Hollywood has conditioned many Americans to believe that even at extreme altitudes, one bullet hole through the skin of a commercial airplane is enough to cause a massive pressurized explosion with enough force to suck passengers and debris into the cold air outside.
But as the debate continues over whether to allow commercial airline pilots, crew and perhaps even passengers carry firearms during flights, aeronautical engineers and other aircraft experts are working hard to educate the public about the realities of cabin pressure, bullets and aircraft vulnerabilities.
In short, they say, don’t believe everything you see on TV.
As Dave Kopel, research director of the Independence Institute, said in a National Review column just days following the Sept. 11 attacks, Hollywood usually fails to “teach real-life lessons about physics.”
“There is only one known instance in which a bullet hole in an aircraft frame yanked objects across the plane, expanded and sucked a person out into the sky. That was the James Bond movie ‘Goldfinger,’” he said.
In a follow-up story, Kopel said, “The risk of a stray bullet creating a decompression that could cause a crash, which I’d reported to be virtually nil, is apparently even less than that.”
Quoting retired Air Force Gen. James Chambers, Kopel points out that the Air Force has plenty of pressurized planes, such as AWACS, which are able to sustain penetration or damage from bullets from enemy fighter-jet machine guns.
“The general said that the worst case would simply require a plane flying at an altitude of about 30,000 feet to hurry down to lower altitudes. If the plane were above 30,000 feet, there would probably be enough breathable air for the pilots to maintain consciousness, even without the air masks,” which fall from overhead compartments in the event of a sudden decompression in the cabin, Kopel said.
Aircraft engineers agree the risk of catastrophe caused by a bullet hole at altitude is low.
“First of all, there already is a ‘hole’ in the aircraft, for regulating the cabin pressure,” says 20-year aircraft engineer Dan Todd. “It’s called the outflow valve. It modulates to maintain desired cabin pressure in response to signals from a cabin pressure controller, which responds to inputs from a selector panel in the cockpit – all automatic when it’s all working normally.”
He added that there is always pressurized leaking past door seals and a few other compartments.
“Remember, the airplane is pressurized by a constant flow of compressed air into the cabin from the engines – via the pneumatic systems and the air conditioning systems,” he said. “If one round, or two or three for that matter pierce the skin, it’s not necessarily catastrophic; air will go whistling out the hole, and the outflow valve will close a little further to maintain the desired cabin pressure.”
Historians also point out what B-17 pilots and aircrews during World War II knew all too well – that even at altitude and full of bullet and flak holes, those planes were legendary for staying aloft.
Besides the realities of pressurized commercial air carriers and the physics involved, firearm technology also can play a part in reducing unintended consequences of firing a shot in-flight.
Armed air marshals, since the 1970s, carried Glaser Safety Slug ammunition, which is a high-velocity handgun ammunition containing birdshot or “dust shot.” It fragments when fired and has extremely low penetrability.
Debate over whether to allow pilots to carry guns comes as the Federal Aviation Administration closed its public comment period on the issue.
As WorldNetDaily reported, the agency, which opened its comment period Dec. 31, has sought the public’s input about how to craft regulations that would permit pilots and other commercial airline crew members to carry firearms and less-than-lethal weapons as a way to beef up in-flight security.
The commentary period ended yesterday.