Skybus Airlines, which had hoped to start flying in March or April, is at least two months from beginning operations.

The company is waiting for certification from the Federal Aviation Administration, which is expected within five weeks, said Bill Diffenderffer, Skybus CEO.

"We?re heading toward flying in May," Diffenderffer said this week. "We went back and forth about announcing our routes earlier, but we decided it would just give our competitors a needless advantage since we can?t sell tickets until we get FAA approval."

While Skybus waits for the FAA to act, much of the groundwork for the airline is falling into place. Skybus has a new $8 million home in Concourse B at Port Columbus. The Columbusbased startup has more than 100 people on its payroll, has ordered planes and engines valued at close to $4 billion and is in the process of moving into 100,000 square feet of leased hangar and office space next to the airport.

The only questions that remain now: When, where and for how much will they actually start flying passengers?

A March or April start date for Skybus has been floated since September. That?s when the city, state and county announced a $57 million incentive package for the airline.

Skybus? application to the agency was accepted Dec. 13. Aviation officials can?t comment on the specifics of an application, but work on the Skybus proposal is "moving along," said Isham Cory, FAA spokeswoman.

Cory added, though, that this required certification process can often take more than a year from the date of application. Gaining certification in less than six months would be "unusual," she said, but not entirely out of the question.

Skybus billboards have been up for several months around Columbus. The latest, a giant banner that takes up the entire side of Downtown?s Brunson Building, went up last week, although the giant butterfly that is supposed to top it off had to wait to be installed until the wind died down.

Diffenderffer said he is eager to tell people about where Skybus will be flying, but says the startup process has been more involved than he expected.

"There are about a thousand moving parts to starting up an airline," Diffenderffer said with a laugh. "If I?d known how many, I probably would?ve run screaming when they asked me if I wanted to run a startup airline."

Central Ohio investors in the airline include Battelle, Huntington Capital Investment Co., Nationwide and Wolfe Enterprises Inc., a subsidiary of The Dispatch Printing Company, publisher of The Dispatch.

mrose@dispatch.com?