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

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

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

Ignoring the obvious: a jamming servo valve, NTSB fails to protect future passengers

PHILADELPHIA – (11/17/1995) Today, the NTSB wraps up three days of investigative hearings regarding the cause of the Pittsburgh crash of USAir Flight 427 on September 8, 1994, which resulted in 132 fatalities. Yet, the NTSB and the FAA still refuse to look at the obvious cause of this crash (also the most likely cause of the 1991 United Flight 585 crash in Colorado Springs): the faulty design of the servo valve — a key component of the Boeing 737s rudder control power unit.

According to internationally-known aviation attorney Arthur A. Wolk, “The NTSB is a ‘broken part’ organization. If a part isn’t broken, then it couldn’t have caused the crash. However, a malfunctioning part can be just as fatal. The servo valve is known to jam — for reasons that become ‘invisible’ after the crash.

“What the NTSB fails to do,” Wolk continues, “is combine the available evidence with known design limitations and come to reasonable conclusions about the cause. The NTSB and FAA know the servo valve is defectively designed, so it can cause rudder reversals and spontaneous (uncommanded) rudder movements. Hundreds of pilots have reported uncommanded rudder movements in Boeing 737s since the aircraft’s original certification, but these complaints fall on deaf ears.”

“The NTSB and FAA should demand modifications of the Boeing 737’s servo valve simply to comply with the Federal Aviation Regulations, but — more importantly — they should demand modifications to save the lives of future passengers.”

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 737’s 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 737’s 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 737’s 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 737’s. In fact, he has scheduled connecting flights just to avoid boarding what he considers a very dangerous aircraft.

-Arthur Alan Wolk