{"id":70649,"date":"2009-03-30T01:23:25","date_gmt":"2009-03-30T01:23:25","guid":{"rendered":"https:\/\/new.dedefensa.org\/index.php\/2009\/03\/30\/le-jsf-qui-transpirait\/"},"modified":"2009-03-30T01:23:25","modified_gmt":"2009-03-30T01:23:25","slug":"le-jsf-qui-transpirait","status":"publish","type":"post","link":"https:\/\/new.dedefensa.org\/index.php\/2009\/03\/30\/le-jsf-qui-transpirait\/","title":{"rendered":"Le JSF qui transpirait"},"content":{"rendered":"<p><p>Est-ce un nouveau front qui s&rsquo;ouvre dans la guerre du JSF, cribl\u00e9e effectivement de fronts, de pol\u00e9miques, de revendications et de contestations de toutes sortes? Pourquoi pasDans tous les cas, il est tentant de l&rsquo;ajouter, un front chaud.<\/p>\n<\/p>\n<p><p>\tLa premi\u00e8re salve de l&rsquo;affaire tombe d&rsquo;une fa\u00e7on anodine, dans un texte que le journaliste d&rsquo;<em>Aviation Week &#038; Space Technology<\/em> (AW&#038;ST) David A. Fulghum met en ligne, le <a href=\"http:\/\/www.aviationweek.com\/aw\/blogs\/defense\/index.jsp?plckController=Blog&#038;plckScript=blogScript&#038;plckElementId=blogDest&#038;plckBlogPage=BlogViewPost&#038;plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a18385f93-7e32-48dd-9101-a9e067dec271\" class=\"gen\">18 mars 2009<\/a>, sur son <em>blog<\/em>. Le texte traite d&rsquo;hypoth\u00e8ses diverses concernant le budget de l&rsquo;ann\u00e9e fiscale FY2010 aux USA. On y trouve l&rsquo;affirmation que le JSF sera soutenu par l&rsquo;administration Obama dans ce budget,  puis, comme par inadvertance, et effectivement de cette fa\u00e7on nous semble-t-il,   ce soutien, malgr\u00e9 de nouvelles pr\u00e9occupations<\/p>\n<\/p>\n<p><p>\t\u00ab<em>The F-35, despite some new worries about heat buildup in the aircraft in some situations, will be supported vigorously in the 2010 budget, says a long-time Air Force acquisition official. Thermal problems were first identified in hot-weather ground operations, he says. The problem was that the fuel-air heat exchanger was not providing enough cooling. In the short-term, at least, they&rsquo;ll just limit hot weather activity.<\/em>\u00bb<\/p>\n<\/p>\n<p><p>\tLe m\u00eame jour, ce m\u00eame <a href=\"http:\/\/www.aviationweek.com\/aw\/blogs\/defense\/index.jsp?plckController=Blog&#038;plckScript=blogScript&#038;plckElementId=blogDest&#038;plckBlogPage=BlogViewPost&#038;plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a56e1285b-880c-470c-8a9e-2bf45c93ff1b\" class=\"gen\">18 mars 2009<\/a> par cons\u00e9quent et si nous comptons bien, Bill Sweetman, que nous <a href=\"http:\/\/www.dedefensa.org\/article-le_jsf_prisonnier_de_la_logique_de_son_virtualisme_16_03_2009.html\" class=\"gen\">connaissons<\/a> bien, ne laisse pas passer le pauvre canard,  c&rsquo;est-\u00e0-dire le JSF une fois de plus boiteux. Il \u00e9pingle le texte de Fulghum, sa citation, commence par ironiser puis d\u00e9veloppe de r\u00e9elles pr\u00e9occupations sur la question mise \u00e0 jour, qui est celle de la temp\u00e9rature entretenue dans l&rsquo;avion, dans les circuits <em>ad hoc<\/em>, pour la bonne marche de l&rsquo;\u00e9norme syst\u00e8me \u00e9lectronique dont le JSF est bard\u00e9. En effet, l&rsquo;annonce de l&rsquo;officiel cit\u00e9 par Fulghum selon lequel il faudrait peut-\u00eatre limiter les op\u00e9rations du JSF par temps chaud, ou dans les pays o\u00f9 il fait chaud en g\u00e9n\u00e9ral, d\u00e9chaine l&rsquo;ironie de Sweetman. Plus loin, il nous propose des r\u00e9flexions peu encourageantes sur l&#8217;emplacement de la tuy\u00e8re d&rsquo;\u00e9jection du moteur, notamment \u00e0 partir de photos montrant que l&rsquo;air chaud des tuy\u00e8res a entam\u00e9 la peinture de l&rsquo;avion  avec l&rsquo;id\u00e9e que des changements concernant cette tuy\u00e8re n&rsquo;ont pas r\u00e9solu le probl\u00e8me  Sweetman termine par un \u00e0 suivre soup\u00e7onneux, comme il se doit. (\u00ab<em>Show-stopper? Probably not. A delay factor? Quite possibly, and one to keep an eye on.<\/em>\u00bb)<\/p>\n<\/p>\n<p><p>\t\u00ab<em>This item caught my eye from Dave Fulghum&rsquo;s post, referring to a certain all-singing, all-dancing omnipotent fighter aircraft: Thermal problems were first identified in hot-weather ground operations, he says. The problem was that the fuel-air heat exchanger was not providing enough cooling. In the short-term, at least, they&rsquo;ll just limit hot weather activity.<\/em><\/p>\n<\/p>\n<p><p>\t\u00bb<em>It&rsquo;s just as well that US forces won&rsquo;t have to operate in hot climates any time soon. According to highly placed sources, the Obama administration expects that the Schleswig-Holstein question, and the assurance of a Protestant successor to the Elector of Hanover, will be the big conflict flashpoints of the next two decades.<\/em> []<\/p>\n<\/p>\n<p><p>\t\u00bb<em>In any event, the JSF has a thermal management problem, and one design change  moving the exhaust  hasn&rsquo;t fixed it, since for the time being it appears that hot-weather operations are being restricted.<\/em>\u00bb<\/p>\n<\/p>\n<p><p>\tL&rsquo;affaire semble s\u00e9rieuse puisqu&rsquo;elle est reprise et tr\u00e8s largement d\u00e9velopp\u00e9e, par David Fulghum \u00e0 nouveau, dans le num\u00e9ro de ce <a href=\"http:\/\/www.aviationweek.com\/publication\/awst\/loggedin\/AvnowStoryDisplay.do?fromChannel=awst&#038;pubKey=awst&#038;channel=awst&#038;issueDate=2009-03-30&#038;story=xml\/awst_xml\/2009\/03\/30\/AW_03_30_2009_p54-125220.xml&#038;headline=F-35+May+Need+Design+Changes+for+Thermal+Management\" class=\"gen\">30 mars 2009<\/a> de l&rsquo;hebdomadaire AW&#038;ST. Cette fois, le bavardage entre confr\u00e8res et n\u00e9anmoins amis (Fulghum et Sweetman) \u00e0 partir d&rsquo;une remarque anodine est devenu un cas bien pr\u00e9cis, un nouveau probl\u00e8me pour le JSF. Dans le texte s&rsquo;accumulent des explications diverses, nombreuses, complexes, en g\u00e9n\u00e9ral fort peu compr\u00e9hensibles, entrecoup\u00e9es de d\u00e9tails assez charmants o\u00f9 il semblerait que, tant que le probl\u00e8me n&rsquo;est pas <em>fixed<\/em>, il faudra que le JSF vole le plus haut qu&rsquo;il peut, quand il le peut, parce qu&rsquo;il fait moins chaud en altitude, qu&rsquo;il vole plut\u00f4t \u00e0 l&rsquo;ombre qu&rsquo;au soleil, qu&rsquo;on n&rsquo;oublie pas de bien remuer la glace dans le <em>shaker<\/em> avant de boire, etc.<\/p>\n<\/p>\n<p><p>\tLe fait est qu&rsquo;on envisage, qu&rsquo;on doit envisager des modifications<\/p>\n<\/p>\n<p><p>\t\u00ab<em>Upgrades to the Lockheed Martin F-35 Lightning II are being considered to improve the fighter&rsquo;s ability to absorb heat from its powerful electronics and systems. The aircraft is meeting the specification for thermal management, but the incoming Joint Strike Fighter program executive officer, U.S. Marine Corps Maj. Gen. (sel.) David Heinz, says he is asking contractors to assess the costs of changes to give it a bigger margin over the requirement.<\/em><\/p>\n<\/p>\n<p><p>\t\u00bb<em>The stealthy F-35 is designed to keep itself cool by dumping heat from the electronics and systems to its fuel. Under most conditions, that presents no challenge, but at the end of a mission the aircraft will have little fuel left to absorb the heat energy, says Tom Burbage, Lockheed Martin executive vice president for F-35 program integration. The toughest part of the specification is to distribute heat to the remaining fuel while operating in hot conditions.<\/em><\/p>\n<\/p>\n<p><p>\t\u00bb<em>Thermal problems were first identified in hot-weather ground operations, says a long-time Pentagon acquisition official. The problem was the fuel-air heat exchanger was not providing enough cooling. In the short term, at least, they&rsquo;ll just limit hot-weather activity.<\/em>\u00bb []<\/p>\n<\/p>\n<p><p>\t\u00bb<em>Aside from potential design changes, there is an operational cooling strategy: fly higher, where the colder airflow over the airframe would help cool it and the fuel. It is not possible to do that on every mission, however, and it is not an option at the end of a flight. This could be a problem for the short-takeoff-and-vertical-landing (Stovl) F-35B, which must be able to hover and land at high power at the end of a mission while keeping fuel temperature within limits.<\/em>\u00bb<\/p>\n<\/p>\n<p><p>\tCe qui nous remplit toujours d&rsquo;un \u00e9tonnement sans fin accompagn\u00e9 de ce qui pourrait ressembler au sentiment irr\u00e9sistible d&rsquo;une certaine satisfaction pour la morale de l&rsquo;histoire, c&rsquo;est le contraste parfois hurlant, souvent r\u00e9confortant, toujours tr\u00e8s popote, qui accompagne ces \u00e9pisodes de la chevauch\u00e9e des hautes technologies. On vous donne la chose la plus formidable, la plus avanc\u00e9e du monde, qui r\u00e9pond \u00e0 un claquement de doigt ou \u00e0 clin d&rsquo;il plein de cils sophistiqu\u00e9s pour faire des choses formidables, comme figurer comme une t\u00eate d&rsquo;aiguille sur un \u00e9cran-radar ou reconna\u00eetre une aiguille dans une botte de foin, et puis l&rsquo;on vous annonce que pour mener \u00e0 terme votre mission vous devrez emporter votre thermom\u00e8tre de poche pour trouver l&rsquo;endroit le plus frais possible pour continuer \u00e0 voler, \u00e9ventuellement en maniant l&rsquo;\u00e9ventail, tout cela en d\u00e9truisant quinze villages de talibans par guidage laser et en abattant un moustique suspect par tir de missile <em>beyond visual range<\/em>.<\/p>\n<\/p>\n<p><p>\tCela \u00e9crit sans tr\u00e8s grand s\u00e9rieux, voici donc le premier cas s\u00e9rieux de ce qu&rsquo;annonce depuis trois ans <a href=\"http:\/\/www.dedefensa.org\/article-le_jsf_attaque_par_la_verite_officielle_des_prix_circa-obama_et_gao_24_01_2009.html\" class=\"gen\">le GAO<\/a>. Le JSF n&rsquo;ayant pas \u00e9t\u00e9 test\u00e9 s\u00e9rieusement (2% seulement des essais en vol de la campagne d&rsquo;essai seront accomplis fin 2009, si tout marche bien,  <em>dito<\/em>, s&rsquo;il ne fait pas trop chaud) et un probl\u00e8me potentiellement s\u00e9rieux se dessinant, c&rsquo;est non seulement \u00e0 des modifications \u00e0 apporter au syst\u00e8me g\u00e9n\u00e9ral qui va \u00eatre produit qu&rsquo;il faut s&rsquo;attendre, mais \u00e0 l&rsquo;application des m\u00eames modifications sur les avions d\u00e9j\u00e0 fabriqu\u00e9s, eux-m\u00eames con\u00e7us \u00e0 la fois comme avions pour la campagne d&rsquo;essais et comme avions devenant avions de production, au statut op\u00e9rationnel normal. <\/p>\n<\/p>\n<p><p>\tL&rsquo;imbroglio JSF se poursuit \u00e0 bon rythme.<\/p>\n<\/p>\n<p><\/p>\n<p><p>\tMis en ligne le 30 mars 2009 \u00e0  01H14<\/p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Est-ce un nouveau front qui s&rsquo;ouvre dans la guerre du JSF, cribl\u00e9e effectivement de fronts, de pol\u00e9miques, de revendications et de contestations de toutes sortes? Pourquoi pasDans tous les cas, il est tentant de l&rsquo;ajouter, un front chaud. La premi\u00e8re salve de l&rsquo;affaire tombe d&rsquo;une fa\u00e7on anodine, dans un texte que le journaliste d&rsquo;Aviation Week&hellip;&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[2],"tags":[4195,5692,8217,250,8216,6769,4247],"class_list":["post-70649","post","type-post","status-publish","format-standard","hentry","category-bloc-notes","tag-aviation","tag-chaleur","tag-fulghum","tag-jsf","tag-modifications","tag-sweetman","tag-week"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/posts\/70649","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/comments?post=70649"}],"version-history":[{"count":0,"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/posts\/70649\/revisions"}],"wp:attachment":[{"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/media?parent=70649"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/categories?post=70649"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/new.dedefensa.org\/index.php\/wp-json\/wp\/v2\/tags?post=70649"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}