Casualties unknown

2002-07-30: Robinson R22 BETA (N4074T) — Mazzei Flying Service — Fresno, CA

Fresno, CA, US

On July 30, 2002, a Robinson R22 BETA (registration N4074T) operated by Mazzei Flying Service was involved in an aviation accident near Fresno, CA. Investigators recorded the probable cause as: the CFI misjudged the terrain and wind conditions. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A helicopter struck uneven ground and rolled over during a quick stop maneuver conducted by a certified flight instructor for a student. The CFI misjudged terrain and wind conditions, leading to a hard landing with main rotor contact to the tail boom.

Accident Overview

The accident occurred during a flight training exercise in which a certified flight instructor (CFI) was demonstrating a quick stop maneuver to a student. According to the investigation, the helicopter collided with uneven ground and rolled over during the maneuver.

Sequence of Events

After performing a series of maneuvers, the CFI repositioned the helicopter and initiated a quick stop demonstration. During this maneuver, the CFI "misjudged the terrain and wind conditions," causing the helicopter to settle rapidly toward the ground. As the helicopter descended, the CFI raised the collective, resulting in a decrease in rotor rpm. The helicopter impacted the ground, became airborne again, and struck the ground a second time. During the impact sequence, the main rotor struck the tail boom. The helicopter came to rest on its left side.

Wreckage and Ground Scar Evidence

An FAA inspector examined the accident site and wreckage. The inspector documented a series of ground scars and debris extending for 195 feet, culminating in the main wreckage. The first identifiable ground scars consisted of two parallel thin scars on the crest of a hillock, dimensionally consistent with the right and left skids. These scars extended for 36 feet and terminated at the edge of a wash. Across the wash, at a distance of 105 feet, ground scars consistent with the tail rotor and stinger assemblies were noted. The tail rotor gearbox, blade assembly, and the most aft portion of the tail boom were found at this location. For the remaining 54 feet uphill to the main wreckage, additional ground scars and debris consistent with the skids were located.

Instructor Actions

The CFI, who was conducting the demonstration, was the sole manipulator of the controls during the quick stop. The source does not specify any further actions or statements from the instructor beyond the misjudgment of terrain and wind conditions.

Probable cause

the CFI misjudged the terrain and wind conditions

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20020731X01270. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.