From: Ray ®	09/11/2001 17:21:14
Subject: re: AVIATION FAQ	post id: 490483
I read that at the time jets started to break the sound barrier, there was massive carnage as plane after plane would disintegrate once they achieved the necessary speed to break this barrier. 1. What I want to know is why they would disintegrate like that? 2. What did they change in the jets to make them capable of breaking sound without the destruction? From: Dan B. ® It was the materials they were made from that caused so many problems. The 'stick and toilet paper' planes had no chance of getting within a bulls roar of the sound barrier. Later development still had planes made if timber and aluminium but this was still no structurally strong enough to hold the forces at 330 m/s. Due to the lack of rigidity, often the control surface located on the outboard section of the wings would cause the whole wing to flex, rather than changing the flow. This would create a problem for pilots who knew not of what was happening and they hit the ground at a very rapid rate. To overcome these shortfalls, the new (60's) planes were fitted with short wings that couldn't flex, and had much sturdier bodies. This allowed a plane to be 'piggy backed' in to the air and dropped though the sound barrier. Current technology allows much, much stronger and stiffer alloys to be used that are very stable at all flight conditions. Fast jets also have many control surfaces and the outboard ones 'lock out' in high-speed flight. Modern fighter planes have a computer to handle all the flight control surface changes and are 100% 'fly-by-wire'. With out the computer - they will crash and burn too. Note that an F/A-18 can fly quite reasonably with one vertical fin and about half a wing missing on one side. The computer can make so many adjustments every second that the pilot will only notice the difference in high flight loads.