NTSB CAROL · Event
Event WPR15LA249
Aircraft involved
Probable cause & findings
The disbondment of a main rotor damper, which resulted in the degradation of its damping action and led to excessive main rotor vibrations and oscillations that caused substantial damage to the helicopter in flight and led to a hard landing.
Factual narrative
On August 23, 2015, about 1645 mountain standard time, a Schweizer 269C, N315TV, sustained substantial damage during a hard landing, at the Falcon Field Airport (FFZ) Mesa, Arizona. The helicopter was registered to Canyon State Aero LLC., and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The commercial pilot was not injured and the passenger sustained minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight. The local flight originated at FFZ about 1615. The pilot reported that during the approach to the ramp area in front of the operator's hangar, he noticed erratic cyclic control movements, and during the landing, the helicopter landed hard. Initial examination of the helicopter by a Federal Aviation Administration (FAA) inspector revealed that the main rotor blades and tail boom were substantially damaged. The helicopter was recovered to a secured local storage facility for further examination. Further examination by the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), an FAA inspector, and a representative from Sikorsky, revealed the helicopter was sitting upright on its skids with the tail boom separated. All three main rotor blades were attached to the main rotor head. The main rotor mast was observed to be tilted. The flight control system was generally intact. All rods and bellcranks were appropriately attached at all their respective points. Flight control continuity with the cyclic and collective was established with the cockpit controls. Continuity to the tail rotor was established from the cockpit pedals to the forward end of the control rod where a facture was observed; and from that fracture point to the tail boom. The electric cyclic trim system was operated and was fully functional with no anomalies noted. The helicopter main rotor mast support structure including the lower transmission housing sustained damage and resulted in the main rotor mast being tilted. Scratches and marks were observed on the mast indicating its movement. Further damage was sustained to the aft cabin bulkhead. The main rotor head was intact and attached to the drive shaft. The swashplate was also intact, and the rotor head rotated freely in the mast bearing. The pitch housings remained attached to the main rotor hub and were correctly installed. The main rotor head dampers were removed and examined, and all three dampers exhibited compression contact marks on the interior of the barrel end caps, which indicated excessive lead lag motion. Additionally, the dampers had internally separated. Further examination of the dampers revealed that one had become dis-bonded and would result in the degradation of its damping capability. The engine was observed to be intact but had been slightly displaced due to the damage to the mast and main gear box mounting. Continuity with all the engine controls was established. When the engine starter was engaged, the engine rotated normally with suction observed on the cylinders and fuel servo inlet. Examination of the helicopter did not revealed any additional evidence of a mechanical malfunction that would preclude normal operation. A review of the maintenance records revealed that the last annual inspection was on June 14, 2015, at 2,368 hours. The dampers were determined to be the original units. The main rotor damper inspection would have been complied with during the August 28, 2011, inspection, at 2,319 hours. Although not required, no specific results of the damper check dimensions were documented. The commercial pilot reported that, after returning from a noneventful personal flight and during the approach for landing, he noticed erratic cyclic control movements. He attempted an emergency landing, but the cyclic continued to move erratically counter-clockwise, and the helicopter subsequently landed hard. Postaccident examination of the helicopter revealed that a main rotor damper had disbonded, which would have resulted in the degradation of its damping capability and excessive main rotor vibrations and oscillations. This would have caused substantial damage in the main rotor mast supporting structure and aft cabin bulkhead before the landing and the erratic cyclic control movements reported by the pilot. Further examination of the helicopter and engine did not reveal any additional evidence of a mechanical malfunction or failure that would have precluded normal operation. 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 propeller/rotor-Main rotor system-Main rotor blade system-Damaged/degraded - C
- C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Prop/rotor parameters-Attain/maintain not possible - C
Verbatim from NTSB's published report. Source file
NTSB_2015_WPR15LA249.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
Beyond the agency record
Search this event elsewhere.
Pre-filled searches into the sources where news + community discussion of aviation events lives. External sources are reported, not agency. Treat them as signal that something happened, not as fact about what happened.
Entity-clustered aviation events in the press — last 24 hr + 30-day archive.
Official agency record + docket.
Investigative docket: factual reports, photos, transcripts.
Long-running aviation incident database (Flight Safety Foundation).
Community NTSB synthesis blog — often has photos and witness reports.
Gold-standard aviation incident blog.
Aviation industry news search.
GA pilot forum — informed but rumor-prone.
GA pilot subreddit search.
Tail-number page — flight history (free tier limited).
AOPA Air Safety Institute search.
Mainstream press coverage. Recent events only.
Privacy-preserving news search.
External links open in a new tab. We don't ingest their content; we deep-link search queries.
Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (stall, maintenance). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- Embry-Riddle Scholarly Commons 2023 · Conference paper
The Value of Strong Partnerships to Build a Successful Aviation Maintenance Career Pathway Program for Transitioning Military Service Members
The aerospace industry is competing with other industries for a qualified workforce, and many of those competing industries are investing heavily in creating workforce development pipelines.
- Embry-Riddle Scholarly Commons 2026 · Journal article (IJAAA)
From Reactive to Predictive: A hybrid Trust-Mediated Adoption Framework for Data-Driven Maintenance in Distributed-Authority Aviation Environments
Modern aviation maintenance operates within increasingly data-intensive technological environments, yet the operational integration of predictive maintenance into routine decision-making remains incon…
- NASA NTRS 2026 · Conference Paper
Computational Analysis of Steady State Aerodynamics of Transonic Truss-Braced Wing Configuration in Deep Stall
This study presents a computational investigation of steady state aerodynamics of the Subsonic Ultra-Green Aircraft Research (SUGAR) Transonic Truss-Braced Wing (TTBW) configuration over a wide range …
- Semantic Scholar 2025 · Article (Applied Sciences)
Decision-Making Framework for Aviation Safety in Predictive Maintenance Strategies
The implementation of predictive maintenance (PM) in aviation presents unique challenges due to strict safety requirements, complex operational environments, and regulatory constraints.
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER)
Low-Resource Automatic Speech Recognition Domain Adaptation – A Case-Study in Aviation Maintenance
With timeliness and efficiency being critical in the aviation maintenance industry, the need has been growing for smart technological solutions that optimize and streamline the different underlying ta…
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER)
A New Trajectory in UAV Safety: Leveraging Reinforcement Learning for Distance Maintenance Under Wind Variations
In the field of aviation, safety is a critical cornerstone, and the operation of Unmanned Aerial Vehicle (UAV) systems is deeply connected with this principle.
Browse the full corpus — academia portal ↗