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Atlas / NTSB / CEN11CA638

NTSB CAROL · Event

Event CEN11CA638

2011-08-29 Menominee, Michigan, United States Airport · MNM None 1 aircraft Status: Completed

Registry · N228F

FAA Aircraft Registry record.

Make / Model

ENSTROM F-28F

Year of manufacture

2007 · 4 years old at event

TCDS

H1CE · ENSTROM HELICOPTER CORP THE

Engine

LYCOMING HIO-360-F1AD (190 hp)

Seats / Engines

3 seats · 1 engine

Last airworthiness date

20250710

ADS-B equipped

Yes — Mode-S A1FF36

Registrant of record

ENSTROM HELICOPTER CORP

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The pilot's failure to maintain control of the helicopter during a hover.

Factual narrative

According to the pilot, the purpose of the company test flight was to measure collective stick forces with the collective bias disabled. The pilot, who was the helicopter's only occupant, lifted the helicopter into a hover and then hovered clear of any obstacles. He reported the collective controls were heavy as expected, but the helicopter was very controllable. During his attempt to position a force gauge between his hand and the collective grip, the pilot lost control of the helicopter and it landed hard onto the ramp. The helicopter's tail rotor blades impacted the ramp and the helicopter came to rest upright. A postaccident examination of the helicopter showed the tail rotor blades were bent, and the tail rotor drive shaft was sheared. The pilot reported he should have taken an observer or other personnel on the flight to assist while he concentrated on flying the helicopter. According to the pilot, the purpose of the company test flight was to measure collective stick forces with the collective bias disabled. The pilot, who was the helicopter's only occupant, lifted the helicopter into a hover and then hovered clear of any obstacles. He reported that the collective controls were heavy, as expected, but the helicopter was very controllable. During his attempt to position a force gauge between his hand and the collective grip, the pilot lost control of the helicopter and it landed hard onto the ramp. The helicopter's tail rotor blades impacted the ramp and the helicopter came to rest upright. A postaccident examination of the helicopter showed that the tail rotor blades were bent and the tail rotor driveshaft was sheared. The pilot reported that he should have taken an observer or other personnel on the flight to assist while he concentrated on flying the helicopter. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

  • C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-(general)-Not attained/maintained - C
  • C Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C

Verbatim from NTSB's published report. Source file NTSB_2011_CEN11CA638.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.