Laser-based turbulence detector could mean safer flights

<!DOCTYPE html> <html> <head><script type="text/javascript" src="https://web-static.archive.org/_static/js/bundle-playback.js?v=7YQSqjSh" charset="utf-8"></script> <script type="text/javascript" src="https://web-static.archive.org/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="https://web-static.archive.org/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("http://www.gizmag.com/clear-air-turbulence-detection-system/28593/","20130824181618","https://web.archive.org/","web","https://web-static.archive.org/_static/", "1377368178"); </script> <link rel="stylesheet" type="text/css" href="https://web-static.archive.org/_static/css/banner-styles.css?v=p7PEIJWi" /> <link rel="stylesheet" type="text/css" href="https://web-static.archive.org/_static/css/iconochive.css?v=3PDvdIFv" />  <title>Laser-based turbulence detector could mean safer flights</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <meta name="robots" content="index,follow"/> <meta name="description" content="A new system to detect invisible and extremely difficult to detect clear-air turbulence (CAT) is currently being tested as part of a European joint project ..."/> <meta name="keywords" content="Aircraft,Flight,Test Flights,German Aerospace Center,DLR,Aircraft"/> <meta name="news_keywords" content="Aircraft, Flight, Test Flights, German Aerospace Center, DLR"/> <link rel="canonical" href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/clear-air-turbulence-detection-system/28593/"/> <link rel="image_src" href="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/hero/delicat.jpg"/> <link rel="alternate" media="handheld" href="https://web.archive.org/web/20130824181618/http://m.gizmag.com/article/28593"/> <link rel="stylesheet" type="text/css" href="https://web.archive.org/web/20130824181618cs_/http://files.gizmag.com/static_styles.min.css?x=1377356456"/> <link rel="stylesheet" type="text/css" href="/web/20130824181618cs_/http://www.gizmag.com/css/dynamic_styles.php?x=1377356456"/> <script src="/web/20130824181618js_/http://www.gizmag.com/inc/css_browser_selector.js" type="text/javascript"></script> <link rel="alternate" type="application/rss+xml" href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/xml/" title="Gizmag Emerging Technology Magazine"/> <link rel="shortcut icon" href="/web/20130824181618im_/http://www.gizmag.com/images/favicon.ico"/> <link rel="apple-touch-icon" href="/web/20130824181618im_/http://www.gizmag.com/images/apple-touch-icon.png"/> <link rel="apple-touch-icon-precomposed" href="/web/20130824181618im_/http://www.gizmag.com/images/apple-touch-icon-precomposed.png"/>   <script type="text/javascript"> var googletag = googletag || {}; googletag.cmd = googletag.cmd || []; (function() { var gads = document.createElement("script"); gads.async = true; gads.type = "text/javascript"; var useSSL = "https:" == document.location.protocol; gads.src = (useSSL ? "https:" : "http:") + "//web.archive.org/web/20130824181618/http://www.googletagservices.com/tag/js/gpt.js"; var node = document.getElementsByTagName("script")[0]; node.parentNode.insertBefore(gads, node); })(); </script>  <script type="text/javascript"> googletag.cmd.push(function() { gpt_leaderboard = googletag.defineSlot('/1007667/ca-pub-1607124478120364/Aircraft_Leaderboard_Top_728x90', [728,90], 'leaderboard') .addService(googletag.pubads()); gpt_islandtr = googletag.defineSlot('/1007667/ca-pub-1607124478120364/Aircraft_IslandTop_Right_300x250', [300,250], 'island_top_right') .addService(googletag.pubads()); gpt_islandbr = googletag.defineSlot('/1007667/ca-pub-1607124478120364/Aircraft_IslandBottom_Right_300x250', [300,250], 'island_bottom_right') .addService(googletag.pubads()); gpt_skyscraper = googletag.defineSlot('/1007667/ca-pub-1607124478120364/Aircraft_Skyscraper_Right_160x600', [160,600], 'skyscraper_right') .addService(googletag.pubads()); gpt_bottom_inc = googletag.defineSlot('/1007667/ca-pub-1607124478120364/bottom_include', [1,1], 'bottom_include') .addService(googletag.pubads()); googletag.pubads().enableSingleRequest(); googletag.pubads().collapseEmptyDivs(); googletag.pubads().set('page_url','https://web.archive.org/web/20130824181618/http://www.gizmag.com/clear-air-turbulence-detection-system/28593/'); googletag.enableServices(); }); </script> <script src="//web.archive.org/web/20130824181618js_/http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script> <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/global_public.js?1377327827"></script> <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/articles_public.js?1377327827"></script> </head> <body> <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/login_comments.js?1377327827"></script>  <div id="fb-root"></div> <script> window.fbAsyncInit = function() { FB.init({ appId: '38456013908', status: true, cookie: true, xfbml: true, oauth: true, channelUrl: window.location.protocol + '//web.archive.org/web/20130824181618/http://www.gizmag.com/fb_channel.php' //channel file to avoid cross domain communication issues }); FB.Event.subscribe('auth.logout', function(response) { if(response.authResponse===null){ //user is logging out of facebook logoutUser(); } }); }; // Load the SDK Asynchronously (function(d){ var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0]; if (d.getElementById(id)) {return;} js = d.createElement('script'); js.id = id; js.async = true; js.src = "//web.archive.org/web/20130824181618/http://connect.facebook.net/en_US/all.js"; ref.parentNode.insertBefore(js, ref); }(document)); var $jqr = jQuery.noConflict(); $jqr(document).ready(function() { var fbuser = checkFBUser(); }); </script>   <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-2235360-4']); _gaq.push(['_setCustomVar', 1, 'Section','Aircraft',3 ]); _gaq.push(['_setCustomVar', 2, 'Writer', 'Darren Quick', 3 ]); _gaq.push(['_setCustomVar', 4, 'PPV_test3', '1', 3 ]); _gaq.push(['_setCustomVar', 5, 'ArticleID', '28593', 3 ]); _gaq.push(['_setCustomVar', 3, 'View', 'Article', 3 ]); _gaq.push(['_trackPageview']); _gaq.push(['_trackPageLoadTime']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://web.archive.org/web/20130824181618/https://ssl' : 'https://web.archive.org/web/20130824181618/http://www') + '.google-analytics.com/ga.js'; (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(ga); })(); </script>  <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/ga_social_tracking_min.js"></script>  <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://edge.quantserve.com/quant.js"></script> <script type="text/javascript">_qacct="p-23Y-rtuj52xr6";quantserve();</script> <noscript><img src="https://web.archive.org/web/20130824181618im_/http://pixel.quantserve.com/pixel/p-23Y-rtuj52xr6.gif" style="display: none" height="1" width="1" alt="Quantcast"/></noscript>   <div class="index" id="top_index"> <div class="index_center"> <ul class="header_links float_left"> <li><a href="https://web.archive.org/web/20130824181618/http://www.youtube.com/user/gizmag" title="Gizmag's YouTube Channel" id="header_youtube">Gizmag's YouTube Channel</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://twitter.com/gizmag/" title="Follow Gizmag on Twitter" id="header_twitter">Follow Gizmag on Twitter</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.stumbleupon.com/to/stumble/stumblethru:gizmag.com?utm_source=GizMag&utm_medium=StumbleThru&utm_campaign=StumbleThruButton" title="Explore Gizmag" rel="nofollow" id="header_stumbleupon">Explore Gizmag</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/xml/" title="Subscribe to Gizmag's RSS feed" id="header_rss">Subscribe</a></li> </ul>  <div id="search_form_top"> <form action="https://web.archive.org/web/20130824181618/http://www.gizmag.com/search/" id="cse-search-box-top"> <div> <input type="hidden" name="cx" value="partner-pub-1607124478120364:cf1bgg5f284"/> <input type="hidden" name="cof" value="FORID:11"/> <input type="hidden" name="ie" value="ISO-8859-1"/> <input type="text" name="q" size="28" class="gsearch"/> <input type="submit" name="sa" value="Search"/> </div> </form> <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://www.google.com/cse/brand?form=cse-search-box-top&lang=en"></script> </div> </div> </div>  <div id="top_strip"><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/tag/product-comparison/" target="_blank">Read our latest product comparisons</a></div> <div class="center"> <div id="header"> <a href="/web/20130824181618/http://www.gizmag.com/" id="logo"></a> <div class="snap_noshots" id="leaderboard"> <script type="text/javascript"> googletag.cmd.push(function() { googletag.display("leaderboard"); }); </script> </div> </div>  <div id="top_stories"> <ul> <li id="top_story0"> <a class="ts_img" href="/web/20130824181618/http://www.gizmag.com/review-minx-go/28793/" title="Review: Minx Go Bluetooth speaker from Cambridge Audio"></a> <div class="ts_title"> <a href="/web/20130824181618/http://www.gizmag.com/review-minx-go/28793/">Review: Minx Go Bluetooth speaker from Cambridge Audio</a> </div> </li> <li id="top_story1"> <a class="ts_img" href="/web/20130824181618/http://www.gizmag.com/cubify-sculpt-3d-printer-models-freeform/28803/" title="Cubify Sculpt to simplify 3D printable model design"></a> <div class="ts_title"> <a href="/web/20130824181618/http://www.gizmag.com/cubify-sculpt-3d-printer-models-freeform/28803/">Cubify Sculpt to simplify 3D printable model design</a> </div> </li> <li id="top_story2"> <a class="ts_img" href="/web/20130824181618/http://www.gizmag.com/smart-glass-nanocrystals/28732/" title="Smart Glass controls both lighting and heat levels"></a> <div class="ts_title"> <a href="/web/20130824181618/http://www.gizmag.com/smart-glass-nanocrystals/28732/">Smart Glass controls both lighting and heat levels</a> </div> </li> <li id="top_story3"> <a class="ts_img" href="/web/20130824181618/http://www.gizmag.com/pensa-tower-optical-digital-viewer/28786/" title="Classic Tower Optical Viewer given solar-powered digital upgrade"></a> <div class="ts_title"> <a href="/web/20130824181618/http://www.gizmag.com/pensa-tower-optical-digital-viewer/28786/">Classic Tower Optical Viewer given solar-powered digital upgrade</a> </div> </li> <li id="top_story4"> <a class="ts_img" href="/web/20130824181618/http://www.gizmag.com/galpin-reinvents-ford-gt/28760/" title="Galpin reinvents the Ford GT with 1,000 horses and a $1 million price tag"></a> <div class="ts_title"> <a href="/web/20130824181618/http://www.gizmag.com/galpin-reinvents-ford-gt/28760/">Galpin reinvents the Ford GT with 1,000 horses and a $1 million price tag</a> </div> </li> </ul> <div id="more_top_stories"> <a id="mts_img" href="/web/20130824181618/http://www.gizmag.com/top_stories/"></a> <a id="mts_txt" href="/web/20130824181618/http://www.gizmag.com/top_stories/">more top stories</a> </div> <div class="clear_both"></div> </div> <div id="content" class="narrow_content"> <div id="article_top" class="summary_details" data-article="28593">  <div class="sd_top"> <a class="vsmall" href="/web/20130824181618/http://www.gizmag.com/aircraft/" style="float: left; margin-right: 9px;">AIRCRAFT</a> </div>  <h1 id="ar_title">Laser-based turbulence detector could mean safer flights</h1> <div class="summary_details_left"> <p>By <a href="/web/20130824181618/http://www.gizmag.com/author/darren-quick/" rel="author">Darren Quick</a></p> <p><em>August 6, 2013</em></p> </div> <div class="summary_details_right"> <div class="has_comments"><a href="clear-air-turbulence-detection-system#comments">4 Comments</a></div> <div class="has_pictures"><a href="/web/20130824181618/http://www.gizmag.com/clear-air-turbulence-detection-system/28593/pictures">3 Pictures</a></div> </div> </div> <div id="article_share_rail"> <div class="as_button"><div class="fb-like" data-href="http://www.gizmag.com/clear-air-turbulence-detection-system/28593/" data-send="false" data-layout="box_count" data-show-faces="false"></div><script type="text/javascript">_ga.trackFacebook();</script></div> <div class="as_button"><a href="https://web.archive.org/web/20130824181618/http://twitter.com/share" class="twitter-share-button" data-count="vertical" data-via="gizmag">Tweet</a></div> <div class="as_button"><div class="g-plusone" data-size="tall" data-href="http://www.gizmag.com/clear-air-turbulence-detection-system/28593/"></div></div> <div class="as_button"><iframe style="overflow: hidden; margin: 0px; padding: 0px; border: 0px; " src="https://web.archive.org/web/20130824181618if_/http://badge.stumbleupon.com/badge/embed/5/?url=http%3A%2F%2Fwww.gizmag.com%2Fclear-air-turbulence-detection-system%2F28593%2F" width="50" height="60" id="iframe-stmblpn-widget-1"></iframe></div> <div class="as_button"><div class="pin-it-button" data-url="https://web.archive.org/web/20130824181618oe_/http://www.gizmag.com/clear-air-turbulence-detection-system/28593/" data-image="http://images.gizmag.com/hero/delicat.jpg" data-description="A new system to detect invisible and extremely difficult to detect clear-air turbulence (CAT) is currently being tested as part of a European joint project called DELICAT (Demonstration of LIDAR based CAT detection)."></div></div> <div class="as_button"><script type="IN/Share" data-counter="top"></script></div> <div class="as_button" id="reddit_button_rail"><script type="text/javascript">reddit_newwindow='1'</script></div> <div class="as_button" id="email_a_friend_rail"><span class="email_a_friend">Email</span></div> </div> <div id="hero_box" style="width: 530px;"> <a id="hero_link" href="/web/20130824181618/http://www.gizmag.com/clear-air-turbulence-detection-system/28593/pictures"> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/hero/delicat.jpg" title="View from the aircraft testing the Ultraviolet 'Light Detection and Ranging' (LIDAR) instr..." width="530" height="298" alt="View from the aircraft testing the Ultraviolet 'Light Detection and Ranging' (LIDAR) instr..."/></a> <div class="pic_caption"> <p>View from the aircraft testing the Ultraviolet 'Light Detection and Ranging' (LIDAR) instrument (Photo: DLR (CC-BY 3.0))</p> <a href="/web/20130824181618/http://www.gizmag.com/clear-air-turbulence-detection-system/28593/pictures" id="gallery_link">Image Gallery</a> (3 images) </div> <div class="clear_both"></div> </div> <div class="article_body"> <div id="top_unit"></div> <script type="text/javascript"> </script> <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> <p>For most air travelers, turbulence provides nothing more serious than the odd moment of extreme panic, but it costs airlines hundreds of millions of dollars each year in injury compensation and aircraft damage. There are various different types of turbulence, but the most dangerous, because it is invisible and extremely difficult to detect, is clear-air turbulence (CAT). A new CAT detection technology that could help pilots choose a smoother route is now being tested as part of a European joint project called DELICAT (Demonstration of LIDAR based CAT detection).</p> <p>As its name suggests, CAT can occur when no clouds are visible, providing no visual cues of its presence. Occurring most often at altitudes of around 7,000 to 12,000 m (23,000 to 39,000 ft), CAT is caused when bodies of air moving at different speeds collide with each other. Researchers at the German Aerospace Center (DLR) say that recent atmospheric studies indicate that CAT will become an even bigger problem in the future as climate change is expected to increase the frequency of CAT.</p> <p>To minimize the dangers of CAT, DLR and its DELICAT project partners are testing a laser-based measurement device on flights throughout Europe. The LIDAR (Light Detection and Ranging) instrument, which was developed by researchers at the DLR Institute of Atmospheric Physics, emits short-wave ultraviolet laser radiation in the direction of the flight. By measuring the reflected signal from oxygen and nitrogen molecules, the device can detect fluctuations in air density and provide a warning of CAT in advance.</p> <p>The system has been installed on a modified Cessna Citation aircraft that will be used in a flight campaign throughout Europe until the end of August. At the end of the test flights, the measurement data will be analyzed. The data will not only be used to demonstrate the system’s efficacy, but will also provide the researchers with information on the conditions in which CAT is likely to form.</p> <p>The research team hopes their work will lead to the development of a detection system that could be integrated into aircraft so that pilots would have advance warning of CAT, giving them the potential to fly around the turbulence or, failing that, time to ask passengers to buckle up.</p> <p>Source: <a href="https://web.archive.org/web/20130824181618/http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-7615/year-all/#gallery/11637" target="_blank">DLR</a></p>    <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://static.fmpub.net/zone/7980"></script> <div id="bottom_unit"> <script type="text/javascript"> </script> <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> </div> </div> <span class="title share_bar">Share</span> <div id="article_share_bar" class="dotsontop share_bar"> <div class="as_button fb_as_button"><div class="fb-like" data-href="http://www.gizmag.com/clear-air-turbulence-detection-system/28593/" data-send="false" data-layout="box_count" data-show-faces="false"></div><script type="text/javascript">_ga.trackFacebook();</script></div> <div class="as_button"><a href="https://web.archive.org/web/20130824181618/http://twitter.com/share" class="twitter-share-button" data-count="vertical" data-via="gizmag">Tweet</a></div> <div class="as_button"><div class="g-plusone" data-size="tall" data-href="http://www.gizmag.com/clear-air-turbulence-detection-system/28593/"></div></div> <div class="as_button"><iframe style="overflow: hidden; margin: 0px; padding: 0px; border: 0px; " src="https://web.archive.org/web/20130824181618if_/http://badge.stumbleupon.com/badge/embed/5/?url=http%3A%2F%2Fwww.gizmag.com%2Fclear-air-turbulence-detection-system%2F28593%2F" width="50" height="60" id="iframe-stmblpn-widget-2"></iframe></div> <div class="as_button"><div class="pin-it-button" data-url="https://web.archive.org/web/20130824181618oe_/http://www.gizmag.com/clear-air-turbulence-detection-system/28593/" data-image="http://images.gizmag.com/hero/delicat.jpg" data-description="A new system to detect invisible and extremely difficult to detect clear-air turbulence (CAT) is currently being tested as part of a European joint project called DELICAT (Demonstration of LIDAR based CAT detection)."></div></div> <div class="as_button"><script type="IN/Share" data-counter="top"></script></div> <div class="as_button" id="reddit_button_bar"><script type="text/javascript">reddit_newwindow='1'</script></div> <div class="as_button" id="email_a_friend_bar"><span class="email_a_friend">Email</span></div> </div>  <span class="title clear_left" id="author_byline_title">About the Author</span> <div class="dotsontop" id="authorcontainer">  <a href="/web/20130824181618/http://www.gizmag.com/author/darren-quick/"> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/author_profiles/34.jpg" alt="Darren Quick" id="bio_pic"/> </a>   Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag.   <a href="/web/20130824181618/http://www.gizmag.com/author/darren-quick/">All articles by Darren Quick</a> <span id="author_byline_links">   </span> <br class="clear_both"> </div>  <div id="tags"> <span class="title">Tags</span> <div class="dotsontop"> <ul> <li>» <a href="/web/20130824181618/http://www.gizmag.com/tag/aircraft/" rel="tag">Aircraft</a></li> <li>» <a href="/web/20130824181618/http://www.gizmag.com/tag/dlr/" rel="tag">DLR</a></li> <li>» <a href="/web/20130824181618/http://www.gizmag.com/tag/flight/" rel="tag">Flight</a></li> <li>» <a href="/web/20130824181618/http://www.gizmag.com/tag/german-aerospace-center/" rel="tag">German Aerospace Center</a></li> <li>» <a href="/web/20130824181618/http://www.gizmag.com/tag/test-flight/" rel="tag">Test Flights</a></li> </ul> <div class="clear_both"></div> </div> </div> <div id="bing_unit"></div>  <span class="title" id="comments">4 Comments</span> <div class="dotsontop"> <div id="comment-246574" class="a_comment"> <p>Will this tech some day help paragliders find thermals :) </p> <span class="name">Robert Kelly</span><br> <span class="date"> 6th August, 2013 @ 05:17 am PDT</span> </div> <div id="comment-246661" class="a_comment"> <p>Once again I get to reminisce about the work we did at Laser Systems in Ann Arbor back in the 60's. We developed a CAT detection system utilizing a ruby laser and I believe we tested it in a Ford TriMotor. We were able to detect CAT out to about 1 mile but at 450 mph or more that doesn't leave time for avoidance. </p> <p></p> <p>We had a pod mounted under each wing. One contained the laser and the other contained the detection system. </p> <p></p> <p>This report doesn't indicate what kind of detection range they get with the UV LIDAR but hopefully it is enough to provide adequate response time. </p> <p></p> <p></p> <span class="name">Mr E</span><br> <span class="date"> 6th August, 2013 @ 10:17 am PDT</span> </div> <div id="comment-246778" class="a_comment"> <p>for all Exec jets, airlines, air cargo, Gen Av planes alone that fly above 30K feet must have. </p> <p></p> <span class="name">Stephen N Russell</span><br> <span class="date"> 6th August, 2013 @ 05:53 pm PDT</span> </div> <div id="comment-247174" class="a_comment"> <p>In late 80ies a genius german paragliding and hangglider enthusiast built a 3 D windshear warning system, which detected particle-movement in all directions up to 3.5 km ahead using LIDAR combined LDA. Built it for fun for paragliding, then sold it to Raytheon... then never heard someting of this technology. </p> <span class="name">Future3000</span><br> <span class="date"> 8th August, 2013 @ 03:24 am PDT</span> </div> </div> <span class="title">Post a Comment</span> <div class="dotsontop" id="comment_form_div"> <div id="comment_form" data-article="28593"> <div id="comments_login"> <form action="/web/20130824181618/http://www.gizmag.com/index.php" name="login_form" id="login_form" onsubmit="return false;"> <p class="bold">Login with your gizmag account:</p> <p id="login_status"></p> <label for="email">Email</label><input type="text" name="email" id="email" value=""/> <label for="password">Password</label><input type="password" name="password" id="password" value=""/> <input type="submit" value="Log In" class="med"/> <div id="options"> <a href="/web/20130824181618/http://www.gizmag.com/register/">Register here</a><br> <a href="/web/20130824181618/http://www.gizmag.com/new_password/">Forgotten your password?</a> </div> <input type="hidden" id="expired_comment" value=""/> </form> </div> <div id="facebook_login"> <p>Or <span class="bold">Login with Facebook:</span></p><br/> <div class="fb-login-button" data-scope="email" data-max-rows="1" data-onlogin="loginFUser(28593);" data-autologoutlink="true"></div> </div> </div> <div class="clear_both"></div> </div>  <span class="title">Related Articles</span> <div id="related_articles" class="dotsontop"> <ul> <li> <a href="/web/20130824181618/http://www.gizmag.com/ncar-storm-guidance-system/12196/" title="An NCAR analysis of the storm that may have claimed Air France Flight 447. Its flight path..."> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/related/ncar-storm-guidance.jpg" alt="An NCAR analysis of the storm that may have claimed Air France Flight 447. Its flight path..."/> </a> <a class="rel_title" href="/web/20130824181618/http://www.gizmag.com/ncar-storm-guidance-system/12196/">New storm guidance system might have averted Air France Flight 447 disaster </a> <p class="rel_date">13th July, 2009</p> </li> <li> <a href="/web/20130824181618/http://www.gizmag.com/x-56a-flexible-aircraft-testbed/21891/" title="Computer image of the X-56A unmanned modular aircraft that NASA will use to test enabling ..."> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/related/x-56a.jpg" alt="Computer image of the X-56A unmanned modular aircraft that NASA will use to test enabling ..."/> </a> <a class="rel_title" href="/web/20130824181618/http://www.gizmag.com/x-56a-flexible-aircraft-testbed/21891/">X-56A to aid NASA in development of new kinds of lightweight, flexible aircraft</a> <p class="rel_date">20th March, 2012</p> </li> <li> <a href="/web/20130824181618/http://www.gizmag.com/go/7470/" title="Improved clear weather detection"> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/related/7470_210607115102.jpg" alt="Improved clear weather detection"/> </a> <a class="rel_title" href="/web/20130824181618/http://www.gizmag.com/go/7470/">Wind detection technology improves airport safety</a> <p class="rel_date">21st June, 2007</p> </li> <li> <a href="/web/20130824181618/http://www.gizmag.com/boeing-747-jumbo-hostel/19483/" title="The Cockpit Suite, where guests can sleep where pilots once traversed the skies (Photo: Li..."> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/related/jumbohostel.jpg" alt="The Cockpit Suite, where guests can sleep where pilots once traversed the skies (Photo: Li..."/> </a> <a class="rel_title" href="/web/20130824181618/http://www.gizmag.com/boeing-747-jumbo-hostel/19483/">The world's first Jumbo Hostel guarantees a turbulence-free night's sleep</a> <p class="rel_date">10th August, 2011</p> </li> <li> <a href="/web/20130824181618/http://www.gizmag.com/vortex-surfing-usaf/24582/" title="Airplane creating vortices made visible by colored smoke (Image: NASA Langley Research Cen..."> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/related/vortex-surfing-1.jpg" alt="Airplane creating vortices made visible by colored smoke (Image: NASA Langley Research Cen..."/> </a> <a class="rel_title" href="/web/20130824181618/http://www.gizmag.com/vortex-surfing-usaf/24582/">U.S. Air Force goes vortex surfing to cut fuel consumption</a> <p class="rel_date">17th October, 2012</p> </li> <li> <a href="/web/20130824181618/http://www.gizmag.com/go/2071/" title="Ian Thorpe debuts revolutionary bodysuit at World Championships"> <img src="https://web.archive.org/web/20130824181618im_/http://images.gizmag.com/related/2071_01.jpg" alt="Ian Thorpe debuts revolutionary bodysuit at World Championships"/> </a> <a class="rel_title" href="/web/20130824181618/http://www.gizmag.com/go/2071/">Ian Thorpe debuts revolutionary bodysuit at World Championships</a> <p class="rel_date">21st July, 2003</p> </li> </ul> <div class="clear_both"></div> </div>  <div id="email_friend_div" class="dotsontop"> <p><em>Just enter your friends and your email address into the form below</em></p> <p><span id="emailfriendnote">For multiple addresses, separate each with a comma</span></p> <form id="emailafriend" name="emailafriend" action="" data-article="28593"> <div id="emailresult"></div> <div class="emailbox"> <label for="youremail">Your Email</label><br/> <input id="youremail" type="text" name="youremail"/> </div> <div class="emailbox"> <label for="friendsemail">Friends Email</label><br/> <input id="friendsemail" type="text" name="friendsemail"/> </div> <input type="submit" value="Send"/> <input type="hidden" name="csrf_token" id="csrf_token" value="25ad2e0ba59056ba657fabe8d695adfd"/> </form> <br class="clear_both"/> <p id="privacy">Privacy is safe with us because we have a strict <a href="/web/20130824181618/http://www.gizmag.com/privacy/">privacy policy</a>.</p> </div>  <div id="search_form_bottom"> <form action="https://web.archive.org/web/20130824181618/http://www.gizmag.com/search/" id="cse-search-box-bottom"> <span class="title">Looking for something? Search our 23,784 articles</span> <div class="dotsontop"> <input type="hidden" name="cx" value="partner-pub-1607124478120364:bqw4wo-1udf"/> <input type="hidden" name="cof" value="FORID:11"/> <input type="hidden" name="ie" value="ISO-8859-1"/> <input type="text" name="q" size="60" id="search_input"/> <input type="submit" name="sa" value="Search"/> </div> </form> <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://www.google.com/cse/brand?form=cse-search-box-bottom&lang=en"></script> </div> </div> <div id="right_cols"> <div class="island" id="island_top_right"> <script type="text/javascript"> googletag.cmd.push(function() { googletag.display("island_top_right"); }); </script> </div> <div id="right_col_a"> <div id="right_col_b"> <div class="ad" id="skyscraper_right"> <script type="text/javascript"> googletag.cmd.push(function() { googletag.display("skyscraper_right"); }); </script> </div> <div class="ad"> <span class="title">Sections</span> <ul class="dots" id="sections_list"> <li><a href="/web/20130824181618/http://www.gizmag.com/features/" class="features_reviews_list">Features</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/reviews/" class="features_reviews_list">Reviews</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/aircraft/">Aircraft</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/architecture/">Architecture</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/aroundthehome/">Around The Home</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/automotive/">Automotive</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/bicycles/">Bicycles</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/children/">Children</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/computers/">Computers</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/digital-cameras/">Digital Cameras</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/electronics/">Electronics</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/environment/">Environment</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/games/">Games</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/goodthinking/">Good Thinking</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/health/">Health and Wellbeing</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/destinations/">Holiday Destinations</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/homeentertainment/">Home Entertainment</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/remarkablepeople/">Inventors and Remarkable People</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/laptops/">Laptops</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/marine/">Marine</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/medical/">Medical</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/military/">Military</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/mobiletechnology/">Mobile Technology</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/motorcycles/">Motorcycles</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/music/">Music</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/outdoors/">Outdoors</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/pets/">Pets</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/robotics/">Robotics</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/science/">Science</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/space/">Space</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/sports/">Sports</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/telecommunications/">Telecommunications</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/urbantransport/">Urban Transport</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/wearableelectronics/">Wearable Electronics</a></li> </ul> </div> </div>  <span class="title">Recent popular articles in Aircraft</span> <ul id="recent_popular" class="vertical_sprite recent_popular_16"> <li id="story0"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/terrafugia-public-flight-demonstration/28701/" title="Terrafugia Transition flying car makes first public flights"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/terrafugia-public-flight-demonstration/28701/">Terrafugia Transition flying car makes first public flights</a> </div> </li> <li id="story1"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/spiri-quadrotor-drone/28700/" title="Autonomous, beautiful Spiri quadrotor drone hits Kickstarter"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/spiri-quadrotor-drone/28700/">Autonomous, beautiful Spiri quadrotor drone hits Kickstarter</a> </div> </li> <li id="story2"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/hybrid-quadrotor-hq-uav/28767/" title="Whaddaya get when you cross a quadcopter with a plane? The HQ UAV"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/hybrid-quadrotor-hq-uav/28767/">Whaddaya get when you cross a quadcopter with a plane? The HQ UAV</a> </div> </li> <li id="story3"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/anti-mosquito-uav/28680/" title="Florida Keys turns to UAVs to take on mosquitos"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/anti-mosquito-uav/28680/">Florida Keys turns to UAVs to take on mosquitos</a> </div> </li> <li id="story4"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/f-35b-first-night-sea-vertical-landing/28785/" title="F-35B makes first vertical night landing at sea"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/f-35b-first-night-sea-vertical-landing/28785/">F-35B makes first vertical night landing at sea</a> </div> </li> <li id="story5"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/smartphone-quadcopter/28756/" title="Autonomous quadcopter uses a smartphone as its brains"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/smartphone-quadcopter/28756/">Autonomous quadcopter uses a smartphone as its brains</a> </div> </li> <li id="story6"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/aerovironment-solar-puma-ae/28695/" title="Solar-powered Puma AE small UAS stays aloft for over nine hours"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/aerovironment-solar-puma-ae/28695/">Solar-powered Puma AE small UAS stays aloft for over nine hours</a> </div> </li> <li id="story7"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/go/4628/" title="Your own helicopter for under US$20,000"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/go/4628/">Your own helicopter for under US$20,000</a> </div> </li> <li id="story8"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/sagita-sherpa-helicopter/27962/" title="Sagita's hot air-powered Sherpa rethinks the ultra-light helicopter"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/sagita-sherpa-helicopter/27962/">Sagita's hot air-powered Sherpa rethinks the ultra-light helicopter</a> </div> </li> <li id="story9"> <a class="vs_img" href="/web/20130824181618/http://www.gizmag.com/dji-phantom-quadcopter-review/26812/" title="Review: DJI Phantom quadcopter"></a> <div class="vs_title"> <a href="/web/20130824181618/http://www.gizmag.com/dji-phantom-quadcopter-review/26812/">Review: DJI Phantom quadcopter</a> </div> </li> </ul> <div class="clear_both"></div> <div class="island" id="island_bottom_right"> <script type="text/javascript"> googletag.cmd.push(function() { googletag.display("island_bottom_right"); }); </script> </div>   </div>  </div> <div class="clear_left"></div>  </div>  <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/footer_tabs.js?1377327827"></script> <div id="footer_outer"> <div id="footer">  <div class="footer_item" id="footer_popular"> <span class="footer_title">Most Popular Articles</span>  <div class="tabbable"> <ul class="nav nav-tabs" id="most_popular_tabs"> <li class="active"><a data-target="#popular_today" data-toggle="tab" data-period="day">Today</a></li> <li><a data-target="#popular_week" data-toggle="tab" data-period="week">Last week</a></li> <li><a data-target="#popular_all" data-toggle="tab" data-period="all">All time</a></li> </ul> <div class="tab-content"> <div class="tab-pane active" id="popular_today"> <ul class="popular_articles"> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/peek-eye-testing-smartphone/28764/">Smartphone-based kit makes eye tests cheap and portable</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/flow-battery/28747/">MIT's flow battery could store solar and wind power on the cheap</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/scripps-drug-sr9009-exercise-mimic/28651/">New drug mimics the beneficial effects of exercise</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/varibike-arm-leg-powered-bicycle/28811/">Varibike lets you pedal with your legs – and your arms</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/ferrari-458-speciale/28778/">Ferrari 458 Speciale, another "most powerful" ever</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/nissan-patrol-guinness-world-record-towing/28806/">Nissan Patrol tows 170.9-ton cargo plane to set new Guinness World Record</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/c-string-underwear/13358/">C-string makes your average thong look like grannypants (NSFW)</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/new-nexus-7-vs-note-8/28745/">2013 Nexus 7 vs. Galaxy Note 8.0</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/ipad-4-vs-galaxy-tab-10-1-specs-comparison/27850/">Samsung Galaxy Tab 3 10.1 vs. iPad</a></li> <li><a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/golfboard/28812/">GolfBoard brings a hint of the waves and slopes to the greens</a></li> </ul> </div> <div class="tab-pane" id="popular_week"> <ul class="popular_articles"> </ul> </div> <div class="tab-pane" id="popular_all"> <ul class="popular_articles"> </ul> </div> </div> </div> </div>  <div class="footer_item" id="footer_commented"> <span class="footer_title">Most Commented Articles</span>  <div class="tabbable"> <ul class="nav nav-tabs" id="most_commented_tabs"> <li class="active"><a data-target="#commented_today" data-toggle="tab" id="commented_today_tab" data-period="day">Today</a></li> <li><a data-target="#commented_week" data-toggle="tab" id="commented_week_tab" data-period="week">Last week</a></li> <li><a data-target="#commented_all" data-toggle="tab" id="commented_all_tab" data-period="all">All time</a></li> </ul> <div class="tab-content"> <div class="tab-pane active" id="commented_today"> <ul class="commented_articles"> </ul> </div> <div class="tab-pane" id="commented_week"> <ul class="commented_articles"> <li><a href="/web/20130824181618/http://www.gizmag.com/scripps-drug-sr9009-exercise-mimic/28651/">New drug mimics the beneficial effects of exercise</a> (36)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/hyperloop-musk-analysis/28672/">Beyond the hype of Hyperloop: An analysis of Elon Musk's proposed transit system</a> (34)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/australia-nuclear-submariine/28706/">Report examines feasibility of nuclear-powered submarines for Australia</a> (26)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/terrafugia-public-flight-demonstration/28701/">Terrafugia Transition flying car makes first public flights</a> (22)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/field-trip-app-google-glass/28777/">Field Trip for Google Glass illustrates the perks (and creepiness) of being a cyborg</a> (15)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/couchbunker-gun-safe-furniture/28758/">CouchBunker conceals a gun safe beneath bullet-resistant cushions</a> (15)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/noomad-three-wheeled-cargo/28727/">Noomad transforms bicycle into three-wheeled cargo bike</a> (13)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/voyager-1-magnetic-field-interstellar-space/28719/">Scientists claim that Voyager 1 left the Solar System last year</a> (13)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/galpin-reinvents-ford-gt/28760/">Galpin reinvents the Ford GT with 1,000 horses and a $1 million price tag</a> (12)</li> <li><a href="/web/20130824181618/http://www.gizmag.com/hybrid-quadrotor-hq-uav/28767/">Whaddaya get when you cross a quadcopter with a plane? The HQ UAV</a> (12)</li> </ul> </div> <div class="tab-pane" id="commented_all"> <ul class="commented_articles"> </ul> </div> </div> </div> </div>  <div class="footer_item nomargin" style="margin: 0px;" id="footer_subscribe"> <div> <form id="footer_email_form" class="form-inline" action="/web/20130824181618/http://www.gizmag.com/index.php"> <span class="small">Subscribe to Gizmag's</span><br/> <span class="large">Email Newsletter</span> <input type="text" name="email" class="email" value="Enter Your Email Address ..." onclick="this.value=''; this.style.color='#999'" id="footer_email"/> <button type="submit" class="bootbtn" id="footer_subscribe_button">Subscribe</button> </form> <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/subscribe_footer.js?1377327827"></script> <div class="subscribe_options"> <a target="_blank" href="https://web.archive.org/web/20130824181618/http://twitter.com/gizmag/" class="twitter_footer greytitle"> <span class="small">Follow Gizmag on</span> <span class="large">Twitter</span></a> </div> <div class="subscribe_options"> <a target="_blank" href="https://web.archive.org/web/20130824181618/http://www.youtube.com/user/gizmag" class="youtube_footer greytitle"> <span class="small">Subscribe to Gizmag's</span> <span class="large">YouTube channel</span></a> </div> <div class="subscribe_options"> <a href="https://web.archive.org/web/20130824181618/http://www.gizmag.com/xml/" class="rss_footer greytitle"> <span class="small">Subscribe to Gizmag's </span> <span class="large">RSS feed</span></a> </div> <div class="subscribe_options"> <a href="https://web.archive.org/web/20130824181618/http://www.stumbleupon.com/channel/Gizmag/" class="su_footer greytitle"> <span class="small">Follow Gizmag on </span> <span class="large">Stumbleupon</span></a> </div> <div class="subscribe_options"> <a href="https://web.archive.org/web/20130824181618/https://plus.google.com/105149739082983197804" class="gplus_footer greytitle"> <span class="small">Follow Gizmag on </span> <span class="large">Google Plus</span></a> </div> </div> </div> <div class="clear_both"></div> </div> <div id="copyright"><em>All content copyright © Gizmag 2003 - 2013</em></div> <div class="clear_left"></div> </div> <div class="index" id="footer_index"> <div class="index_center bottom_strip"> <ul> <li><a href="#top">Top</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/">Home</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/about/">About</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/contact/">Contact</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/privacy/">Privacy</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/termsofuse/">Terms & Conditions</a></li> <li><a href="/web/20130824181618/http://www.gizmag.com/advertise/" class="brighter">Advertise</a></li> </ul> </div> </div>  <link rel="stylesheet" type="text/css" href="/web/20130824181618cs_/http://www.gizmag.com/inc/jqmodal/jqModal.css"/> <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/jqmodal/jqModal.js"></script> <div id="subscribe_overlay_container" class="jqmWindowModSize"></div> <script type="text/javascript" src="/web/20130824181618js_/http://www.gizmag.com/inc/subscribe_overlay.js?x=1377368177"></script>  <script src="https://web.archive.org/web/20130824181618js_/http://static.getclicky.com/js" type="text/javascript"></script> <script type="text/javascript">clicky.init(110681);</script> <noscript><p><img alt="Clicky" width="1" height="1" src="https://web.archive.org/web/20130824181618im_/http://in.getclicky.com/110681ns.gif"/></p></noscript>  <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://static.fmpub.net/site/gizmag"></script>  <script type="text/javascript"> var _sf_async_config={uid:4159,domain:"gizmag.com"}; (function(){ function loadChartbeat() { window._sf_endpt=(new Date()).getTime(); var e = document.createElement('script'); e.setAttribute('language', 'javascript'); e.setAttribute('type', 'text/javascript'); e.setAttribute('src', (("https:" == document.location.protocol) ? "https://web.archive.org/web/20130824181618/https://s3.amazonaws.com/" : "http://") + "static.chartbeat.com/js/chartbeat.js"); document.body.appendChild(e); } var oldonload = window.onload; window.onload = (typeof window.onload != 'function') ? loadChartbeat : function() { oldonload(); loadChartbeat(); }; })(); </script>  <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://s3.amazonaws.com/new.cetrk.com/pages/scripts/0008/8786.js"> </script>   <div id="bottom_include"> <script type="text/javascript">googletag.cmd.push(function() { googletag.display("bottom_include"); });</script> </div>  <script type="text/javascript" src="https://web.archive.org/web/20130824181618js_/http://static.fmpub.net/zone/8204"></script>         </body> </html>

CINXE.COM

Laser-based turbulence detector could mean safer flights