{"id":2613,"date":"2025-11-15T18:10:50","date_gmt":"2025-11-15T17:10:50","guid":{"rendered":"https:\/\/acriv.org\/WP\/?page_id=2613"},"modified":"2025-11-15T18:10:50","modified_gmt":"2025-11-15T17:10:50","slug":"%e2%9b%88%ef%b8%8fle-givrage","status":"publish","type":"page","link":"https:\/\/acriv.org\/WP\/%e2%9b%88%ef%b8%8fle-givrage\/","title":{"rendered":"\u26c8\ufe0fLE GIVRAGE"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"553\" height=\"439\" src=\"https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-13.png\" alt=\"\" class=\"wp-image-2614\" style=\"width:754px;height:auto\" srcset=\"https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-13.png 553w, https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-13-300x238.png 300w, https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-13-378x300.png 378w, https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-13-310x246.png 310w, https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-13-132x105.png 132w\" sizes=\"auto, (max-width: 553px) 100vw, 553px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-8c278585bd6c5bcaeb3d048fb0bd8ef6\"><strong>METAR:<\/strong>\u00a0LFRN 151630Z AUTO 17006KT 130V190 9999 BKN008 BKN014 OVC021 <strong>13\/13<\/strong> Q1005 TEMPO 3000 SHRA BKN008 BKN020CB<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"418\" height=\"160\" src=\"https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-14.png\" alt=\"\" class=\"wp-image-2615\" style=\"width:321px;height:auto\" srcset=\"https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-14.png 418w, https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-14-300x115.png 300w, https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-14-310x119.png 310w, https:\/\/acriv.org\/WP\/wp-content\/uploads\/2025\/11\/image-14-150x57.png 150w\" sizes=\"auto, (max-width: 418px) 100vw, 418px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-text-align-center has-vivid-red-color has-text-color has-link-color wp-elements-5a285df40ff286cab19bc63771aef889\">Temp\u00e9rature : <strong>13\u00b0C<\/strong> \/ Point de ros\u00e9e :  <strong>13\u00b0<\/strong>C \/ Humidit\u00e9 : <strong>94%<\/strong> => <strong>Risque de GIVRAGE SEVERE<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>Le givrage en aviation est un ph\u00e9nom\u00e8ne s\u00e9rieux qui peut affecter <strong>la cellule<\/strong> (aile, d\u00e9rive, pare-brise\u2026), <strong>les commandes de vol<\/strong>, ainsi que <strong>les moteurs<\/strong> (surtout moteurs \u00e0 piston, mais aussi turbines). Il survient lorsque de <strong>l\u2019eau en surfusion<\/strong> (gouttelettes d\u2019eau liquide \u00e0 une temp\u00e9rature n\u00e9gative) frappe l\u2019avion et g\u00e8le instantan\u00e9ment.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">\u2708\ufe0f <strong>1. Le givrage cellule (aile, gouvernes, pare-brise\u2026)<\/strong><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83d\udccc <strong>Conditions d\u2019apparition<\/strong><\/h2>\n\n\n\n<p>Le givrage cellule survient principalement :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Dans des <strong>nuages<\/strong> entre <strong>+5\u00b0C et \u201315\u00b0C<\/strong>, qui contiennent de l\u2019eau en surfusion.<\/li>\n\n\n\n<li>En <strong>pluie vergla\u00e7ante<\/strong> : extr\u00eamement dangereux \u2192 accumulation rapide.<\/li>\n\n\n\n<li>En <strong>brouillard givrant<\/strong> : gouttelettes fines, formation lente mais persistante.<\/li>\n\n\n\n<li>Par <strong>forte humidit\u00e9<\/strong> et T\u00b0 proche du point de gel (m\u00eame au sol).<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u26a0\ufe0f <strong>Cons\u00e9quences sur le vol<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Diminution importante de la <strong>portance<\/strong> (jusqu\u2019\u00e0 30\u201340 %).<\/li>\n\n\n\n<li>Augmentation forte de la <strong>tra\u00een\u00e9e<\/strong>.<\/li>\n\n\n\n<li>D\u00e9gradation des performances :\n<ul class=\"wp-block-list\">\n<li>vitesse de d\u00e9crochage augmente,<\/li>\n\n\n\n<li>taux de mont\u00e9e r\u00e9duit,<\/li>\n\n\n\n<li>consommation plus \u00e9lev\u00e9e.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Blocage des gouvernes.<\/li>\n\n\n\n<li>Obstruction du pitot ou des prises statiques \u2192 <strong>indications an\u00e9mom\u00e9triques fausses<\/strong>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">\u2708\ufe0f <strong>2. Le givrage moteur<\/strong><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>2.1. Moteurs \u00e0 piston (carburateur)<\/strong><\/h2>\n\n\n\n<p>C\u2019est le cas le plus connu.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udccc <strong>Quand cela appara\u00eet<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Temp\u00e9rature : <strong>\u20135\u00b0C \u00e0 +20\u00b0C<\/strong>, humidit\u00e9 \u00e9lev\u00e9e \u2192 m\u00eame quand il fait <em>chaud<\/em>.<\/li>\n\n\n\n<li>M\u00e9lange air-essence refroidi par l\u2019effet Venturi \u2192 givre dans le <strong>carburateur<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u26a0\ufe0f <strong>Sympt\u00f4mes<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Perte progressive de <strong>puissance<\/strong>.<\/li>\n\n\n\n<li>Baisse du <strong>RPM<\/strong> ou vibration.<\/li>\n\n\n\n<li>Fonctionnement moteur irr\u00e9gulier.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2714\ufe0f <strong>Pr\u00e9vention<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Activation du <strong>r\u00e9chauffage carburateur<\/strong> en conditions propices (humide, T\u00b0 proche du point de gel).<\/li>\n\n\n\n<li>Utilisation syst\u00e9matique du carb heat :\n<ul class=\"wp-block-list\">\n<li>en descente prolong\u00e9e (manette gaz r\u00e9duite \u2192 gros risque),<\/li>\n\n\n\n<li>en cas de suspicion de givrage.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>2.2. Moteurs \u00e0 turbine<\/strong><\/h2>\n\n\n\n<p>Le givrage concerne :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Admission d\u2019air<\/strong> (d\u00e9bit insuffisant).<\/li>\n\n\n\n<li><strong>Aubes du compresseur<\/strong> (perte de rendement).<\/li>\n\n\n\n<li><strong>Sondes<\/strong> (TAT, pitot\u2026).<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2714\ufe0f <strong>Pr\u00e9vention<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Activation des <strong>syst\u00e8mes anti-ice<\/strong> (leading edge, inlet anti-ice).<\/li>\n\n\n\n<li>Respect des proc\u00e9dures constructeur (temp\u00e9rature, humidit\u00e9, pluie givr\u00e9e).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">\u2708\ufe0f <strong>3. Comment identifier le givrage<\/strong><\/h1>\n\n\n\n<h3 class=\"wp-block-heading\">\u2744\ufe0f <strong>Sur la cellule<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Givre visible sur les bords d&rsquo;attaque, pare-brise ou antennes.<\/li>\n\n\n\n<li>Vibrations a\u00e9rodynamiques.<\/li>\n\n\n\n<li>Vitesse indiqu\u00e9e incorrecte ou chute de la vitesse r\u00e9elle.<\/li>\n\n\n\n<li>Perte de taux de mont\u00e9e \/ pouss\u00e9e.<\/li>\n\n\n\n<li>N\u00e9cessit\u00e9 d\u2019un angle d\u2019attaque plus \u00e9lev\u00e9 pour maintenir la m\u00eame vitesse.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2744\ufe0f <strong>Sur le moteur (piston)<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Chute du RPM (h\u00e9lice \u00e0 pas fixe).<\/li>\n\n\n\n<li>Perte de manifold pressure (h\u00e9lice \u00e0 pas variable).<\/li>\n\n\n\n<li>Fonctionnement irr\u00e9gulier du moteur.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2744\ufe0f <strong>Sur turbine<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Vibrations, param\u00e8tres moteurs anormaux.<\/li>\n\n\n\n<li>Avertissements \u201cICE DETECTED\u201d.<\/li>\n\n\n\n<li>Perte de performance.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">\u2708\ufe0f <strong>4. Comment \u00e9viter ou limiter le givrage<\/strong><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\u2714\ufe0f <strong>Avant le vol<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u00c9tudier soigneusement les cartes m\u00e9t\u00e9o :\n<ul class=\"wp-block-list\">\n<li>nuages givrants (stratus, nimbostratus),<\/li>\n\n\n\n<li>temp\u00e9rature \u00e0 altitude,<\/li>\n\n\n\n<li>humidit\u00e9,<\/li>\n\n\n\n<li>pr\u00e9sence de pluie vergla\u00e7ante.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u2714\ufe0f <strong>En vol<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Activer <strong>anti-icing<\/strong> AVANT d\u2019entrer dans une zone givrante, pas apr\u00e8s.<\/li>\n\n\n\n<li>Modifier l\u2019altitude (souvent une couche plus chaude existe).<\/li>\n\n\n\n<li>Faire demi-tour si la situation se d\u00e9t\u00e9riore.<\/li>\n\n\n\n<li>En VFR : \u00e9viter la p\u00e9n\u00e9tration en nuages dans une plage de T\u00b0 critique.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u2714\ufe0f <strong>Au sol<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>D\u00e9neiger\/d\u00e9givrer la cellule avant le d\u00e9collage \u2192 m\u00eame une fine pellicule de givre peut r\u00e9duire la portance de <strong>30 %<\/strong>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">\u2708\ufe0f <strong>5. En r\u00e9sum\u00e9<\/strong><\/h1>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-vivid-red-color has-text-color has-link-color\"><thead><tr><th>Type de givrage<\/th><th>Quand ?<\/th><th>Sympt\u00f4mes<\/th><th>Pr\u00e9vention<\/th><\/tr><\/thead><tbody><tr><td><strong>Carburateur<\/strong><\/td><td>+20\u00b0C \u00e0 \u20135\u00b0C, humidit\u00e9<\/td><td>Perte de RPM, moteur irr\u00e9gulier<\/td><td>R\u00e9chauffage carburateur<\/td><\/tr><tr><td><strong>Cellule<\/strong><\/td><td>\u201315\u00b0C \u00e0 +5\u00b0C dans nuages<\/td><td>Perte de portance, tra\u00een\u00e9e \u2191<\/td><td>Anti-ice, \u00e9viter zones givrantes<\/td><\/tr><tr><td><strong>Turbine \/ admission<\/strong><\/td><td>Air humide proche du gel<\/td><td>Vibrations, pertes performances<\/td><td>Inlet anti-ice, proc\u00e9dures<\/td><\/tr><tr><td><strong>Sondes Pitot \/ statiques<\/strong><\/td><td>Humidit\u00e9 + froid<\/td><td>Indications fausses<\/td><td>Pitot heat ON<\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>METAR:\u00a0LFRN 151630Z AUTO 17006KT 130V190 9999 BKN008 BKN014 OVC021 13\/13 Q1005 TEMPO 3000 SHRA BKN008 BKN020CB Temp\u00e9rature : 13\u00b0C \/ Point de ros\u00e9e : 13\u00b0C \/ Humidit\u00e9 : 94% => Risque de GIVRAGE SEVERE Le givrage en aviation est un ph\u00e9nom\u00e8ne s\u00e9rieux qui peut affecter la cellule (aile, d\u00e9rive, pare-brise\u2026), les commandes de vol, ainsi que les moteurs (surtout moteurs<\/p>\n<p><a class=\"more-link\" href=\"https:\/\/acriv.org\/WP\/%e2%9b%88%ef%b8%8fle-givrage\/\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-2613","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/pages\/2613","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/comments?post=2613"}],"version-history":[{"count":1,"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/pages\/2613\/revisions"}],"predecessor-version":[{"id":2616,"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/pages\/2613\/revisions\/2616"}],"wp:attachment":[{"href":"https:\/\/acriv.org\/WP\/wp-json\/wp\/v2\/media?parent=2613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}