The Mystery of Flight 427

by Bill Adair

  The Boeing witnesses had a different spin. Carriker, the test pilot, stuck to the company line that the soda can valve should prevent rudder hardovers. Boeing did not require any pilot training for a hardover, he said. “We don’t train for events that don’t occur.”

  When the parties got their turn, ALPA leader Herb LeGrow asked a pointed question to remind everyone that Carriker had never flown for an airline. That tactic was used by both parties at the hearings. Boeing and ALPA tried to land punches on each other and toss softballs to their own people. Carriker struck a nerve with ALPA when he referred to “average” pilots. That brought laughter from the room because everyone realized that in the union’s view there was no such thing as an average pilot. They were like children from Lake Wobegon. They were all exceptional.

  LeGrow also sparred with McGrew, the Boeing engineer, about the crossover point and the company’s willingness to include ALPA members on a new Roll Team that was investigating reports of sudden rolls by 737s. McGrew said, “We at Boeing have offered to the parties and to the NTSB in the past to please send representatives at any time to come and sit with us as we go through this investigation. We would be happy to accommodate you.”

  The union official shot back, “Mr. McGrew, I’ve been the coordinator of this accident since September 8th of last year and I have received no such communication from the Boeing Airplane Company.”

  “Excuse me, Mr. LeGrow, but I made that same statement sitting at the stand back in January.” Later, McGrew scoffed at the importance of the crossover point. “Our basic position today is that the airplane has proved its airworthiness over the years and that this is probably not a significant item,” he said. Boeing was planning improvements to two rudder system components, but neither one appeared to have played a role in the Hopewell crash. “There were no faults found in the mechanical systems of the airplane,” he said.

  Once again, McGrew’s self-confident manner came on strong. He got snippy when anyone suggested that anything was wrong with the airplane. Haueter questioned whether older 737s should be required to meet current safety standards, but McGrew said it wasn’t necessary. “If you buy a toy wagon for your child, and it wears well and is still usable when he’s your age and has [his own] child, should you go out and re-fit it again? It’s perfectly functional and works, nothing wrong with it.”

  Haueter grinned and said, “I guess using your analogy, we wouldn’t put airbags in cars nowadays.”

  McGrew retorted, “I think now we’re getting into arguing the relative safety statistics of the automobile versus the airplane. And I think you’ll lose.”

  Relations between Boeing and the safety board were getting rocky. NTSB officials said Boeing had not told them about the Roll Team until two days earlier—even though the team had been investigating the incidents for more than a month. Boeing had distributed a packet of lists and charts showing that many “suspicious” rolls reported by 737 pilots were actually encounters with wake turbulence. Boeing’s point was that there was no gremlin in the plane and that pilots just overreact when they hit a wake.

  Included in the Boeing packet was the Roll Team’s list of 737 incidents and the company’s conclusion on each one. The first twelve were attributed to wake turbulence, five were blamed on minor airplane malfunctions, and three on pilots. If Boeing had left Flight 427 off the list, the NTSB would not have made such a fuss. But there it was, listed as “Roll Event No. 2.” The “Boeing conclusion” for the crash was listed as “wake turbulence.”

  That was heresy. Only the NTSB was supposed to determine a probable cause. It looked as if Boeing was saying it had solved the case while the safety board was still stumped. Yes, the wakes might be a factor, but they were not the primary cause. McGrew and other Boeing officials apologized when they testified, saying that the Roll Team was a sincere attempt to help the airlines. They said it never crossed their minds that it might be related to the investigation. McGrew likened it to other minor changes that Boeing had made to the 737 without any need to notify the safety board. “I must tell you that we probably won’t tell you when we change the brand of tires that we start putting on airplanes, either.”

  Hall was miffed. He told McGrew that the Roll Team looked like a parallel investigation without the NTSB, That could damage the integrity of the safety board’s effort, Hall said. The board should be notified of any work that might be related. “It’s like the Holiday Inn. The best surprise is no surprise.” McGrew took his licking on the stand without complaining further, but again he felt he was a victim of Hall’s grandstanding. The NTSB staff not only knew about the Roll Team, McGrew said later, but there was an NTSB person on the team.

  Still, McGrew faulted himself for not doing a better job of communicating with the NTSB, informing the top officials ahead of time. He was a great engineer, but he realized he still had a lot to learn about politics.

  In an interview a month later, Hall was still complaining about Boeing’s behavior. “I think somebody [at Boeing] went brain-dead, to think they’ll put together a team to look at rolls, but it had nothing to do with this investigation.”

  Hall had promised Haueter and Phillips that he would let them keep the investigation going as long as they needed, until they had exhausted everything. But he was growing pessimistic. “It looks like it will be very difficult” to solve the mystery, he said. “I’ve always said that good luck comes only after hard work. We’ve certainly worked hard enough. Maybe that will help us.”

  When the rickety 737 landed at Boeing Field, the pilots were relieved. They said it had been a white-knuckle flight. The old bird just didn’t have much life left in her.

  The plane, Ship 213, was what USAir called a “runout.” It had flown for twenty-seven years, but the airline found it was no longer economical to keep it. In contrast to the newer plane used in the Atlantic City flight tests, USAir squeezed every last mile out of Ship 213 and then donated it to the Museum of Flight in Seattle. The wings and tail were going to get chopped off so the fuselage could be used as a theater. John Little, the museum’s assistant security manager, greeted the pilots as they got off the plane and peeked inside the cockpit. It must have been a scary flight, he decided. There was a Bible on top of the instrument panel.

  A USAir maintenance official had realized that the plane would be ideal for a series of destructive tests of some of the most bizarre theories—that a rudder cable had snapped in flight or that a fat guy had stepped through the floor onto the cable. No one had pushed too hard for them. They were the kind of tests that might bend an airframe, so they couldn’t be performed on a jet that would ever be flown again. But the retired plane gave them a perfect opportunity. The tests would allow the investigators to see the forest instead of the trees. They had run hundreds of experiments on individual components of the 737. Now they could see how everything on the plane worked together.

  On the first day of the rudder tests, Haueter and Hall held a press conference at the Museum of Flight, which was adjacent to Boeing Field. The podium was set up directly beneath a green-and-white replica of the B&W, Boeing’s first plane. Haueter played a video and explained how the tests would be conducted. Hall then announced that he was appointing a panel of “the greatest minds in hydraulics” to review the NTSB’s work on the Hopewell and Colorado Springs crashes to see if there was anything else they should do. It was an extraordinary step that showed the NTSB was practically desperate.

  Haueter didn’t like the idea of an expert panel. Why did they need a bunch of so-called experts? Phillips knew more about the 737 rudder system than just about anybody on the planet. It was as though Flail was saying the NTSB wasn’t smart enough to figure it out. But Phillips had actually been one of the people behind the idea. He and another NTSB engineer thought it would be helpful to have an impartial panel to bring new brainpower and validate the safety board’s work. Maybe fresh eyes would see something that the safety board had not. Hall said his direction to the panel would be this: “If the
re’s anything we missed, tell us.”

  As Hall spoke in the museum, the rudder tests on Ship 213 were under way down the street in a hangar where Boeing had once fixed B-52s. The pipsqueak 737 was parked between two gargantuan 777s, the shiny new Boeing aircraft that had just started flying. The tiny USAir plane had been opened up like a patient on the operating table. A tail section had been removed so Boeing technicians could attach wires to the PCU. Two Boeing vans were parked beside the plane. One was filled with computers and test equipment that would keep track of the results. The other van was like a life support system, pumping the 737’s systems with false information so the old bird would think it was still flying. A gallon of Starbucks House Blend was parked beside the plane, to provide fuel for the investigators.

  The fat guy theory had been discounted by just about everyone. McGrew joked that it was possible only if the fat guy wore high heels, which would have broken through the floor. But everyone had agreed to one last test. The plane’s floorboards had been removed so the investigators could see the cables that ran beneath passengers’ feet. Technicians climbed into the cargo bin, where they could look up through the cables into the passenger cabin. They hooked a ratchet onto the rudder cable that would simulate the weight of the fat guy. By cranking on the ratchet, they could add weight in 50-pound increments. The device had a weight gauge so they could watch as the guy went from skinny to obese. Other investigators stood outside the plane, watching to see if the rudder moved. If it slammed hardover, they would know the fat guy was more than just a joke.

  “Ready?” someone asked.

  “Okay,” Phillips said.

  The guy started at 50 pounds, more of a kindergartner than a fat guy. No movement of the rudder.

  He got heavier, up to 100. Still no movement.

  At 150 pounds, the rudder barely budged. At 200, there was a slight movement, and at 250, a tiny bit more. The instruments in the van showed the rudder had moved only 3.2 degrees, an insignificant amount. (By contrast, the rudder on Flight 427 actually moved about 21 degrees.)

  Later that day they tried the cable-cut test. Someone sat in the cockpit and moved the rudder pedals to make sure they worked properly, doing slow sweeps back and forth. Then the pilot took his feet off the pedals and a technician cut one of the cables with a big bolt cutter.

  Twaang! The noise echoed like a gunshot through the huge hangar as the cable snapped and recoiled through the plane like a broken rubber band. Outside, Cox saw the rudder panel shudder, but it didn’t turn. Technicians installed a new cable and cut it in a different spot. Twaang! But again, the rudder didn’t turn.

  They did more than one hundred other tests and the plane passed them all. The rudder system still seemed to be invincible. But Phillips remained surprisingly optimistic. He knew they were still a long way from finding the cause, but he was patient. Each test gave them new data and brought them another step closer.

  Across the street in the M-Cab simulator, Boeing’s lobbying campaign was under way.

  M-Cab had become a tool of persuasion to show how Emmett and Germano could have prevented the crash. At McGrew’s suggestion, Boeing engineers had installed a switch that allowed anyone sitting in the pilots’ seats to take control of Flight 427 and, without much effort, to keep the plane from crashing. It was a roller coaster ride with a message. Point the nose down (Emmett or Germano had mistakenly tried to pull it up), twist the wheel, and you have saved 132 lives.

  Boeing invited Hall to ride the latest simulation to see how easily the crash could have been avoided. If Hall, a country lawyer who was not a pilot, could save the plane, surely Emmett and Germano should have.

  Boeing test pilot Michael Hewett, a balding former navy pilot who looked strong enough to bench-press a 737, led Hall across the ramp into the white cab and invited him to sit in the right pilot’s seat. Hall would act as the first officer on Flight 427. The simulator would reenact a rudder hardover, and then Hall would have the opportunity to recover the plane to keep it from crashing.

  Hewett believed that pilots had to assert themselves in the sky but that the crew of Flight 427 had failed to take charge. He said the cockpit tape showed that Captain Germano had “no command presence.”

  In the simulator, Hewett’s point was simple: The pilots could have avoided the crash by easily turning the wheel completely to the right and pushing the stick forward to let the airplane gain a little speed. The 737 would have lost altitude, but everyone would still be alive. Hewett summed it up by saying that to pilots, “speed is life.”

  Hall buckled himself in and M-Cab started its imaginary flight, cruising along at 6,000 feet. Cox was also riding in the simulator, sitting in the observer seat just behind them. Hall had invited him along because he knew Hewett was going to do a hard sell and he wanted Cox to provide a counterpoint.

  Hewett started by demonstrating the recovery himself. He said the standard reaction time for a pilot allows three seconds, so he would count off before he recovered. When the plane started to go nose down, as the phantom pilots pulled back on the stick, Hewett flipped the switch to take control of the plane and counted, “One-thousand-one, one-thousand-two, one-thousand-three.” He then turned the wheel to the right, gained control of the plane, and leveled off. He had prevented the crash.

  Now it was Hall’s turn. When the rudder suddenly went hardover, Hall followed Hewett’s instructions and quickly turned the wheel to the right. “Hold it! Hold it!” Hewett told him. The simulator started to plunge toward the ground, but he stopped the roll and brought the nose back up. “Ease it out,” Hewett said. Hall had saved the plane.

  “That’s with no pulling or pushing at all,” Hewett said. All he’d had to do was turn the wheel right and hold it there.

  Hewett then mentioned one of the mysteries of the cockpit voice recorder—the fact that neither pilot had given any clues about what was happening to the rudder. If the PCU was jammed, “Wouldn’t you be saying, ‘It’s jammed! Goddammit, it’s jammed!’?”

  They flew again and Hall again recovered. But Cox didn’t like the way the session was going. It seemed to him that Hall was hearing only Boeing’s side of the story. He told Hall that it was understandable that the pilots pulled back on the stick. If they looked out the window, all they saw was the ground looming closer. “The airplane is not responding the way they want it to,” Cox argued. “The windscreen is full of the ground and it is understandable that they would try to reduce the number of variables that they are facing.”

  “But,” said Hewitt, “anybody who has ever been trained in a jet knows, with the stickshaker going off, the only way to recover is to let up on the stick. His first reaction should have been to push up on the stick.”

  Hall tried again. “There’s the rudder in full hard,” Hewett said. “Right wheel! Right wheel!”

  But Hall turned left. The plane crashed.

  “I almost recovered,” Hall said.

  After the session, Hall said Hewett was too heavy-handed. The Boeing engineers had had nearly eighteen months to figure out how to recover. Emmett and Germano had had just ten seconds. “No one who was flying the plane had been trained what to do,” Hall said.

  19. BLAMING GOD

  May 1965

  FAA Offices

  Renton, Washington

  “This valve,” said Boeing hydraulics engineer Ed Pfafman, “is what we consider our safety feature.”

  Another Boeing engineer boasted that the unique valve-within-a-valve and a separate backup unit would create three ways to move the rudder on the new 737, which he said was “above and beyond the call of duty.” Some planes had only two.

  But as the Boeing engineers explained the plans for the 737’s rudder system, FAA officials were skeptical. They were worried that the valve-within-a-valve might not be sufficiently redundant.

  “The thing that is disturbing me is that you have more eggs in one basket here,” said FAA official Charlie Hawks. “It does shake me a little bit,” he added. “At th
is moment, at least, I’m still a little jumpy about it.”

  The valve had been invented by Robert R. Richolt, a young Boeing engineer who had designed sophisticated valves on the Lockheed Electra. He had been so successful that he had retired and was living on a yacht when he was hired by Boeing. The dual valve was first used on the rudder of the 707 and the elevators in the 727. Richolt’s 1963 patent application for the 737 said the valve was “fail-safe” and that the device “provides an override feature in case the main slide becomes seized…. This eliminates the quick reaction time required of the pilot to prevent a crash.”

  Redundancy is a fundamental tenet in designing airplanes, a concept that engineers jokingly call the “belt and suspenders approach.” If your belt fails, your pants are still held up by your suspenders.

  On many transport jets, such as the older 727, there was redundancy on the tail itself. The rudder was split into an upper panel and a lower panel. If one malfunctioned, the other one could control the plane or be turned the opposite direction to neutralize the problem. But that wasn’t the case on the 737, which, during Boeing’s push for fewer parts and better reliability, was designed with one big rudder panel.

  The 737 rudder system was unusual. On most big jets, rudders are powered by separate valves rather than by the valve-within-a-valve. Many planes, such as the newer 757 and 767, have a special feature called a “breakout.” If two valves detect that the other one is jammed, they break it out of the system.

  But despite their reservations in the mid-1960s, FAA officials ultimately decided that the unique 737 valve met federal standards. The rules back then were relatively vague—they said that manufacturers must protect against failures “unless they are extremely remote.” That phrase was not defined, which gave Boeing leeway. The company convinced the FAA engineers that Richolt’s invention complied.