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  • Harrier Matches JSF Range - Official
    Posted by Bill Sweetman 1:39 PM on Mar 06, 2009

    Commenter Solomon Shorter's assertion that the F-35B Joint Strike Fighter has more than twice the payload and range of the Harrier started me thinking. Popular sites and standard fact sheets say one thing, my 1996 Jane's something else.

    How about the US Navy's official aircraft characteristics manual? Fortunately, someone decided that the Harrier was so old, that had to be historic, so they put it on the web.

    OK, this is not an entirely fair comparison. The JSF is stealthy and supersonic and has an integrated sensor suite, and this is the original AV-8B, which had a piece of chewing gum stuck to the windshield as a bombsight.

    But on the other side of things, the JSF is a brand-new airplane supported by tens of billions of dollars in investment. Today's Harrier is, essentially, an upgraded version of the original Hawker P.1127, which was ordered five years after the RAF retired its last front-line Spitfires. The P.1127 was a purely experimental aircraft (at the time, the RAF had no requirement for it) and Bristol had cobbled the engine together from Olympus and Orpheus parts.

    Most of the Harrier's evolution took place in two programs, both of which were cheap substitutes for more ambitious projects that had been canceled. The original RAF Harrier GR.1 incorporated bits and pieces of the avionics developed for the supersonic HS.1154, scrapped in 1964. Around 1975, British Aerospace and McDonnell Douglas proposed a much improved aircraft with a bigger engine - but both the UK government and the US Navy choked on the price tag and the result was the re-winged AV-8B. The Pegasus engine has likewise been upgraded piecemeal-fashion along the way.

    blog post photo

    But the bottom line is this: with 2,500 pounds of weapons, plus the gun pod, the AV-8B has a hi-lo-hi operational radius of 508 nm. The F-35B's design radius, with no gun, two 1,000-pound bombs and two AMRAAMs, is 450 nm:  the most recent numbers (from 2007) show it exceeding that and just about equalling the AV-8B's range.

    Of course that comparison does not allow the F-35B the use of external fuel, which would add 70 nm or so to the radius if F-35A figures supplied to Norway are correct. But that gives away one of the JSF's two key advantages over its veteran predecessor.

    In part this shows the price of stealth (which tends to increase empty weight) and supersonic speed (subsonic aircraft, like the Buccaneer, A-4, A-6 and A-7, have always tended to out-range the competition).

    But from an operational point of view, it's important:  the premise behind a STOVL-equipped carrier is that it can operate on its own, without air support from another carrier or from land (and the latter includes tankers).

    So the offensive and defensive reach of the air wing is determined by two factors: how far the fleet needs to stand off from land, which determined by the threat from missiles or submarines, and the combat radius of its aircraft. And without tankers, there needs to be a solid margin between combat radius and mission distance, because there's nowhere to divert. You don't want two un-anticipated minutes of burner use to cost you a ditched aircraft.

    And all of this is not to say that JSF is not projected to meet its requirements:  but you do wonder why they were written that way in the first place.

    Tags: ar99, jsf, harrier

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