Allegiant Air's livery features a bright sunburst design on the tail, emphasizing the airline's sun destinations. A similar livery is used by Jet2.com on aircraft which carry the Jet2holidays livery, the only difference being the airline name on the aircraft.

Several airlines feature a sun motif on their tail (vertical stabilizer). The most famous and direct answer is:

Japan Airlines (JAL).

Its logo is the “tsurumaru” — a red circle (symbolizing the sun) with a stylized crane inside, all set on a dark red background on the tail. The sun is a central element.

Other airlines with prominent sun designs include:

1. ANA (All Nippon Airways): While its primary livery features a blue and white “Inspiration of Japan” wave, ANA’s older and some special liveries prominently feature a rising sun motif, often on the fuselage and sometimes echoed on the tail.
2. Air China: Its logo is a stylized phoenix, but the tail is often painted bright red, which can be interpreted as a sun symbol, especially combined with the airline’s name.
3. Sun Country Airlines: This U.S. low-cost carrier has a bright yellow sun design directly on its tail.
4. Solaseed Air: A Japanese regional airline whose name combines “sol” (sun) and “seed,” and its livery features a bright, smiling sun on the tail.
5. Sun-Air of Scandinavia (operates as British Airways franchise): Features a large, stylized sun on its tail.

If you’re thinking of one specific, iconic image, Japan Airlines’ red sun circle is the most globally recognized.