Frost Crystals on Airplane Window

March 27, 2020


Photographer: Kevin Saragozza
Summary Authors: Kevin Saragozza; Jim Foster

The photo above shows frost crystals on an airplane window that I observed a few weeks ago on a flight from the Canary Islands (Spain) to Rome, Italy. Ice flowers such as this will form on a windowpane if the outer plate is exposed to very cold temperatures (-40 F or -40 C is not unusual at flight altitude) and sufficient moisture is available to crystalize onto the surface. These crystals are in between the windowpanes -- airplane windows generally consist of three acrylic panes.

Note the circular symmetry of the crystals about the small hole. This breathing hole is on all commercial airplane windows. It’s an engineering feature designed to address differences between the low atmospheric pressure outside of the window and the much higher pressure on the inside of the window. The hole also serves to help prevent the buildup of moisture between the windowpanes. Photo taken on February 22, 2020.

Photo Details: Camera: HUAWEI LLD-L31; Exposure Time: 0.0026s (1/386); Aperture: ƒ/2.2; ISO equivalent: 50; Focal Length (35mm): 26.