An Aeromexico Boeing 777 arrived in the Spanish capital on Tuesday, marking the first trans-Atlantic commercial flight powered in part by biofuel.

"Fantastic" was pilot Francisco Fernandez Sarda's description of the flight from Mexico City to Madrid's Barajas International Airport.

The plane made the journey on a mix of 55 tons of conventional aviation fuel and 20 tons of fuel made from the plant jatropha curcas.

Passengers were "very happy" to be part of the historic flight, the pilot said, adding, "all the necessary tests were done and we knew that everything was going to go well."

Aeromexico plans to start using the less-polluting jatropha mix on weekly flights between Mexico and Costa Rica, Fernandez Sarda said.

Tuesday's flight was made possible by a November 2010 accord between Spain and Mexico to collaborate on development of biofuels for use in aviation.

The project includes Aeromexico, Boeing and Spain's Development Ministry.

Commercial aviation faces the challenge of finding substitutes for conventional fuel and meeting that goal requires "solid institutional support," Boeing España chief Pedro Argüelles said Tuesday at Barajas International.

Boeing began testing biofuels in 2006 and "great strides have been made" since then, the executive said.

Argüelles acknowledged, however, that problems remain in expanding the volume of biofuel production enough to bring down the price.

Jatropha grows in various parts of the world, including the southern Mexican state of Chiapas.