Californians have spotted a giant penis drawn in the sky.

Pilot

Pilot

Following the sighting on the artistic experiment, two Marine Corps pilots were grounded to allow an investigation into the drawing.

Maj. Josef Pattern told Marine Corps Times: ''The T-34C crew that is being investigated for flying a pattern resembling an obscene image are currently not flying pending the results of an ongoing investigation.''

Oddly, people have praised the drawing on social media.

One Twitter user noted: ''On the bright side, this shows how greatly proficient these pilots are. They've been trained well.

''We can be proud that our fighter pilots are probably the best in the world, and drawing a penis with this amount of skill, and precision proves it!''

Similar phallic stunts have happened before.

In November last year, an aircrew who flew a Navy Warplane in the shape of a penis above the town of Okanogan, Washington were grounded.