Monday, July 22, 2013

The F-35 Issue: 'Food' for Thought?

No. Thin Intellectual Gruel

Someone in Italy named 'Gherardo Albano' has an internet ‘editorial’ up that was linked to by AV Week (for some unfathomable reason). The title: “The F-35 Issue: Food for Thought”.

But the intellectual gruel he offers is so thin, that if it were real food, an anorexic supermodel wouldn’t bother to throw it back up. It is so bad, I decided to Fisk it here for posterity.  The editorial is in italics. My comments are in purple.

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UPDATE #1 29 July 13: For 'some' reason, you may have trouble getting to the site in the above link to original post under examination. I'm getting feedback from a couple of people that the link is "broken", yet the link when entered into the browser works fine-- It is almost as if the traffic to the link is being blocked when accessed from this site (who knows?). If the link doesn't work for you, type:" http://www.lindipendente.eu/wp/en/2013/07/13/f-35/ " without the "" marks in your browser.
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We begin....

These days there’s a big discussion on whether Italy should buy 90 Lockheed Martin F-35 Lightning IIs. The aim of this article is to analyze the overall picture within which such an important decision should be taken. In particular, there are two separate fields of analysis, one purely military and another related to economic issues. Let’s analyze them separately.

Sounds acceptable for the purposes of sharing information…so far. I note here, however that we must remember that ‘Economic’ Power is an equal to Military Power as two of a Nation’s Elements of Power. They support each other and the Nation itself.

Military matters
From a strategic point of view, at the moment, it is not foreseeable that a crisis may result in a conventional war. ...

Whoa! Stop. Right. There.
 
Rarely does an author open an argument with a logical fallacy, in this case a “Non Sequitur”. Usually, employers of this tactic try to lull an audience into a stupor before they try to slip one of these by their readers. Note: There’s a dash of “Begging the question” here as well, where something is first expressed as a presumed truth, and then later used to fallaciously support a claim or conclusion.
 
Casual readers, especially those of a like-mind with an author, might still miss his use of this logical fallacy because it is executed en passant; carefully avoiding the unwritten non sequitur (“it does not follow”). The ‘does not follow’ part isn’t expressed, but is presumed as unspoken fact to support the arguments that will soon follow.
I wonder if the author has legal training because this has the flavor of an ‘opening argument’, otherwise I have to doubt the author was even aware of his transgression. This does not bode well for the rest of the opinion piece, for it hints that the author is a ‘true believer’ of some sort. The only question is: a ‘true believer’ in “what?”. My main concern at this point now is how much will Albano’s remaining argumentation will rest on ‘beliefs’ instead of ‘facts’?
The ‘does not follow’ part? The fact that “it is not foreseeable that a crisis may result in a conventional war” does not preclude an ‘unforseen’ conventional war. It does not follow that because one cannot envision a conflict, a conflict will not arise. In fact, History tends to tell us that the wars we ‘see coming’ are often the wars we are able to sidestep…into the wars we don’t see coming and that usually bite us in the end. I think my first question to the author at this point would be “How many years before Operation Allied Force or even the recent military intervention in Libya, did you ‘foresee’ either/both of the conflicts coming?” The second would be “Why didn’t you do something to prevent them?”

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UPDATE #2 31 July 13: I initially was going to refernce this link to punch up the point that we tend to not see (cognitive sense) 'coming', the wars we end up fighting: 25th Annual Military History Seminar- the Keaney Session , but thought it might be a little overkill. I've revised my thoughts on the subject, in part as a response to reading the first part of "Unknown's" comment in the thread for this post.
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   …Of course this does not mean that we can dismantle the entire military. Defense continues to be necessary to every nation, in the present geopolitical framework, including peaceful countries such as Switzerland and Sweden, and certainly cannot be dismantled if it cannot be restored quickly in case of emergency.

Ahh! Pabulum designed to allay fears concerning the author’s reasonableness: An observation that only the most rabid anarchist or peacenik might find objectionable. Are we being ‘lulled’?

As far as we are concerned, the Italian Air Force now has a line of flight divided between air defense, consisting of about 72 Eurofighter Typhoon, and attack, consisting of 36 AMX International AMX and 48 Panavia Tornado PA-200. Then there are of course all the other non-combat operational units like tactical transport, refuelers, rescue, VIP transport, training, and so on. The Italian Navy has about 15 McDonnell Douglas AV-8B Harrier II Plus aircraft characterized by the ability of short take-off — the vertical take-off is militarily marginal — and short or vertical landing. This capability is an essential but expensive element of protection of the fleet which makes it different from most of the other navies in the world.

The audience is thus presented with a description of how the author, using a ‘Royal We’ editorial style, views and mentally organizes the Italian Navy and Air Force. I have no problem with the explanation, except perhaps the last sentence. It makes an assertion that may or may not be true as to the uniqueness of the Italian STOVL capability and relevance to the fleet.
But the assertion is completely unsupported, and I imagine there are several arguments that might be made against it (one comes immediately to mind). I note here that I wouldn’t disagree with the author on this point. The last sentence expresses a presumption the readers are expected to simply accept as ‘fact’.
We will see later that this sets up a ‘STOVL capability of the F-35B will be essential because I say it is essential’ argument: the author presents more build up to his “begging the question” fallacy.  

The combat aircraft lineup is now a dim memory of what it was in the eighties, when during the Cold War there were more than 200 aircraft for air defense and 350 for the attack role. They have already been reduced due to the organic decrease of the external threat. What remains can be considered a core of resources, human, material and methodological facilities to maintain the expertise, knowledge, methodologies and a minimum of military capability in case the need arises.

I have no major problem with this part except the view of ‘military capability’ as expressed is rather sophomoric. The confused taxonomy listing ‘military capability’, which is a combination of knowledge (expertise), methodologies (along with missing ‘hardware’ and ‘doctrine’), in the list itself may be a translation error. I believe a far better ‘book’ definition of military capability can be found in the definition of the Military Element of a nation’s power.

It is clear therefore that cutting or reducing it further would mean loosing [sic] a capability that needs between 5 to 10 years to build up again if a serious threat becomes visible. Italy would rebuild their forces almost from scratch hoping to have the time to do it. New combat-ready rookie pilots would need about 5 years. Ordering, receiving and organizing for new aircraft, performing maintenance, recruiting technicians, would again require between 5 and 10 years. In the case of the Navy, rebuilding would take much longer if we were to lose the aircraft carriers.

No. And though I’m tempted to go into excruciating detail why ALL of the author’s imagined timelines to reconstitute a force are pure hokum, I will resist the urge and merely point out the timelines appear to focus only on a time to train up the end-use operator/maintainer. Even if you get a cadre of “new combat-ready rookie” pilots in 5 years (a highly suspect assumption as-- unlike the children of Lake Wobegone-- not all fighter pilots are ‘above average’), how long will it take to train up enough force leaders that have the experience and knowledge/skills and doctrinal support to lead them?
I’ll call this “B.S.” but am willing to retract same if anyone can show me a contemporary peacetime military organization that has developed, fielded and employed an advanced military capability after replacing an existing capability much less creating a new capability in under 10 years…. ”successfully”. The 5-10 year time span offered clearly provides nothing for the organizational, doctrinal and infrastructure development required to actually field and execute military power by a modern homogenous society, much less a Western democracy as fractured politically as Italy (or the U.S.A. for that matter).

The above considerations lead me to say that maintaining a capacity in the defense sector by replacing aircraft that reach the end of service life with more modern and competitive aircraft (relative to hostile forces) is a crucial need. The alternative would be a great risk for our country given the current geo-political instability worldwide.

Other than the “above considerations” shouldn’t lead anyone anywhere, this may seem reasonable…on the surface.
We will soon see how the author defines “more modern and competitive aircraft”. Guess what he leaves out or diminishes? Any bets they involve aspects of combat aircraft design that F-35 was built upon?

The attack aircraft in question will still need to be replaced over the next 6-12 years for reasons of obsolescence and useful life. The older a plane becomes, like a car, the more maintenance costs until the situation becomes untenable.

This is what is known as the “setup”. I always look for this part on a point of argument. It is where your debate opposition states something he doesn’t expect an argument over then delivers a contrarian ‘but’, as in “Yes. Blah blah blah, but XXXXXXXXXXXXXXX.” Some of the best advice I ever received was from an Air Force Lt Col (Engineer) during TASVAL79 who told me: “Always remember Mac, everything before the ‘But’ is Bullsh*t.  The setup indicates we are about to be spoon-fed the Bullsh*t.
Also note the author lists “obsolescence” and “useful life” yet only just touches on one aspect of the impacts at the end of “useful life”.

The current situation is the following:
• The AMX are technologically obsolete and should be replaced soon;

I’ll buy that, but for reasons I already know. WHY does the author think they (or the other aircraft for that matter) are “technologically obsolete”? It seems the author is twisting himself into contortions avoiding the details concerning what makes a fighter aircraft “obsolete”.

• Tornadoes are being updated and this standard can last another five-ten years or even more;

Even if it were true, 5-10 years is ‘tomorrow’ even if you have a replacement in hand. I note (again) the author is using a form of “begging the question”: we are expected to accept his claim is ‘true’ because he states it as a ‘truth’.

• AV-8B Navy aircraft have 20 years of operating life and do not need to be replaced now, but in the medium term, unless unexpected problems of maintenance arise.

Assuming the Italian AV-8’s haven’t been flown into the ground and won’t be in the future, I’ll buy 20 years on the airframe durability. But an airplane is far more than just the airframe, and the author somehow fails to mention the relative obsolescence of the AV-8 design itself.
 I’ll not pursue the hole in the author’s argument for now, except to first ask: “What makes this author ignore the fact that like all pre-5th Generation aircraft, obsolescence will probably overcome the aircraft before they are ever close to being worn out?”
Oh, and about the authors last turn of the phrase using the weasel words “unless unexpected problems of maintenance arise”: In my 40+ years of aerospace experience “unexpected problems of maintenance” have never failed to “arise”. Why assume otherwise? 

Let’s see now what could be the alternative having already narrowed down to the most plausible hypothesis:

Has anyone seen any ‘narrowing down’ yet? I didn’t either.

1. replace the strike aircraft with the F-35 variants A and B, taking into account that B is the only possible replacement for the Navy’s AV-8B as there are no other STOVL aircraft types;
2. replace the AV-8B with F-35B and all others with more Typhoon, Tranche 3, which have advanced attack capabilities.

What happened to #3? After all, it is only the freakin' ‘current plan’:
3. replace the AV-8B with F-35B and the AMX/Tornados with the F-35A. If the author sees fit to ignore the current plan, why then shouldn’t we also consider an expansion on that plan to come up with a ‘#4’?:
4. retire some/all Typhoons in recognition of the inherent Air-to-Air capability that F-35As bring to the Air-to-Air fight.

This suggests that for the Navy it is important to buy the F-35B while the Air Force has in fact two possible choices. Let us see the features of the two possible candidates.

Well, since the author saw fit to selectively attenuate his list of options ahead of time, of course he would reach this conclusion.

The development program for the F-35 is not proceeding well. …

“Not proceeding well”. One may argue the point using the “as compared to what?” other modern (last 50 years) and similarly advanced technical development efforts or even to simply other large, highly complex, government programs-- as the F-35 program fall into both categories. I would therefore challenge Mr. Albano to name one program in either category that did/has not experienced as many or more challenges than the F-35 program. I also challenge him to name any of them that did a better job of dealing with them than the F-35 program has to-date. This is the kind of simplistic thought that makes my Aerospace Engineer blood boil. But on the plus side, it provides me yet another opportunity to quote a favorite: J. R. Pierce.
Novices in mathematics, science, or engineering are forever demanding infallible, universal, mechanical methods for solving problems.
(I never tire of referencing Dr. Pierce)

… Let’s say that there were basic errors: starting production of the plane when the development was still in progress and the desire to develop three versions — Standard A, B vertical take-off, C for aircraft carriers with catapult — from a single basic design coming to affect all versions with the requirements of the most difficult vertical take-off version. This has led to a significant increase in costs and the forced relaxation of specifications to be met, without which the project would had [sic] been unfeasible. …

“Let’s say?”—This is yet another ‘Begging the Question’ logical fallacy, only this one is a ‘twofer’: two popular, yet unsubstantiated/perverted criticisms in one. They are: 1) ‘Concurrency’ and 2) ‘STOVL Requirements adversely affected CTOL and CV designs’.
1. Concurrency. ‘Some’ claim concurrent development increases cost and schedule. This assertion on the F-35 has become a rather popular ‘political’ truth, but it is still not an actual truth. ‘Concurrency’ when studied by those with expertise to do so has consistently been shown to benefit advanced programs, and IMHO I’ve adequately covered this topic many times on many web domains, but have dealt with it most completely in 2011 in my Congressional Bloviation on Concurrency post, so I will not go into detail again here. But I will note that the post stands up well, especially in light of the Undersecretary of Defense for Acquisition, Technology and Logistics testifying before Congress just a month ago that “Concurrency costs are coming down faster than program estimates, and production costs are coming down as well.”
2. STOVL Requirements adversely affected CTOL and CV designs. This is perhaps one of the most tiresome canards propagated by the anti-JSF crowd. ALL aircraft design involves tradeoffs. In the case of the F-35, the dominant tradeoffs were made between the requirements to perform air-to-air and air-to-ground missions. In all the assertions that the F-35’s design was ‘compromised’ somehow because of the STOVL requirement, I have not once read once ‘how’ the design was allegedly ‘compromised’.
The author can’t name one any more than any other before him. The most dominant ‘F-35B unique’ requirement in the total design effort was ‘low weight’ in support of the STOVL operation. If anything that requirement drove better F-35 CTOL/CV designs as well. There are perhaps some dimensioning restrictions in the design for ship-borne operations, but even with those the most a critic could claim is that they ‘might’ have driven a different (not necessarily better) design than the F-35A model would have been as a standalone design.
NOTE: from this point forward, Albano’s opinion piece really starts rambling all over the place so I will be inserting comments in brackets as often as possible. If his thoughts were better organized, I would have been finished yesterday. If I don’t use brackets […], I would have to chop up his sentences as well as his paragraphs, making it even tougher for the reader to follow.

… In any case we are talking about a highly advanced aircraft not only for the use of new stealth technology — which basically means opposing radar has difficulty in detection — but also for new production technologies and the integration of a lot of electronics called sensor fusion — to put it simply, allowing better awareness of the situation around the aircraft.

Mr. Albano obviously has no idea how important Low Observables and F-35-grade Sensor Fusion are to the modern air combat equation judging by how this entire piece is written. The “difficulty in detection” is a “damning with faint praise” fallacy. Low Observability disrupts the entire kill chain at every step, from attempts to detect to terminal weapon end game, and forces an opponent to have to begin the process all over again when the chain is broken. 

The program currently sees continuation of testing, and the manufacture of aircraft is not yet at the minimum standard for combat. [So? Is this a recognition of an already recognized ‘risk’?] In short, the aircraft to the current date is not satisfactory [It is still in LRIP, Duh!], but over time it will be excellent in the attack role. It will remain however, in my opinion, insufficient in the role of air defense, since it hasn’t a powerful enough radar. [“However” is another form of “But”--See earlier note on that topic. As to “not powerful enough”, Mr. Albano has no idea know how “powerful” it is. I also seriously doubt he has any idea how the whole of F-35 ‘Sensor Fusion’ is greater than the sum of its parts, including the AESA.]

In addition, currently the F-35 can only carry two anti-aircraft missiles when in stealth mode and this severely limits the ability to deal with numerous enemy formations [Patently false. Current plans call for maximum of 4 internal A2A missiles, with provisions for more. The capability supports very favorable projected exchange loss ratios, so Albano’s “opinion” which based on who-knows-what misinformation is of no consequence]. Kinematic capabilities also contribute to a poor verdict on its air to air performances. [More opinion based upon….what? There isn’t enough information in the public domain for outsiders to pass judgment on the subject, only conjecture.]
Cost for purchase and maintenance remains to be firmly determined, which will be discussed later.
Count the internally-carried Air-to-Air missiles in the baseline plan...

Yes, it is all just ‘estimates’ now. Just like the future costs of any aircraft, even ones that are now flying, So?.

The alternative to the F-35A is the Typhoon, a European project which is already mature owing to further development with the so-called Tranche 3 (T3) that Italy should acquire, funds permitting, to complete the line of air defense. [Italy isn’t buying the F-35 to replace the Typhoon in the Air Superiority mission, so what is Albano’s point?] The T3 develops the plane incorporating a new type of AESA radar and new types of weapons for air-to-air and air-to-ground combat, increasing significantly the military value and configuring it as a true multi-role aircraft. The Typhoon does not have stealth technology, but has top rated kinematic capabilities — speed, acceleration, turning — and self-defense exceeding the F-35. [No. See earlier comment about kinematics and exchange rates] For comparison a Typhoon has at least six missile, has wider antenna coverage and can go higher and faster.

'Wider’ antenna coverage? Does he mean scan angle? Is he talking about the current or future EFA radar? In any case this can be countered by the F-35 changing operational techniques, so “So What?”. The Typhoon is far more observable at every range and angle with far less situational awareness than an F-35. It can go higher and faster than an F-35… sometimes. Such as when it’s not carrying any significant go-to-war payload.
The plane on the left can carry two 2K lb precision weapons and 2 Air-to-Air Missiles to 50K ft+ and fly 1000+ nm and dash at M1.6 in this configuration. The plane on the right with the same load? Not so much.  


A comparison of the F-35 and Typhoon T3 must be set to a period of the useful life of about 30 years which brings me to the following considerations:

1. the F-35 is more technologically advanced and this is reflected in a number of benefits including that in the next 10-15 years, a further development potential is possible to adapt the plane to new threats;

Ah. Cherry-picking a timeframe. How about for the next 30-40 years? The Typhoon conceptual design is already 30 years old, based on even older requirements and designed for a different (pre-stealth) age. It will be lucky if it is viable in any scenario in 15 years.

2. the stealth technology is the F-35′s primary means of protection from interception, but there are many plans to reduce the effectiveness of this technology and high maintenance costs of stealth protection is a sustainability issue;

I’ve lost count of the assumptions, myths and half truths presented in Albano’s piece as ‘fact’ that we’re expected to accept. These are two more.
First: Low Observability. LO is a combination of technology, techniques and tactics. It is no more ‘static’ than the efforts to defeat it, and it is always developed and applied with an eye towards of continuous improvement. This is yet another case where someone with no actual background assumes the LO an aircraft starts with, is the LO it ends with. We do pre-planned product improvements on all aircraft systems, and operational techniques always evolve over time, What makes anyone think LO is any different? Albano needs to start someplace on this topic, so he can start here, and I’ve already provided the link to Grant’s Radar Game.
Second: LO High Cost of maintenance. Mr. Albano has obviously missed all the discussions on how the F-35 had LO supportability designed-in based upon experiences of the past. If he were a serious student of maintainability and supportability, he would have observed that in all the reports that have criticized the F-35 to-date, there have been none -- zero, zilch, nada -- that have criticized the F-35 Sortie Generation Rates. You don’t get the SGR you are looking for if you have excessive maintenance burdens of any type.

3. Italy overall has few aircraft and multi-role capability, although not a main requirement, will definitely have value. In this respect, the Typhoon is great for air defense while the F-35 is marginal;

Need I point out that Albano is again ‘begging the question’? And over a point tangential to the reasons the Italians are buying F-35s in the first place? I’d like to also pose the question as to “How great are you at air defense?”, if low observable opponents will most likely ‘see’ you before ‘you’ see them?

4. in the attack role the F-35 is invaluable in the event of a confrontation with technologically advanced opponents in the early days of the war when air defenses are fully functional; when the fight shifts to trucking bombs, the two aircraft are substantially equal.

‘Substantially equal’? This is ‘begging the question’ again. Does the Typhoon have anything like the F-35’s ability to distinguish friend from foe on a fluid battlefield? Does the Typhoon have anything that provides a pilot with a clear view of the target in the day, night, in any direction and in all weather conditions? More importantly, can the Typhoon do so with a reasonable expectation of not being successfully engaged by Surface-to-Air threat? As proven in Operation Allied Force, where the Serbians elected to shepherd their air defense resources, you can never be certain to have eliminated the Surface to Air threat, you can only have varying degrees of confidence you have been able to attrit/mitigate it. Flying a non-LO aircraft over hostile territory is an invitation to eventually get shot down. How “equal’ a bomb-truck can a Typhoon be if attrition is factored in? Answer: not very equal at all.
 
A single flight line on the Typhoon would have major economic benefits  for training, spare parts and so forth  while the same proposition cannot be said for the F-35 since it is not an interceptor. 
 
We now see Albano, having praised the secondary strike capability of a Typhoon, making no examination of the F-35’s capabilities in the Air-to-Air mission. While no doubt the F-35 would have to perform the mission differently than a Typhoon (the Typhoon’s great top speed in a relatively clean configuration is a direct product of the ‘Interceptor’ mission requirement),it has not been shown that the F-35 could not perform the mission. If viewed as a ‘fleet’ vs. ‘individual fighter capability’ could an argument be made that an “all F-35” fleet in greater, same, or fewer total numbers than a combined F-35/Typhoon fleet could perform both A-A and A-G roles? Has Albano reduced this effort to a EFA Typhoon advocacy paper?

In the future, industries are developing unmanned combat aircraft vehicle (UCAV) stealth such as the X-47B. These are designed, much like the F-35, to carry out attacks in extremely dangerous air defences. Therefore, the specific strength of the F-35 could in the future be better carried out by a European UCAV.

The X-47B just now completed the technology demonstration step in the combat UAV evolution. Whatever the follow-on program produces if it even materializes, it will still be only the first step on a long journey that will take several generations of developments, and still, it may never make the manned combat aircraft 'obsolete'. File this under ‘wishful thinking’.

Regarding the choice of the Air Force to ask for 60 F-35As and 15 F-35Bs, I consider that, assuming we stick to the F-35, the best solution would be to buy all F-35As because: the B version costs 30% more than the A; is, performance wise, inferior to the A version; but most importantly because the operational motivation is rather weak. In fact, the F-35Bs were required by the Air Force to be used in support of expeditionary situations where adequate runways are not available. If this is the need, then it would be more effective to use F-35As for the Navy, considering an increased purchase to 20. To save money, in case of F-35 purchase, a unified management of today’s separate lines of flight of the two armed forces, including training, should be enforced.

This part is so disjointed I hardly know where to begin. First the F-35B is essential for the Navy because it can operate off the Cavour. Now the Navy should buy land based versions? The author’s ‘logic’ holds only if the Navy never goes farther asea than where the land-based F-35As can support it. While throwing around a ‘30% higher cost’ number is Albano aware that the STOVL sortie generation rate specification is about 33% higher than the F-35A or F-35C? What ‘costs’ are he using to compare F-35A and F-35B unit costs? Is he aware the program is managed to minimize total life cycle costs instead of initial procurement unit costs? Is he aware that in a 25-30 year weapon system lifetime, typically 2/3rds of total costs are in sustainment?

Economic and industrial matters
The Typhoon is a plane in which the domestic industry’s original share — design and production — was 21%, but in the case of additional, future purchases may be negotiated higher. [Very nice. Good luck with that. How many future EFA sales are expected? A large percentage of “very little” is ‘not much’. ] Also with the manufacturer of the Typhoon consortium, in case of additional purchases, or beyond the commitments entered into with the consortium, you could negotiate a package of financial compensation even exceeding 100%, just like the big world buyers (India, Brazil, Korea, etc.). In addition, the extension of the production of the Typhoon could lead to further sales abroad, with additional financial benefits for Italy.

In light of the procurement history and dearth of potential customers, that sounds like an awful lot of wishful-thinking to me. The Eurofighter program cost and schedule history make the F-35 look like a model acquisition program. 

In contrast, the Italian share of the F-35 project is 4% for Development and is not assessable for the production, as the supply tenders are still in progress. Italy has invested over the years about 1 million U.S. dollars in the development of the F-35 and so did Finmeccanica partnering with the MoD for the “FACO” in Cameri. We must consider that, while the percentage is lower, it is on a much larger number of planes and a hypothetical 4% of 2,000 aircraft is comparable with a 100% of 75 aircraft. Technologically, Italian companies are fully conversant with Typhoon production technologies while those of the F-35 are partially unknown. The original contribution to the development of the F-35 was finalized contingent on the acquisition of new technologies for Italian companies, but the U.S. has severely limited these knowledge transfers.[It should be noted here that is precisely the kind of criticism the F-16 Multinational program dealt with in the early days. We must observe that the technological benefits received by the partner nations brought most of them back for more with the F-35. This smacks of frustration borne on wings of unreasonable expectations.] In addition, if Italy will purchase F-35s, any national enhancement, update or integration cannot be performed without U.S. approval and involvement, so the F-35 should be considered a “limited sovereignty airplane”.

Not true. But a commonly repeated oversimplification often committed by people who ‘think’ they understand how the F-35 software design works. The author is apparently unfamiliar with MILS or EALS-7 . Users will be able to ‘nationalize’ their own aircraft if new systems are required and add weapons (the aerospace equivalent of adding an ‘App’) if they wish. But the idea behind the common core software design is to ensure commonality and in turn reduced software maintenance cost over the life of the program. Canada, Australia, and the UK are planning to jointly develop a ‘reprogramming laboratory’ of their own (page 77). There is nothing stopping Italy from doing the same on their own or in concert with another partner nation. 

Both the UK and Israel have strongly opposed the American policy in this regard, but for now, only Israel has managed to get limited access to electronic systems in order to make partial integrations nationally. To better understand the implications, if tomorrow the Italian Air Force requires the integration of a weapon or an external tank, it would have to ask the U.S. to perform it, paying and waiting for their development cycles in which, predictably, they would not be a priority. [Again, NOT true (see above). But I suppose it is a convenient appeal to nationalism and trade protectionists]
On acquisition costs for the F-35, there is an extensive bibliography, made of figures difficult to compare and review — a real jungle — so if there are two numbers are one is double the other, they could be both true since they are based on different assumptions. [And include different cost items, or ‘different year’ currency values, or both. So what?]
In addition the F-35 is in the development stage and not yet in full production, having acquisition costs that vary from year to year. We now have, for the A model, an approximate figure well above $100 million. Flight costs per hour is also a topic for fortune tellers, but the numbers are scaring the USAF. ['Scaring': A fallacious Appeal to Emotion directed at the uninformed]
The Typhoon is well known for acquisition and flight costs. [Not so much “well known” as seen as an outcome to be avoided]
Conclusions
In my view, the purchase of the F-35 should be only for the 15-20 copies for the Navy, to be purchased along a period of 7 to 10 years from now, allowing the maturation of the aircraft and the reduction in purchasing costs. To date, a fully operational aircraft is scheduled for 2019, if there are no serious problems on software development, a key component in the present day for a fighter plane. The Air Force, in contrast, has a technological option that makes it possible, even if with operational differences, to purchase the F-35A or the Typhoon.

Only if you actually believe the Typhoon will be effective and survivable for the next 30 years or so.

It is my opinion that it is useful, both economically and industrially, that Italy, since there are no orders signed besides 3 F-35As, reviews in detail the alternatives, requiring two offers, with guaranteed costs and industrial compensations, for the two alternatives: Typhoon T3 and F-35A. The timing for the purchase of the 75 aircraft, may be over a fairly long period and without immediate financial commitments. In case of confirmation of the F-35, it would be desirable that the purchases were delayed until 2018 to 2020, in time to start replacing the AMX.

Oh yes, because everything is always cheaper if you stretch out the purchase and do it later (/sarc). Apparently the author has never heard of Economic Order Quantities.

This would be a nice as we consider the current crisis that does not allow for non-essential digressions. Defense cannot be neglected, but we can certainly wait a few years before deciding and purchasing.

My Conclusion:
Mr. Albano’s screed is ill-conceived, poorly written, drivel. It remain so even when allowing for what must be lost in the English translation. He presents nothing more than a laundry list of unsubstantiated and/or perverted anti-JSF complaints with a dash of pro-Eurofighter ‘feelings’ (vs. fact). In law, it is said that if the facts are on your side then argue the facts. If the law is on your side, then argue the law. If you have neither the facts nor the law on your side, then ‘pound on the table’. Mr. Albano is clearly ‘pounding on the table’.

Veritas Locutus Est, Causa Finita Est

Tuesday, July 16, 2013

There Be Some Naughty Cuba-NoKo Arms Goings-on Here

Arrrrgh! A NoKo "Fan Song Swan Song"?

This is developing fast! The BBC and others report "North Korean ship with 'military cargo' held by Panama"

The Ship? The delightfully named "Chong Chon Gang" .

First reports just mentioned 'missiles' and 'missile tech' with pics, the text suggesting possible missile containers:

Military Contraband Hidden under 'Cuban Raw Sugar'
But that didn't look like a 'missile container to me, what with those 'parts' attached to it like we see in the picture. This looked vaguely familiar.....Kind of like a piece of this (in red):

Backside of  Fan Song Radar  
If you still can't 'see' the resemblance, how about if I clip, flip and magnify the detail?


Fan Song Detail, Flipped Upside Down
See the resemblance now?

Details emerging:
1. Allegedly (wink wink, nudge, nudge) there was an 'anonymous tip' about some drug smuggling.
2. Chong Chon Gang crew resisted Panamanian forces when they tried to board.
3. The NoKo freighter's Captain had a 'heart attack', and has now tried to commit suicide.
4. Seeing 'Fan Song' radar 'dish' showing up in some articles now.

The 'Fan Song' is an oldie but a goodie, usually associated with the SA-2 missile system, which with upgrades can still be a nasty piece of trouble for even modern jets. A description of the Vietnam Era system:
An S-Band FAN SONG radar is installed in one of the centrally located vans and provides target position data to a computer. It also has the added task of providing individual target position data on as many as three missiles. It must do this at the same time as it is providing target information to a system computer. The requirement for a single radar to track and lock on to as many as four targets simultaneously necessitates that the radar continually look at several points in space. This requirement implies that the FAN SONG searches, or scans, at the same time that it locks on to, or tracks, several targets. This was in fact the case. The FAN SONG technique of locking on while searching is called Track-While-Scan.

The target tracking data that the FAN SONG radar must provide to the missile computer is azimuth, elevation and range. To provide this information, the FAN SONG has two transmitters operating at different frequencies, each feeding an antenna. One antenna produces a sectoring azimuth beam and the other a sectoring elevation beam. The dimensions of each of the beams are 2 degrees by 10 degrees. The 2-degree wide, 10-degree high azimuth beam is scanned right to left for 20 degrees. The 2-by-10-degree elevation beam is scanned up and down 20 degrees. The two sweeping beams intersect to cover a 10-by-10-degree sector.
Source
Newer versions are believed to be more capable. I'll bet this deal was a 'complicated' one to start with, and it just got more complicated.


 

Thursday, July 04, 2013

Pierre Sprey: Expert?

Pffft! More Like POGO's 'Circus Barker'

(File Under "Know Your Reformer")
Hat tip 'munny' at F-16.net

Pierre Sprey: Old Whine in a Cracked Bottle

There's a new You Tube Video (link here) up with Pierre Sprey blathering his usual nonsense about 'complex' vs 'simple', 'heavy' vs. 'lightweight' fighter performance... blah... blah... blah. As if he ever knew d*ck about the topic at hand. Virtually everything he says is just as wrong or worse than the first time he spouted it off.  Remember, this is all part of the POGO P.A.C.E. propaganda strategy.

I left a few comments that were smaller than I would've liked because the format doesn't allow me to put together a larger coherent one such as:

Pierre Sprey has never ‘designed’ anything with wings, and he still doesn’t know diddley-squat about aircraft design OR air warfare . He played a bit role in developing top level requirements at OSD for a couple of years, basically parroting whatever John Boyd or Everest Riccione were hawking that day. His ‘expertise’, as well as much that which is claimed about the rest of the so-called ‘Reformers’ was pure fabrication by James Fallows. Those fabrications have been echoing in the halls of the anti-defense lairs for consumption by the useful idiots ever since.
Best summary* of Sprey I’ve read:
While working on the F-X, Boyd met Pierre Sprey, a weapons system analyst on the OASD/SA staff, whose background was similar to [Alain] Enthoven’s but much less distinguished. By his own account, Sprey was a dilettante with an engineering degree but no military experience. After graduation from Yale, Sprey became a research analyst at the Grumman Aircraft Corporation for space and commercial transportation projects. He came to OSD/SA in 1966, where he declared himself an expert on military fighter aircraft, despite his lack of experience. Sprey admitted being a gadfly, a nuisance, and an automatic opponent of any program he was not a part of.   

*Source: Pierre Sprey, Oral History Interview by Jacob Neufeld, 12 June 1971, K.239.0152-969, AFHRA, 9, passim. , as cited in THE REVOLT OF THE MAJORS: HOW THE AIR FORCE CHANGED AFTER VIETNAM, Marshall L. Michel III, 2006 (PDF).

Michel gets a little too 'Fighter Pilot Uber Alles' in his thesis, and I found myself having to force my eyes to read past those parts, but it still is a good read. If you want to read a really cold-blooded delivery of a takedown concerning the so-called ‘reformers’--including Sprey-- buy and read “Military Reform: the high-tech debate in tactical air forces” by Walter Kross.

Clearly POGO is focused on Canada as a 'weak link' in the JSF coalition at this time.

Sunday, June 30, 2013

The F-35 and the Infamous “Sustained G” Spec Change: Part 4 (of 4)

Note: See Part 1, Part 2 and Part 3 for flight conditions, and important background information.

Let’s get into the hard numbers right from the start in this comparison as I’m sure no one expects our F-35A_H in any configuration to surpass the F-16A in the ‘lightweight’ (50% internal fuel, minimal armament) configuration we’re using:
F-16A Configuration Baseline
As a reminder, here is the sustained G difference between the two:


Sustained Gs: Spec F-35A_H vs. Lightly Loaded F-16A
In the chart above we find, the F-35A_H baseline shows the possible ‘high , ‘low’ and range in between of possible values compared to the much-vaunted F-16A’s performance.

The other expressions of turning ability that fall out from these values are Bank Angle:




Bank Angle: Spec F-35A_H vs. Lightly Loaded F-16A
…and of course "Sustained Turn Rate" expressed in Degrees per Second:


Sustained Turn Rate: Spec F-35A_H vs. Lightly Loaded F-16A
Clearly, the F-16A configuration's sustained turn performance, even compared to the best possible F-35A_H turn rate at 'spec' weight, goes beyond 'Superior' and  approaches the level of 'Dominance'. This indicates it would be pretty stupid for an F-35 driver to get in a protracted turning fight with an F-16A if each combatant needed to get behind the other to 'get the kill'. 

But what about a turning fight when the F-35A_H weight is at other likely F-35A_H values?

To parallel the process we followed in comparing the F-35A_H with the F-4, I’ve selected some feasible alternative loaded weight F-35A_H configurations to compare the possible performance of the F-35A_H with our lightly-loaded F-16A:
Three F-35A_H Load Configurations. (*Assumes fuel burn is constant when in reality as weight goes down fuel burn rate goes down in 'cruise'. Using this assumption, the F-35 is actually penalized: retaining more fuel than needed than the F-16.)
As you can see, Case A will be an F-35A_H with the same fuel load fraction (50%) as the F-16A’s. Case B adjusts the F-35A_H fuel load to yield an equivalent thrust-to-weight ratio as the same F-16A in the 50% Fuel Load configuration. Case C is a little more nebulous, but my ground rule assumption that fuel burn is constant though the weights are going down penalizes the F-35 more than the F-16, this is my ‘best estimate’ of what equivalent fuel loads would be for the airplanes to each be able to fly 500 nm at 30k feet to get back to their home bases. Even if my Case C range assumption is off, both fuel loads are realistic for a possible aerial encounter some distance from home base. Case B and C are remarkably close to each other, but still produce differences in performance:
Looking at all three cases, using the same formulas and physics as we've applied in Parts 1-3, the ranges of possible F-35A_H’s turn performance for comparison to the Lightweight F-16A are found:
Three F-35A_H Configurations: Three Ranges of Possible Turn Performance   

Here are the ranges of possible F-35A_H sustained turn rate performance for these three cases, when charted against the F-16A’s 50% Fuel Load Configuration performance:
   
Three F-35A_H Configurations: Closer to F-16A's Light Configuration Turn Performance   

Thus we can see that 30-40% of the possible values for the F-35A_H in Case A (50% Fuel Load) would place the F-35A_H in relative parity (less than 2 Degrees/Sec, see part 2) with the F-16A, and there are fewer, but still ‘some’ possible values for Cases B and C that would also make the F-35A_H in ‘parity’ with the F-16A. Obviously from what we’ve seen so far, the lighter the fuel load, more likely the F-35A_H could be on a par with the lightly loaded F-16A when it comes to sustained turn performance.

Every Pound of Load Difference Affects Lighter Aircraft More than Heavier Aircraft 

We’ve shown the F-35s sensitivity to fuel load in regards to turn performance, but the sensitivity of lighter aircraft to the proportionally similar fuel loads is even greater, as every pound of fuel represents a larger percentage change in the fuel fraction of the total weight. Observe the differences in performance between a full internal fuel load and a half-full internal fuel load on the F-16A:

Full Internal Fuel Reduces F-16A Sustained Turn Rate Considerably 

A full internal fuel load, even with our ‘light’ F-16A weapons load brings the sustained turn rate performance of the F-16A down significantly. What if our ‘Spec’ loaded F-35A_H was compared to the an “F-16A-like” aircraft carrying full internal fuel. Envision the “F-16A-like” aircraft had just jettisoned its external fuel tanks to do combat with our F-35A_H carrying 60% internal (and total) fuel.

How would the turn performance of the two aircraft compare? It would look like this:

Sustained Turn Rates: F-35A_H Baseline vs. Full Internal Fuel F-16A

Over half (~2/3rds) of the possible sustained turn rates for our F-35A_H Baseline aircraft are on a par with an F-16A carrying a full internal fuel load.

What does a comparison of our Case A, B and C configurations with a full internal fuel-loaded F-16A look like? That comparison looks like this:
F-16A 'Like' Aircraft With Full Internal Fuel Vs. Lighter F-35A_H Configurations (Fixed F-16A Label)

From this chart we see that ALL possible sustained turn rate values for the F-35A_H using any of the three selected fuel load cases are on a par with our ‘full internal fuel load’ F-16A.

Conclusion:

Depending on amount of fuel carried by each aircraft, the F-35A is capable of sustained turn performance on a par with the F-16A. Assuming the F-16A is still the ‘best’ in a sustained turn that there’s ever been at 15K feet and M.8, then that means the F-35A is capable of holding its own against all comers in a sustained turn when flown properly in competent hands.

This would be a lot more exciting news if Sustained Turn Rates were still as important today as they were before the advent of the All-Aspect missile attack. I wonder what technical performance metric the critics will criticize next?

Closing:

Why This Topic and Why Now? The impetus for this mini-series of posts springs from all the things that seemed to be hitting the headlines while I was out having a life (of sorts) away from the web. Things like the usual POGO Clown Posse faux alarm protestations that arose in response to the recent F-35 performance spec changes: Protestations that were then flung like monkey-you-know-what by the usual suspects for consumption by the innumerate and ill-informed around the globe. Further, once industry and defense pilots who’ve actually, y’ know, FLOWN one or more of the three F-35 versions-- probably in response to the flingin’—got a little vocal with positive comments on the F-35’s maneuverability, the ‘Anti’ crowd and business scavengers went DEFCON1 trying to drown them out.

I see the next couple of years as make or break for the F-35….critics.

  The number of F-35 pilots will reach critical mass in this timeframe, and the Anti-JSF'ers know that once that happens, unless the plane really IS a bust, no amount of hyperbole and lying coming from POGO and its fellow travelers will be able to sustain a false 'image of failure' for the F-35.

The increasing desperation of the anti-defense, anti-JSF action-network is palpable…and delicious. But their outrageous claims must still be contested with facts, and their Misleading Vividness must be undone by sober observations. They must be contested lest their deceptions gain any real traction or (equally undesirable), their deceptions provide cover to others who would kill the F-35 for their own evil, or more likely, ignorant and misguided motives who would use the F-35 misinformation as a useful tool.

What Next on the F-35 Front?

With the F-35 numbers in the field climbing, expect the ‘Reform’ types to focus on generating “Cost! Cost! Cost!” misconceptions more than on technical performance topics. It doesn't mean every little glitch won’t get a snarky article posted someplace in the manner of targets of opportunity, but that won’t be their primary focus.

Sunday, May 26, 2013

The F-35 and the Infamous “Sustained G” Spec Change: Part 3

(Links to Part 1 and Part 2)

F-4E vs F-35: The F-35 does not have F-4 'like' Sustained Turn Performance
I selected the F-4E for one of two comparisons for a reason beside the fact that it represents the low end of aircraft data in hand: This is to be an Anti-(Not to be confused with ‘Counter’) Propaganda post. When I read a Golden-Armed Meat Servo quoted claiming the F-35 had 1950s ‘F-4 like’ turn performance based solely on the sustained turn spec change, I had to chuckle at the use of ‘misleading vividness’ and ‘damning with faint praise’ in reference to a comparison with the venerable F-4 . I wonder if such bluster was scripted for him by another meat-servo (generic) working in the Boeing Business Development Office? I wonder, because it is a good ‘hook’ of a sound bite for the ‘low-information’ public…but a pretty stupid one when you get down into details.

The F-4 in Our Analysis

The F-4E in our comparison isn’t a product of just the 1950s, But one of progressive improvement from the 1950s through the 1970s. The F-4 design was constantly tweaked throughout its operational life. It has been observed that the F-4 had seven different wings over its evolution through about 1980 if you count the test canard-equipped F-4 configuration (Bennett and Rouseau, 1980), and I believe the AF’s leading edge slat (LES) configuration was wing #4 or #5.

The ultimate USAF F-4E dogfighter IMHO, was the ‘slat-bird’ with TISEO, a far different aircraft than even the Non-Slat F-4E configuration that my late Father-in-Law flew in Vietnam (or the non-slat F-4Es we in the 57th FIS were still flying out of Keflavik Iceland in the early 80’s).

Eventually, all serving USAF F-4Es would get the LES treatment, and it was for good reason. Wind tunnel data for the Post-Vietnam LES wing had predicted a remarkable improvement in controllability (Hollingsworth and Cohen, 1971):


From "Determination of F-4 Aircraft Transonic Buffet Characteristics"; E. G. Hollingsworth, M. Cohen, Journal of Aircraft; Vol 8, No. 10; October 1971.
…and when the design was first executed on the YF-4E, flight test validated those significant improvements (Hollingsworth and Cohen):
From "Determination of F-4 Aircraft Transonic Buffet Characteristics"; E. G. Hollingsworth, M. Cohen, Journal of Aircraft; Vol 8, No. 10; October 1971.
 
Col Robin Olds smote “highly maneuverable” MiGs while flying comparatively less agile and capable F-4Ds. Think about what he could have done in a F-4E ‘Slat Bird’.

From the charts above we find the basic aerodynamics of the late model F-4E are clearly ‘superior’ (even using our grading methods) to the 1950’s or 1960s F-4 image that still resides in most people’s minds. From history, we know that it was lethal when in capable hands against far more 'agile' aircraft of its day.

Now we will take note of the specific weight and drag circumstances used for the F-4 in our comparison.

Source: GD fighter Weapon Symposium "Fighter Performance" Handbook, Circa 1986
The configuration of our F-4E (50% internal fuel, 2 AIM-9s and 2 AIM-7s, and a nose load of 20mm) closely describes a fighter that is either 1) on a short range point defense mission, 2) or has dropped its wing tanks a “half-internal fuel load” ago. Either way, it seems the F-4 we describe had better be on its way home or to a tanker pretty soon on ‘Mil’ power if it hopes to make it back to his base.

The F4-E in our static ( i.e. “snapshot”) comparison has a sustained G turn rate slightly above the F-35A_H (Low) boundary configuration.   How might that change if we lowered the F-35A_H fuel load to something comparable to the F-4E’s? By ‘comparable’ I do not mean ‘the same’, I mean a fuel load that will allow the F-35A_H to fly as long or far as an F-4. This "apples to apples" comparison can be reasonably estimated.

While the F-4E in its modeled configuration is no doubt 'lightweight', it does have a slight but measurable sustained turn advantage compared to our representative F-35A_H(Low) but is at a greater disadvantage against the F-35A_H (High) boundary configuration. It must be remembered the later-generation fighters have tailored-airfoil wing designs developed using Computational Fluid Dynamics to wring as much efficiency as possible and with blended fuselage-wing profiles would be superior to a wing using a catalog airfoil or airfoils (In the case of the F-4, it uses a modified NACA 0006.4-64 airfoil at the wing root transitioning to a modified NACA 0003-64 airfoil at the tips, Source) The F-35A_H in our example now assumes a far higher fuel fraction of total weight in fuel is onboard than the F-4E example. What if we reduced the amount of fuel on the F-35 to be more operationally equivalent to the F-4E’s fuel load?

Normalizing the ‘Fighting Weight’

We can adjust the fuel fraction of the F-35 by adjusting fuel carried (downward) to approximate the equivalent fuel of the F-4. What is important is to closely approximate the fuel on board the F-35 that is an ‘equivalent’ needed by the F-35. I’m going to avoid quantifying the ‘time element’ up front and use it later as a "punch line". In making the adjustments, let us give as much benefit of the doubt as possible to the F-4E example. Two of the biggest benefits of first building a ‘worst case’ scenario in parametric modeling for studies that I perform are 1) If a solution is an obvious one, even with everything ‘going against it’ it is easy to get even Management on board with the solution and 2) If the solution is an obvious one I don’t have to do any more excursions – it’s a great time saver.

Our Assumptions:
1) We assume the F-4 has no higher drag/’total thrust’ ratio than the F-35A_H while maneuvering, though the F-4E is heavier and the overall F-4 design was originally optimized for intercepts at higher altitudes and supersonic speeds and has a less efficient (for maneuvering at lower altitudes) ‘catalog’ higher aspect-ratio wing (modified NACA 0006.4-64 at the wing root and NACA 0003-64 at the wingtip ).
2) The Specific Fuel Consumption (SFC: pounds of fuel per hour-pound of thrust) at all throttle settings is assumed to be equivalent between the two aircraft. Besides having a much older J79-17 engine design in the F-4E, there is no FADEC as in the F-35A_H. Though the J79 engines in the F-4 may have a very slightly lower SFC in afterburner than the F-35A_H’s F135 engine, they will have significantly higher SFC in Mil Power (Max throttle no Afterburner)—these are typical differences between turbojets and turbofan engines.
3) Since the F-35A_H has higher thrust-to-weight in Mil Power AND Afterburner and a much higher Mil Power/Afterburner ratio, the higher efficiency of the F135 is even more apparent, but we will ignore that higher efficiency in our analysis and call it ‘a draw’.

So if we assume the drag/total thrust ratio and fuel efficiency (SFC) are equivalent between the two aircraft, all we now have to do is account for the disparity in non-fuel weight and thrust ratings. The F-4s fuel fraction in this modeled configuration is about 14.5%. To get the same fuel fraction in the F-35A_H, we would reduce the fuel carried from about 11800 lbs to about 5120 lbs. But since we assume we need all that extra thrust in the F-35A_H to do the same amount of ‘work’ as the F-4E, we need to add enough fuel back into the F-35A_H to ensure it has the same relative endurance as the F-4E. The F-35A_H has slightly more than 26% more thrust than the F-43 (43000 lbs vs 34000 lbs), so we will increase our assumed F-35A_H fuel load by adding that same percentage to the intermediate 5120 lb value to arrive at an “F-4 equivalent” fuel load for the F-35A_H of 6474 lbs.

Note that by using the higher 43K pounds of thrust figure vs. any lower thrust value, we are requiring our F-35A_H to carry more fuel than otherwise. Again, this is done to give the F-4E every possible benefit before deriving sustained G turn rates in our comparison. Our two contender’s configurations in this excursion are therefore as identified in the table below.

Normalized Fuel Weights and Configurations for Comparing F-4E and F35A_H

F-35A_H Sustained Turn Performance at F-4E Equivalent Fuel Loads

We can now use these numbers to derive the estimated changes to the range of possible “Sustained-G Turn” capability for the F-35A_H.  The nice thing about 'sustained turns' for doing this kind of extrapolation is that we are dealing with states of equilibrium. We can take the 'g' load and multiply by the aircraft weight to arrive at the total Load Factor and equivalent lift required. At a lighter weight, the same lift and total load is achieved at a higher bank angle and the same load divided by the new lighter weight yields a higher g-rating. As the aircraft is still flying at same speed and altitude, which requires the same wing performance/ efficiencies which have the same drag effects in our region of operation.

Use the figure from Part 1 (left) to visualize the force vector relationships and how they change as the weight is decreased. If the dark blue weight 'vector' is smaller, to get the same equivalent lift and load factor found at max turn and heavier weight, the bank angle is greater.

The only assumption I am making in this case is that the Center of Gravity (CG) shift is not a factor. If the CG shifts forward or aft because of the weight difference, there may be some variation, but modern aircraft are designed to optimize the CG as fuel burns down, so this factor is ignored.

The F-35A_H Sustained turn bang angle and 'G' boundaries we used earlier for the higher weight assumption thus shift noticeably higher when the F-35A_H fuel load is reduced to something comparable to the modeled F-4E configuration. 

The High and Low Boundaries of the F-35A_H Sustained G Turn Capability Increases
Dramatically When Aircraft is Loaded Comparable to the F-4E Configuration.
This higher bank angle at the same .8 Mach at 15K feet altitude operating conditions thus increase the range of possible Sustained Turn rates of our F-35A_H accordingly:
F-35A_H Sustained Turn Rate Range at F-4E Equivalent Fuel Load.

F-35A Sustained Turn Capability: Clearly NOT ‘F-4 like’

It should be obvious to even those most critical of the F-35 that I could have made a slew of small errors at the margins in this analysis and it wouldn’t have significantly changed the end result. When configured at “apples to apples” operating weights, the F-35A_H clearly outclasses the F-4E. We can say that at these configurations, the F-35A_H is "better" to "superior" in comparison to the F-4E. 

Nails in the F-4E’s Coffin

The F-35 airfoil efficiency is also not reduced by external stores in its ‘Day 1’ configuration. With its superior fuel load the F-35 can 1) pick and choose the time to engage, probably without the F-4 ever knowing it was there and 2) capitalize on its superior thrust/weight ratio and better controllability at higher angles of attack (AoAs) .
In addition, if you refer to the E-M diagrams in the previous post and above, you will observe that the bleed rate ‘isobars’ for the F-4 in a turning condition are much closer together than for aircraft in later generations. I suspect the F-35’s E-M diagram looks much more similar to later generation fighters than the F-4’s.

The Final Nail: Fuel Consumption

If we refer to the ‘Dash-1” flight manual for the F-4E and view the combat fuel consumption plots, we find several important bits of information.
1. The plots assume supersonic wing-level flight. 
2. The plots show a range of fuel consumption: from minimum afterburner to maximum afterburner and for an ICAO ‘standard day’ as well as a 10 degree warmer day.  
3. The plot for the closest configuration to the F-4E configuration we are using is the for 4 x AIM-7s instead of the 2 x AIM-7 and 2 x AIM-9. But that’s OK, because the AIM-7 carriage is lower drag than the AIM-9 on the F-4 (Pylons and launcher on wing vs. semi-conformal on fuselage) so we have another negative we ignore to give benefit to the F-4E in the comparison.

This is the plot:
F-4E Combat Fuel Burn Plot

The Punch Line

Now, while our F-4E versus F-35A_H ‘engagement’ wouldn’t be straight and level and above Mach .8 much less Mach 1.1 (the lowest speed at 15k Ft with Min Afterburner In the plot), the fuel burn rate in afterburner is still relevant, and likely still very optimistic for our purposes, as the F-4E would certainly be using higher-rate afterburner settings in such an engagement. So to giving more benefit of the doubt to the F-4E, and assuming it was using only the minimum afterburner to maneuver against a more powerful and lighter F-35, we get to the ‘punch line’ I alluded to earlier:
720 lbs/minute fuel burn rate and 6020 lbs of fuel on board = about 8 minutes 20 seconds before the F-4 crashes, hits a tanker, or lands.
That’s assuming all the fuel on board is usable, though it is not. From this fact alone, it should be obvious to the reader that the F-4E configuration that could theoretically compete with an F-35 in a “sustained turn” competition was “infeasible”—an F-4E “strawman” that was good for highlighting that even with every advantage, and flying as light and slick as possible, the F-4 sustained turn rate doesn’t quite match up to more modern aircraft. I suspect that was the entire purpose of including it in the Fighter Weapon System Symposium materials in the first place: a benchmark to compare against the F-16 that was designed to make the F-16 ‘look good’.

Next in Part 4: F-35A_H vs. the F-16A Sustained Turn Performance. What will we find?

Sunday, May 19, 2013

The F-35 and the Infamous “Sustained G” Spec Change: Part 2

(Part 1 Here)
I want to reiterate that this series of posts is for the purpose of developing an understanding of aircraft performance parameters and the factors that influence them. It is not at all about providing answers (we don’t have enough relevant information about the aircraft we’re surveying, much less how they were/are or will be employed) but it is about how to THINK about the questions in the first place.

Let’s begin this post with an updated version of the table I showed the last time:
Selected Legacy Aircraft Configurations
I’ve added an ‘F-18C Light’ configuration to the mix because I found enough information graphed in a General Dynamics handbook on Fighter Performance from a 1985 Fighter Weapons Symposium (FWS). The book is a recent find of mine from a used book store very near the old GD, now Lockheed Martin plant: the same Plant 4 where F-35 output is being ramped up and boutique batches of F-16s still issue forth form time to time. From what I can tell, General Dynamics hosted this event and distributed material to operational F-16 squadrons around the world for years.


GD fighter Weapon Symposium "Fighter Performance" Handbook, Circa 1986
We’ll take the sustained G numbers from the charts for the aircraft configurations above and then crank out the sustained turn rates and similar numbers for a hypothetical F-35A ‘Bowman’ configuration and operating conditions. We'll use the upper and lower bounds of possible F-35A Sustained G values (between 4.6 to 5.3) to give us a range of possible sustained turn rates for that F-35 configuration/set of conditions/assumptions. The formula is:
Turn Rate =Velocity Squared /(G *tan Ø)*
(G *tan Ø)/Velocity; where Ø is still, as shown in the previous post, the “bank angle”.
*originally mis-typed formula for turn radius, but all rate values presented used correct formula (I checked the spreadsheets). Hazards of changing direction in middle of analyses, I guess.
Note that I include 5.3gs as the upper boundary partly because we do not know how close the F-35 came to meeting that spec, but more because we know the ‘grade’ must be against some weight that includes some fixed aircraft dry weight, and we do not know how ‘light’ or ‘heavy’ the F-35 will be until after the final weight accounting that is sometime in the future. Right now, per the latest DOT&E report, we know as late as December the F-35A was nearly 1% below the projected weight needed to meet performance specs. If it comes in below spec weight, it will have sustained turn performance higher than what is currently ‘predicted’ based upon the spec weight. 

F-35A_H Sustained Turn Rates Derived From Possible Range of 'Sustained G' Capability of 'Bowman Configuration' (Corrected**)
**Table corrected to show only difference between 'High' and 'Low' F-35A_H is assumed Sustained G performance boundaries

We now have the high and low boundaries for the possible raw sustained turn rate for our hypothetical F-35 (To keep things concise, let’s call it the ‘F-35A_H’ from now on in this series) and can compare it to the derived Sustained Turn rates for our selected legacy aircraft configurations:

Sustained Turn: F-35A_H vs Legacy Aircraft

Don’t Go There

I presume the above is the kind of raw comparison that sets simple minds down the ‘F-35 can’t turn’ path. Don’t go there – you don’t know enough about what matters…yet. The next thing we need to do is highlight the relative importance or unimportance of the differences shown.

Since we are using the boundaries of our F-35A_H performance in covering the range of possible performance, I’m going to present the ‘low’ boundary evaluation first (Remember, among other things, we don’t really ‘know’ the altitude at which this spec change was applied, we are ‘assuming’ for 'learning' purposes only):
Sustained Turn: F-35A_H (Low) Estimation Vs. Legacy Aircraft

Determining Turn Rate Parity, Superiority and Dominance

The rules used for assignment of comparative parity, superiority, and dominance ranges above and to follow are not mine. Consulting Raymer* (page 105) provided me with my first indication:
An aircraft designed for air-to-air dogfighting must be capable of high turn rate. This parameter dѱ/dt or ѱ, will determine the outcome of the dogfight if the aircraft and pilots are evenly matched otherwise. When air-to-air missiles are in use, the first aircraft to turn towards the other aircraft enough to launch a missile will probably win. In a guns-only dogfight, the aircraft with the higher turn rate will be able to maneuver behind the other. A turn rate superiority of 2 deg/s is considered significant.
*Aircraft Design: A Conceptual Approach 3rd Edition; D.P. Raymer;AIAA Education Series; 1999.

I had originally intended to use the ‘2 deg/s’ standard to evaluate which aircraft had ‘significant’ advantage over others when, in reviewing my ‘Fighter Performance’ handbook, I found an expansion on Raymer’s observations:



Sustained Turn Rate Equality, Superiority and Dominance
I can’t find the basis for the yardstick stated by Raymer and expanded upon in the FWS handbook, but I imagine it has to do with the typical engagement segment duration where a sustained turn difference would typically yield a ‘significant’ or even ‘dominant’ advantage.

Using the same methodology for our upper bound F-35A_H (High) configuration we find the F-35 fares quite a bit better in the comparison:

Sustained Turn: F-35A_H (High) Estimation Vs. Legacy Aircraft
So in closing Part 2, we see that the possible range of the 'Bowman' F-35A_H's Sustained G performance is broad enough that if the actual F-35 performance is just a little better than the new Sustained G spec value, it will yield turn rates on a "par" with all but the F-15C and F-16A. If the actual performance is closer to the 'old'  spec, the F-35A_H configuration we have modeled comes much closer to "parity" with our F-15C and F-16A configurations.

"What If"? (Parts 3 and 4)

These comparisons are rather static and one-dimensional and the relationships can change dramatically with changes to the armament and fuel carried. It is instructive to note the very large difference in F-18C sustained turn-rate performance based on the variation in weight (which is why I included the 'F-18C Light' data in the first place). Now consider the 'Bowman Configuration' assumption of 60% fuel on board for the F-35 also means that the F-35A_H's fuel load, as a fraction of the total weight, appears to be significantly larger than any of the other aircraft we are comparing. This hints that there may be equally 'realistic' if not more realistic F-35A configurations with far higher sustained turn capability than is attainable at the 'Bowman' weights.

I think it will be worthwhile (and fun) to look at things from a ‘1 v 1’ perspective with the two extremes of possible comparisons in our selected group: F-35A_H vs. the F-4E, and F-35A_H vs. the F-16A, and exploring the 'what ifs' of having slightly different configurations in our comparisons. I anticipate (but won't know until I get there) that I will be illustrating the F-4E at very light weights is not to be trifled with, and that the F-35A, when using comparable fuel weights, based upon equivalent fuel needs will be seen to have solidly 'respectable' sustained turn performance in comparison to other modern aircraft.

Part 3 will look at the F-35A_H vs F-4E.

BONUS GRAPHIC

From the Fighter Weapons Symposium Handbook, we see that the F-16A is/was about the 'cream of the crop' when it comes to Sustained G turns:
Sustained G: Thrust to Weight Matters Too 
So do you think the latest Sukhois do any better? IMHO they're probably more to the right on the X-axis but not any higher on the Y-axis compared to the 'old' Su-27s.