Thor and Iron Man have no problem getting around at supersonic speeds, but not every superhero can fly.  So what happens when The Avengers need to assemble to save the day, but saving the day isn't in walking distance?   They take the Quinjet.  What is the Quinjet?  Glad you asked.  Wikipedia:

Used primarily by the Avengers, the quinjet first appeared in The Avengers #61 (February 1969) and was designed by the Wakanda Design Group, headed by the Black Panther, T'Challa. Each one is equipped with VTOL capability and five turbojet engines. A quinjet can reach Mach 2.1. Two highly specialized ultra-large Quinjets were used to transport various superheroes through space in the Infinity Crusade mini-series.  Quinjets are infamous for being destroyed soon after they appear. Also, in the New Avengers/Transformers crossover, the Decepticon Ramjet escapes, disguised as Captain America's quinjet.

After the jump, you can check out some concept art for the Quinjet.  Keep in mind that this may not be what it looks like in the final film.  The Avengers opens in 3D on May 4th.

Via Spidermedia.ru.

avengers-movie-image-concept-art-quinjet-01

Here's the official synopsis for The Avengers:

Marvel Studios presents in association with Paramount Pictures "Marvel's The Avengers"--the Super Hero team up of a lifetime, featuring iconic Marvel Super Heroes Iron Man, The Incredible Hulk, Thor, Captain America, Hawkeye and Black Widow. When an unexpected enemy emerges that threatens global safety and security, Nick Fury, Director of the international peacekeeping agency known as S.H.I.E.L.D., finds himself in need of a team to pull the world back from the brink of disaster. Spanning the globe, a daring recruitment effort begins. Starring Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Jeremy Renner and Samuel L. Jackson, and directed by Joss Whedon, "Marvel's The Avengers" is based on the ever-popular Marvel comic book series "The Avengers," first published in 1963 and a comics institution ever since. Prepare yourself for an exciting event movie, packed with action and spectacular special effects, when "Marvel's The Avengers" assemble in summer 2012. In "Marvel's The Avengers," superheroes team up to pull the world back from the brink of disaster when an unexpected enemy threatens global security.