rmm
Posts: 518
Joined: Sun Feb 04, 2001 10:34 am

Diff P&W's On Classic 747

Sun Oct 21, 2001 11:40 am

Does anyone know why Boeing/Pratt changed the engine cowling
on some early 747's then changed it back to the old style on the
747-300?

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Photo © David Morrell



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Photo © Philippe noret



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Photo © Brian Wilkes



Thanks
Rmm
 
charliecossie
Posts: 408
Joined: Wed Oct 10, 2001 5:17 am

RE: Diff P&W's On Classic 747

Sun Oct 21, 2001 1:11 pm

What makes you think the Madagascar a/c has JT9's?
 
rmm
Posts: 518
Joined: Sun Feb 04, 2001 10:34 am

RE: Diff P&W's On Classic 747

Sun Oct 21, 2001 1:34 pm

A few things,

a) P&W logo on #2 engine.
b) The only other similiar looking engine for that model was the CF6-50.
It doesn't have the pointed tail cone like the -50. Have a look at some
KLM 742's and you'll see what I mean.
c) Commercial Jet Aircraft Census - http://www.bird.ch/bharms/asr_sh00.htm
lists the original build config of this particular Air Madagascar A/C with
JT9-70A

Rmm
 
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yyz717
Posts: 15689
Joined: Mon Sep 10, 2001 12:26 pm

RE: Diff P&W's On Classic 747

Sun Oct 21, 2001 3:57 pm

PW offered the JT9D-70A engine from the mid-70's...with the GE-like nacelle.....as pictured on the Air Madagascar aircraft above. It was only ordered by Air Mad, SAS, Seaboard World. The new nacelle design was found to be heavy & not efficient, so updated PW engines for the 742 such as the 7Q engine reverted to the original nacelle design/shape.

Neil/Toronto

I dumped at the gybe mark in strong winds when I looked up at a Porter Q400 on finals. Can't stop spotting.
 
charliecossie
Posts: 408
Joined: Wed Oct 10, 2001 5:17 am

RE: Diff P&W's On Classic 747

Sun Oct 21, 2001 4:18 pm

Apologies.
Now that I've actually looked at the picture I can see
that it's the -70.
 
timz
Posts: 6081
Joined: Fri Sep 17, 1999 7:43 am

RE: Diff P&W's On Classic 747

Mon Oct 22, 2001 5:34 am

I read somewhere that P&W was trying for commonality with the DC-10 (and the A300, they hoped). Think it said the JT9D-70 (or 7O?) was about the same as the -7Q aside from the nacelle.
 
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yyz717
Posts: 15689
Joined: Mon Sep 10, 2001 12:26 pm

RE: Diff P&W's On Classic 747

Mon Oct 22, 2001 5:39 am

Ya, what you say rings a bell Timz.

I do recall reading that the rather bulbous size of the -70 engine added drag & weight.
I dumped at the gybe mark in strong winds when I looked up at a Porter Q400 on finals. Can't stop spotting.

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