in-line groups. Thus a V-6 engine has two banks of three cylinders at an angle driving a common crankshaft, a V-12 two groups of six in-line. Broad arrow or W engines have three groups, one vertical and the two others symmetrically angled at less than 90° on either side. Both the air-cooled Anzani 3-cylinder fan engines of the "pioneer era" of aviation, and the later, "Golden Age of Aviation"-era British Napier Lion 12-cylinder, triple-bank liquid-cooled inline aviation engine could be said to have this layout when seen from a "nose-on" view. See also Tiwaz (rune) Notes References External link Heraldic charges