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Old 17th Sep 2012, 10:37
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ORAC
Ecce Homo! Loquitur...
 
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Shenyang J-31

AWST (Ares): China's New Stealth Fighter. Not a repeat from December 2010


The US defense secretary is on his way to Beijing. Time to unveil a new stealth fighter...

Short take-off and vertical landing has been one of the two driving requirements behind the Joint Strike Fighter design, the other being stealth.

STOVL dictated the single engine, and the STOVL solution chosen for the F-35 demands a big vertical bay behind the cockpit, and a main engine located unusually far forward, to keep the driveshaft length within reason and to put the lift-cruise nozzle in the right longitudinal location for balance. This constrains the weapon-bay volume and shape, and effectively subdivides the bays into four zones - two AAM bays and two heavy store sections. As Amy Butler reports in Aviation Week this week, too, the weapon bays, wrapped around the engine, get hot and noisy.

If you ever wondered what a JSF might look without those constraints, we now have a live, physical example. Unfortunately......



.....it's Chinese.

One of the photos of the new Shenyang stealth fighter, apparently designated J-31, that appeared on Chinese defense websites over the weekend is such a colossal gimme that it has to have been deliberate. Direct head-on shot? Check. Commercially available aircraft tug? Check. Extreme telephoto, so that perspective effects are lost in the noise? Check.



Sheesh, guys, can't you make it a challenge?

The J-31's wingspan is an F-35-like 37.5 feet, unless my Soviet-watching skills have deserted me. This makes it smaller than the F-22 and considerably smaller than the Chengdu J-20. A good early guess is that the engines are Klimov RD-93s - imported in large numbers for the JF-17 - with a Chinese-built engine to follow. Turning to the side view of the jet, it looks as if the engines are installed to the rear of the bulkhead that carries the main landing gears. And with no lift fan bay to worry about, the designers have been able to install long weapon bays on the centerline: what will be interesting is how the inlet ducts are routed to optimize internal space.

Overall, the most important point is that the J-31 does not look like a competitor for the J-20 - but as a complement to it. Which, again, might point to the new fighter being a JSF to the J-20's F-22. And if you wonder about the detail similarities of the shape to the F-22 and F-35, remember this quote from 2010:

In the past year (2009) alone, Lockheed Martin found “six to eight companies” among its subcontractors “had been totally compromised – emails, their networks, everything” according to Lockheed Martin chief information security officer Anne Mullins.
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