Re: Air Canada DC-9s questions

From:         101334.1352@compuserve.com (Glenn Bridgland)
Organization: CompuServe Incorporated
Date:         11 Oct 96 19:44:49 
References:   1
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Jean-Francois Mezei <jfmezei@videotron.ca> wrote:

>On a recent DC-9 flight on Air Canada (LGA-YUL), I noticed the year
>"1967" on a plaque on the left side of the entry door frame. (My first
>flight in a DC-9 in years)

>I would be interested in knowing when the DC-9s were first introduced,
>and when they were at their apex of sales, and when did sales of new
>DC-9s stop ? Was the DC-9 immediatly replaced by the MD80 or was there a
>few years in between ?

>Are there still a lot or DC9s that were built prior to 1970 in service
>in North America, or was the one I flew a true/rare "vintage" one ?

I can't tell you the dates of production, but as recently as 1989 I
was flying DC9-30 series of this vintage.  Well-maintained, they were
still in good shape.  There are a lot of them still around.

>Also, I noticed a hole in the leading edge of the tail, just above the
>fuselage. Is this an air intake for the apu ?

It's the intake for the cooling air going to the airconditioning heat
exchangers.  The APU air intake is a set of doors under the aft
fuselage.

>Also, the rubber gasket on the front door seemed quite different from
>other more modern planes. Is this the actual air tight barrier when door
>is closed, of does this very visible rubber gasket serve a protective or
>other function ?

Being of the "plug" type, the door itself does most of the sealing by
fitting the frame very tightly, with only a small additional rubber
seal needed.  The larger rubber gasket you saw is mainly protective,
as you suggested.

>Finally, through an opening between the wall and overhead bins, I
>noticed a copper pipe (looked like copper) running along the wall with
>some hookups for every row. The pipe was about 1cm in diameter. Had it
>not been for the Valuejet crash where those oxygen generators were
>described, I would have thought that this pipe would have been the
>oxygen supply. I seems too small for the air supply for the over head
>air nozzles. What would this pipe be used for ? Is it possible that on
>some models of DC9s, the oxygen was centrally supplied through such a
>pipe as opposed to having individual generators over every row ?

You may indeed  have been looking at the oxygen supply line, as the
passenger oxygen is stored in a cylinder on the flight deck; at least
it was on ours.  Chemical generators were introduced (I think) with
the MD80.