(Tribune News Service) — A jet plane is a complex piece of machinery built on redundancies; if one system fails, another takes its place.
That holds true in many facets of aircraft design — except, apparently, when it comes to the cockpit door.
“People inside the cockpit can lock the door in such a way that the people on the outside can’t get in,” said Steven J. Meyers, a Chicago-based aviation accident expert.
Investigators of this week’s Germanwings crash in the French Alps that killed 150 people think a rogue co-pilot locked out his more experienced colleague, leaving the frustrated pilot pounding on the cockpit door as the plane was steered straight into a mountain.
“What can he do?” said Pete Gall, a retired airline pilot who teaches aerospace engineering at West Virginia University. “The only thing he can do is knock on the door, which he apparently tried to do. Then he can go to the number pad, type in the code and wait 30 seconds.
The problem is the pilot in the cockpit can override that.
“The pilot in the cockpit can close and lock the door so no one — no one — can get in.”
Aviation safety experts Thursday described U.S. efforts following the Sept. 11, 2001, terrorist attacks to make the cockpit an impregnable safe haven from hijackers.
But those measures — bulletproof doors, keypad locks, the presence of air marshals, protocols for how the crew can block access to the cockpit — could have deadly side effects if the lockout theory in the French crash holds true.
“With any safety mitigation … there are unintended consequences,” said Thomas Anthony, director of the University of Southern California’s aviation and security program.
Federal Aviation Administration spokeswoman Laura J. Brown declined to address questions about the lack of an override system for pilots outside the cockpit, saying, “We don’t generally discuss security issues like this.”
The FAA requires that there be two qualified crew members in the cockpit at all times; when a pilot leaves, a relief pilot or flight attendant enters.
Lufthansa, the parent company of budget carrier Germanwings, and other international carriers do not have the same requirement, The Washington Post reported.
Gall, who has flown a variety of commercial planes, including an Airbus A320 such as the one that went down in the Alps, said all have door mechanisms that function the same way. A switch in the cockpit controls the lock; a numeric keypad outside can open the door, but it cannot override the pilot’s command.
“This system is designed so that if a hijacker wanted to get into the cockpit and take over the airplane, there is no way that they could do it. With mechanical systems, like a hydraulic system, you can have a primary and a backup and secondary backup. But when it comes to something like this, how do you have a backup system?” Gall said.
“Right now, if the pilot wants to lock you out, they’re going to lock you out and you’re not going to get in, and nothing is going to get you through that door unless you have a battering ram. Other than that, you’re stuck.
“Now with this happening, there may be changes.”
Meyers, president and chief technical officer of DVI Aviation, independent accident investigators, predicts the Germanwings crash will trigger a review of cockpit safety and flight-deck protocols.
“In aviation, regulations are written in blood,” Meyers said. “Another term you often hear is ‘tombstone engineering,’ which means once an accident takes place and a new scenario that people haven’t thought about happens, everyone goes back to the drawing board to find preventive measures. I would expect that to be the case here as well.”
Already, some European carriers are changing procedures. The BBC reported that Canadian, German, Norwegian and British airlines have pledged to require two crew members to always be in the cockpit.
Even so, should pilots have a way to override the cockpit door’s locking mechanism?
Gall notes that any terrorist who discovers an override procedure leaves the cockpit vulnerable.
“There’s no completely foolproof system that’s out there,” Meyers said.
©2015 Pittsburgh Post-Gazette. Distributed by Tribune Content Agency, LLC.
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