Friday, July 20, 2018

Settling with Power / Vortex Ring State: Robinson R44 II, N944DC, accident occurred July 08, 2018 in Okawville, Washington County, Illinois

Federal Aviation Administration / Flight Standards District Office; Springfield, Illinois

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Okawville, IL
Accident Number: GAA18CA430
Date & Time: 07/08/2018, 1900 CDT
Registration: N944DC
Aircraft: Robinson R44
Aircraft Damage: Substantial
Defining Event: Settling with power/vortex ring state
Injuries: 1 None
Flight Conducted Under: Part 137: Agricultural 

The helicopter pilot reported that, before starting aerial application flights for the day, he calculated that about 490 pounds of chemical would bring the helicopter's weight near the manufacturer's maximum gross weight limitation.

After an aerial application flight, he landed on a platform located on top of a chemical reloading truck and reloaded the chemical tank with the pre-calculated amount. Once reloaded, he maintained a stabilized hover over the truck and transitioned to forward flight. When the helicopter cleared the truck, the "engine [made] a lower sound" and the main rotor low revolutions per minute (RPM) horn activated and the caution light illuminated. He immediately added power, lowered the collective to restore main rotor RPM, and pitched forward to gain airspeed but the helicopter would not climb. He then decided to perform a roll-on landing on the adjacent field, but the helicopter landed hard.

The helicopter sustained substantial damage to the tail cone, tail rotor blades, and fuselage.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.

The pilot added that after the accident, he recalculated the helicopter's weight and balance. He determined that during the reloading operation, the chemical tank was not empty with about 80 pounds of chemical remaining and the added precalculated amount of chemical exceeded the maximum gross weight limitation. 

Pilot Information

Certificate: Flight Instructor; Commercial; Private
Age: 26, Male
Airplane Rating(s): None
Seat Occupied: Front
Other Aircraft Rating(s): Helicopter
Restraint Used: 3-point
Instrument Rating(s): Helicopter
Second Pilot Present: No
Instructor Rating(s): Helicopter; Instrument Helicopter
Toxicology Performed: No
Medical Certification: Class 2 With Waivers/Limitations
Last FAA Medical Exam: 05/31/2018
Occupational Pilot: Yes
Last Flight Review or Equivalent: 05/11/2018
Flight Time:   1727 hours (Total, all aircraft), 1064 hours (Total, this make and model), 1655 hours (Pilot In Command, all aircraft), 181 hours (Last 90 days, all aircraft), 112 hours (Last 30 days, all aircraft), 10 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Robinson
Registration: N944DC
Model/Series: R44 II
Aircraft Category: Helicopter
Year of Manufacture: 2011
Amateur Built: No
Airworthiness Certificate:Normal 
Serial Number: 13203
Landing Gear Type: Skid;
Seats: 4
Date/Type of Last Inspection: 07/05/2018, 100 Hour
Certified Max Gross Wt.: 2500 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 1421.49 Hours at time of accident
Engine Manufacturer: Lycoming
ELT: Not installed
Engine Model/Series: IO-540-AE1A5
Registered Owner: Skyline Helicopters Llc
Rated Power: 245 hp
Operator: Skyline Helicopters Llc
Operating Certificate(s) Held: Agricultural Aircraft (137)

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KBLV, 459 ft msl
Distance from Accident Site: 14 Nautical Miles
Observation Time: 2356 UTC
Direction from Accident Site: 278°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 4 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 70°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.16 inches Hg
Temperature/Dew Point: 30°C / 21°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Okawville, IL
Type of Flight Plan Filed: None
Destination: Okawville, IL
Type of Clearance: None 
Departure Time:  CDT
Type of Airspace: Class G 

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 None
Latitude, Longitude: 38.517500, -89.565556 (est)

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