Date: 10 Dec 97 04:05:02 From: firstname.lastname@example.org (James Matthew Weber) Organization: Customer of Access One Pty Ltd, Melbourne, Australia References: 1 2 3 4 Followups: 1
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On 09 Dec 97 03:54:26 , "Damon Marcus Lewis" <email@example.com> wrote: >James Matthew Weber wrote in message ... >>It was more than just the sonic boom. The aircraft was is >>exceptionally noisey. I have friends who used to live in Twyford UK, >>just outside Reading. They were directly under the path of Concorde >>for the trip to JFK, and about 35 miles from the end of the runway. >>Everyafternoon about 4PM the whole house rattled. > >Were the rules for take-off different in the United States? I live under the >former flight path the Concordes took upon approach to Dulles, and I can't >recall them being any louder than another plane. I rarely saw them on >takeoff, so I can't really compare. But, my question is did the Concorde >follow different rules until it was off the coast to keep them quieter? The short answer is yes. On takeoff in the USA, the afterburners are shut off about 30 seconds into flight, and remain off until the aircraft begins the runup to Mach 1, which occurs only after the aricraft is out to sea. Dulles is a good way from the Atlantic Ocean, so once burners are off, the aircraft flies about 20 minutes before beginning the runup to Mach 1. Out of JFK, it usually takes a lot less time to get clear of the mainland. I believe out of Heathrow, they leave the burners on, and begin the runup to Mach 1 as soon as they are clear of traffic, even it is is over the UK. I believe ATC in the UK is pretty good about getting them clear of the airport traffic in a hurry. I'd also point out the aircraft is a lot quieter on approach than on takeoff. On approach, the aircraft is much lighter, and the burners will always be off.