To make matters worse, he had been removed from his job as the 737 chief engineer and given a different position, overseeing new Boeing models. It was a lateral move, but he did not want to go. His bosses didn’t mention burnout as a reason for his reassignment, but McGrew figured that was one of the factors. He stayed involved in the Flight 427 effort, but he found less time each week to work on the investigation.
He was frustrated at the NTSB’s lack of effort in studying the pilots. Sure, the human factors team had pursued several leads that Boeing wanted, but McGrew had heard that Brenner, the NTSB human factors investigator, believed the pilots had their feet on the floor and never knew when the rudder went in. How could Brenner say such a thing? There was no conclusive proof of that, and in McGrew’s view, there was evidence to the contrary. McGrew and most people at Boeing still believed that Emmett or Germano (most likely Emmett, since he was the flying pilot) had mistakenly slammed his foot on the pedal and then pulled back on the control column, stalling the airplane and causing the crash.
McGrew and other Boeing officials had been traveling the world to reassure airlines about the safety of the plane. They were under tremendous scrutiny. A series of stories in the Seattle Times said Boeing had not responded to the rudder problems, despite many incidents. McGrew found that allegation preposterous. He said the company had thoroughly investigated the incidents and had found no systemic problem.
He said he felt no pressure from Boeing management to defend the plane and had done so only because there was no evidence that the rudder system had malfunctioned. Likewise, he said, the company’s costs for lawsuits had no effect on what he did. “If it’s a ton of money, that’s too bad,” he said one day while driving up Interstate 405 to a meeting. “If there’s something wrong, you’ve got to fix it.” He was convinced that Emmett and Germano just got into a situation that was over their heads.
McGrew and other officials thought it was time to throw the equivalent of a Hail Mary pass. They would go over Haueter’s head directly to the board members, the five political appointees who would vote on the probable cause. Rick Howes, the Flight 427 coordinator in Boeing’s air safety investigation office, made a courtesy call to Haueter. Howes said Boeing was going to be “aggressive” in informing the board.
The result was a spiral-bound booklet called the “Boeing Contribution to the USAir Flight 427 Accident Investigation Board.” It was the classic Boeing approach—slick color renderings of what Germano saw from the cockpit and a view from behind the plane, matched with Boeing’s analysis. The renderings were the same ones that Haueter had seen on the posters in the conference room a year and a half earlier, but this time they had Boeing’s comments on why the plane was innocent:
The rudder system on the Boeing 737 airplane has been operated successfully for 73 million flight hours. In all of these hours of service history, there has been no known occasion when there was a full uncommanded rudder input. Nor has there been any known occasion when a rudder malfunction produced an event that was not controllable by the flight crew. Most important, the extensive investigation conducted to date into the rudder system used on USAir Flight 427 confirms that this system was fully operational during the upset.
Boeing was careful not to criticize the pilots too much. The booklet said it was understandable that they had made a mistake after they were startled by the wake turbulence: “It is known that pilots respond to roll upsets by using rudder. It is also well documented that rudder inputs once made can be forgotten or ignored and maintained for the remainder of the flight.” The booklet said Emmett and Germano were surprised when they were jostled by the wake turbulence. They tried to respond to the roll, but overcorrected with the left rudder pedal.
“In all likelihood, the crew became absorbed in making other control inputs as the upset sequence developed, and simply failed to perceive that a full rudder input had been made.” The booklet quoted from a USAir document that said when pilots respond to upsets, “our biggest problem has been stepping on the wrong rudder!!” The booklet said there was no evidence of any failure of the rudder PCU and that Flight 427 would have been recoverable if the pilots had not pulled back on the stick. It ended with this:
Boeing believes there are persuasive reasons to support a conclusion that the USAir Flight 427 accident was caused by an unexpected encounter with wake turbulence, rudder commands by the crew and a failure to apply correct recovery techniques.
Haueter believed that the “Boeing Contribution” was designed to kill Phillips’s safety recommendations. The booklet didn’t mention them, but it arrived the week before the board was scheduled to discuss them and it clearly tried to deflect attention away from the plane.
But the booklet ended up having no effect on the recommendations. The safety board delayed them by two weeks so that Bob Francis, the board member working on the TWA 800 crash, could have more time to review them, but the safety fixes were approved unanimously with no significant changes.
The recommendations were sent to David Hinson, the FAA administrator, in an exhaustive twenty-six-page letter that cited the Eastwind incident and the crashes of USAir 427 in Pittsburgh and United 585 in Colorado Springs. The letter said the investigation of the USAir crash had not been completed, but that the NTSB had found 737 safety problems “that need to be addressed.”
McSweeny, the FAA aircraft certification chief, was his usual defensive self in responding to the recommendations. He downplayed their importance, saying that the FAA had been addressing many of the same issues with previous airworthiness directives that grew out of the Critical Design Review. He said they would consider the NTSB’s recommendations but that “you want to be very careful when you change [the 737]. You need to make sure that your tinkering does not cause a problem.” Once again, McSweeny sounded as though he was protecting Boeing.
21. THERMAL SHOCK
A hydraulic valve had to pass a battery of tests to get accepted by Boeing. One test shook it violently, like a can of house paint in a mixer. Another test moved the valve back and forth 5 million times. The most brutal test froze the valve to minus 40 degrees Fahrenheit and injected it with hot hydraulic fluid. That represented the worst imaginable condition—an overheated hydraulic pump when the plane was in frigid air at 35,000 feet. Hot fluid would shoot into the frozen valve, causing it suddenly to expand. The test was called thermal shock.
Boeing did not manufacture its own valves, just as it didn’t build most of the parts for its planes. Instead, it relied on hundreds of suppliers such as Bendix. The company did not make the unique valve for the 737’s rudder, but it was bidding to make a similar one for Boeing’s giant new plane, the 747. Bendix engineers built a prototype of the valve to undergo the standard battery of tests—the paint shaker, the marathon, and thermal shock.
The tests were held in a gray stucco building in an industrial section of North Hollywood, not far from the Burbank airport. The lab, which took up most of the first floor, was filled with a thick, oily smell from all the hydraulic fluid. The room was a veritable torture chamber for a hydraulic valve. The lab even had special steel containers called crash boxes that were used the first time a valve was pressurized, in case it exploded.
Upstairs was a man named Ralph Vick, an engineer who worked on some of the company’s most important projects. Vick was not directly involved in the bid for the 747 valve, but he kept close tabs on the tests because he—like everyone else in the company—desperately wanted to win the big Boeing contract.