The National Transportation Safety Board has released a preliminary report for the “firm” emergency landing of a helicopter at Kalispell City Airport Monday morning.

No one was injured in the incident, reported to emergency dispatchers at about 10:30 a.m.

A caller at Legends Stadium reported “seeing a helicopter going down way too fast” and “hearing a loud crash.”

Several local fire departments initially were dispatched but were advised to disregard a short while later after someone at the airport was contacted and confirmed that everything was OK.

According to the safety board report, a flight instructor and student were onboard the helicopter and performing a fourth practice autorotation — a descending maneuver that can be used to safely land in the event of a complete engine failure.

The flight instructor told an investigator that midway through the simulated emergency maneuver, the helicopter’s engine quit. He immediately took control of the helicopter and performed a “firm” emergency landing at the airport.

The helicopter sustained substantial damage as a result of the main rotor blades impacting the tail rotor blades, the report said.

The helicopter was moved to a secure storage facility for further examination.

Jim Bob Pierce, owner of Red Eagle Aviation, said the student throttled the main rotor RPMs down too low, causing the engine to quit.

The low main rotor speed also caused it to bend and hit the tail rotor during the landing, he said.

“When it goes too slow it kind of flops around,” Pierce said of the main rotor.

The maneuver is a common training exercise and something that’s always done over the airport, Pierce said.

“Usually we do power recoveries at the bottom and come to hover. That’s what failed to happen,” Pierce said.

Reporter Tom Lotshaw may be reached at 758-4483 or by email at tlotshaw@dailyinterlake.com.