TR
Topic Author
Posts: 939
Joined: Thu May 03, 2001 1:28 am

The P&W JT9D-70 - Special Engine?

Thu Aug 30, 2001 11:04 pm

Can anyone bring me info on the P&W JT9D-70 engine seen her on this 747?

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Click here for full size photo!

Photo © Andries Cafmeyer


It is very visible that the engine looks much more like the GE CF6-50E2 engines also offered for classic 747s than the "standard" JT9D engine seen here:

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Click here for full size photo!

Photo © Craig Murray


What is the story of the JT9D-70? was it a special engine option that simply turned out to be unsaleable? I know that SAS and Air Madagascar also had 747s with the JT9D-70 engine!

Thanks for any info
Thomas
 
cfalk
Posts: 10221
Joined: Mon Dec 04, 2000 6:38 pm

RE: The P&W JT9D-70 - Special Engine?

Fri Aug 31, 2001 12:12 am

The first engine available for the 747 when it was introduced was the JT9D-7, and was the only engine available until 1973 or 74. The JT9D-7 came in a long list of varieties:

JT9D-7A
JT9D-7AH
JT9D-7W
JT9D-7J
JT9D-7F
JT9D-7R4G2
JT9D-7Q
JT9D-7FW
JT9D-70
JT9D-70A

to name a few. As to their differences, I expect only God and P&W can know.

Cheers,

Charles
The only thing you should feel when shooting a terrorist: Recoil.
 
timz
Posts: 6101
Joined: Fri Sep 17, 1999 7:43 am

RE: The P&W JT9D-70 - Special Engine?

Fri Aug 31, 2001 1:19 am

As I recall the JT9D-70 (or maybe -7O) was the "same" as the -59 on the DC-10-40, and commonality with the DC-10 (and A300, P&W hoped) was the reason for the different nacelle. Seems to me the -7Q was the "same" engine, modified to use the usual P&W nacelle.

Wasn't the 747 originally powered by the -3 or -3A?
 
cfalk
Posts: 10221
Joined: Mon Dec 04, 2000 6:38 pm

RE: The P&W JT9D-70 - Special Engine?

Fri Aug 31, 2001 1:25 am

According to Bill Harms, The prototype and the first 17 planes that followed all had the JT9D-7A. After that they started going into different variations.

Charles
The only thing you should feel when shooting a terrorist: Recoil.
 
timz
Posts: 6101
Joined: Fri Sep 17, 1999 7:43 am

RE: The P&W JT9D-70 - Special Engine?

Fri Aug 31, 2001 1:28 am

Wouldn't Bill Harms just be telling us what they have now (or had when retired)?
 
Guest

RE: The P&W JT9D-70 - Special Engine?

Fri Aug 31, 2001 1:30 am

The -70A was specifically designed as a 'hot and high' performer, and was replaced by the -7J.

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