{"id":1371,"date":"2016-09-15T11:02:17","date_gmt":"2016-09-15T16:02:17","guid":{"rendered":"https:\/\/jasonblair.net\/?p=1371"},"modified":"2017-01-12T15:37:45","modified_gmt":"2017-01-12T20:37:45","slug":"ceiling-not-ceiling-not-ceiling","status":"publish","type":"post","link":"https:\/\/jasonblair.net\/?p=1371","title":{"rendered":"A ceiling is not a ceiling is not a ceiling."},"content":{"rendered":"<p>For those of us who have flown IFR actively, we know that sometimes a 500&#8242; overcast ceiling will allow us to easily get down an ILS approach to our destination airport when sometimes the same reported 500&#8242; ceiling on an ATIS will leave us going missed because we didn&#8217;t have the visibility to actually find the airport at the bottom of the approach.<\/p>\n<p>In August this year, the FAA released an updated version of the Aviation Weather Advisory Circular AC 00-6B (<a href=\"https:\/\/www.faa.gov\/regulations_policies\/advisory_circulars\/index.cfm\/go\/document.information\/documentID\/1029851\">click here to get a copy<\/a>\u00a0). In taking a little time to review it the other day, I ran across a graphic that highlighted a key point pilots can make note of when listening to weather information before flying an approach. While many of us kind of know the basic considerations of this instinctively, a little review never hurt anyone.<\/p>\n<p>In the AC, the FAA notes,<em> &#8220;Not all ceilings are equally hazardous to a pilot. An indefinite ceiling is more hazardous than an equal ceiling caused by a layer aloft. Once a pilot descends below a ceiling caused by a layer aloft, the pilot can see both the ground below and the runway ahead. However, an indefinite ceiling restricts the pilot\u2019s slant range (air-to-ground) visibility. Thus, the pilot may not see the runway ahead after he descends below the indefinite ceiling (see Figure 16-6).&#8221;<\/em><br \/>\n<a href=\"https:\/\/jasonblair.net\/wp-content\/uploads\/2016\/09\/ceilingsgraphicjpg.jpg\"><img decoding=\"async\" class=\"aligncenter size-full wp-image-1372\" src=\"https:\/\/jasonblair.net\/wp-content\/uploads\/2016\/09\/ceilingsgraphicjpg.jpg\" alt=\"ceilingsgraphicjpg\" width=\"854\" height=\"520\" srcset=\"https:\/\/jasonblair.net\/wp-content\/uploads\/2016\/09\/ceilingsgraphicjpg.jpg 854w, https:\/\/jasonblair.net\/wp-content\/uploads\/2016\/09\/ceilingsgraphicjpg-300x183.jpg 300w, https:\/\/jasonblair.net\/wp-content\/uploads\/2016\/09\/ceilingsgraphicjpg-768x468.jpg 768w, https:\/\/jasonblair.net\/wp-content\/uploads\/2016\/09\/ceilingsgraphicjpg-493x300.jpg 493w\" sizes=\"(max-width: 854px) 100vw, 854px\" \/><\/a><\/p>\n<p>When we are thinking about flying in IFR weather with low ceilings, there is much to consider.<\/p>\n<p>The FAA goes on to talk more about a low ceiling. <em>&#8220;Stratus is the most frequent cloud associated with low ceilings. Stratus clouds, like fog, are composed of extremely small water droplets or ice crystals suspended in air. An observer on a mountain in a stratus layer would call it fog. Stratus and fog frequently exist together. In many cases, there is no real line of distinction between the fog and stratus; rather, one gradually merges into the other. Flight visibility may approach zero in stratus clouds. Stratus over land tends to be lowest during <\/em>night<em> and early morning, lifting or dissipating due to solar heating by late morning or early afternoon. Low stratus clouds often occur when moist air mixes with a colder air mass, or in any situation where <\/em>temperature-dewpoint<em> spread is small.&#8221;<\/em><\/p>\n<p>So next time you are considering flying into low ceilings, think a little more deeply about what the METAR is reporting. Is it a solid overcast? Or should you expect that even when you descend below a layer that you will have difficulty with forward or slant range visibility also that could hinder your ability to complete an approach to a desired destination.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>For those of us who have flown IFR actively, we know that sometimes a 500&#8242; overcast ceiling will allow us to easily get down an ILS approach to our destination airport when sometimes the same reported 500&#8242; ceiling on an &hellip; <a class=\"more-link\" href=\"https:\/\/jasonblair.net\/?p=1371\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1371","post","type-post","status-publish","format-standard","hentry","category-aviation"],"_links":{"self":[{"href":"https:\/\/jasonblair.net\/index.php?rest_route=\/wp\/v2\/posts\/1371","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jasonblair.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jasonblair.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jasonblair.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jasonblair.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1371"}],"version-history":[{"count":1,"href":"https:\/\/jasonblair.net\/index.php?rest_route=\/wp\/v2\/posts\/1371\/revisions"}],"predecessor-version":[{"id":1373,"href":"https:\/\/jasonblair.net\/index.php?rest_route=\/wp\/v2\/posts\/1371\/revisions\/1373"}],"wp:attachment":[{"href":"https:\/\/jasonblair.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1371"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jasonblair.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1371"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jasonblair.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1371"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}