CSS：SVG animation

html{background-color: #28505D;}
.planePath {stroke: #D9DADA; stroke-width: .1%;stroke-width: .5%; stroke-dasharray: 1% 2%;stroke-linecap: round;fill: none;}
.fil1{fill: #D9DADA;}
.fil2{fill: #C5C6C6;}
.fil4{fill: #9D9E9E;}
.fil3{fill: #AEAFB0;}

<svg viewBox="0 0 3387 1270">
  <path id="planePath" class="planePath"
        d="M-226 626c439,4 636,-213 934,-225 755,-31 602,769 1334,658 562,-86 668,-698 266,-908 -401,-210 -893,189 -632,630 260,441 747,121 1051,91 360,-36 889,179 889,179"></path>
  <g id="plane">
    <polygon class="fil1" points="-141,-10 199,0 -198,-72 -188,-61 -171,-57 -184,-57 "></polygon>
    <polygon class="fil2" points="199,0 -141,-10 -163,63 -123,9 "></polygon>
    <polygon class="fil3" points="-95,39 -113,32 -123,9 -163,63 -105,53 -108,45 -87,48 -90,45 -103,41 -94,41 "></polygon>
    <path class="fil4" d="M-87 48l-21 -3 3 8 19 -4 -1 -1zm-26 -16l18 7 -2 -1 32 -7 -29 1 11 -4 -24 -1 -16 -18 10 23zm10 9l13 4 -4 -4 -9 0z"></path>
    <polygon class="fil1" points="-83,28 -94,32 -65,31 -97,38 -86,49 -67,70 199,0 -123,9 -107,27 "></polygon>
  </g>
  <!-- Define the motion path animation -->
  <animateMotion xlink:href="#plane" dur="5s" repeatCount="indefinite" rotate="auto">
    <mpath xlink:href="#planePath"></mpath>
  </animateMotion>
</svg>