CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIzMiIgaGVpZ2h0PSIzMiIgZmlsbD0ibm9uZSI+PHBhdGggZmlsbD0iI0IyMEYwMyIgZD0iTTE2IDNhMTMgMTMgMCAxIDAgMTMgMTNBMTMuMDE1IDEzLjAxNSAwIDAgMCAxNiAzbTAgMjRhMTEgMTEgMCAxIDEgMTEtMTEgMTEuMDEgMTEuMDEgMCAwIDEtMTEgMTEiLz48cGF0aCBmaWxsPSIjQjIwRjAzIiBkPSJNMTcuMDM4IDE4LjYxNUgxNC44N0wxNC41NjMgOS41aDIuNzgzem0tMS4wODQgMS40MjdxLjY2IDAgMS4wNTcuMzg4LjQwNy4zODkuNDA3Ljk5NCAwIC41OTYtLjQwNy45ODQtLjM5Ny4zOS0xLjA1Ny4zODktLjY1IDAtMS4wNTYtLjM4OS0uMzk4LS4zODktLjM5OC0uOTg0IDAtLjU5Ny4zOTgtLjk4NS40MDYtLjM5NyAxLjA1Ni0uMzk3Ii8+PC9zdmc+);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '914a6c3149703dad',cH: '1IwiH9.ra9cxzCDodoKbFSZ3X8XBvjnAiM4lLEyo7LE-1740011789-1.2.1.1-Ik07saCG0yWjMGC1HpXYqWb7eP9PbIKp5vaIjq3utzcZA4AcrWr.GD.06QSghDYf',cUPMDTk: "\/search?q=Air%20transport&__cf_chl_tk=pOGOp4IxaeUo10roAsV.1fnYTaTUJv0kuwpGw040H2w-1740011789-1.0.1.1-z0He0ihFh9at35LeQ16moJjM_3Tdp07AZNq.2aCYvms",cFPWv: 'g',cITimeS: '1740011789',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported-browser",fa: "\/search?q=Air%20transport&__cf_chl_f_tk=pOGOp4IxaeUo10roAsV.1fnYTaTUJv0kuwpGw040H2w-1740011789-1.0.1.1-z0He0ihFh9at35LeQ16moJjM_3Tdp07AZNq.2aCYvms",md: "XHSTFwRIlPgNk3Dn5XBJSBWaXHhisRDGEWnpJd1iq2M-1740011789-1.2.1.1-eJ3A8cHiYhxcy_c_2FBaOoE_LHvPH_uPwdGpUdS6PkGRPy4sXB4.wy6H5s4lK6rL7EAY9.SJSkRopAuTOQc.pQWjs_y91r8sHEomqa6UE.9xS5Puf3cD7DSV72e8zqV_rTQ63YFtyPx2oDG4rbjQ_N1EkU2y2R994P4lGSz8YFiDA77DKKazHSE3w2XyO9Dy7aPOZXhcoShT1LsmN0PtYPi1TgU0gVDp.uoZfrn5Gp1jGWKmLhfaP8tv18Pi.n2kkY8VPwxXEjzI4b2lZdIh3w3FXUG.zLzvlg63gnS4zWREuxKA7A0Hnl9p7eul4Vj4hn33KAYhrBzXWznwxbFqabGZI9K9rDx4TmKZfL6djwmmO2g.WyeF3Uj4nNBkSNvIAcP8xrobJoKKbhSkLl1GHdkzlu0SjHal4ZeEohQv8vrceVRqqapCM5Yk4anedP5bL_REvmYjy.7DoyauincthHyTMmWH70amr.aLXJjPPaG3KnCI.d1MmXwt0QqEZH1_.7suD5Yusu1I5r2SkTWgiVft5sCG51805DCUYlQ_IFg9xgHKk6SnSB7QHzvTn1EHonW1dbPMgIFXzsER1y0PtMNWOr_XOODC7AJa0XAxp84rtBiItNPN2ishNE.XB4VAslvD.7f4OdnPkK5V4MUBcTrcn7UDjf26seTNzHJtfHvWgR.LpiUXpEf4p.DQlrdg999VcMc46s77_tzjnZn9fCqV.YNkou1_n4Se3ZY7xJKlmXRaFcFrN2USuFioeDGEEj05XdWwC0MAYYFj0mCYsDyFUtClbnygehDmucDAO2hq2B4dEgBlQBANYIysnRidjDvZYqo5pKvz78c4DvFOgt8uLIJFyogBbxysV8OWVhEoSt.vSmPni0Hngyc.7tUeWa.ewmGwpkygb3.T02EtW6Iyr0gCdQKv_rG9Deh9ehjW961OAnP.Q4pSRDUGc5b7GVk9gcIZ1zft_pQqwOl_P628z6geabMZPUQHCyBcew4mM9zBIObXSYoPv5Lk4hRG42YITOCJ9eFvPTj8hWmWp9uiADUfgrSQDMFXtdQF7gfUAcFB_sf9axFOFyI0lRTyVIkUBCw5vm97l1l6wKLPG2yNoX1fSAtwUHyx.nG0EVjoBHC36ydcmf.naY0yB8vWwohQmMbPnUxCcRQBLFQU8nscKzzwI.8ccuUhVEZ1SWVNgLibbIuDDjq4iIi1TbY.A8YRU9jYNkTqCBxgYFVeY5vvmPvtT8hok2T0yCAP7vri_5N313WS.BqhZ6sDm9d4yercAr49kklWOe4c87hEhH0N0X7v2aS7A92BXa.JWLDZ9KXM.5jR1pCdi_9PLj2crQdc1zSQpbN4SU1s.1u9s0jSRTrLEf2xBmLRWmOhjnS8mKAnmNykJdMWAXhsMt9AafsYhhGsDqo.fhFjIsQX4MUczuy5izPeXmmaWFZb1jE6n13_bbwEtzYVz3uclzhG.VMzfj7QiV9lBA2tx0jJ0_IwY78Prd.GkFS9UnanmyoCkfWhynACysP_l3O1.3Fpv7WPj4wC89z5jdlZetrcjatJnVI4_Fni8A.fLQ8MxCZgqGAzPHSsOZqw5mnktuVb_YmFqBhw5AIq4MZeGQpfPC2KxC7f72NsS7JUZPOp2Fhkt6HEf3R1AidAQOdmzajspEUF8dfSOIcHfnapzpOMtIT2dD8Dpk2tBqkOp9MpNtqPyBL6bSzUmV_Pw0Smk1FF9XwmnJFy87Jgwu9Pyg_UA7HP75DkTHSCfpt06OwurdBNBpLGk6t8wqnGMbb56eLla4kq86Az8r2g8zIYks2EMBkYgaRgH4TE0EXiU_3ffaSAxMk0OpE1lq.Ofj94cBt3qAnIB8G5eG896ruiH0qGeHZXxkLsLw7D_9AU6qN9YoOByQKzrbLbm.R860tLWYOn",mdrd: "TKPxAEuMJeGnfBm3_0na7rzk1YiyBklMsRgDgLEpcOo-1740011789-1.2.1.1-0z6h9MJ2iV_mXs1NEkolZJdoJA92zl4zHVR2026e7Xv36ThWlJ1NQ8L0ZhB0L8Da1xFnmSAc0kxV8mz4L_S9W0R8gIZDPt6dzEhgAXcwEdLJ5ns1LMi982EZZJugVZO8_HQ3W72wM8RsmSIlu4N8v4ELF.hkFjW_Cqzhjl.85Ps8FmV1jIvHpDKsbb223V1CeyrocU0qqZBpv1O46htoeq0xHZosAGJkBsAQER7RgvRqs0BB4pat52MFAvQuoReTA7Ocwv4WJjh7dpEYYOQBJeWi2OKo7aqtUcf47Fn6XgEfmLQf78oW9IDtU_iMXhIk5Xvq3La02lQF.rZ3efUiINZcVtA917PNaUNtn38Gyp.gN6LUbo28jV3WodzVP_b3YEU.C83azCf4XdoTe7DyIYecgqA7MGiCZOE5on75vOaoBvyksEeDcTVioxnu3FHN0vS3hHwNjgDGKiO.ubq3fWlImrv_BsNV1PqgJcjU0H9.2HxxyYp_el5kgVRvEV9nYoVFXtsM8hqql5oq5W9fWYzmInweuYUoS6RAGc6QA.s9Hl4cVo7ysuJ2vtCWnx5GKRURQv8VhATsLCqUyqodK_daFq5jyoiAhSu7N75N7zi_cG1lO3H8BaV88.nWRgaTg4PHl1z00RSeSZ59iebTeilMFj8Cp1qV0feMol8_B6tlt69J.R3RIlGBLqdEpQ1kyNNvyNlN4MwCFkgTW8LF66gTxX1PDdvOk81cocLXfvIMFjMYAG9tDxjByrYHG._8xLcfNAHzHrkk0_giwCcc_VvCHyxpFRznGgWbSMgNM5tbSg4t51415n2VnR7pAzK_xt1hRJFaWekGZaKKf20aVSsHWKUxWSQrM6nTpJ8KmnyRWe.gutB4jsHz0twFTn9qgUYUl5aJ1.rbss0Kvq594YlovvueI0Cp1J6i2wH6FTwnh_dSqD2PuAF7Fdwyxi5OIWD8zASP3HqJVCNb3UwaY9HEMjfWhuay5DVgtuzu7GLxajdGPS1ftPBxB3dZxMtpn1wkKnrVwIW5lGzqJ9pqRU.DL69HOJi9px1ND42wwHBpYciWH3xRL15NJn.rgNVro3KjfSbeSr3Pxe0_H5njUN6dbFcC0._zyNE_Aa7j1ykAIBx1D2RmV1V2kV.XB_.x6FWQDtyS_ux0VJmTYr4Ums9NbzgbVeZSeRievADMAO8VyDXpU15ANiOk9P_Viwp4qBm2xP9MaQo0BzrKZRTfAo9z37mekzuO_Nnuvy7BQLeGwIvaQ6jtvzH8T2rkzyZ7ClbC8H5siRq68tm7_Navh2NL4WHVBYY1GVL3rv__N9QIrs.YuJgCE2V5c.gNAH9ZuL3z8AkE9dallF2USH6S6lNn2txAQQBX2sELaa.U.KZL8sUbLi9dPmMBkYRJUQJAfhCNY__i8hs4C5kaoSaGxt06TbR3NBOJtXYBXGJqAoBrpFfbI8g3ju3k3faj0H9nCV1__Hpv1x1nUvhpkfn3HeEwpNgpxnTsGWL6QcF5V.M0IdHh7uBu..vEouhzVO8VFAAUAexTIZLA44edqS4EjsBODAVgu2Bot09Cdxi0xH4GIuhWeXIswv23kuQTFIrKkJrBqQPLVu9RrfbtFiET_ogMCDv89bxLHMvRFZQYZ4bc2qh5PGrASdGV4N6mNFdSjCybi9TW5A._JgHaa5C.19DEX11HEC6Fd7AS.nULfn9pw6sgKruFZEnthj87OnJA0kbouih5QDFqLDn9ehfcI7iHGzK49IqOOAksSCHDfUrlpnBcabSNEtekDAy6tj7RBKlEgdjx_cdB9EnP.7D4_wZmnE9W4jpc_h7ufYVkOEgwH3FzmPMA2WcrnkBLWNRR2Dx0ZR9tIEwZwW9AMjrX30J80QbYG6tOOnaALiL591bZinkbmvca2_gNxnk4HhW65gvRIm4neHpG_IEQKQNHiC2.BdER40KA6tFKBDj4MmHJyOkjBUCDiM_T_0Qe8EOU"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=914a6c3149703dad';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/search?q=Air%20transport&__cf_chl_rt_tk=pOGOp4IxaeUo10roAsV.1fnYTaTUJv0kuwpGw040H2w-1740011789-1.0.1.1-z0He0ihFh9at35LeQ16moJjM_3Tdp07AZNq.2aCYvms" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>