a variometer.
<a href="//commons.wikimedia.org/wiki/User:Umberto_NURS" title="User:Umberto NURS">Umberto NURS</a>
2014-01-02 14:27:59
<p>This file was derived from: <a href="//commons.wikimedia.org/wiki/File:Faa_vertical_air_speed.JPG" title="File:Faa vertical air speed.JPG">Faa vertical air speed.JPG</a>: <a href="//commons.wikimedia.org/wiki/File:Faa_vertical_air_speed.JPG" class="image"><img alt="Faa vertical air speed.JPG" src="https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Faa_vertical_air_speed.JPG/50px-Faa_vertical_air_speed.JPG" decoding="async" width="50" height="44" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Faa_vertical_air_speed.JPG/75px-Faa_vertical_air_speed.JPG 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Faa_vertical_air_speed.JPG/100px-Faa_vertical_air_speed.JPG 2x" data-file-width="339" data-file-height="297"></a><br></p>
<ul><li><a href="//commons.wikimedia.org/wiki/User:Giggy" title="User:Giggy">Giggy</a></li></ul>