The nation's air tour industry experienced six aviation accidents last year, including two in Hawai'i, according to the Federal Aviation Administration.

The national total was the lowest annual number in at least 26 years.

Although numbers may vary from year to year for no apparent reason, the number of air tour accidents in Hawai'i and across the nation has been on the decline. Over the past 10 years, there was a national average of 13 air tour accidents annually, down from more than 18 per year over the previous decade, according to FAA statistics.

In Hawai'i, there was an average of 2.5 air tour accidents annually over the past 10 years, down from 3.6 per year during the 1990s. On average, there's been less than one fatal air tour crash per year for the past 20 years.

Advancements in aircraft technology, stricter FAA rules and better dialogue on safety issues between the air tour industry and federal agencies are credited with the improvement in aviation accident statistics.

The two Hawai'i accidents last year include the June 17 crash of a tour plane on the slopes of Mauna Loa that killed three. The National Transportation Safety Board has not released its report on the cause of the crash.

The other involved a tour helicopter that made a forced landing Feb. 7 near Hilo, resulting in minor injuries to five people.

Overall, there were 11 aviation accidents and incidents in the state last year, six involving general aviation or noncommercial flights, according to the NTSB. Federal law defines an aircraft "accident" as an event involving death or serious injury or substantial aircraft damage. An event is classified as an "incident" when there are no injuries and aircraft damage is minor.

The only other Hawai'i air fatality occurred Jan. 14, 2008, when a small cargo plane crashed in the ocean south of the Lihu'e Airport, killing the pilot.

SPECIAL RULE CREATED

In 1996, the FAA implemented a special air tour rule in Hawai'i called SFAR-71 that established a range of safety requirements and procedures. These include requiring tour flights that travel over the ocean to be equipped with floats or to provide passengers with flotation gear.

The rules also set a minimum altitude of 1,500 feet and mandate that pilots file a helicopter performance plan before each flight and that passengers be given a briefing on water-ditching procedures.

Because of its success in Hawai'i, the rule was extended to air tour operators across the country two years ago.

Two fatal Kaua'i tour helicopter accidents just days apart in March 2007 spurred regulators to exert greater scrutiny of the air tour industry and served "as a wake-up call for the air tour industry itself," said Ian Gregor of the Federal Aviation Administration's Western-Pacific Region.

The FAA has since assigned a third of its inspection staff at its Honolulu Flight Standards District Office, about seven inspectors, to monitoring helicopter and fixed-wing air tour operations, rather than splitting their time between overseeing airlines and air tour companies, he said. The inspectors check for compliance with FAA regulations and at times conduct covert surveillance of air tour operations, Gregor said.

More inspectors will be added in the next few months, he said.

The FAA also co-sponsors an annual air tour safety symposium in Honolulu that brings together aviation officials, pilots and air tour operators to discuss safety issues.

EFFORTS 'BEARING FRUIT'

Meanwhile, Hawai'i air tour operators started their own safety working group three or four years ago, and industry associations have developed programs to help air tour companies improve their safety practices, according to Dave Chevalier, owner of Blue Hawaiian Helicopters, which operates on four islands.

"There's been a very concerted effort on safety, more than ever before in the air tour industry, and maybe that's bearing fruit," he said.

There are no statistics on the number of passengers or flight hours flown by air tour companies in Hawai'i. Blue Hawaiian, an industry leader, carries more than 120,000 passengers a year, Chevalier said.

The 1,500-foot minimum altitude rule was a major concern for air tour operators when SFAR-71 was implemented, but Chevalier said the FAA has become more willing to allow pilots to deviate from the rule to avoid quickly forming cloud cover over mountains that has been a factor in a number of air tour crashes in Hawai'i.

"The FAA has worked very well with operators on the safety front to make sure pilots have weather deviations where they need to," he said.

So far in 2009, there have been four aviation accidents in Hawai'i, all in January and none involving air tours. The single fatality occurred Jan. 16 when a glider crashed on Mauna Loa, killing the pilot.

The other U.S. air tour accidents in 2008 included two in California, one in Arizona and a fatal plane crash in Utah that killed two people. Three of the accidents involved airplanes, one a helicopter.