CEN19LA187

NTSB accident investigation · Robinson R22 · Danbury, TX · June 28, 2019

Accident · No injuriesClass 3 · LimitedFinal report
Date
June 28, 2019, 11:32 local (16:32 UTC)
Place
Danbury, TX
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N26498Robinson R22
Defining event
Maneuvering-low-alt flying: Sys/Comp malf/fail (non-power)
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
Federal Aviation Adminsitration
FAA report
20190628010739A
Case key
99724

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

A failed electrical relay, which provided an improper indication of a governor and clutch problem, which resulted in the pilot conducting a precautionary landing during which he failed to maintain sufficient main rotor speed.

Findings · 3

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 low-altitude pollination operations over a rice field when the governor caution light and the clutch caution light illuminated in succession; in response, the pilot reduced engine power. While landing in the field, the main rotor blades drooped and hit the tail cone, substantially damaging the helicopter. Postaccident inspection found that a failed electrical relay caused the governor light to illuminate, but the electrical relay by itself would not affect governor operation. No other anomalies were found with the helicopter, including the clutch system, that would have precluded normal operation. The accident sequence is consistent with the pilot responding to the governor caution light by reducing power but then letting the main rotor speed decaying too much during landing, such that the main rotor blades drooped and hit the tail cone.

Factual narrative

On June 28, 2019 at 1132 Central Daylight Time, a Robinson R-22 Beta helicopter, N26498, impacted terrainnear Danbury, Texas. The commercial pilot was not injured. The helicopter was substantially damaged. The helicopter was registered to a corporation and operated as a 14 Code of Federal Regulations Part 137 pollination flight. Visual meteorological conditions were reported at the accident site and along the route of flight about the time of the accident. The pilot reported to the FAA he was conducting pollination activities when the "clutch" light illuminated and would not go out and he began to loose power, so he "set it down" in the field. He pilot told the mechanic selected to repair the helicopter that he was flying low over the agricultural field when the "GOV" (governor) caution light illuminated, followed by the "clutch light" illuminating. He felt the helicopter began to lose rotor speed and responded by rolling the engine power. He landed the helicopter vertically and did not split the skids; however, the main rotor speed decayed sufficiently enough that a main rotor blade drooped and struck the tail cone, substantially damaging the helicopter. The mechanic reported that during an examination of the helicopter the "actuator" engaged and disengaged normally, the drive belts were in good condition, and the clutch rotated normally. The governor light remained illuminated regardless of the switch position. He traced the light to a faulty electrical relay that caused the light to illuminate, and stated the faulty relay would only cause the light to come on and would not affect the governor operation. He verified the governor operated normally when electrical power was applied. No other anomalies were found with the helicopter.

Aircraft

Registration
N26498
Reported as
Robinson R22 (BETA)
Category
Helicopter
Serial number
0836
Built
1988
Engine
Lycoming O-320 SERIES, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Standard Aviation Svcs
Registered owner
Hartland Helicopters Llc
Airworthiness certificate
Standard, Normal

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
37
Injuries
None
Certificate
Commercial
Medical
Class 2, With waivers/limitations
Last flight review
January 23, 2019
Flight hours
1,100 total · 850 in this make and model · 100 in the last 90 days

Weather

Conditions
Visual (VMC) · Day

Docket · 2

The files NTSB released with the investigation on September 9, 2019, on NTSB’s docket system: statements, records, photos and specialists’ reports. 113 KB 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.

Other investigations on N26498 · 1

Matched to the same aircraft by N-number and date.