# NTSB WPR16LA132: Robinson Helicopter R44, N8325X, El Centro, CA, June 28, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: June 27, 2016, 20:10 local (Jun 28, 2016, 03:10 UTC) - Place: El Centro, CA - Coordinates: 32.752223, -115.46499 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.7522&lon=-115.4650&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 93480 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR16LA132 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93480/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93480 - Page: https://openairdocs.org/ntsb/WPR16LA132 ## Probable cause A loss of main rotor rpm and airframe vibration for reasons that could not be determined based on the available information, which resulted in a forced landing to sloping terrain and the helicopter rolling over. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Robinson Helicopter R44, 11 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=7640120), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Robinson Helicopter R44, 56 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640120), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Enroute-cruise: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Robinson Helicopter R44, 13 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=7640120), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis The helicopter pilot was performing an agricultural flight when he felt an airframe vibration, which was followed by the main rotor low rpm warning and a loss of rotor rpm. He reduced collective and the vibration and warning horn stopped. As he began to maneuver for a landing, he increased the collective and leveled the skids and again felt an airframe vibration and noted a loss of rotor rpm. During the landing on sloping terrain, the right front skid toe dug into the soft dirt and the helicopter came to rest on its side, resulting in substantial damage. Examination of the helicopter revealed no mechanical anomalies that would have precluded normal operation, and the reason for the vibration and loss of rotor rpm could not be determined based on the available information. ## Factual narrative On June 27, 2016, at 2010 Pacific daylight time, a Robinson R44 helicopter, N8325X, was substantially damaged when it was involved in an accident near El Centro, California. The pilot was not injured. The helicopter was operated as a Title 14 Code of Federal Regulations (CFR) Part 137 agricultural flight. The pilot reported that, during the preflight inspection, the main fuel tank was about half full and the auxiliary fuel tank was 1/4 full. He completed the preflight inspection and performed an engine start and run up; both were normal. After departure, the pilot climbed the helicopter to 400 ft above ground level (agl) and flew toward the field. While in cruise flight, the pilot felt a vibration in the airframe followed immediately by the low rotor rpm warning. He noted that the rotor rpm was decreasing, which he arrested by reducing collective. At that point, the airframe vibration had either stopped or subsided, and the low rotor rpm warning stopped. The pilot entered a shallow right turn and located a dirt road as a forced landing site. As he approached at 50 ft agl, he began to flare and increased engine power; the engine rpm increased to the green arc and matched the rotor rpm. As he increased the collective and leveled the skids, he again felt the airframe vibration and the rotor rpm decreased. As the helicopter neared the ground, the pilot saw that the dirt road was down sloping. He turned toward the right and landed. During the ground slide, the right front skid toe dug into the soft dirt and the helicopter pitched forward and to the right. The main rotor blades contacted the ground, and the helicopter came to rest on its right side. Federal Aviation Administration (FAA) inspectors examined the helicopter and noted that the main rotor blades were coned upward with chordwise creases from the hub to the tip. The right-side skid toe had broken off just forward of the forward attachment point. The tail boom was buckled just aft of the fuselage attachment point. The tail rotor blades, and tail skid were undamaged. The horizontal stabilizer exhibited crush deformation. The collective was in the full-up position and the pedals were stuck in the full-left position. The FAA inspectors did not free the collective or pedals to perform the flight control continuity check. All four V-belts remained intact, with the three forward V-belts displaced forward off their tracks. The alternator belt remained intact. The left main fuel tank contained about 6 inches of fuel and the right auxiliary fuel tank contained about 2 inches of fuel. Samples of the fuel revealed no debris and coloration consistent with 100 low-lead aviation fuel. ## Aircraft - Registration: [N8325X](https://openairdocs.org/deregistered/N8325X-2018-06-01), registration cancelled 2018-06-01, S/N 0207, built 1995 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER R44 (UNDESIGNAT) - Registry model: [Robinson Helicopter R44](https://openairdocs.org/model/robinson-helicopter-r44) (registry code 7640120) (OpenAirDocs) - Registry engine: [Lycoming O-540-F1B5](https://openairdocs.org/engine/lycoming-o-540-f1b5) (registry code 42353, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 0207 - Year built: 1995 - Airframe hours: 1208.7 - Engines: LYCOMING O-540-F1B5 250 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Custom Ag - Registered owner: John Reed - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, May 26, 2016 - Departed: PVT, El Centro, CA - Destination: PVT, El Centro, CA - Flight plan: Company VFR - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review December 28, 2015; seat: right; flight hours: 390 total, 0 in this make and model ## Weather - Conditions: Visual (VMC), Night - Wind: 170° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 109 °F, dew point 54 °F - Altimeter: 29.68 inHg - Observed at: KIPL, 8 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20160627024859A](https://openairdocs.org/incident/20160627024859A), Jun 27, 2016: Robinson Helicopter R44, Calexico, CA, Substantial damage. The pilot was en route to a field where he would begin a 14 CFR part 137 aerial application operation. While in cruise flight at approximately 400 feet, the… ## Docket (3 files) The files NTSB released with the investigation on February 2, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93480. 5.3 MB in all. - Pilot's statement (item 1, PDF, 2 pages, 894 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11857354&FileExtension=pdf&FileName=Pilot%20Statement%20N8325X_Redacted-Rel.pdf - FAA record of interview (item 2, PDF, 4 pages, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11857161&FileExtension=pdf&FileName=2016-06-28%20Record%20of%20Visit_Redacted-Rel.pdf - Photos (FAA) (item 3, PDF, 2 pages, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11856992&FileExtension=pdf&FileName=Photos%20(FAA)-Rel.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.