Thursday, September 18, 2008

JSF in the news again

There was a brief flurry of JSF-related newspaper coverage in the Australian mainstream media a few days ago - I missed some of it as I was travelling, but the gist of it was that the RAND Corporation held some sort of computer-based exercise in Hawaii which put the F-35 Joint Strike Fighter up against members of the Su-27 family, and it got comprehensively whacked.

More recently, Jane's Defence Weekly ran an opinion piece by Pierre Sprey and Winslow Wheeler charging that the JSF is overweight and underpowered, isn't manoeuverable and lacks payload. Jane's published a response in the same edition by Lockheed Martin's JSF program chief Tom Burbage and General Chuck Davis, the Program Executive Officer for the JSF at the pentagon. 

The exchange was fairly heated and, to me, highlighted a couple of things: first of all, many critics of the JSF don't understand that it shouldn't be assessed the way you'd assess a legacy fighter: it is a very different type of aircraft designed in a different way, to be built in a different way and to fight in a different way. Secondly, the solution many of its critics put forward to the problems with the JSF amount to a combination of the F-22A Raptor - which is extremely expensive - and some sort of legacy aircraft: the F-15, F/A-18 Super Hornet, even (God help us!) the F-111.

The debate over the JSF and its value relative to the F-22A and some of the legacy jets mentioned above has been impassioned, to put it politely. As a specialist defence writer I've been fortunate enough to receive comprehensive unclassified briefings about the JSF itself and the wider program: manufacturing, industry participation and the autonomic logistics system.  

While it's possible to argue that the Australian government could have been more assertive in pursuing Australia's interests in this program, especially in terms of industry participation, the JSF program seems to this journalist to make sense. It actually answers many of the criticisms of fighter programs which have gone before. 

That said, I'm very aware there are huge areas of the program which are heavily classified. Analysts, reporters and commentators (such as myself) simply don't know how much they don't know about the capabilities of the aircraft and how it might be flown in combat.  I do know that if you try to compare only what's known about an aircraft such as the JSF or F-22A with what's widely known about aircraft such as the MiG-29 and Su-27/30/35 family, you're not really making a valid comparison. I don't pretend to know more than that.

It is not my job to mount a case defending the JSF. To do that (or to damn it) comprehensively I'd need access to classified platform, weapon and sensor performance and operational tactics which I know I'm simply not going to see. The only people who do see it are a small cadre of officials and planners in each of the participating nations. It is possible to infer something about the aircraft from their behaviour.

Their ongoing support for the aircraft, especially those whom I know to have been suspicious or downright dismissive until they received classified briefings on the project, suggests a high level of capability that doesn't derive solely from the weight/thrust/payload/range/wing loading of the aircraft. As for the cost of the JSF, thanks to the Royal Norwegian Air Force we're getting a decent handle on what the jet will actually cost to buy and operate through its service life: US$5.75 billion over about 25-30 years for 48 aircraft; that includes a US$2.27 billion through-life support package; not including the US$668.2 million initial support cost, that works out at US$58.7 million per aircraft.

That's a 2008 dollar price; by 2013 or 2014 when Norway starts taking delivery the figure will have climbed somewhat. But it sets an accurate benchmark against which to measure other contenders.

As for platform performance compared with recent legacy platforms such as the F-16 (and it must be remembered that Sprey and Wheeler were charter members of the so-called 'Light Fighter Mafia' which coalesced around the legendary John Boyd during the 1970s and resulted in the creation of the F-16), I'd offer the following thoughts. 

Years ago, a Rolls-Royce test pilot went to Edwards Air Force Base with a Harrier 'jump jet' to carry out some tests on the aircraft's Rolls-Royce Pegasus engine. As is customary, every test flight was accompanied by a chase aircraft - in this case an F-4 Phantom. The pilot reported gleefully that the supersonic Phantom had to use afterburner to keep up with the lighter, more nimble Harrier; it ran out of fuel fairly quickly. On subsequent flights the Phantom had to carry external fuel tanks - and couldn't keep up because of the extra drag.

More recently, an RAF Jaguar pilot complained that he'd been ordered to carry drop tanks when ferrying his aircraft from Lossiemouth in the north of Scotland to Decimomanu in Sardinia (measure it on a map - it's a hell of distance!). Without drop tanks, in 'clean' configuration the Jaguar had just about enough fuel to fly the distance non-stop, though without a safety margin on arrival. With the extra drag created by external drop tanks, he barely had the endurance to reach the middle of France!

The point of these anecdotes is this: most combat aircraft today, except for the JSF and the F-22, carry their stores and additional fuel externally. It's unusual to see TV footage today of an F-16, F-15 or Hornet/Super Hornet that isn't carrying at least two external fuel tanks and half a dozen external weapons. The JSF carries all of its fuel internally - and carries more than the F-22, indeed more even than an F/A-18 with external tanks. The difference this makes is huge. To illustrate this, on a recent test flight, the F-35A took off for the first time with its maximum internal combat load of two 2,000lb JDAMs and two AMRAAMs. Naturally, these were carried internally; the chase aircraft was an F-16 carrying two external fuel tanks, but no other external stores. 

JSF test pilot Jon Beesley describes the sortie thus: 

QUOTE I had the opportunity yesterday to fly the F-35 for the first time with the INTERDICTION COMBAT load of  two GBU 31 (2,000lb JDAMs) and 2 AIM -120 missiles. In current fighters there is an expectation of performance degradation when carrying 5000lb of ordnance but the internal carriage made any degradation hard to discern.


The acceleration in MAX AB (afterburner) takeoff was very quick and interestingly there is an increase in the acceleration rate above 120 KCAS. The takeoff roll was very near to the 3500’ prediction. Once airborne I came out of AB relatively soon after lift off and continued to climb and accelerate in MIL power in a 10 deg to 15 deg climb attitude. There was plenty of performance. The climb out with full internal weapons carriage was particularly impressive to me. The climb rate seemed to be only slightly hindered by the stores carriage with climb angles near 15 deg in MIL power while in a 30 deg bank turn back over the field. Very pleasant to see clean fighter climb rates and angles while carrying a combat load. The chase aircraft still required brief inputs into AB to keep up with me. This is especially impressive because the 325 KCAS climb speed is well below the optimum climb speed profile for the aircraft.

We only did a brief handling qualities test point on this mission but the handling qualities with this combat loading were indistinguishable from the aircraft with no stores.
Landing occurred with 4500lb of fuel and was easily stopped inside of an 8000 ft. runway length with brake temperatures cool enough to taxi straight back to the hangar. END QUOTE

Do you see the point? An F-16 carrying only two external tanks and no external weapons had to use afterburner to keep up with a JSF which was using military power (ie no afterburner) while carrying a full war load of weapons internally. Think what that means for fuel consumption, for combat acceleration, for energy management in air combat manoeuvres, for sortie endurance and for range. 

The point I'm trying to make here is that it's a huge mistake to make comparisons on the basis of imperfect knowledge - and Sprey and Wheeler should know enough about fighter design and performance to appreciate the difference internal fuel and stores carriage can make.

I'm not saying I know better than these two gentlemen or anybody else engaged in the debate, but I try to listen critically to what I'm told, and base my conclusions on facts (as they're available to me) and rational analysis. 

 





1 comment:

  1. Just found your blog Gregor, and I very much appreciated your take on this. Sounds very sensible, and I'm glad there's a few in the defence media community of this country who are still able to make the case for trusting, just a little, those who are charged with making this important selection. Sadly, we hear very little like this in the broader media.

    Still at ADM, I take it?

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