Posts: 29
Registered: Feb 99

Local News : Tuesday, February 22, 2000

Boeing told FAA in secret of 737 rudder hazard before 1994 crash

by Byron Acohido
Seattle Times staff reporter
Boeing knew for years that pilots had no way to overcome dangerous rudder problems that could occur while flying 737 jets at low speeds, but waited until after two planes crashed to acknowledge the problem, newly released court documents indicate.

The documents, which include letters from Boeing to the Federal Aviation Administration, were filed in a lawsuit against Boeing and its rudder-parts supplier, Parker Hannifin Corp., by the families of two people who died in the 1994 crash of a US Airways 737 near Pittsburgh.

The suit, filed in Chicago, was settled late last year, with Boeing agreeing to pay $25.5 million to the two victims' families. The Seattle Times then asked Cook County Circuit Court Judge Judith Cohen to release records that might otherwise be sealed in the wake of the settlement. This week, Cohen ordered most of the court papers released.

The documents establish the companies' long-standing awareness of the rudder's propensity to deflect on its own. What's more, the papers show Boeing discovered in the early 1980s that there was little pilots could do to recover from some rogue deflections, yet failed to point out the significance of that finding to safety regulators and airlines.

Boeing insists it did nothing wrong, and everything it was required to by federal safety regulations.

Records from the court file indicate:

Boeing's original 1963 patent for the valve that controls the 737's rudder, along with other documents, describe potentially catastrophic consequences from the valve jamming and causing the rudder to deflect on its own.

While certifying the 737-300 for commercial service in 1984, Boeing conducted flight tests that showed at low speeds - below what's called a "crossover speed" - there was nothing a pilot could do to neutralize a jammed rudder.

Boeing waited until 1992 - the year after a defective rudder flipped a United Airlines 737-200 slowing to land in Colorado Springs - to discuss the safety implications of the crossover-speed hazard with the FAA. Twenty-five people died in the Colorado crash.

In discussing the hazard with the FAA, Boeing insisted that the agency keep the information to itself, saying it was a trade secret. The FAA complied.

Two years later came the Pittsburgh crash. The US Airways 737-300 was slowing to land when a rudder deflection twisted it into a precipitous dive, killing all 132 onboard.
It wasn't until late 1995 - after the National Transportation Safety Board (NTSB) inadvertently learned about the crossover-speed danger - that 737 pilots began flying faster during takeoffs and landings to minimize the hazard.

Those disclosures helped the families of two Pittsburgh crash victims, Thomas Kinsey and Denise Jenkins, win the settlements from Boeing and Parker Hannifin.

On the eve of the opening of a jury trial in November, the companies agreed to pay Kinsey's wife, Ramona, $14 million and Jenkins' husband, Christopher, $11.5 million.

But Ramona Kinsey remains bitter. Boeing officials, she says, "blame everything that goes wrong on somebody else. They don't care who they hurt or what they say or what they do. They'll do anything to get off their responsibility."

After The Times requested the court records, Boeing took the unusual step of compiling a 16-page, point-by-point rebuttal of issues raised by Kinsey's Chicago-based attorney, Donald Nolan. The company gave the rebuttal to reporters this week.

In it, Boeing says it has never misrepresented anything about the 737's design and never suppressed any safety information. The company accuses plaintiffs' attorneys of making "inaccurate arguments" in court proceedings.

Mike Denton, director of project strategy and development at Boeing, said in an interview this week that federal regulations do not specifically require manufacturers to account for a crossover-speed hazard. Additionally, Denton said, the FAA itself participated in the 1984 flight tests during which the crossover speed was noted.

"We discussed it openly . . . this is the way the airplane behaves, so noted, but in my perception it was not seen as an issue," Denton said. "I think we were open and honest in our dealings with the FAA and the airlines."

However, court records show that data from those tests made no references to any safety risk. Regulators and airlines now consider the phenomenon a hazard.

Nolan, Kinsey's attorney, said Boeing more than doubled its settlement offer once the company's knowledge of the crossover-speed hazard emerged as a central issue in the lawsuit.

"Up until the day before the trial, they said they would never pay more than $5 million, but that night they paid $14 million," Nolan said. "That settlement speaks far louder than any press release about what a good product they have. We had damaging evidence against them and they did not want to have a finding by a jury in the United States that the 737 is defective."

Rudder still a safety concern

The 737, the world's most widely used model with more than 3,100 jets in service, is statistically very safe. Older model 737-100s and -200s have crashed 1.06 times for every million flights, while newer model 737-300s, -400s and -500s boast a crash rate of just 0.41 per million. That compares to a rate of 1.83 crashes per million flights for all commercial jets.

But the rudder remains a safety concern for the NTSB. Last March, the board ruled that rudder jams had caused the 737 crashes in Colorado Springs and Pittsburgh, without specifically identifying what went wrong with the valve. The board also has blamed rudder jams for the near crash of an Eastwind Airlines 737 in Richmond, Va., in June 1996 and the emergency landing of a Metrojet 737 in Baltimore last February.

Boeing, while formally accepting the NTSB's rulings, continues to blame the Colorado Springs crash on a freak weather occurrence and the Pittsburgh crash on pilot error. And the company maintains its examinations of the rudder valves from the Eastwind and Metrojet 737s turned up no evidence of jamming.

"Even today, this is a valve that's very, very reliable, that hasn't seen any jams," Denton said.

The 737 is the only large commercial jet with a rudder controlled by a single hydraulic valve. All other jetliners have multiple valves backing up each other.

The rudder is the hinged panel on the upright tail section, controlling the aircraft's left-to-right direction of travel. The valve works by directing pressurized hydraulic fluid to deflect the rudder. If the valve jams, it can direct fluid to the wrong place at the wrong time, causing unwanted deflections.

When the FAA certified the single-valve rudder for the original 737-100 in 1967, Boeing assured the agency the valve would never jam. Yet pilots soon began reporting rudder malfunctions disrupting 737 flights. The reports, now numbering in the hundreds, have continued until today.

The FAA initially saw no great danger because Boeing had assured the agency that even if the rudder valve did jam, pilots could easily counter a rogue deflection by deploying wing panels called ailerons.

It would take until last April for lawsuits to unearth company records indicating Boeing, in fact, saw the crossover speed as a potential hazard in 1984 while testing the new 737-300 for certification, even though the company at the time did not specifically point out the hazard to the FAA.

It wasn't until investigators began asking pointed questions about the Colorado Springs crash that the crossover speed emerged as a safety concern.

'Proprietary' information

In a Sept. 14, 1992, letter to the FAA, Boeing advised the agency that the 737's comparatively small ailerons lacked the leverage to neutralize a rudder deflection once the aircraft slowed below the crossover speed.

In that letter, Kenneth Usui, Boeing airworthiness manager, advised Donald Riggin, manager of the FAA's aircraft-certification branch in Renton, that Boeing considered information about the crossover speed "proprietary" and was providing it "on a confidential basis."

"Boeing does not authorize the FAA to retain any portion of these materials," Usui wrote. "They should be returned to Boeing immediately following use by the FAA, including any copies thereof which the FAA may make in the course of its review."

FAA officials decline to say how the agency responded. Boeing now says the wording of Usui's letter acknowledging that the crossover-speed hazard was standard practice, a routine means to keep sensitive information from competitors.

"Certainly we thought we were open and honest about it, but we weren't advertising it as a big deal," Denton said of the 1992 letter. "It gets back to the FAA regulations. There isn't a specific requirement that says this cannot occur. It wasn't perceived as an issue, even in 1984 when we demonstrated it."

A month after the Usui letter, on October 8, 1992, officials from Boeing and Parker Hannifin in Irvine, Calif., met in Seattle to discuss what to do about new information that the 737 rudder was capable of jamming in such a way that the rudder would move in the opposite direction of a pilot's command.

The officials reviewed a cost-benefit analysis chart posing four choices. The chart stated that the company could "do nothing" and replace suspect rudder valves "only at customer request." While costing Boeing nothing, that option would result in "high safety concern" and possibly raise questions about whether the 737 was properly certified as safe to fly.

Alternately, the chart said, Boeing could "minimize safety concern" by calling for installation of improved rudder valves on all 737s in two to three years. Such action could mean grounding some jets and result in "undue customer penalty."

Two other options were set forth in the chart: Boeing could make rudder-valve improvements across the 737 fleet in either four years or seven years, with corresponding costs and safety benefits.

The company chose seven years. According to the cost-benefit chart, such a move would "reduce safety concern" while avoiding the costly prospect of having to ground some jets until improvements could be made.

Boeing's Denton said the do-nothing option wasn't seriously considered. The choice of making improvements to the valve within two to three years was rejected because Parker Hannifin couldn't produce parts quickly enough and because airplanes might have to be grounded at remote airports, he said.

"We came up with a plan that would allow them (airlines) to do these fixes in a way that works best with their maintenance operations," Denton said, noting that Boeing also asked airlines to inspect the rudder every three to four months. "If you allow them to do the work with people who normally do that work, that's the safest way."

Simulator was more forgiving

On Sept. 8, 1994, a fully loaded US Airways 737-300 took off from Chicago with an unimproved rudder valve. About an hour later, while slowing for a routine landing approach into Pittsburgh, the aircraft suddenly swerved left and dove 6,000 feet into a ravine.

As part of the crash investigation, Boeing invited NTSB representatives and officials from US Airways and the FAA to Seattle in late 1994 to fly a 737 flight simulator.

Each person who flew the simulator was able to easily recover from a sudden rudder deflection simply by turning the control wheel to deploy the ailerons and letting the jet's nose drop to gain speed.

Boeing's interpretation: The US Airways pilots must have mistakenly steered the jet into the ravine. Perhaps the pilots panicked when the aircraft was jostled by the turbulence - known as wake vortex - swirling from the wingtips of a Delta 727 flying four miles ahead, Boeing theorized.

What NTSB investigators didn't know was that Boeing's simulator had been programmed so that the ailerons could neutralize a rudder deflection at speeds much lower than the US Airways jet had been flying. The crossover-speed threshold was much more forgiving.

NTSB investigators didn't completely buy Boeing's theory of pilot error, but they were stymied by a lack of physical evidence pinpointing a rudder malfunction. So the safety board agreed to conduct $1 million worth of wake-vortex flight testing.

Boeing lobbied to hold the tests in Seattle with Boeing pilots in charge, but the NTSB insisted the tests be conducted at the FAA's flight center in New Jersey. The tests proved what many experts thought all along: Wake-vortex encounters are inconsequential for big jets.

But the experiment did yield a surprise for the NTSB: The 737's ailerons actually had negligible ability to counter a sudden rudder deflection when flying at or below the speed the US Airways jet had been flying.

Within a few weeks of that revelation, US Airways ordered its 737 pilots to speed up during landing approaches and takeoffs. The airline wanted the pilots to maintain the ability to counter a rogue rudder deflection as long as possible.

Other airlines soon ordered their 737 pilots to take off and land at higher speeds.

In the summer of 1997, Boeing conducted new flight tests that gave the company a "better understanding" of how quickly the airplane would twist into a dive given an acute rudder deflection at low speeds, Denton said. The flight-simulator program was updated the following year based on fresh calculations from those tests, he said.

In a sworn deposition taken last April for the Chicago lawsuit, US Airways chief pilot James Gibbs testified that Boeing had insisted until late 1995 that there was no crossover-speed danger associated with the 737. Gibbs testified that awareness of the crossover speed was "absolutely" critical to flying 737s safely.

"Not knowing about the phenomenon would put the crew in a position where they had an uncontrollable aircraft, and they wouldn't know why," Gibbs testified.

Boeing counters: "It is much more important for a pilot to be able to promptly apply the correct recovery techniques to an upset, no matter what the cause, than to try and ascertain whether an airplane is above or below some imprecise crossover speed."

Flying slightly faster on takeoffs and landing "is not a panacea," Denton said, adding that pilots need to understand how an airplane behaves and be proficient at unusual recovery techniques. With Boeing's help, many airlines began instituting such training after the Pittsburgh crash.

Nolan, the plaintiff attorney, contends putting the onus on pilots to recover from a rogue rudder deflection violates a federal law requiring commercial aircraft to be designed so that it does not require extraordinary pilot skills to deal with a flight-control malfunction.

Meanwhile, the NTSB says the 737 rudder remains dangerous and that several improvements Boeing has made do not eliminate the possibility of potentially catastrophic valve jams. Boeing and the FAA are studying an NTSB recommendation, issued last March, calling for the 737 rudder to be redesigned so that it is no longer controlled by a single valve.

"Good design removes the defect," Nolan said. "It doesn't put people in emergency situations and say, 'If the pilots react perfectly, everything will be OK.' "

http://www.seattletimes.com/news/nation-world/html98/boe_19991107.html