Casualties unknown

Instructor loses control of helicopter during hover due to student overcorrection (N7456F)

Rialto, CA, US

On January 6, 1990, a Hughes 269C (registration N7456F) operated by C.a.r.i. Aviation was involved in an aviation accident near Rialto, CA. Investigators recorded the probable cause as: The instructor pilot's failure to maintain control of the helicopter during hover by allowing the student pilot to overcorrect the controls and not taking immediate corrective action, which resulted in ground resonance. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

An instructor pilot lost control of a helicopter while hovering after allowing a student to overcorrect the controls, leading to ground resonance and a rollover.

What happened

The accident occurred while a helicopter was in a hovering configuration. The instructor pilot, who was acting as the pilot in command, reported that he lost control of the aircraft during this phase of flight. The primary factor contributing to the loss of control was the student pilot's overcorrection of the flight controls. The instructor acknowledged that he failed to take immediate corrective action when the situation began to deteriorate.

Upon recognizing the developing instability, the instructor attempted to recover from what developed into a ground resonance condition. Despite these efforts, the helicopter rolled over onto its side shortly after the onset of the resonance event. No prior mechanical problems with the aircraft were reported by the crew or maintenance personnel before the incident.

Probable cause

The instructor pilot's failure to maintain control of the helicopter during hover by allowing the student pilot to overcorrect the controls and not taking immediate corrective action, which resulted in ground resonance.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X22433. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.