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Orion 21 Top Speed?

SCAT15F From United States of America, joined Feb 2007, 402 posts, RR: 0
Posted (3 months 1 week 4 days 10 hours ago) and read 1867 times:

Wondering if anyone has any info on the top speed of the Lockheed Martin Orion 21 which lost to the P-8. It was essentially the same airframe as the P-3 but with 7150 hp PW150's.

The P-3 set a speed record back around 1970 of 501 mph with 4509 hp Allison T-56's. It's listed top speed was 473 mph. The Orion 21 does have a heavier MTOW, but has the same frontal area, 10,600 additional hp and much more efficient 8 bladed props.

I am guessing that the top speed for Orion 21 had to be at least 520 mph; maybe as high as 540. The same speed range as the P-8, but with far better acceleration and loiter capability.

LM never released performance data other than payload to the public that I am aware of. Anyone have an inside scoop?

2 replies: All unread, jump to last

KC135TopBoom From United States of America, joined Jan 2005, 11712 posts, RR: 52
Reply 1, posted (3 months 1 week 3 days 17 hours ago) and read 1624 times:

I don't believe LM ever released the spec on the Orion 21, but it was going to be an updated P-7A, which could do about 350 KIAS, had it been selected.

SCAT15F From United States of America, joined Feb 2007, 402 posts, RR: 0
Reply 2, posted (3 months 1 week 3 days 10 hours ago) and read 1530 times:

Quoting KC135TopBoom (Reply 1):
it was going to be an updated P-7A

Interesting. As I recall the P-7A used the T407 turboprop of 6000 hp which has now become the GE 38.

I believe the MTOW of the P-7A at 171,000 lbs is the same as Orion 21