matt weber wrote:

On Mon, 30 Jun 2003 22:19:42 GMT, Guy Alcala
wrote:

JB wrote:

They've been orphans in QF operations for a very long time. Whilst I'm sure
there is a cost, I doubt that it's enough to really be a problem. There is
already plenty of expertise in place with regard to maintenance of these
engines.

I suspect it depends on exactly how the deal is structured. Are they going PFI,
is it going to be fully RAAF, some hybrid? On the orphan issue, does Qantas
want to get rid of them because they're too small, because they _are_ orphans
and not cost-effective, or some other reason? The other issue might be how
widely available parts will be for the JT9 for 20 years or so; after all, the
last new JT9D was produced in 1990. The JT9D seems likely to disappear from
service long before the other engines.

There are no pilot training/currency issues. If that's all the RAAF have,
then they won't have a currency or training problem. In practice, I operate
all three types of engine, and there aren't any practical issues, other than
remembering (or not) a few different limits. Procedurally more or less
identical.

Good to know. What's the thrust on the JT9s, compared to the other engines?
Payload capability operating from Learmonth and Tindal is likely to be a factor.

Guy
JT9D's covered a wide range, but I believe the 767-200's have 7R's,
which in this application are 50,000 pounds thrust each. Runway
requirement/lift capability is rarely much of an issue with the -200.

It appears that the Qantas 767-200ERs probably have a MTOW of 350,000 lb., judging by
a Boeing 767-200/200ER runway length takeoff chart* which shows a/c with the
JT9D-7R4D/7R4E or CF6-80A/A2 engines for that weight, and I agree that at that MTOW
takeoff distances should rarely be a problem, even in hot conditions.

*Found on the web some time back.

You can get several variants of the CF6-80 for the 767-200ER, as well
as PW4000's. For thrust pick a number from 50,000 to about 57,000
pounds.

Takeoff Runway length Charts for 200ERs with MTOWs of 380,000 (CF6-80C2-B2 or PW
4052) and 387,000 lb. (CF6-80C2-B4 or PW4056) on hot days (ISA +17C) show that runway
length is definitely becoming a factor. So, if they stick with lower gross weight
200ERs, no problem, but if they want to maximise payload and fuel offload in hot/high
conditions, the lower gross weight JT9D-powered a/c aren't going to cut it. While
the JT9D 767s shouldn't be anywhere near as limited in TOW as the USAF KC-135Es were
when based in the Gulf (or the really pitiful KC-135As), that still could be a
significant operational limitation. It will be interesting to see what the RAAF
decides to do (or rather, what the Government's willing to pay for), given that used
767 airframes seem to be relatively cheap and available these days. Guess it depends
what the market for freighter conversions is as well.

Guy