The Mystery of Flight 427

by Bill Adair

  “No,” she said. She pointed to her brother-in-law. “But this is his identical twin.”

  They talked for forty-five minutes, discussing their experiences since the crash and plotting how they could compile a seating chart by talking with other families. Finally Tina left and Brett returned to bury the brooch.

  Deciding to leave Brett alone, Pfeiffer climbed up an embankment to a wreath of silk roses. There were 132 roses on the wreath, each one tagged with a passenger’s name.

  Brett knelt in the dirt. He had not brought anything to dig with, and there were no sticks around, so he pulled out the piece of wreckage the kid had given him and used it to dig a little hole. He set the gold brooch inside and covered it up. He said a prayer and watched his tears fall to the dirt.

  Just as Pfeiffer got to the wreath, a small gust of wind blew one of the roses to the ground.

  He bent to pick it up and looked at the name on the tag: Joan Van Bortel.

  Pfeiffer came down to the road and handed the rose to Brett.

  “Brett, it’s a sign from God.”

  Brett filled his pockets with the wreckage of Flight 427, with squares of aluminum and a big bolt with a serial number on the side. There was so much debris that he could have filled a pickup truck. He took it back to his home in Illinois because he wanted proof that the NTSB had left evidence behind.

  He had read in Newsweek that some crashes had been solved by evidence as tiny as a filament in a lightbulb. If that was the case, why didn’t the NTSB take every piece? He called the Newsweek reporter who had written the story and described what he had found. The magazine ran a brief item about his findings in its Periscope section on November 7,1994. The magazine quoted Brett as saying, “It’s not like we had to excavate. The pieces were lying at our feet.” An unnamed NTSB spokesperson was quoted as saying that investigators “took everything that was usable. We knew we were going to leave some pieces behind but we don’t think they’re of any consequence—what’s left is for souvenir hunters.” That infuriated Brett. Souvenir hunters?! Why would anyone want a piece of an airplane in which 132 people were killed?

  A few days later, Mike Benson of the NTSB public affairs office called Brett and tried to explain further. Benson said the wreckage was left because investigators were getting a repetitive pattern. The smaller pieces were of no significance. Benson did ask him to send the bolt, however. But a few weeks later, Brett got a letter from the NTSB saying the bolt was of no consequence.

  Brett had gone years without crying, but he was now breaking down every day. He went days without laughing. He thought it was strange, how he had always taken laughing for granted. But there was nothing in his life that was the least bit amusing. His first good laugh finally came when he noticed that Joan had left the price tag on the crystal frame he had taken to Pittsburgh. That was typical of her. She didn’t worry about the small stuff.

  It took several weeks to tell the bureaucracy that Joan had died. He found that the government, Joan’s employer, Azko Nobel, and the credit card companies were sympathetic, but it was still painful to tell the story again and again. He increased his running. It was just about the only thing that provided any relief. He could put his mind on hold and focus on the pain in his legs instead of the one in his heart. He drove to the forest preserve where he and Joan had often hiked, and he ran sprints up and down Mount Trashmore. He put hundreds of miles on his mountain bike, riding a long trail that connected several nature preserves. He wore Joan’s engagement ring on a chain around his neck now. It hurt sometimes when he rolled over in bed and the little prongs that had held the missing diamond dug into his chest, but Brett did not want to repair it. He wanted the ring left exactly as they had found it at the crash site.

  Life felt meaningless to Brett, so he quit his job. He spent his days reading books about death and grief. He also visited the tiny Lisle library to read articles about the Flight 427 investigation, the FAA, and aviation safety. He learned that the FAA had a dual mandate—to regulate and promote aviation—simultaneously. What a conflict of interest! Critics said that the agency had a “tombstone mentality” and did not act until people had died.

  His bitterness against USAir grew. He felt that the airline had been unresponsive to his requests about the Flight 427 seating chart. It wasn’t until he and Tina Connolly had started compiling names that the airline decided to tell families who had been sitting beside their loved ones. He was also mad that the airline had reneged on some of its offers to pay for a church contribution and to fly friends and relatives to Joan’s memorial service. The more he read about USAir’s safety record, the more he disliked the company. The Pittsburgh crash was the airline’s fifth fatal accident in five years. The FAA had beefed up its inspections of the company a couple of weeks before the Pittsburgh crash because of the other accidents. If Joan had known that, he doubted she would have flown USAir.

  When Haueter’s air traffic investigators checked radar tapes for other planes in the vicinity of Flight 427, they found that the closest was a Delta Air Lines 727 that was 4.2 miles ahead. That was more than a mile beyond the FAA’s minimum spacing, so there was plenty of room between them. But when the air traffic group mapped the radar tracks of both planes, investigators discovered that the instant at which Flight 427 crossed the Delta jet’s wake was the exact moment when things started to go wrong.

  Big jets left wakes in the sky just as cruise ships left them in the water. Wakes were powerful spinning tubes of air the size of sewer pipes that kept spinning after a plane was miles away. They were invisible, but definitely noticeable. When a plane encountered a wake, it felt like a strong bump or it jostled the plane slightly to one side. Pilots could easily recover, but they might have to roll their wings level or adjust their heading.

  Wake turbulence experts from NASA studied Flight 427’s radar data and said there was plenty of evidence of a wake encounter. The calm weather on September 8 had been ideal for long-lasting wakes. The flight data recorder showed that the USAir plane’s indicated airspeed jumped from 190 to 195 knots in one second. A big 737 cannot speed up that quickly, but that kind of change is often caused by an encounter with wake turbulence, which alters the flow into the airspeed sensors. But the NASA experts doubted that the wakes could have caused the accident. They might have rolled the plane slightly, but they weren’t strong enough to flip the 737 upside down.

  One of Haueter’s bosses, Bud Laynor, was especially interested in the effects of a wake. As test after test cleared the plane’s rudder valve, Laynor became more and more intrigued by the possibility that the wake had severely jostled Flight 427. But Haueter thought that was impossible.

  “If that’s so,” he told Laynor, “why aren’t we crashing them every day at National Airport?”

  Still, Haueter acknowledged that it was possible that the wake had triggered some other kind of malfunction. The bumps may have activated the yaw damper, a device that made tiny adjustments to the rudder to make a flight smoother. If there was some kind of jam in the hydraulic valve, the rudder might have suddenly turned to one side—a problem known as a hardover.

  Unfortunately, the government and the airline industry knew relatively little about wake turbulence. Engineers knew that wakes could be strong, but they didn’t know how strong or how planes would behave when they crossed wakes at different angles. So Laynor began to push for a special flight test. He wanted to fly a 737 behind a 727 to re-create the conditions before the crash. Special equipment would measure the effects on the plane and show whether the wake could have flipped Flight 427 out of the sky.

  The wreckage had been in the Pittsburgh hangar for seven weeks, the odor growing worse each day. It was a musty mixture of jet fuel, Clorox, and God-knew-what-else. The plane seemed to be decaying.

  Dave Supplee, the USAir mechanic from Tampa, had been summoned back to the creaky hangar to rebuild the front sections of Ship 513. That wasn’t unusual in a crash investigation, to put wreckage back together and look for patter
ns. But most accidents left large pieces that could easily be identified. That was not the case with Flight 427. There were thousands and thousands of pieces that were blackened, scarred, dented, flattened, and chipped. Putting them together was akin to working the world’s most difficult jigsaw puzzle after the family dog had chewed up the pieces and they had been set on fire.

  At Boeing’s insistence, Haueter agreed that his structures team would reassemble the wheel wells, rudder cables, the leading edges of the wings, the floor beams, and the forward pressure bulkhead (the area just behind the nose of the plane). The group would examine the wreckage for evidence of birds, explosions, cracks, or fires. Haueter was still considering the possibility of a sudden failure of the rudder cables, a collapse of the floor beams or an explosion in the wheel well, a critical area where the landing gear came close to vital hydraulic lines, pumps, and cables.

  Much of the USAir wreckage had been laid out on the hangar floor in the rough shape of the plane, but thousands of small, unidentified pieces had been tossed into three giant Dumpsters. The contents were poured onto the floor, and Supplee and other team members waded in.

  “We’re going Dumpster diving!” they exclaimed.

  For two days they rummaged through the piles, looking for pieces they could recognize. Most were no bigger than a business card and were so badly charred that they looked like burned peanut brittle. The team started with the floor beams but found only 15 to 20 percent of them. So Supplee and his colleagues dove into the pile again.

  Full-size blueprints had been spread out under Plexiglas so the team could locate each piece. Once Supplee found a piece that looked familiar, he searched for its location on the blueprint. He got a huge feeling of accomplishment when he was able to find the right spot. But the task was maddening. He kept asking, “Where’s the rest of the plane?”

  After several days, everyone realized the effort was impossible. There were huge gaps at the front of the plane. The wreckage had been so badly burned or so disfigured by the impact that there was no point in continuing. Supplee was discouraged. It seemed as if they had accomplished so little.

  Still, the wreckage provided a few answers. Notches on the floor beams showed that the rudder cables had cut into them, which meant the cables were taut at impact and had not broken in midair. The burn pattern on the reassembled wreckage was random, which indicated that there was no fire or explosion until the plane hit the ground.

  The partial reassembly of the front sections of the plane also allowed the structures team to look for evidence of birds. It was a long shot. Bird blood or feathers could have been washed away by the Clorox solution. But it was worth a check, especially around the slats, the movable panels on the leading edge of the wings. Boeing officials continued to suggest that a bird might have hit the slats right at the hinge. That could have caused the slat to pop up, making the plane roll to the left.

  The bird scenario was one of a dwindling number of theories. Haueter was also interested in the gurgling sound that passenger Andrew McKenna had reported on the plane’s previous flight from Charlotte to Chicago. The NTSB got an early explanation of the sound a few days after the crash, from a USAir pilot who sat in the cockpit on that flight and said his knee was leaning on a PA microphone button. But the issue had popped up again because of theories involving the electronics and equipment bay, where the computers and gyros were kept. There had been a few other incidents where water from the lavatory toilet had leaked into the bay and short-circuited the electronic hardware. The phenomenon was known as “blue water contamination,” a nice way of referring to toilet water.

  USAir had not been much help in pursuing the suspicions about the gurgling sound. The safety board had asked for a complete list of passenger names and phone numbers for the Charlotte-Chicago flight McKenna was on, but the airline had provided only thirty of them. To add to the mystery, Gerald Fox, USAir’s O’Hare maintenance chief, did not tell investigators about the call he received about the strange noise until three months after the crash. The woman who reported the sound to Fox had never been found, nor had several other people who talked about the sound at Gate F6.

  After dozens of phone calls, Haueter’s investigators could track down only thirteen passengers, and only two of those had heard an unusual noise—McKenna and a woman who was sitting a few rows behind him. The woman did not think the sound was unusual, and she accepted the flight attendant’s explanation that it came from the PA system. Haueter decided to put the gurgling inquiry to rest. The pilot’s explanation about the noise was reasonable, and it seemed unlikely that the sound was important. If there had been leakage of blue water that caused a short circuit, it probably would not have made a sound and could not have moved the rudder as far as estimates said it had gone.

  In the meantime, Flight 427’s power control unit continued to pass every test. Samples of hydraulic fluid from the PCU, along with samples from other USAir, Southwest Airlines, and United Airlines planes, were sent out for testing. The safety board even spiked one sample with bleach to make sure technicians from Monsanto did not tamper with the results. The Flight 427 samples passed, although several of them were unusually dirty.

  Technicians at Boeing tried a test using a typical rudder valve and hydraulic fluid so gummed up with particulates that it looked like Dijon mustard. The contamination was much worse than anything the investigators had found on the plane, but they wanted to see how much the valve could endure before it malfunctioned. The fluid was so thick that it kept destroying Boeing’s hydraulic pumps. But in test after test, for thirty hours, the equivalent of stomping on the rudder pedal five thousand times, the valve worked fine.

  The bird theory was still alive, mostly because Boeing was so insistent about it. Members of the structures group were back at the Pittsburgh hangar, where the windows had been covered with black paper. They shut off the lights, donned strange-looking orange sunglasses, and shone a black light along the wreckage. The sunglasses were supposed to make it easier to see the faint glow from bird remains. It was a bizarre scene: people wearing weird sunglasses walking slowly around the wreckage, waving a black light the size of a baseball bat.

  On the number three leading edge slat, they saw a faint glow. They brought the light closer. It wasn’t bright, but it was definitely stronger than the surrounding area. They switched on the hangar lights and examined the spot carefully. It was a small clump of material that looked like dirt or mud. It wasn’t bird proof by any means, but it was worth testing.

  It was time to call Roxie Laybourne, the world’s premier expert on feathers.

  Laybourne, who was eighty-four years old, was a legend among crash investigators. She was a tiny woman with short gray hair and thick eyeglasses who worked at the Smithsonian Institution’s National Museum of Natural History. She wore a white lab coat and Reeboks, and she walked hunched over because of back and neck problems. She had begun studying feathers in 1960 after a Lockheed Electra collided with a flock of starlings in Boston, killing sixty people. Suddenly the government cared a lot about birds.

  Identifying them was an odd but necessary task in aviation. Engine and airplane manufacturers needed to know how well their products could take a direct hit from a laughing gull, a Cuban whistling duck, or—their biggest fear—a Canada goose. Once they got Laybourne’s reports, they knew how much damage different birds could cause, which enabled them to improve their products to better withstand a bird strike.

  Examining feathers under her microscope, Laybourne had discovered unique patterns in the stringy fragments of feathers called downy barbules. Some barbules had little triangles, others had rings. She found similarities between birds from the same family, even those that lived thousands of miles apart. Pigeons and doves were easiest to identify because the nodes on their barbules looked like crocuses. The hardest were songbirds because their nodes all looked alike.

  With tiny feather fragments—some no bigger than bread crumbs—Laybourne solved thousands of bird strike cas
es. In one, she used a fragment of down from a pilot’s shoulder patch to identify the herring gull that broke through the canopy of a Harrier military jet. She also used her skills to help Customs identify birds smuggled into the United States, and she once helped the FBI catch a murder suspect.

  Laybourne’s office at the museum was a reflection of her unusual occupation. Her bookshelf included Birds of Nepal and Raptors. On her door were a poster from the Israeli Air Force warning pilots to watch out for birds and a Far Side cartoon that showed Santa Claus and his reindeer splattered on the nose of a jumbo jet. She was philosophical about the conflict in the skies. “As long as you have man and birds flying,” she said, “you have the potential for problems.”

  Cindy Keegan, the head of the airplane structures group for the Flight 427 investigation, brought the suspicious clump to the museum. But when Laybourne saw the tiny brown sample, she doubted she could be much help. It was smaller than a dime, a mixture of sand and dirt but nothing that even remotely looked like a feather. She eyeballed it for a moment and then examined it under the magnifying glass she wore around her neck. Nothing. She pulled off the cover on the microscope, put a sample on a slide, and took a closer look. Still nothing.

  The next day, two other bird strike experts happened to stop by her office. One, Major Ron Merritt, headed the Air Force’s famous BASH Team. The other, Eugene LeBoeuf, was the FAA’s chief bird scientist. After examining the sample, they agreed that it was only dirt and vegetation.

  Laybourne phoned the NTSB. “There’s no bird material here,” she said.

  11. BACKDRIVE

  The data recorder on Flight 427 was like an eyewitness to the crash with one eye closed. It took only thirteen measurements of the flight, which provided an incomplete picture of what happened. It saw the plane yaw to the left and then roll out of the sky, but it didn’t see why. That meant the NTSB and Boeing had to make educated guesses about what had happened. Investigators were pretty sure the sudden yaw was caused by the rudder. No other flight control on a 737 could cause that kind of movement. But they did not know whether the rudder moved because the pilots stomped on the pedals or because something went wrong in the hydraulic system.