McDonald, a native of London, most recently worked at Sam Schmidt Motorsports as chief race engineer for the car driven by Alex Tagliani and previously served as a race engineer for Andretti Green Racing, which became known as Andretti Autosport following the 2009 season.
In his previous stint with the team, McDonald notched eight IndyCar Series victories with Dario Franchitti during a four-year span, including a win in the 2007 Indianapolis 500. McDonald also engineered Franchitti to the series championship that same year.
McDonald began pursuing a career in motorsports in 1984 after serving two years in the Royal Navy. His first job in racing was with the Brabham Formula 1 team where he designed and built a quarter-scale wind tunnel. He continued as an engineer in F1 through 1996 before leaving to become technical director for PacWest Racing in the CART series. McDonald spent four years with PacWest prior to joining Team Green and Franchitti in 2002.
MICHAEL ANDRETTI, CHAIRMAN, PRESIDENT AND CHIEF EXECUTIVE OFFICER,
"We're excited to have Allen back with our team. He was a great asset to us in the past, and I'm confident he will bring a lot to the table and make an immediate impact for us. He clearly knows what it takes to be fast and knows how our operation works, so it should be a smooth transition for him."
ALLEN MCDONALD, DIRECTOR OF ENGINEERING, ANDRETTI AUTOSPORT:
"I'm looking forward to working with Andretti Autosport once again. We did some great things together in the past and the goal is to get back to that level of consistency and success. Everyone here is focused on the same goals and is ready to do whatever it takes for us to get there. That effort begins this weekend at Texas Motor Speedway."