# NTSB GAA18CA430: Robinson R44, N944DC, Okawville, IL, July 9, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 8, 2018, 19:00 local (Jul 9, 2018, 00:00 UTC) - Place: Okawville, IL - Coordinates: 38.517501, -89.565551 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.5175&lon=-89.5656&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Settling with power/vortex ring state](https://openairdocs.org/ntsb-events/244) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 26, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 97835 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA18CA430 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97835/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97835 - Page: https://openairdocs.org/ntsb/GAA18CA430 ## Probable cause The pilot's improper preflight weight and balance calculation, which resulted in his operating the helicopter over its maximum gross takeoff weight and in its subsequent failure to climb. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Aircraft capability: maximum weight](https://openairdocs.org/ntsb-findings/01061035): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Robinson Helicopter R44 II, 9 cases](https://openairdocs.org/ntsb-findings/01061035/cases.md?model=7640122), [All aircraft, 152 cases](https://openairdocs.org/ntsb-findings/01061035/cases.md) - [Planning/preparation: weight/balance calculations](https://openairdocs.org/ntsb-findings/02061015): Personnel issues › Task performance · Pilot; cases with it: [Robinson Helicopter R44 II, 3 cases](https://openairdocs.org/ntsb-findings/02061015/cases.md?model=7640122), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/02061015/cases.md) - [Inspection](https://openairdocs.org/ntsb-findings/02061500): Personnel issues › Task performance · Pilot; cases with it: [Robinson Helicopter R44 II, 1 case](https://openairdocs.org/ntsb-findings/02061500/cases.md?model=7640122), [All aircraft, 29 cases](https://openairdocs.org/ntsb-findings/02061500/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Preflight or dispatch event](https://openairdocs.org/ntsb-events/030); cases with it: [Robinson Helicopter R44 II, 2 cases](https://openairdocs.org/ntsb-events/030/sequence.md?model=7640122), [All aircraft, 355 cases](https://openairdocs.org/ntsb-events/030/sequence.md) - [Takeoff: Settling with power/vortex ring state](https://openairdocs.org/ntsb-events/244) (defining event); cases with it: [Robinson Helicopter R44 II, 6 cases](https://openairdocs.org/ntsb-events/244/sequence.md?model=7640122), [All aircraft, 52 cases](https://openairdocs.org/ntsb-events/244/sequence.md) - [Takeoff: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Robinson Helicopter R44 II, 24 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7640122), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Robinson Helicopter R44 II, 95 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640122), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The helicopter pilot reported that, before starting agricultural application flights for the day, he calculated that about 490 lbs of chemical would bring the helicopter's weight near the manufacturer's maximum gross weight limitation. After an agricultural application flight, he landed the helicopter on a platform on top of a chemical reloading truck and reloaded the chemical tank with the precalculated 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 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 but had about 80 lbs of chemical remaining and that the added precalculated amount of chemical exceeded the helicopter's maximum gross weight limitation. ## Factual narrative 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. ## Aircraft - Registration: [N944DC](https://openairdocs.org/aircraft/N944DC), registered now, S/N 13203, built 2011 (OpenAirDocs) - Reported make and model: Robinson R44 (II) - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Lycoming IO-540-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 13203 - Year built: 2011 - Airframe hours: 1421.49 - Engines: Lycoming IO-540-AE1A5 245 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Skyline Helicopters Llc - Registered owner: Skyline Helicopters Llc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 5, 2018 - Departed: Okawville, IL - Destination: Okawville, IL - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 26; injuries: none; commercial, flight instructor, private; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review May 11, 2018; seat: front; restraint: 3-point; flight hours: 1,727 total, 1,064 in this make and model, 1,655 as pilot in command, 181 in the last 90 days, 112 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 86 °F, dew point 70 °F - Altimeter: 30.15 inHg - Observed at: KBLV, 14 nm away ## Docket (1 files) The files NTSB released with the investigation on May 9, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97835. 956 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 956 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40472764&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.