 jlbishop wrote: |
What is unusual about the materials used to construct the vertical stabilizer of a 747? John |
|
Which version? The 747-400 had a complete redesign of the tail which utilized a lot of composite materials.
The story goes that they were trying to save some weight on the airplane and told a new hire engineer to figure out a way to save a little weight in the tail section. He redesigned the whote section using composite materials and saved so much weight they had to rebalance the entire airplane. They also installed a fuel tank in the vertical stabilizer, possibly the horizontal too. I don't remember.
Someone told me this story when I worked at Boeing. I started there at the end of the 747-400 program, so I missed any more direct stories about it.
I do personally know about two interesting avionics bugs that were found during flight test. If the pilot programmed the auto pilot to descend from say 30,000 to 20,000 feet, instead of a gentle descent, the plane would go into a power dive. The first time it happened, the plane pulled 5 gs on the pull out. At least one of the flight test engineers lost his lunch and when they landed at Moses Lake, Washington, the guy wanted to walk home (over 100 miles).
Another bug came up with SAS started their over the pole route. They were going to hand out certificates to people when they flew directly over the north pole. The navigation computer couldn't handle passing through 0,0 so the plane did an 'S' around the pole. I was supporting the test engineers on tracking down that one. They got to spend all day flying over the north pole in a 747, back and forth.
Then there was the unfortunate timing when Boeing announced the 737 Convertible the same week of the Aloha Airlines 737 that lost a section off the top of its fuselage in flight. By convertible, they meant able to be converted from passenger to cargo easily.
Bill