also, design of particular aircraft
[link|http://the.honoluluadvertiser.com/2001/Jan/18/118localnews1.html|http://the.honolulua...18localnews1.html]
Boeing says the 737 was designed to decompress safely with as much as a 40-inch crack in the plane\ufffds skin, the 0.036-inch thick, aluminum outer layer of the fuselage. Instead of an explosive decompression, the hole in the skin is supposed to release internal pressure in a controlled way. In the Aloha accident, investigators concluded that more damage occurred \ufffd about 18 feet of the fuselage tore away \ufffd because many fatigue-caused cracks had gone undetected.
Austin says that a weakened fuselage was not the main reason for the extensive damage.
A 10-inch-by-10-inch hole opened, he says, in the roof of the cabin at a location known as body station 500. (Body stations are points on the fuselage that are measured in inches from near the nose of the jet to the rear.) A powerful stream of air swept an Aloha flight attendant off her feet and toward the hole, Austin says. Her head and right arm went through the hole, he says, but her body momentarily plugged it, blocking the escaping air and creating a jolt of pressure that ripped the jet apart. The flight attendant was swept out, and her body was never found.
"Slamming the door on a 700 mph jet stream creates a localized, short-duration high-pressure spike, up to several orders of magnitude (greater than) the allowable design pressure," Austin says. "This is a fluid hammer."
thanx,
bill
Any opinions expressed by me are mine alone, posted from my home computer, on my own time as a free american and do not reflect the opinions of any person or company that I have had professional relations with in the past 50 years. meep
