Federal Aviation Administration officials are reviewing proposals to improve the flight safety of powered hang gliders known as "trikes" after three fatal crashes involving six deaths in a 14-month period in Hawaii.

"We are evaluating a variety of recommendations," FAA spokesman Ian Gregor told the Honolulu Star-Advertiser. "It is premature to discuss any potential changes at this time."

Gregor said the FAA held an internal meeting a couple of weeks ago about operations in Hawaii of weight-shift control aircraft, the type of light sport aircraft involved in the three fatal crashes. A fourth craft crashed in August 2009, resulting in nonfatal injuries.

Families of passengers killed in trike crashes said they support changes that would improve safety and disclosure.

Washington state resident Patty Hanson, whose life partner, Kim Buergel, died in a crash Feb. 15 on Kauai, said the FAA should be working toward that goal.

"I think it’s a good thing," Hanson said. "I would hope they would make stricter rules and regulations so that these tragedies can diminish."

A Star-Advertiser investigation published on May 21 found that in at least two of the fatal crashes here recently, passengers flying in the trikes did so to take tours.

Under Federal Aviation Administration rules developed in 2004, trike operators are banned from conducting commercial tours but may sell the flights as introductory pilot training.

A National Transportation Safety Board investigator has acknowledged that while trike operators take passengers for "introductory flight training," most passengers never become pilots.

Two visitors accompanying those who died on tours told the Star-Advertiser their understanding was they were sightseeing and no one told them about the ban on commercial trike tours.

Trikes and other light sport aircraft fly under fewer flight restrictions and reduced margins of safety compared with tour airplanes and helicopters.

Pilots in tour airplanes and helicopters in Hawaii are required to fly at least 1,500 feet from the nearest ground to give them a margin of safety for recovery.

Trike pilots as well as other light sport pilots also fly fewer hours of instruction before conducting passenger flights and may fly at their discretion at any height in unpopulated areas.

A witness of the fatal crash on May 17 said he saw the trike aircraft banking a turn within 60 feet of a cliff in north Kauai.

A witness of the fatal crash on Feb. 15 said he saw a trike pilot and passenger flying about 150 feet above the ocean when the aircraft went into a dive, then leveled off and dove straight into the water.

In a separate Kauai crash that resulted in survivors, a trike pilot and passenger flying 3,000 feet high were injured after the aircraft lost control, but deployed a rocket-propelled parachute system about 200 to 300 feet above the ground.

Tricia Moran, the sister of Kathryn Moran, who died in a trike crash on the Big Island on April 21, 2010, said there definitely needs to be changes in federal flight rules.

"I’d hate to see more people dead as a result of sightseeing, using these trikes," she said.

The National Transportation Safety Board is investigating the cause of the three crashes and has not issued final reports.