[meteorite-list] Wales: why no sonic boom

From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Thu Apr 22 10:28:23 2004
Message-ID: <AF564D2B9D91D411B9FE00508BF1C86901B4EDE8_at_US-Torrance.mail.saic.com>

Hi Jim and list,

Just a quick reply to one of the questions Jim posed in
his post:

> ... I'm curious why there was no supersonic boom mentioned
> by the observers.Was the plane too high??

For environmental reasons, the Concorde doesn't go supersonic
until it is out over open ocean. I'm not sure if St. George's
Channel between Ireland and the UK qualifies or not -- perhaps
the Concorde deliberately skirts Ireland to the south so that
it can go supersonic earlier. (Interestingly enough, the Porthcawl
wide field-of-view image points to a trajectory with an azimuth
a bit south of due west -- enough to avoid an overflight of
Ireland.) In any case, it was certainly subsonic when it flew
over southern Wales, so no sonic boom would have been heard
there.

As for the plane's altitude, perhaps one of our list members
who has more flying experience can answer how quickly commercial
jets reach cruising altitude (recognizing, of course, that the
Concorde is hardly an ordinary commercial jet). Cruising altitude
for the Concorde is ~60,000 feet (over 18 km), so it seems to me
it will take some time (more than 30 minutes?) to get there.

Cheers,
Rob
Received on Wed 08 Oct 2003 02:39:44 PM PDT