CEN13LA228

NTSB accident investigation · Robinson Helicopter R44 II · Buffalo, SD · April 13, 2013

Accident · No injuriesLimited investigationFinal report
Date
April 13, 2013, 12:15 local (18:15 UTC)
Place
Buffalo, SD
Injuries
4 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N424DPRobinson Helicopter R44 II
Defining event
Landing: Hard landing
Weather
Visual (VMC) · Day
Status
Completed · report December 11, 2013
Report
Approved by Office Director
NTSB office
Central Region
Parties
Federal Aviation Administration, Robinson Helicopter Company
FAA report
20130413008959A
Case key
86659

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 pilot’s failure to maintain adequate main rotor rpm while maneuvering at a low altitude in gusting wind conditions, which resulted in an emergency landing on uneven terrain.

Findings · 4

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.

Action: lack of actionPersonnel issues › Action/decision · PilotRobinson Helicopter R44 II: 6 casesAll aircraft: 792 casesProbable cause
Wind: gustsEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeRobinson Helicopter R44 II: 10 casesAll aircraft: 1,199 cases
Performance/control parameters: prop/rotor parametersAircraft › Aircraft oper/perf/capability · Not attained/maintainedRobinson Helicopter R44 II: 17 casesAll aircraft: 182 casesProbable cause
Terrain: sloped/uneven terrainEnvironmental issues › Physical environment · Contributed to outcomeRobinson Helicopter R44 II: 10 casesAll aircraft: 270 casesProbable cause

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 stated that, while maneuvering during a sightseeing flight at an altitude of between 100 and 150 feet and an airspeed of 50 knots, he reversed course into a strong, gusting tailwind. After making the turn, the low-rotor rpm horn activated. The pilot lowered the collective and executed an emergency landing to uneven terrain, during which the tail boom and landing gear separated from the fuselage of the helicopter. An examination of the airframe and engine, which included a successful functional test of the engine, revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

Factual narrative

On April 13, 2013, about 1215 mountain daylight time, a Robinson R-44 II helicopter, N424DP, serial number 11036, was substantially damaged after impact with terrain near Buffalo, South Dakota. The commercial pilot and three passengers did not report any injuries. The helicopter was registered to Double D Choppers LLC and operated under the provisions of 14 Code of Federal Regulations Part 91 with no flight plan filed. Day visual meteorological conditions prevailed for the flight, which originated from private land near Buffalo, South Dakota, about 1210. While maneuvering on a sightseeing flight at 100-150 feet above ground level and 50 knots airspeed, the pilot reported that he reversed course from the southeast to the northwest. After making this turn, he noticed that the low rotor speed horn activated. The pilot lowered the collective and executed an immediate landing into uneven terrain, during which the tail boom and landing gear were separated from the fuselage of the helicopter. The weather station at Harding County Airport (K2WX), Buffalo, South Dakota, located 14 nautical miles south of the accident site, reported the following conditions at 1156: wind 120 degrees at 22 knots with gusts to 28 knots, 10 miles visibility, temperature 8 degrees Celsius (C), dew point minus 2 degrees C, altimeter setting 29.46 inches of mercury. Following the accident, the engine was functionally tested on the accident helicopter. The engine started without hesitation and ran continuously at different power settings, including idle and 100 percent rpm. During the engine test, no anomalies were noted with the engine or its associated engine controls. Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The pilot was an experienced fixed-wing agricultural spray pilot. At the time of the accident, he reported a total flight experience of 12,020 hours; of which, 306 hours were flown in a helicopter and 89 hours were flown in this make and model of helicopter. On April 5, 2012, he was the pilot of a Robinson R-22 helicopter accident, which also involved a low rotor RPM condition and forced landing. Review of Robinson Safety Notice SN-18 revealed: OVERCONFIDENCE PREVAILS IN ACCIDENTS A personal trait most often found in pilots having serious accidents is overconfidence. High-time fixed-wing pilots transitioning into helicopters and private owners are particularly susceptible. Airplane pilots feel confident and relaxed in the air, but have not yet developed the control feel, coordination, and sensitivity demanded by a helicopter. Private owners are their own boss and can fly without discipline, enforced rules, or periodic flight checks and critique by a chief pilot. A private owner must depend on self-discipline, which is sometimes forgotten. When flown properly and conservatively, helicopters are potentially the safest aircraft built. But helicopters are alsoprobably the least forgiving. They must always be flown defensively. The pilot should allow himself a greater safety margin than he thinks will be necessary, just in case.

Aircraft

Registration
N424DP
Reported as
Robinson Helicopter R44 II
Category
Helicopter
Serial number
11036
Airframe hours
940
Engine
Lycoming IO-540 SER, 300 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Double D Choppers LLC
Registered owner
Double D Choppers LLC
Airworthiness certificate
Standard, Normal
Last inspection
Annual · April 2, 2013 · 10 hours before
Departed
Buffalo, SD
Destination
Buffalo, SD

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
41
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land, Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Last flight review
March 27, 2013
Seat
Right
Flight hours
12,020 total · 89 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
120° at 22 knots, gusting 28
Visibility
10 statute miles
Lowest ceiling
11,000 ft broken
Temperature
46 °F, dew point 28 °F
Altimeter
29.45 inHg
Observed at
K2WX, 14 nm away

Docket · 2

The files NTSB released with the investigation on July 31, 2013, on NTSB’s docket system: statements, records, photos and specialists’ reports. 652 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.