The president of the tour company whose helicopter crashed at Princeville Airport Thursday said he is deeply worried that inflatable floats installed as a safety measure on his company's A-Star helicopters could have played a role in the crash that killed four people and injured three others.

"If something did go wrong with the floats, I don't know. Something could have happened to the helicopter aerodynamically," said Heli USA president Nigel Turner, who was on Kaua'i yesterday — company headquarters is in Las Vegas — to support families of the dead and injured.

Turner said he had not confirmed that the aircraft's emergency inflatable pontoons had been deployed before the crash, but he suspects it is possible.

Pilot Joe Sulak, who died in the crash, had more than 10,000 hours of flight experience and was the company's lead pilot and the trainer of other pilots.

"I've just been talking to the pilot's family. He saved hundreds of lives in Vietnam and flying medical flights. Joe's family has been around aviation all their lives. He has been with us nearly four years," Turner said.

Sulak reported before the crash that he was experiencing hydraulic problems with the seven-seat aircraft. Landing without hydraulic assistance is a regularly practiced procedure for pilots, and Sulak had successfully landed without hydraulics a week before the crash during a test flight, Turner said.

"The only thing that's changed is the floats. Did the floats accidentally deploy?" he said.

With respect to the hydraulics on the helicopter, Turner said that because of previous issues that include one crash that followed a hydraulic failure on an A-Star aircraft, it is the company's policy to replace hydraulic pumps long before the end of their normal rated service life.

"We've been changing these pumps at half the life that's actually required, just to be on the safe side," he said.

The National Transportation Safety Board is leading the investigation into the crash. The helicopter had been scheduled to be moved yesterday from the crash site on the grass next to the Princeville Airport runway to a hangar at Lihu'e Airport, said state Department of Transportation spokesman Scott Ishikawa. There, the helicopter will undergo detailed analysis by federal officials, insurance officials, and engine and airframe manufacturer representatives.

Federal Aviation Administration and NTSB investigators were diverted from their probe of the Heli USA crash yesterday to the site only about five miles away where another tour helicopter crashed. But except for their geographic proximity, the accidents seemed quite different.

The aircraft are different: a seven-seat A-Star operated by Heli USA and a five-seat Hughes 500 operated by Inter-Island Helicopters. They fly out of different airports — Heli USA from Princeville and Inter-Island from Burns Field, also called the Hanapepe Airport or Port Allen Airport. The A-Star crashed near the beginning of its flight, apparently associated with a mechanical problem, while from initial reports, the Inter-Island crash may have followed catastrophic damage to its tail rotor — perhaps by a foreign object.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.