The debate about why the rudder moved was fueled by the fact that 737 pilots rarely used it in flight. Pilots of smaller planes had to use the rudder during turns, but the aerodynamics of the 737 were different, and there was no need to use the rudder during a turn. Pilots used it primarily for landings in strong crosswinds and in the rare case of engine failure.
To help sort out what had happened to Flight 427’s rudder, the NTSB and Boeing decided to try a technique known as a backdrive. Engineers took the numbers from the flight data recorder and fed them into the computer that ran Boeing’s M-Cab flight simulator. The M in “M-Cab” stood for “multipurpose,” which meant the simulator was a chameleon. It could be programmed to perform like any Boeing jet. M-Cab was usually used for dull engineering tests, but this time it would be used to re-create the crash and see how 132 people had died.
It was a ghost flight. The plane would roll and twist the same way it had on September 8, as if the pilots were still at the controls. The instruments would spin the same way they had in Ship 513, and the control column would move back and forth as if Emmett were still pulling on it, trying to prevent the crash.
In a cavernous room three stories high, M-Cab stood like a long-legged elephant with a Boeing logo on the side. Its legs resembled huge shock absorbers, allowing the cab to rock back and forth so pilots believed they were flying. It was built to fool the pilots, using gravity, motion, sound, and computer displays to give a realistic sensation of flight. There was a sense of danger when M-Cab was about to start, as if the big beast might go crazy, fall off its legs, and crash to the ground. That was especially true with the Flight 427 work because in order to simulate the deadly plunge of the plane, Boeing had to push back the mechanical safety stops that limited how far M-Cab could go.
The brains of the beast were in a computer room next door, where technicians controlled the cab. Computers the size of refrigerators were lined up at one end of the room. At the other end, technicians and engineers could watch the white cab and talk to the pilots through an intercom. Pilots referred to the Flight 427 simulation as “rock and roll.” They often began the rides by saying, “Let ’er rip.”
Haueter walked across the ramp to the white cab and climbed into the mock cockpit. He was curious to find out what the ride would show. He had studied charts about what had happened to Flight 427 dozens of times, but it would be much better to feel what the pilots had encountered instead of looking at lines on a piece of paper.
He knew the pilots had made a crucial mistake. They pulled back on the control column at a critical time, and that made the plane stall. Had they just pushed the stick forward and let the plane lose some altitude, they probably could have prevented the crash. Also, the pilots had not acted quickly enough to turn the wheel completely to the right, which might have countered the effects of a rudder hardover, regardless of whether it was caused by man or machine.
Haueter was not shy about blaming pilots. He had gone toe to toe with ALPA on the 1988 crash of Delta Flight 1141 in Dallas—Fort Worth, and he’d been amazed at how ridiculous the union had been, claiming there was some kind of malfunction of the plane that caused it to crash a few seconds after takeoff. But Haueter and the other investigators were convinced that the pilots had simply forgotten to set the flaps, the panels on the wings that gave the plane extra lift so it could get off the runway. Haueter had also blamed pilots for a crash in Hawaii—the guy flew right into a cliff—and one in Alabama in which the pilots got hopelessly lost. Yet he was still skeptical about whether Emmett or Germano would have stomped on the pedal and held it there. Good pilots—especially ones with thousands of hours like Emmett and Germano—just didn’t do that.
Haueter took the right seat, where Emmett had sat. He reached below to a lever and adjusted the seat until his feet could reach the rudder pedals. He was about to see how 132 people had died, but he would not get choked up about it. He coped with the gruesome side of his job by building a big emotional wall. The facts got in, but the horror stayed out. Still, he expected it would be a bumpy ride and figured he would get a good jolt from the G-forces.
The cockpit looked the same way it had to Emmett and Germano. The altimeter read 6,360 feet. The airspeed indicator read 190 knots. Looking through the cockpit window, Haueter could see blue and green squares that were supposed to represent Hopewell Township and the surrounding area. Jim Kerrigan, a Boeing engineer riding with Haueter, told the M-Cab technicians that they were ready. Flight 427 began again.
M-Cab descended from 6,300 feet and banked slightly to the left. Haueter heard the steady click-click-click of the rudder trim. It felt like a routine turn. Boeing did not have a copy of the cockpit tape, but Haueter had heard it so many times he knew what the pilots would say at each moment. Oh, yeah, I see zuh Jetstream. Sheeez. Thump. Whoa. The cab jerked to the left and then back again, rattling the metal seats and panels and tossing Haueter left and right. Hang on, hang on. Another jerk to the left and then the whoop-whoop-whoop of the autopilot warning horn. Haueter had been watching the computer image of a blue sky and hazy horizon out the cockpit window, but suddenly all he could see was the green and blue squares of the ground, looming closer. Hang on. Ohhh, shiiiiit. What the hell is this!!? He had his hands lightly on the control column and felt it come back, as if the phantom pilots were trying to pull the nose up to avoid certain death. He felt the stickshaker go off like a jackhammer, warning that the plane was stalling. He was almost face down now, watching the ground spin closer and closer. Oh shit! Pull! The jackhammer continued rat-a-tat-tat-rat-a-tat all the way down, until the ground filled the windscreen God! Pulllllllll! and the cab jerked to a stop. Noooo.
As violent as the end was, Haueter was surprised that the initial yaw and roll were so smooth. He had expected to get bounced around more severely before he was rolled to the left. But the whole thing happened seamlessly and fast. They were making a routine turn like they had thousands of times, and twenty-eight seconds later they were dead.
Haueter flew it again. He let the machine jerk him back and forth as he looked for some sort of cue that would have triggered Emmett or Germano to stomp on the rudder pedal. A 737 pilot might use the rudder in a crisis, to quickly counteract a roll. But in that case a pilot most likely would step quickly on the pedal and let it out—not hold it down all the way to his death. As the phantom pilot again pulled the stick back, Haueter searched for a reason they might have held the rudder.
He couldn’t think of one.
He flew it ten more times. The more he flew, the more unlikely it seemed to him that Emmett or Germano had stomped on the rudder pedal. There were a few bumps from the wake, but nothing that would make them press the rudder all the way. Instead, it felt like an aerobatic move called a spin entry. A stunt pilot deliberately held the rudder in and pulled back on the stick so the plane would flip out of the sky and corkscrew toward the ground.
Haueter unsnapped his seat belt and climbed out of the chair. As he walked out of the simulator, he was even more convinced. Nothing had happened to Flight 427 that would have made a seasoned pilot stomp on the pedal.
Within days of the crash, families of the victims of Flight 427 were inundated with mailings from lawyers.