# NTSB CEN19LA121: Bell OH 58A, N109PD, Omaha, NE, April 16, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: April 16, 2019, 07:30 local (12:30 UTC) - Place: Omaha, NE - Coordinates: 41.414443, -96.108329 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.4144&lon=-96.1083&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration, Rolls Royce Corporation - NTSB case key (mKey): 99266 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA121 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99266/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99266 - Page: https://openairdocs.org/ntsb/CEN19LA121 ## Probable cause A partial loss of engine power for reasons that could not be determined based on the available evidence. ## 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: [Bell OH-58A, 8 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=1181579), [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. - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Bell OH-58A, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=1181579), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Autorotation: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bell OH-58A, 12 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1181579), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis Shortly after takeoff and while climbing through 200 to 250 ft above ground level in a left turn, the pilots of the helicopter noted an audible horn, low main rotor rpm, and a loss of altitude” indicating a loss of rotor RPM and engine power." The flying pilot entered an autorotation to recover rotor rpm, and the pilots located a forced landing location. Upon touchdown, the forward landing gear skids dug into the soft terrain, and the helicopter rocked forward and backward, resulting in the main rotor contacting the tail boom. An examination of the helicopter revealed no preimpact mechanical anomalies that would have precluded normal operation. The engine was removed and placed in a production test cell for an engine test run. The engine responded normally to all power demands without surging or hesitation. Based on the available evidence, the reason for the partial loss of engine power could not be determined. ## Factual narrative On April 16, 2019, at 0730 central daylight time, a Bell OH-58A helicopter, N109PD, impacted terrain during an autorotation following a reported partial loss of engine power near Omaha, Nebraska. The pilot and co-pilot were not injured, and the helicopter sustained substantial damage to the tail boom. The helicopter was registered to and operated by the Omaha Police Department (OPD) as a public aircraft operations flight under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed in the area at the time of the accident. The flight originated from the North Omaha Airport (3N0), Omaha, Nebraska, at the time of the accident and was destined for Blair, Nebraska. According to the pilot, shortly after takeoff and climbing through 200 to 250 ft above ground level in a left turn, the pilots recognized an audible horn, low rotor RPM, and a loss of altitude "indicating a loss of rotor RPM and engine power." The pilot, who was seated in the right seat, entered an autorotation in an attempt to recover rotor RPM. The pilot and co-pilot observed the best suitable landing area was north and west of 3N0. Upon touchdown in the soft terrain, the forward landing gear skids dug into the terrain, and the helicopter rocked forward and backward which then caused the main rotor blades to contact the tail boom. The helicopter came to rest upright with the tail boom separated from the airframe. The pilots shut down the engine, which continued to operate about 35% N1, waited for the engine to stop, and exited the helicopter. A review of the maintenance records revealed that on March 15, 2019, the Rolls Royce T63-A-720 250-C20C engine shut off uncommanded during the cool down cycle. A 200-hour inspection was completed on March 16, 2019, at a total airframe time of 12,089.3 hours, which included the removal of fuel control and fuel pump, and replacement of the fuel filters. The fuel pump and fuel control were checked by a certified repair station and reinstalled onto the engine. No mechanical anomalies were noted during subsequent ground and flight tests. On March 21, 2019, the engine shut off uncommanded during the cool down cycle. The fuel control throttle rigging was checked, no obstructions were found in the intake/particle separator, and the helicopter was returned to service. At the time of the accident, the total airframe and engine times were 12,099.2 hours and 6,588 hours respectively. On April 23, 2019, the helicopter was examined by a Federal Aviation Administration (FAA) inspector, and representatives from the OPD and Rolls-Royce. No preimpact mechanical anomalies were noted during the examination with the airframe or engine. The engine was removed for further examination and testing. On July 16, 2019, the engine was examined at a Rolls-Royce's authorized maintenance center, Lafayette, Louisiana, under the supervision of the FAA. The engine was placed in a production test cell for an engine test run. The engine successfullycompleted ground idle, flight-idle, max-continuous-power, takeoff power runs, and "wave-off" maximum power increases. The engine responded normally to all power demands without surging or hesitation. ## Aircraft - Registration: [N109PD](https://openairdocs.org/deregistered/N109PD-2020-02-07), registration cancelled 2020-02-07, S/N 71-20455 (OpenAirDocs) - Reported make and model: Bell OH 58A (No Series) - Registry model: [Bell OH-58A](https://openairdocs.org/model/bell-oh-58a) (registry code 1181579) (OpenAirDocs) - Category: Helicopter - Serial number: 71-20455 - Year built: 1971 - Airframe hours: 12099.2 - Engines: Rolls Royce 250-C20C 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft - local, Public use - Operator: Omaha Police Department - Registered owner: Omaha Police Department - Airworthiness certificate: None - Last inspection: 100 hour, March 16, 2019 - Departed: 3NO, Omaha, NE - Destination: BTA, Blair, NE - Airport: 3NO, North Omaha Airport - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 42; injuries: none; commercial; medical: class 2, with waivers/limitations; last flight review September 20, 2017; seat: right; restraint: 3-point; flight hours: 4,115 total, 3,950 in this make and model, 4,115 as pilot in command, 44 in the last 90 days, 23 in the last 30 days - Co-pilot; age 46; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review April 15, 2019; seat: left; restraint: 3-point; flight hours: 5,327 total, 2,925 as pilot in command, 38 in the last 90 days, 5 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Observed at: OMA, 7 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 20190416002889A](https://openairdocs.org/incident/20190416002889A), Apr 16, 2019: Bell OH-58A, Omaha, NE, Substantial damage. Shortly after takeoff, approximately 200-300 feet, the a/c lost power. The pilot initiated an auto rotation and performed an off field landing near the… ## Docket (4 files) The files NTSB released with the investigation on December 5, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99266. 4.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478644&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Excerpts of Maintenance Information (item 2, .PDF, 419 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478645&FileExtension=.PDF&FileName=Excerpts%20of%20Maintenance%20Information-Master.PDF - Rolls Royce Engine Report (item 3, .PDF, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478646&FileExtension=.PDF&FileName=Rolls%20Royce%20Engine%20Report-Master.PDF - Statement of Party Representatives to NTSB Investigation - Rolls Royce (item 4, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478647&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation%20-%20Rolls%20Royce-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.