tag:blogger.com,1999:blog-21894908.post3707765814989613213..comments2023-11-01T02:19:14.796-05:00Comments on Elements Of Power: The F-35 and the Infamous “Sustained G” Spec Change: Part 3SMSgt Machttp://www.blogger.com/profile/08126690689798203866noreply@blogger.comBlogger13125tag:blogger.com,1999:blog-21894908.post-44938024449501813862016-02-26T20:30:31.220-06:002016-02-26T20:30:31.220-06:00Hi Paul,
The guy who did the comparison was doing...Hi Paul, <br />The guy who did the comparison was doing it as a disparagement. I just showed his comparison was not only wrong, but stupidly wrong. ;-) SMSgt Machttps://www.blogger.com/profile/08126690689798203866noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-65202082384757272562016-02-26T20:28:39.838-06:002016-02-26T20:28:39.838-06:00HI Kenny,
Thanks for the kind words first of all. ...HI Kenny,<br />Thanks for the kind words first of all. My use of the 60% fuel weight was based upon what is believed to be the DoD's preferences and I didn't see any reason not to pick that as a starting point either. I didn't check your numbers, but they aren't really pertinent to the setting of the F-35's KPPs. I find 60% fuel an acceptable ground rule - and I'm certain DoD picked this using the same basic logic, was the relevance of 60% fuel to the F-35's combat effectiveness at a specific combat radius. 60% fuel load is a good value if you want to be able to engage the enemy for some period of time at the combat radius, have enough fuel to still get back to a point where you can be refueled (air or ground), and still a comfortable remaining fuel margin for safety when you land or hit a tanker. SMSgt Machttps://www.blogger.com/profile/08126690689798203866noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-36589180704743836092016-02-23T09:13:26.744-06:002016-02-23T09:13:26.744-06:00Why does any one bother to compare the F-4 with th...Why does any one bother to compare the F-4 with the F-35?<br />Different decades to begin with, thus could not be a competitor to begin with.Anonymoushttps://www.blogger.com/profile/05229780580025876761noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-32075746190740120432016-02-18T23:51:12.029-06:002016-02-18T23:51:12.029-06:00First off, let me compliment you on the incredible...First off, let me compliment you on the incredible work and excellent analysis. <br /><br />However, something has occurred to me while reading the F-35 sustained turn rate articles. In the first part, you make the assumption to load all aircraft with 60% fuel. This is a very fair metric to start with, and great for making assumptions. But the F-35 was built to have the range of an F-16/18/AV-8B with drop tanks. So would it not make sense to try and account for this disparity? It would raise the F-35's turn radius by a bit, but likely not as much as the later comparison with an F-4 and F-35 loaded with the same amount of fuel. The idea being to give the most realistic picture possible. <br /><br />Here is what I've come up with. An F-16 loaded with 60% fuel is 4,200 lbs (assuming 7,000 lb total internal capacity). However, the capability to have 2x370 gal and a 300 gal fuel tank can raise it's total capacity to 14,000 lbs. Thus meaning it's only carrying 30% of it's total fuel capacity. Thus an F-35 equivalently loaded at 30% is 5,550 lbs. Using the F-18C as a metric, with 10,860 lbs of internal capacity. 60% of which is 6,516 lbs. The F-18C can carry 3x330 gal fuel tanks assuming a weight/gal of about 6.73 (what the weight from the F-16 comes out to be) the total fuel capacity is about 17,460 (I took 6,600 from the drop tanks, low balling in for the F-18C works against the F-35 in this instance). which gives 6,516 as about 37.32% of it's total internal capacity. Which would mean the F-35's internal fuel load would be about 6,904 lbs.<br /><br />If any of these numbers are wrong, then I apologize. But I hope I may still get my point across. I feel this would be more accurate than just applying a 60% fuel load across the board (or an equal fuel loading) for weight comparison purposes given the same mission. <br /><br />Thank you for your time, and I hope you find this helpful. Kenny Beeryhttps://www.blogger.com/profile/10790661749590764683noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-1196209429237158312013-06-17T19:16:40.718-05:002013-06-17T19:16:40.718-05:00I checked out the paper you mentioned -- it is qui...I checked out the paper you mentioned -- it is quite interesting. One of the statements I see coming from today's "reformers" seems to be that low-observability is "useless." According to the armchair generals on the Interwebz, "everything is observable below two GHz" and low-frequency radars have some kind of magic anti-stealth properties. Yes, it is true that low frequencies begin to produce half-wave resonance effects, but at the 0.5 GHz to 2.0 GHz range -- which is where all non-OTHR or "passive" low-frequency radars operate, the half-wave resonance effect is still relatively small -- even at 0.5 GHz, the half wavelength is a foot long, so only the very small leading edges of the aircraft will resonate -- and those leading edges are typically covered with radar-absorbent materials. It is commonly stated by the anti-JSF crowd that RAM doesn't work below 800 MHz, but it seems that the actual radar absorbing material isn't the only component of RAM. I found a pretty interesting document about how engineers at Lockheed found new components to add to RAM to improve its abilities against low-frequency radar.<br /><br />http://www.airplanedesign.info/52-radar-stealth.htm<br /><br />So it appears that the addition of other components to RAM can make it effective against C/D-band radars.<br /><br />So it seems that the only radars that can reliably defeat low-observable technology are extremely low-frequency VHF radars commonly used in OTH roles, where half-wave resonance affects the entire aircraft and even with supplementary materials, RAM is ineffective.<br /><br />However, with VHF radars, you have to deal with the fact that you only get a 2D image (so no altitude information, and thus no ability to fire a missile based off of a VHF track), the resolution is so poor that, at typical detection ranges, you only know where the aircraft is within several kilometers (or more!), and the radar set is large and not particularly mobile (moving it is difficult, and some designs are completely immobile), so it is easy to attack it with, say, a missile fired from an SSGN.<br /><br />So, it seems like the anti-JSF crowd isn't entirely correct when it comes to low-frequency radar, either...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-21894908.post-13347782013956945792013-06-13T23:22:18.180-05:002013-06-13T23:22:18.180-05:00Hi Alec,
The arguments being made today against th...Hi Alec,<br />The arguments being made today against the BVR missiles and engagements are exactly the same that were being made by essentially the same, with a few new protégés, faux 'Reformers' as in the 70s and 80s. They are just as false and without merit as they were the first time these ideologically driven, and militarily-challenged charlatans made them. <br />I recommend you Google up "The Revolt of the Majors: How the Air Force Changed After Vietnam". It is the doctoral thesis (Auburn U)of a retired AF Colonel and AF Historian Marshall L. Michel III. It builds a very coherent picture (though with a surprising number of typos) of how training AND technology make the AF an effective fighting force. You could probably skip to near the end around Chapter 12 for some AMRAAM, BVR, and 'Reformer' perspective, but you would so yourself a disservice if you didn't read the whole (~450 pages) thing. I keep a copy for the references alone.<br />I won't get into what AMRAAM capabilities might 'be' except to say that ALL missiles are designed to work in a dense electromagnetic environment. After all, who, if they knew anything about the technology involved, would suppose otherwise? There are textbooks on testing guided weapons that had sections devoted to the validation and verification of counter-counter-measures. So it is not as if the challenges are unknown or ignored, and I think it is pretty foolish of some to assume they are. While a missile might go into a box and then not be used for up to 10 years, most are returned to depots for repairs at one time of another. These missiles are not only upgraded with advertised 'block upgrades' or mods, but typically receive latest software updates as a matter of routine. Also the 'Vanishing Vendors' phenomenon occurs on all systems. This requires program offices to to find other suppliers to provide parts. When it comes to electronic components, that typically means more robustness and improved performance as well. The missile design does not stay static any more than the aircraft's. SMSgt Machttps://www.blogger.com/profile/08126690689798203866noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-13497629660521714772013-06-12T23:12:55.564-05:002013-06-12T23:12:55.564-05:00Really great article! I was wondering, since you ...Really great article! I was wondering, since you were involved in military programs, if you'd have an answer to this question...<br /><br />One of the statements made by the anti-JSF crowd (Kopp, Wheeler, etc) is that BVR missiles are "useless" and "ineffective" in aerial combat. On the AirPowerAustralia website, Kopp cites a 46% Pk figure for the AIM-120 AMRAAM. However, it appears that, in order to get this figure, Kopp and Goon excluded all successful non-BVR AMRAAM shots, excluded instances where more than one missile was fired at the target, and a successful interception was carried out, and deliberately included instances where pilots fired their missiles well outside of the AMRAAM's NEZ in order to achieve a mission kill, and intentionally not attempting to hit the target. So, would you say that the AMRAAM, and especially the new AIM-120D version, would be capable in an actual combat situation, and that Kopp and Goon are just skewing the data in this situation to "prove" the ineffectiveness of the F-35?<br /><br />Also, Kopp tends to talk a lot about how the AMRAAM would have its Pk reduced even further by DRFM (Digital Radio Frequency Memory; a kind of repeater jamming). However, I believe I've read something about how, because the new -120D AMRAAM has a two-way datalink, the F-35 pilot could use the DAS to determine which targets are "real" and which are created by repeater jamming (as returns produced by DRFM obviously don't have a thermal signature), and could use the datalink to "tell" the AMRAAM which return is the actual target. Have you heard anything to that effect?<br /><br />Obviously, a lot of information on the AIM-120 is classified, and air-to-air missiles might not be your area of specialty, but since you work/have worked in military programs and seem pretty knowledgeable about military matters, what is your opinion on the AMRAAM?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-21894908.post-86729349633722178562013-06-11T12:24:12.702-05:002013-06-11T12:24:12.702-05:00I did some probing towards Lockheed for my book r...I did some probing towards Lockheed for my book research at the time. Basic answer was that the F-35 has similar roll-performances as the F-16, and better instentaneous turn-rate. Which seems logical, as it can pull much more AOA. To me it indicates that the F-35 follows in the footsteps of the F-16, having good - if not very good - transient performances in the transonic regime. That is: to execute the shortest possible OODA-loop. And that's really before we start to take into account the sensors and SA.<br /><br /><br />Bjørnar<br />Oslo<br /><br />energohttps://www.blogger.com/profile/00708298173280622010noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-67911071818440386432013-06-10T22:22:35.542-05:002013-06-10T22:22:35.542-05:00Bjørnar
I'm about to wrap the next post up, an...Bjørnar<br />I'm about to wrap the next post up, and I'm seeing pretty much what you did. They may start out as slightly lower performers in the sustained turn category, but bigger planes handle payload variation with less adverse impact. It's all about weight fractions if you have enough power. While I'm not tackling T/W ratios, you can see the same for that category as well. After a couple of excursions where I lighten up the F-35, I'm doing one where I load up the F-16A with fuel to replicate what its condition would be on an intercept- right after dropping fuel tanks. Looking at the T/W ratios, I can see indications why some pilots flying the F-35 rate its 'kinematics' highly.SMSgt Machttps://www.blogger.com/profile/08126690689798203866noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-9508030357386204862013-06-08T11:05:58.263-05:002013-06-08T11:05:58.263-05:00As you have covered in other posts, manuvering per...As you have covered in other posts, manuvering performance is a complex set of dynamic factors. While the F-35 isn't a stellar performer in some respects, it is certainly better than some give it credit for.<br /><br />A few years ago, I did a simple comparison chart on fighter specs for a mainstream book on the F-35. I compared the 8-10 most popular fighters and based the W/L and T/W numbers on fuel fractions in a light A-A and heavy A-G configuration. No dramatic changes, but certainly tipped the scale in favor of the F-35 and Flanker which have similar large fuel fractions and better absorbs Heavy weapons due to it size.<br /><br />Keep up the good work!<br /><br /><br />Bjørnar<br />Oslo<br />energohttps://www.blogger.com/profile/00708298173280622010noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-70804538442615732522013-06-01T22:21:43.735-05:002013-06-01T22:21:43.735-05:00I would have responded earlier, but I was incommun...I would have responded earlier, but I was incommunicado on a business trip.<br />Thanks for the kind words and sticking with me on the series. Most people's eyes glaze over at the slightest hint of math. <br />I think I'll close the series with the F-16A comparison and a summary wrapping up and going back to where it started with the 'E-M Backgrounder' post. SMSgt Machttps://www.blogger.com/profile/08126690689798203866noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-22180108950809937962013-05-31T13:30:30.064-05:002013-05-31T13:30:30.064-05:00Concur, very good posts on the subject. The questi...Concur, very good posts on the subject. The question about fuel fraction is particularly relevent in my view. AS the F-35 is designed to carry external drop tanks internally, it changes the idea of drag and T/W completely.<br /><br />B. Bolsøy<br />Osloenergohttps://www.blogger.com/profile/00708298173280622010noreply@blogger.comtag:blogger.com,1999:blog-21894908.post-52520508378063811562013-05-28T03:42:14.371-05:002013-05-28T03:42:14.371-05:00Brilliant! Keep up the good work. Brilliant! Keep up the good work. Houston1125https://www.blogger.com/profile/16891074719848560528noreply@blogger.com