Remembering Flight 427: Hopewell disaster 'changed aviation history'
A Boeing 737 takes off or lands somewhere every two seconds. The best-selling jetliner in history is a workhorse, used for about one of every three commercial flights worldwide.
But a crash two decades ago in Western Pennsylvania confounded investigators for years and made the narrow-body jet the most feared airplane in the world for a time.
“The 737 is a much safer plane today because of Flight 427, and the crash started a movement that changed the way survivors of crash victims are treated,” said Tom Haueter, a former director of aviation safety at the National Transportation Safety Board who led the Flight 427 crash investigation. “It changed aviation history.”
NTSB investigators identified a glitch with the 737's rudder control system after a 4 1⁄2-year probe into the Sept. 8, 1994, crash of USAir Flight 427. Just after 7 p.m. that day, the flight from Chicago inexplicably plunged about 6,000 feet in 21 seconds on approach to Pittsburgh and crashed into a wooded hillside in Hopewell, Beaver County, at 300 mph. All 132 aboard died, more than 80 of whom were from Pennsylvania.
Ultimately, a problem with the 737's rudder was to blame. Investigators determined the hulking plane's rudder servo valve — about the size of a soda can — reversed and jammed.
“There were a lot of passengers who wouldn't get on a 737, and investigators were greatly concerned that another crash would occur before we figured out the problem,” Haueter said.
The lengthy crash investigation came to include the 1991 fatal crash of United Airlines Flight 585 near Colorado Springs and a near-disaster involving Eastwind Airlines Flight 517 approaching Richmond.
Boeing spent about $1 billion redesigning the rudder system and retrofitting about 4,000 jets. It and USAir paid millions more to family members of crash victims.
The crash
The deadly plunge of Flight 427 six miles from Pittsburgh International Airport scarred many who witnessed it, from shoppers at the busy Green Garden Plaza off what is now Interstate 376 to children playing at a nearby soccer complex.
“I noticed the plane because it was abnormally low, so low that you could distinguish things on it that you'd normally never see, even though we were so close to the airport,” said Jason Moka, now 30, who was playing at the soccer complex.
“It went belly-up and then nose-dived behind the tree line. I remember hearing a loud sound and the ground shaking, and then a huge mushroom cloud came up,” said Moka, a sales manager at a BMW dealership who lives in Mars. “I didn't understand the full scope of what happened back then. I was 10. Being older now, it affects me differently. I think about all the families that were devastated.”
Beaver County Sheriff George David, then an Aliquippa police officer, was working on his 67-acre farmstead in Hopewell when he heard a plane scream past, then an explosion. The plane went down near the edge of his property. Debris filled his hay fields.
“I came up right away, and what I witnessed was not a good thing. It was stuff that no one should see, and it impacts me to this day,” said David, who routinely directs visitors to the crash site that has a memorial stone in a clearing. He expects he will direct visitors there for years to come.
The only people he turns away: “I've had some ghost seekers come up the lane. I tell them we don't want none of that here.”
The fix
Haueter said solving the mystery of the crash was tough.
“We never found a broken piece that we could hold up and say, ‘Here's the problem.' ”
There were other complicating factors.
Boeing, a partner in the investigation, argued the plane was not to blame and had an impressive safety record, Haueter said.
Aviation technology was far less advanced. Today's jets can record up to 500 parameters, or sets of data, that chronicle aspects of a flight's performance almost moment-by-moment. Flight 427 investigators had about two dozen parameters to work with, including basics such as altitude, flight speed and the position of flight controls.
“We didn't have rudder position (monitored). If we had that back then, we probably would have solved the investigation in a year or a year and a half,” Haueter said.
Instead, it took a near-crash in Virginia in 1996 to help crack the case. It bore similarities to the fatal crashes of Flights 427 and 585. In the latter cases, a wind disturbance prompted pilots to press a rudder pedal one direction, but the rudder inexplicably flapped the opposite way.
Heavy wind off the Rocky Mountains rocked Flight 585; wake turbulence from a larger jet a few miles ahead jolted Flight 427.
“Suddenly, all the pieces fit. This problem was so new and so different that the pilots didn't have time to figure it out in time. We investigated it for years. The pilots had seconds,” Haueter said.
Boeing agreed in 2000 to change flight crew and maintenance procedures and the rudder control design, said Miles Kotay, a Boeing safety spokesman. The company provided so-called rudder retrofit kits to airlines with 737s, sending out the last ones in March 2010, Kotay said.
“The rudder-system enhancement made an airplane with an excellent safety record even safer by making that system reliably redundant,” Kotay wrote in an email.
Tom Fontaine is a staff writer for Trib Total Media. He can be reached at 412-320-7847 or tfontaine@tribweb.com.
