- Date
- August 21, 2021, 13:30 local (17:30 UTC)
- Place
- Port Orange, FL
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Approach
- Aircraft
- N9285Enstrom 280
- Defining event
- Approach-VFR pattern final: Sys/Comp malf/fail (non-power)
- Weather
- Visual (VMC) · Day
- Status
- Completed
- Report
- Approved by Office Director
- Investigation class
- Class 3
- NTSB office
- Eastern Region Aviation
- Parties
- Enstrom Helicopter, FAA/FSDO
- FAA report
- 20210821022239A
- Case key
- 103759
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The failure of the tail rotor drive shaft at the coupling due to torsionally applied shear stress.
Findings · 1
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The pilot was conducting a local flight when just prior to touchdown, the helicopter began to spin to the right and made an uncommanded climb and spin to the right. The pilot applied full left rudder pedal, but the helicopter continued to spin to the right. He lowered the collective and landed hard on the skids, which resulted in substantial damage to the fuselage. Postaccident examination of the helicopter revealed the tail rotor driveshaft was separated and free to spin inside the coupling. Metallurgical examination of the driveshaft revealed the bolt holes in the driveshaft were distorted, consistent with torsional shear-stress in the clockwise direction.
Factual narrative
On August 21, 2021, about 1330 eastern daylight time, an Enstrom 280C, N9285, was substantially damaged when it was involved in an accident in Daytona Beach, Florida. The pilot was not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91personal flight. According to the pilot, he conducted a local flight around Spruce Creek Airport (7FL6), Daytona Beach, Florida, and was approaching to land. Just prior to touchdown, the helicopter made an uncommanded climb and started to spin to the right. The pilot applied full left pedal, but the helicopter continued to spin to the right. He lowered the collective and the helicopter landed hard on the skids. The left skid was damaged during, fuselage frame, and the tail rotor blades were damaged during the landing. Postaccident examination of the helicopter revealed that the tail rotor driveshaft was free to spin inside the coupling and not connected by a through bolt. The coupling and a section of the drive shaft were forwarded to the National Transportation Safety Board’s Material Laboratory for further examination. The examination revealed that the bolt holes in the drive shaft tube were mechanically distorted consistent with the presence of an axially applied torsional shear-stress in the drive shaft tube in the clockwise direction. Macroscopically, the fracture surface in the drive shaft tube was consistent with overstress due to torsionally applied shear stress (for more information, see Materials Laboratory Factual Report in the public docket for this investigation).
Aircraft
- Registration
- N9285
- Reported as
- Enstrom 280 (C)
- Category
- Helicopter
- Serial number
- 1003
- Built
- 1978
- Airframe hours
- 2,326
- Engine
- Lycoming HIO-360-EIAD, 205 hp, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Registered owner
- Mark Sherman
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · March 1, 2021
- Airport
- 7FL6 · Spruce Creek, runway 24, 4,000 × 176 ft
- Equipment
- Electronic flight bag or handheld device, ADS-B
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 73
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 3, With waivers/limitations
- Last flight review
- July 28, 2021
- Seat
- Left
- Restraint
- 4-point
- Flight hours
- 4,829 total · 62 in this make and model · 3,455 as pilot in command · 49 in the last 90 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 250° at 5 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- 18,000 ft broken
- Temperature
- 93 °F, dew point 75 °F
- Altimeter
- 29.96 inHg
- Observed at
- KDAB, 6 nm away
- METAR
- KDAB 211753Z 25005KT 10SM SCT044TCU SCT055 BKN180 BKN250 34/24 A2996 RMK AO2 SLP144 TCU SW-NW DSNT SE-S T03440239 10350 20261 57007 $
Docket · 7
The files NTSB released with the investigation on July 26, 2023, on NTSB’s docket system: statements, records, photos and specialists’ reports. 21.9 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.