<a href="//commons.wikimedia.org/wiki/File:Flag_of_the_United_States.svg" class="image" title="United States of America"><img alt="United States of America" src="https://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Flag_of_the_United_States.svg/22px-Flag_of_the_United_States.svg.png" decoding="async" width="22" height="12" class="thumbborder" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Flag_of_the_United_States.svg/33px-Flag_of_the_United_States.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Flag_of_the_United_States.svg/44px-Flag_of_the_United_States.svg.png 2x" data-file-width="1235" data-file-height="650"></a> <a href="//commons.wikimedia.org/wiki/United_States" title="United States"><span title="country in North America">United States of America</span></a>, <a href="https://en.wikipedia.org/wiki/San_Francisco_International_Airport" class="extiw" title="w:San Francisco International Airport">San Francisco International Airport</a>. <a href="https://en.wikipedia.org/wiki/San_Francisco_and_Oakland_Helicopter_Airlines" class="extiw" title="w:San Francisco and Oakland Helicopter Airlines">San Francisco and Oakland Helicopter Airlines</a> <a href="https://en.wikipedia.org/wiki/Sikorsky_S-61" class="extiw" title="w:Sikorsky S-61">Sikorsky S-61L</a>, N4606G, c/n 61-224 taken in 1974.
Piergiuliano Chesi
CC BY-SA 3.0
Own work from slide