五千年(敝帚自珍)

主题:【原创】F-35的苦日子还没有开始呢 -- 晨枫

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            • 家园 抱歉,是要解决,你是对的

              [据航空周刊网站2012年9月19日] 洛马公司解决美国海军F-35C战机尾钩设计问题的方案接近出炉。原有设计在早期测试中无法钩住阻拦索的原因有两点:一是尾钩的尖端不足以锋利,无法确保从下部“钩到”阻拦索;二是阻尼器没能确保尾钩“抓住”阻拦索。其结果是尾钩在着陆时处于弹跳状态,降低了成功实施阻拦着陆的成功率。洛马公司作为F-35战机的主承包商,对尾钩进行了重新设计并解决了以上问题。在测试中,磨尖了钩尖但未修改阻尼器的临时设计成功地抓住了尾钩。尾钩问题是近一年前发现的,重新设计工作随即展开。公司官员希望在明年夏天对新尾钩的最终设计及其阻尼器进行测试。舰上测试将在2014年进行。(中国船舶工业综合技术经济研究院 程之年)——图片显示尾部多了一块鼓包

              • 家园 削尖挂钩可以做到容易挂上

                但也容易脱钩;阻尼器的问题在于尾钩长度。这些都是已知的问题和解决措施,难处在于都是互相矛盾的,精细妥协后能否真正解决问题,现在还难说。说起来,最初设计也是精细设计的结果,不是随心所欲的。

      • 家园 消息很及时,很乐啊

        酌情录取其中1000人到中国来工作怎么样?

        • 家园 这个不容易,这些人都50-60了,国内有年龄歧视,再说

          这些人写代码速度又不如国内华为的码工,又不可能像华为的人那样加班.他们现在虽然很惨了,但美国现在的经济比09年还是好多了,他们干了三十年了,多少有点积蓄,军火公司也许还有养老金,他们降低点要求再混几年就可以退休了.其中搞关键技术的,说不定还签了啥协议不能跟别国打工了,美国人还是很把这种协议当回事的.

          当初中国可以去苏联找这种人是因为苏联是完全崩溃了.美国只是在走下坡路,离崩溃还有点距离.

    • 家园 又出毛病了,f35内置蛋仓温度过高,接近导弹环境温度极限

      f35内置蛋仓温度过高,接近导弹环境温度极限。可能导致JDAM炸弹自曝,或者影响AIM120D电子元件正常工作。

      Developers of the multinational F-35 are finally embarking on a multi-year campaign to demonstrate the single-engine stealthy fighter's ability to dispatch weapons. But uncertainties loom about the impact of internal-carriage requirements on those weapons' effectiveness.

      The Lockheed Martin F-35, and the F-22 before it, have introduced a new level of complexity into the air-launched-weapons world by demanding that munitions long anchored on external wing and belly pylons of legacy fighters be carried in small, stealthy internal bays. The Air Force decided decades ago to forgo large payloads—epitomized by the F-15 Strike Eagle—in pursuit of a significantly reduced radar cross section, allowing for fighters to evade air defenses and penetrate into enemy air space.

      While the F-22 was a step in this direction, the F-35 is expected to carry far more weapon types in its bay, which has a challenging thermal and acoustic environment. Although the bay has not presented developers with conditions beyond the specifications of weapons slated for use in the F-35, engineers acknowledge there is little margin. “We are within about 10-12 degrees in most cases. But it is close” to the design specifications of some weapons, says Charlie Wagner, weapons integrated project team lead for the F-35 Joint Program Office. “It is not that simple, though. Maybe I can get [a weapon] that hot. But can I get it hot for an hour? Or can it be that hot for two days?”

      Wagner says experts in the military are studying the potential prolonged and cumulative effects of operating so close to margin for weapons such as the 1,000-lb. GBU-32 Joint Direct Attack Munition (JDAM) and GBU-31 2,000-lb. version. Both ground-attack weapons are slated for early use on the aircraft. A thornier issue, perhaps, will be the environmental impact of the bay on weapons employing more sophisticated electronics, sensors and motors, such as the Raytheon AIM-120C7/D Advanced Medium-Range Air-to-Air Missile (Amraam) or British AIM-132 Advanced Short-Range Air-to-Air Missile (Asraam). “I don't know if the weapons people know that for sure,” says Wagner. “We are pushing what they designed to. . . . If I'm going to the extreme of what they tested [a weapon] to, they may not have a real good understanding of how that is going to affect the weapon over the next 20 years.”

      Operating near or at the margins is not new for the F-35 program, which has suffered problems keeping the F-35B to the required weight. Though the weight issues have been resolved—with roughly 300 lb. of margin now on the aircraft, according to Marine Corps Commandant Gen. James Amos—developers are loath to run into similar problems with the operating margins of weapons in the F-35 bay. This is especially true as the Pentagon faces major funding cuts in the coming years; shortcomings in programs could make them vulnerable for reductions or terminations by Congress.

      As scientists and engineers continue to study these issues, the flight-testing program is moving forward. The first jettison test took place Aug. 8, when a GBU-32 was dropped from BF-03, a short-takeoff-and-vertical-landing F-35B at NAS Patuxent River, Md. The trial was designed only to ensure safe separation, and the weapon was inert. This is the first in a short series of such jettison tests. At least two are slated for next month, including the first drop of a GBU-31 from a conventional-takeoff-and-landing F-35A.

      The F-35 maintained a speed of roughly Mach 0.65 at level flight for the first drop; higher speeds are slated for future demonstrations. However, Wagner notes that it is not urgent to test high bank angles for JDAM drops because, in the field, the F-35 will likely be employed primarily in level flying conditions to maintain the lowest radar cross section possible for ground-attack missions.

      Varied angle-of-attack maneuvers will come into play when engineers begin testing the use of Amraam on the F-35. As pilots will want to “fire and forget” their air-attack weapons, they will need to employ them in a much larger flight envelope than the ground-attack munitions.

      Unlike the JDAM series, Amraam is powered by a solid-rocket-fuel motor and is dispatched from its position on the door of the F-35 weapon bay. JDAMs are carried on a bomb rack mounted inside the belly.

      Initially, developers plan only to demonstrate safe separation of the Amraam, using test bodies lacking a rocket motor. They hope to actually fire an Amraam from the F-35 by the end of January, Wagner says.

      Although the three F-35 types share some elements, each weapon model must be tested separately on each fighter version. Those trials will be conducted in parallel, he says. The program prioritizes tests of internal-carriage weapons, as those are required for the Block II and Block III F-35 releases; Block IIB software is what the U.S. Marine Corps will use for declaring initial operational capability (IOC) with its F-35Bs.

      The first external weapons will be used in Block III, which is the software version required for IOC for Air Force and Navy models; Block III will be released no earlier than 2017. Introduction of the Boeing GBU-39 Small-Diameter Bomb, a 250-lb. glide weapon, is slated for the Block IV software release at the end of the decade. This weapon was developed by the Air Force specifically to maximize the number of ground targets that the F-35, with its limited internal-bay space, can attack on a single mission; four SDBs can be mounted in place of each JDAM position, allowing for the F-35 and F-22 to each carry eight of the weapons internally. The SDB II, a version incorporating a tri-mode seeker for all-weather, day/night engagements, is now being developed by Raytheon. The first units will be delivered for operational use in 2016 (see p. 61).

      The F-35 also is being developed to carry nuclear weapons. Testing of nuclear munitions on the fighter is not slated to begin until after the aircraft development phase is complete.

      In the meantime, F-35 developers are sharing the thermal and acoustic data being collected from the bay with the weapon manufacturers. While the bay environment is close to the design specifications of weapons already in the arsenal, the developers hope that sharing this information will help engineers crafting next-generation munitions to design them with those environmental factors in mind, Wagner says.

      The Aug. 8 weapon separation test was a major milestone for the Pentagon-led F-35 program. To view a video of it, check out the digital edition of AW&ST on leading tablets and smartphones, or visit AviationWeek.com/jdamdrop

      Integrating a number of diverse weapons onto the F-35 will be critical to the stealthy fighter's utility for its global customers. To view an interactive chart of weapons slated for use on the F-35, check out the digital edition of AW&ST on leading tablets and smartphones, or visit AviationWeek.com/jsfweapons

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      看来还是要加钱才行

    • 家园 网上查了一下,F35用的是power pc on

      Integretiy,AdaMULTI IDE(Ada/C/C++),这里面我除了Ada没用过,其他的都用过。power pc的型号没提到,但这种环境可能和通讯的环境差不多,QUICC? 这些都还是比较好用的东东吧。软件环境都来自green hills.

      Link: http://www.ghs.com/news/archive/211031l.html

      2400万行其实不算太多,我参加过开发一个光交换机,在类似的开发环境下大约有200万行C/C++代码(其中大约三十万行是第三方软件,只需要移植),写这么多代码,我们用了不超过40人,写了三四年,总代价不超过5000万吧,因为整个公司的VC投资也就1亿左右。按我们这个效率推算,f35软件用他1000人搞5年,一人一年20万,10亿美金就够了?当年我们那种效率还拼不果华为而关了门,主要原因不是东西部好,而是东西太贵。现在的洛马的效率,嘿嘿,你懂的。。。。。。

      • 家园 可是呀可是

        这个东东,不是线性的。

        项目复杂多一倍,人员,时间多一倍不止。

        项目复杂多10倍,人员,时间就可能多100倍不止。

        所以,也难说。

      • 家园 不知道你们的投资里,软件测试占了多少比例?

        F-35那样的,应该有很多软件可以从第三方或者以前的东西移植过来,但整合和测试是一个麻烦事。F-35要是软件总投资“只有”10亿,恐怕洛马做梦都要笑醒。这计划现在每年投资是520亿!

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