Kansas City, Mo. ? City officials have approved a plan for almost $70 million in improvements at the Wheeler Downtown Airport, which is primarily used for private planes and corporate jets.

A master plan, recently approved by the City Council, identifies the improvements, including a federally mandated extension of the airport’s runway area, the realignment of Lou Holland Drive, new taxiways and additional hangars. It would be one of the biggest and most expensive facelifts in the airport’s 77-year history.

Almost 75 percent of the project would be eligible for grants from the Federal Aviation Administration, said Steven Benson, a Lee’s Summit consultant who assisted the Kansas City Aviation Department with the plan. Revenues generated by the airport, including leases and fuel fees, would pay for the rest.

“This is one of the premier corporate airports in the country,” Benson said. “This master plan is a way to ensure that it continues to operate as a first-class reliever airport.”

More than 145,000 aircraft a year use the airport, which sits at the confluence of the Missouri and Kansas rivers just north of downtown Kansas City. But the location — the airport is bounded on three sides by the Missouri River and on the fourth by U.S. 169 — poses a challenge for airport officials who must extend the main runway area.

The FAA recommends that Wheeler Downtown Airport have 800-foot safety areas at the ends of the main runway. Should the airport fail to meet the federal standard on runway safety areas, it could lose funds for future capital improvements.

That extension of the main runway probably will be built on the Missouri River levee, which has protected the airport from floodwaters. A section of Lou Holland Drive would be relocated beyond the levee.

Those improvements would cost about $40 million.

The master plan identified almost $30 million in other improvements, including adding new taxiways and removing others for the sake of efficiency and safety for pilots and passengers, building more hangars on both the east and west sides of the airport, and moving the fuel storage area to the airport’s southwest side.

The projects will take several years to complete, airport officials said, and will increase the airport’s capacity to 216,000 flights a year from about 145,000 now.