on a Boeing 737 has absolutely no role to play in serving to prevent a rudder hardover caused by an errant rudder power control unit. In fact, because of defects in the standby rudder actuator, it can actually make the situation worse. These statements, then, from the FAA are even more frightening in the face of this lengthy investigation and at least three accidents taking hundreds of lives. It means that the FAA still doesn't have a clue about the fundamental and basic operation of an aircraft that it certified.

The problem is very simple. The Boeing 737 is the only transport category airplane that has a single actuator for the rudder, which is in violation of the federal regulations which require redundancy. Boeing got around the redundancy requirement by performing an analysis, without flight tests, that established that the chance of failure was so remote, it didn't have to have a redundant design. The FAA went along with it, and it was wrong. In fact, the FAA and Boeing admit that the Failure Modes and Effects Analysis performed to obtain that certification was wrong. Therefore, certification was wrong. Therefore, the airplane should have been grounded or fixed. It is neither.

In the face of overwhelming evidence that the rudder was the cause of at least three unsolved Boeing 737 rollover accidents in the last decade, the FAA recently granted certification to three new 737 models, the -600, -700 and -800 Series. In a stunning abdication of its responsibility to ensure safety, the FAA granted that certification with, yes, a single rudder actuator in each of those aircraft. In short, the advanced model Boeing 737 being produced at the rate of 24 a month continue to have the same fundamental flaw that the 3,000 existing 737s have -- no redundancy in the rudder control system.

The FAA also claims that now pilots are being trained to handle the problem of a runaway rudder. This also demonstrates that the FAA is out of the loop and out of touch with the reality of airline pilot training. The advanced maneuvers training (or upset training, as it has been called by the pilots) presumes that the rudder malfunction no longer exists. In other words, the rudder, which may have gone to full travel and caused the airplane to be upset in the first place, has now returned to its normal position. Unfortunately, when the rudder fails in a Boeing 737, it stays there, so all the upset training and all the advanced maneuvers training in the world won't protect the crew and passengers of a Boeing 737 with an errant rudder.

The FAA and the NTSB also laud the changes that were recommended by the NTSB and implemented in Boeing 737 rudder control systems. These included an inspection to determine that adverse tolerances in the manufacture of the servo valve in the rudder could not stack up and cause a malfunction, changes in the design of the servo valve purportedly to prevent rudder malfunction, and the addition of a rudder limiter that would keep the rudder from going full travel and, therefore, allow the pilots to regain control using the ailerons on the wings, which could overpower the rudder. Unfortunately, none of those changes either has or will work to prevent an accident under the most critical phases of flight -- landing and takeoff.

The rudder limiter is designed not to function at altitudes 700' above the ground and below on landing and 1,000' above the ground and below on takeoff. So at a point in time when the crew has the least possible altitude within which to regain control of the aircraft, the potential for rudder malfunction is uncorrected. Even with the current modifications, the United 585 crash in Colorado Springs would still likely have occurred.
There is always a risk when interpretation of safety regulations is stretched, strained, winked at or disregarded, and that is, an accident. How many more accidents? How many more people will die before those who should be held accountable are held accountable?

According to the NTSB, there may be recommendations to split the rudder of the 737, like the 727 rudder, and use two actuators to provide a level of redundancy required by the regulations, and certainly called for by the accident history. The FAA and Boeing decry such a recommendation, claiming that it would harm the systems in the aircraft and be expensive. Neither the agency responsible for safety nor the manufacturer of the aircraft ultimately responsible for safety address the harm to the other set of systems which will result from the failure to implement these necessary modifications, and that is the systems of the human beings aboard these aircraft. It is those systems that need to be protected at all cost.

But what is perhaps most indefensible in this flurry of sound bites and competition among federal agencies to gain the political upper hand of looking like they are doing something to help the public in the face of an inexcusable eight year delay is the abject failure to appreciate how modern technology can make correction of the 737's flaws far less expensive and less complicated than envisaged or complained of.

We live in a fly-by-wire technology era, where wires instead of hydraulic lines and electric actuators instead of hydraulic actuators are the way aircraft are designed and built. In short, the Boeing 737 can have a second actuator electrically operated and driven and equipped with a comparator, such that if the hydraulic actuator and the electrical actuator don't agree, the rudder will not move. It's cheap, it's simple, it can be implemented relatively quickly, and it can solve the problem.

With regard to the 737 Advanced model aircraft and the certification without rudder activator redundancy, while the NTSB sat back and let it happen, shame on the U.S. Government, shame on the FAA, and shame on the NTSB.

These new airplanes should never have been certificated without a dual rudder actuator, and had the NTSB applied enough pressure, they wouldn't have been. The NTSB has demonstrated a lack of accuracy and thoroughness in accident investigation historically, but now delay can be added to its list of inadequacies.
It is stunning that the first scanning electron micrographs of the United 585 rudder control servo valve that were obtained by the NTSB, were obtained not as a result of its own metallurgical analysis of this suspect component, but of photographs that were supplied by none other than an expert hired by Arthur Alan Wolk. It is stunning that the NTSB didn't know until weeks ago that the servo valve of both United 585 and USAir 427 had metal burrs left in them during manufacture that were not in compliance with the drawings; in other words, manufacturing defects, and that those burrs could cause jamming of the slides of the rudder actuator. It is frightening to think that eight years after initiating an investigation into the crashes of three airplanes full of people that the NTSB is just getting around to having a hearing to tell people what everybody in the industry knew within hours of the accidents -- they were all caused by the rudder, and if you have an airplane with a single rudder actuator, when the regulations require two, that's probably why the rudder caused the accident.
The FAA, Boeing and the NTSB say that the necessary changes in the 737 already in the process of being implemented make a safe airplane even safer. Statistically, that's probably true. After all, 90,000,000 hours and only a few crashes that we know were caused by the rudder. That's a pretty good record. So, I guess then, we have abandoned the principle that when we actually know of a reason for an aircraft crash, it must be fixed so that others will not lose their lives.

So, really instead of having a little machine that checks your boarding pass when you get on a Boeing 737, each passenger should simply spin a roulette wheel, because that is exactly the gamble every passenger and every crew member takes when he or she gets aboard a Boeing 737 with a single rudder actuator. I suggest your carry-on bag should be a parachute!

Wednesday, January 15, 1997

BOEING BELATEDLY MODIFIES UNSAFE 737 RUDDER CONTROL

BUT NATIONALLY-KNOWN AVIATION ATTORNEY SAYS, "IT'S TOO LITTLE, TOO LATE."
PHILADELPHIA

-- January 15, 1997 -- What is perhaps the most appalling irony yet in the Boeing 737 air crash investigation debacle, is the announcement today by Al Gore that Boeing has agreed to modify their 737 rudder control to prevent rudder hardovers and the resulting complete lack of control of the aircraft. Nationally-known aviation attorney, Arthur Wolk, made the recommendations being discussed today five years ago.

Says Wolk, "While pronouncing an airplane that has taken hundreds of lives from this defect known to Boeing and Parker Hannifin (the rudder control system maker) for 25 years as safe, the government has made it look as though Boeing, in an interest solely motivated by public safety, has decided to make changes which are unnecessary." "In fact," continues Wolk, "without these changes, the Boeing 737 is a time bomb, with every flight holding the potential for a rudder hardover, a loss of control, and a crash killing all aboard."
"It is sickening that Boeing, which has taken the position in the litigation that has arisen from the crashes of United 585 in Colorado Springs and USAir 427 in Pittsburgh that the rudder had nothing to do with either of these accidents, is now being lauded for taking steps which should have been taken when the airplane was certified in the late 1960s to prevent these accidents from happening," says Wolk.

"Knowing of the hundreds of warnings of accidents waiting to happen in Boeing 737s over the years, Boeing and Parker Hannifin allowed two planes to crash, killing all aboard, and possibly a third, while denying that the rudder could ever cause such a calamity," says Wolk.

Wolk concludes, "What the NTSB, the FAA and Boeing are conceding now is that the airplane's rudder control is unsafe. What makes this announcement so appalling is that the airplane still flies every minute of every day while the government and the manufacturers know that an accident can happen at anytime. This is unprecedented in aviation history."

Friday, September 8, 1995

THE BOEING 737 -- HOW SAFE ARE THESE PLANES

September 8, 1995 marked the one year anniversary of the crash of USAir Flight 427 in Pittsburgh, and the cause of the crash is still unknown. Yet, an estimated 60,000 - 70,000 people board approximately 2,000 Boeing 737s daily -- planes that have a proven defect, according to nationally known aviation attorney Arthur Alan Wolk, that makes them unsafe.

In 1991, Americans witnessed the fatal crash of United Flight 585 in Colorado Springs and three years later saw haunting similarities in USAir Flight 427 -- both crashes resulted after unexpected rolls. As recent as July 25, 1995, we heard about another incident, but that pilot was fortunate enough to have been able to override his 737's uncommanded roll.

But what the public doesn't know is that these have not been isolated incidents. Actually, there have been hundreds of unexpected rolls reported and documented in the discovery proceedings of 737 legal cases.
Nonetheless, our country's "best" minds in aviation (the FAA and the NTSB) still haven't figured out why 737s roll. Why haven't they identified the cause for the fatal crashes and even more important, why haven't they responded to what the British AAIB identified as the problem? Wolk says this is why: "The FAA is too cozy with the industry it's supposed to regulate. It would rather support Boeing, our country's largest exporter, than protect human lives by forcing Boeing to pay the tremendous amount of money required to fix a significant design flaw."

According to Wolk, the "significant flaw" is in the rudder-control unit. What causes the plane's death roll and dive is called a "rudder hardover" which means the rudder moves as far and as quickly as it can to one side. In a recent Newsweek article, Wolk is quoted as saying, "How Jim Hall (NTSB Chairman) can stand there and say, 'We're still baffled,' is beyond me. Everybody on the inside of the investigation knows -- not believes, knows -- it's the rudder." Wolk, himself, has purchased a Boeing 737 rudder-control unit, has gotten his hands on Boeing's computer data and has incorporated the information into his own computer system, and has done extensive research on the "servo valve," which Wolk believes to be the culprit in faulty rudder-control units.

Some will say the FAA addressed the rudder problem late in 1994, when it issued an airworthiness directive requiring airlines to replace the power control units of their 737s by March 1999. But Wolk says this was done just to pacify the public's fear, and no one in the FAA really knows if this will work. "If the FAA doesn't know what caused the crash, how can they fix the problem?" asks Wolk. "The FAA is telling the airlines to replace the 737 power control units with other faulty units -- the problem is not mechanical, it is one of design. And Boeing hasn't changed that and the FAA hasn't enforced a change."

You may be interested to know that Wolk refuses to be a passenger on 737s. In fact, he has scheduled connecting flights just to avoid boarding what he considers a very dangerous aircraft.

Wednesday, January 25, 1995

FAA IS MISSING THE BOAT BEFORE ANYBODY ELSE GETS KILLED 2 SIMPLE CHANGES MAY PROTECT PUBLIC WHEN, AS FAA NOW ADMITS IN USAIR 427, THE RUDDER WAS TO BLAME

PHILADELPHIA -- January 25, 1995 -- "It's incomprehensible, says nationally-known aviation litigator, pilot and spokesperson for aviation safety, Arthur A. Wolk, "that the FAA today finally admitted the rudder played a likely role in the Pittsburgh USAIR crash, but does not know why. (The FAA previously certified the Boeing 737 and its rudder control system.) Anyone who has studied the Pittsburgh crash, and its striking similarity to the United 585 Colorado Springs crash, can point to the rudder as the most likely cause, and provide two simple interim solutions.

"What happened, on September 8th, was the airplane's power control unit (PCU) design flaw stuck again. When the yaw damper signaled the PCU to move the rudder, the unit activated the rudder to compensate, to a limit of 2 to 4 degrees. But that 2 to 4 degree limit doesn't work, because in both Pittsburgh and Colorado Springs, the unit overreacted and went into full deflection, causing the airplane to roll over."

Wolk says the FAA's recent suggestion for pilots to switch off the yaw damper when uncommanded rudder movement occur, is too late. "The rudder can move into full deflection within seconds and the pilot doesn't have a chance. If the rudder moves 18 degrees, the airplane rolls over and dives."

"Before more innocent passengers are killed, and before the PCU is redesigned, the FAA should mandate two mechanical adjustments. First, the authority of rudder movement must be limited to less than 18 degrees. Second, pilots must be given sufficient means to control the roll by training them to increase power to the "down" wing engine, reduce power to the "up" wing engine, and use the ailerons on the wing opposite to the direction of the roll.