Millions of dollars in taxes and fees collected from airline passengers have paid the bill for improvements at northern Utah's Brigham City airport, which caters to business jets and sees no commercial traffic.

But airport officials say the improvements were long overdue, and the airport was encouraged to apply for the funding by the Federal Aviation Administration.

A review by The Associated Press found the airport in Brigham City, about 50 miles north of Salt Lake City, received $6.2 million in 2005 and $8 million in 2006 from the federal Airport Improvement Program — several times more than any other airport in the state.

The improvements were needed for safety purposes, past and current airport chiefs said.

Much has changed at the airport since the federal government carved a dirt airstrip in Brigham City in the early 1930s to act as an emergency landing field for the early days of aviation. In recent years, the airport has accepted an increasing amount of business and freight traffic for companies in northern Utah, said city administrator Bruce Leonard, who served as public works director for 23 years. The city's director of public works oversees the running of the airport.

In the early 1990s, the airport was classified as a utility airport, Leonard said, but business jet activity was increasing and larger aircraft were using the runway.

The airport began the process of applying for permits to reconstruct the airport so larger planes could land safely.

"That's when the FAA came in and said your airport needs to be upgraded," Leonard said.

The airport received funding through the AIP of $24 million over three years. The airport is scheduled to use the final $7.5 million of that allotment to finish up improvements by December this year, said Blake Fonnesbeck, the current public works director.

The airport has used the money to lengthen the runway by 1,000 feet, add a full-length taxiway parallel to the runway and 500 feet of "safety area" on either side of the runway that's free of obstacles.

Both Leonard and Fonnesbeck said the decision to upgrade the airport was approved by the FAA after the airport in Tremonton closed, and there was a need for a regional facility in the area.

The improvements being made at the airport will not upgrade it sufficiently to accept a commercial passenger plane. It is a general aviation airport with no tower and no landing fees used almost exclusively by local pilots of small planes and businesses.

A message left by the AP for a regional FAA spokesman was not immediately returned Friday.

The AIP has distributed $7.1 billion to airports of all sizes throughout the country since 2005. Most of the money was collected from commercial airline passengers, and about $2.2 billion of the AIP distributions since 2005 have gone to small airports with little or no commercial passenger service, many of them near popular recreation or tourist destinations.

The president of the National Business Aviation Association says without help from the federal government in the form of passenger taxes many small airports couldn't survive.

All Americans see some benefit from small airports throughout the country, said Ed Bolen. They aid emergency preparedness and critical services such as medical evacuations and mail delivery, he said.