U.S. Sen. Mazie Hirono is asking federal transportation officials for more information about helicopter accidents in Hawaii and whether there has been appropriate follow-up with air tour companies in light of the deadly helicopter crash in Kailua on April 29 that killed the pilot and two passengers.

The helicopter crashed on Oneawa Street in a residential neighborhood.

The Hawaii Democrat sent letters on Tuesday to Robert Sumwalt, chairman of the National Transportation Safety Board, and Dan Elwell, acting administrator for the Federal Aviation Administration, requesting a report of helicopter accidents in Hawaii over the last five years.

Hirono also requested a detailed history of problems associated with the Robinson R44 helicopter, which was model that crashed in Kailua, as well as an accounting of all air tour accidents and unintended landings in Hawaii.

The Robinson R44 is the best-selling civilian helicopter, but also has a long history of deadly crashes, an investigation by the Los Angeles Times last year found.

The National Transportation Safety Board is leading an investigation into the April 29 crash. The Federal Aviation Administration regulates the operation of helicopters.

“I understand that two NTSB investigators are in Hawaii and that your agency expects to issue a preliminary accident report this week, but the final report will identify the causes of the accident,” Hirono wrote in her letter to Chairman Sumwalt. “In this regard, can you detail the steps of the investigation to identify the causes of the accident and the estimated length of time the NTSB will take to complete the final report? Can you also provide an accounting of all air tour accidents and unintended landings in Hawaii for the last five years, the findings, recommendations and requirements from each of these incidents? I have separately written the Federal Aviation Administration to find out whether there has been appropriate follow up with the air tour companies/industry in each instance.”

Sen. Hirono Letter to NTSB by Honolulu Star-Advertiser on Scribd

Hirono Letter to FAA by Honolulu Star-Advertiser on Scribd