Fifteen months after it created a sensation at the New York International Auto Show, Terrafugia’s “flying car” will make its first airshow appearance later this month, as the Woburn company works on a next-generation prototype.

The Transition is scheduled to fly and drive July 31 at the Experimental Aircraft Association AirVenture in Oshkosh, Wis.

“We’ve had the vehicle on display there since 2006, and every year, people ask us when they can see it fly,” said Richard Gersh, vice president of business development. “So we’re very excited about the chance to demonstrate before a very large and enthusiastic crowd.”

The company did a demonstration at Lawrence Municipal Airport last October for a select group of investors and prospective buyers, Gersh said, but AirVenture will be the Transition’s first airshow.

The road-ready light sport aircraft still has a long way to go before it’s ready for production, though.

In August 2012, Terrafugia said it had received more than 100 orders for the $279,000 aircraft, and the first delivery was expected this September.

But testing — and a new prototype that could be done by the end of this year — has pushed back that date to early 2015 or 2016, assuming the Transition wins certification from the Federal Aviation Administration and the National Highway Traffic Safety Administration.

“Based on what we’ve learned from testing, our engineers have called for some changes,” Gersh said. “But the overall look of the vehicle will be very similar.”

Robert Mann, an airline industry analyst and former airline industry executive, said the delays are indicative of the central problem Terrafugia faces.

“You see the difficulty in trying to be a compromise between a land vehicle and an aircraft,” Mann said. “When you compromise, you tend to not do either very well.”

But Jake Schultz, a technical analyst for Boeing and author of “A Drive in the Clouds: The Story of the Aerocar,” tips his hat to how far the Transition has come.

“I … look forward to what this team still has in their old kit bag,” Schultz wrote in an email. “Their team has not sat on the sidelines and talked about what could be done some day. They are out working every day to actually make it happen. There have only been two flying cars that have been certified — the Aerocar and the Airphibian — so theirs will be the first in nearly 60 years.”