Before Hall arrived, the safety board had not paid much attention to victims’ families. Investigators would politely answer questions, but they thought their job was to find out why planes crashed, not to provide grief counseling. When Hall heard that the families were unhappy and had formed a support group, however, he told the NTSB staff to help them. In his view, helping the families was exactly what the Clinton-Gore approach called for. He asked the NTSB staff to set aside reserved seats in the ballroom for the families and arranged a meeting with them one night after the testimony. He had Haueter come along to answer questions.
About a hundred family members came to the meeting room on the mezzanine level. Hall opened the session by explaining the NTSB’s role and the purpose of the hearing. Haueter updated the families on the investigation and went through the plans for the remainder of the hearing. Then it was time for questions. The 737 sure seemed to have lots of rudder problems, someone said. Why not ground it?
That wasn’t up to the NTSB, Haueter said. His agency would only make recommendations to the FAA, and it needed solid evidence before it made such a serious request. So far, he hadn’t found the evidence.
Why have Boeing people up there? someone else asked. “They’re just going to lie to you.”
Haueter and Hall explained the party system. “These people know the plane’s systems best,” Haueter said.
Someone else was amazed about the lack of measurements on the flight data recorder. “Why aren’t you doing anything about that?”
“Look, you’re preaching to the choir. The safety board has been saying that for years,” replied Haueter. Hall vowed to bring up the issue with the FAA.
The families had a litany of complaints about USAir—the long delays in confirming who was on the plane, the poorly trained employees, and the airline’s refusal to share the names of other families.
Hall listened and came away convinced that the families had been mistreated. The things they wanted were reasonable. USAir didn’t have to pamper them, but the company should have shown a little common decency. Hall would have preferred that the airlines do it on their own, but they had shown they did not care enough to do it right. It was time for the government to get involved.
The hearing revealed growing tension between the NTSB and Boeing. The company had fought some of the NTSB’s requests for data, had stamped “PROPRIETARY” on several items and said the board could not release them to the public because of Boeing’s confidentiality agreements with the airlines. Days before the hearing, the NTSB learned about several 737 incidents that Boeing did not include on a list that Phillips had requested.
Haueter was surprised that the company was so disorganized. He didn’t think Boeing was deliberately hiding anything, but he was disappointed that it could not keep track of important data. Chairman Hall was furious. He reminded a Boeing official of the request for all incidents and asked, “Is that simple enough?”
Another Boeing official acknowledged that the company should have included a rudder incident involving an Air France 737 on the list, but the report did not sound serious to Boeing employees when they first heard about it. When the testimony concluded, Hall told McGrew he was concerned that the company’s list of 737 incidents was incomplete. “When we end up in a situation, Mr. McGrew, just to be straight with you, that we request information and then another party sends us information that is pertinent that we didn’t get from you, it causes concern.” Hall said he knew that things fell through the cracks, but he told McGrew to “go back and examine every crack so we don’t have any question that there’s been any incident with this rudder or any of these systems that might assist us.” Hall then apologized for being so harsh. “I’m from Tennessee and I don’t know to express myself any more than just that way.”
McGrew was angry. He felt like he had been used so Hall could get his name in the press. The NTSB staff knew all the details about the Air France rudder kick. Either they didn’t tell Hall or Hall conveniently ignored it so he could land a few punches on Boeing. McGrew did not like the fact that politicians were getting involved in plane crash investigations. The NTSB was becoming a political beast, under enormous pressure to come up with an answer. And McGrew was not sure they would come up with the correct answer.
As the hearing concluded, reporters gathered around Haueter and Hall to get their reactions to the week. Haueter had consistently told the press that he was confident he could solve the mystery. A reporter asked how he could be so confident with so little good evidence.
“It’s based on experience and the data available,” Haueter said. “I’ve seen two other accidents I’ve worked on where I had much less data than this, much less help than this, and we determined probable cause very definitively. I can’t say I identified any new alleys [to investigate] this week… but there are a lot of avenues available that have to be fully explored.”
As McGrew returned to his office in Renton, he was more confident than ever that nothing was wrong with his airplane. It bothered him that critics were saying Boeing might be covering up a hidden flaw in the plane. McGrew said he felt no pressure from lawyers or anyone else to protect the plane. If the 737 had a flaw, Boeing wanted to find it.
McGrew approached that mission with vigor. He spent hours reading reports on the crash and led daily meetings of Boeing engineers. Ninety-five Boeing employees had worked 42,000 hours on the investigation, with twenty-three of them dedicated to it full-time. It had cost Boeing $1.5 million. McGrew had become obsessed with the crash. Occasionally, he awoke at 3 A.M. with questions about a theory, crawled out of bed, put on his bathrobe, and went downstairs to his home computer. He would pull up a spreadsheet of 427’s flight data and try adjusting ratios and parameters to see what effect they would have. Then he would go into the office that morning and ask one of his engineers to try a new computer run.
He kept a list of theories titled “Items Under Consideration.” It had eighty-five possibilities, including everything from bird strikes to thrust reversers. All but eleven had been ruled out. Many of those eleven were long-shot theories that were likely to be disproved by future tests. The investigation had largely become a tug-of-war between two theories—a rudder system malfunction and a mistake by the pilots.
From the start, McGrew had been open to the possibility that something was wrong with the 737. That was the classic engineer’s approach, to consider every possible failure mode of your creation. That’s why redundancy is such an important concept in aircraft design. If something fails, there is at least one backup, often two. The rudder system had lots of redundancy. Every lever inside the power control unit had a second lever that moved in concert, in case one should break. In the valve itself there were two slides in case one should jam. It was powered by two hydraulic systems in case one should fail. And there was a standby actuator with its own valve in case the main PCU stopped working.
But McGrew’s plane had come up clean. Test after test failed to find anything wrong with the 737 rudder system. The PCU would not reverse, the valve didn’t leak, and there were no marks to indicate that it had jammed. The hydraulic fluid from the USAir plane had been dirtier than it was supposed to be, but tests found that made no difference. You could make the fluid as thick as Dijon mustard and the valve could still do the job. The bottom line, as summed up by Phillips in his report, was that the PCU was “capable of performing its intended functions.” Besides, the worldwide fleet of 737s had an extraordinary twenty-seven-year record, with 65 million flight hours and an extremely low crash rate. If there was a flaw in the rudder system, it would have shown up years earlier. McGrew felt it was time to take a closer look at the human part of the equation—the pilots.