# NTSB DFW08TA092: Robinson R44, N402PD, Topeka, KS, April 5, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: April 5, 2008, 00:03 local (05:03 UTC) - Place: Topeka, KS - Coordinates: 39.069179, -95.620788 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.0692&lon=-95.6208&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report December 24, 2008 - Report: Approved by Office Director - Parties: City of Topeka Police Dept., Robinson Helicopters, FAA FSDO - NTSB case key (mKey): 67761 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW08TA092 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/67761/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=67761 - Page: https://openairdocs.org/ntsb/DFW08TA092 ## Probable cause A malfunctioning magneto, resulting in a high engine rpm and low rotor warning indications. A contributing factor was the impact with a light pole, during the precautionary landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ignition system: magneto/distributor](https://openairdocs.org/ntsb-findings/01057414): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Robinson Helicopter R44 II, 3 cases](https://openairdocs.org/ntsb-findings/01057414/cases.md?model=7640122), [All aircraft, 101 cases](https://openairdocs.org/ntsb-findings/01057414/cases.md) - [Rotorcraft flight control: main rotor control](https://openairdocs.org/ntsb-findings/01046710): Aircraft › Aircraft propeller/rotor · Damaged/degraded; cases with it: [Robinson Helicopter R44 II, 1 case](https://openairdocs.org/ntsb-findings/01046710/cases.md?model=7640122), [All aircraft, 28 cases](https://openairdocs.org/ntsb-findings/01046710/cases.md) - [Object/animal/substance: pole](https://openairdocs.org/ntsb-findings/03022010): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Robinson Helicopter R44 II, 4 cases](https://openairdocs.org/ntsb-findings/03022010/cases.md?model=7640122), [All aircraft, 142 cases](https://openairdocs.org/ntsb-findings/03022010/cases.md) - [Light condition: dark](https://openairdocs.org/ntsb-findings/03036020): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; cases with it: [Robinson Helicopter R44 II, 8 cases](https://openairdocs.org/ntsb-findings/03036020/cases.md?model=7640122), [All aircraft, 448 cases](https://openairdocs.org/ntsb-findings/03036020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Robinson Helicopter R44 II, 9 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7640122), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Robinson Helicopter R44 II, 26 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7640122), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: 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 During a routine night surveillance flight, the helicopter's pilot heard the single reciprocating engine "fluctuate" slightly; he noted that the engine's rpm gauge was above the "normal operating limits", and the gauge [needle] was "jumping up-and-down". In order to keep the engine within operating limits, the pilot disabled the engine governor and decreased the engine rpm. During the return to base, the pilot heard the engine rev up and the low rotor rpm alarm. During the precautionary landing in a parking lot, the helicopter's main rotor blade contacted a light pole. The helicopter subsequently made a hard landing, coming to rest on its side. The magneto, governor controller, clutch actuator, engine/rotor tachometer and drive-belts were removed for examination. The governor, clutch actuator, tachometer, and drive belts all passed either a visual or electronic test inspection. A visual inspection of the magneto revealed that the exterior of the magneto was absent any damage, but was lightly covered with an "oil like" liquid. The magneto was bench tested and produced regular sparks beginning at 196 rpm's. The magneto’s signals to the governor box were clear and equal, with only a very slight overlap between both signals. The magneto was disassembled; the light oil like substance was present on the inside of the magneto. The inspection also revealed "whiskers" of residue/corrosion on the magneto contacts; which were black instead of the normal silver color. During the test it was noted that the magneto should have produced a regular spark at 150 rpm, and that the residue/corrosion could send extra impulse signals to the governor box; producing an indication that the engine is revving. However, it was also noted that because there was only a slight overlap of the electrical signals, and since the magneto passed the other test items,a malfunction could not be duplicated. ## Factual narrative On April 5, 2008, about 0003 central daylight time, a single-engine Robinson R44 helicopter, N402PD, was substantially damaged after impacting a light pole during a precautionary landing in a parking lot near Topeka, Kansas. The commercial pilot and two observers were not injured. The helicopter was registered and operated by the Topeka Kansas Police Department. Night visual meteorological conditions prevailed for the Public Use flight. The pilot reported that during a routine surveillance flight, he heard the helicopter's engine "fluctuate" slightly; he then looked at the engine gauge and saw that the engine rpm gauge was above the "normal operating limits", and the gauge [needle] was "jumping up-and-down." In order to keep the engine within operating limits, the pilot disabled the engine governor and decreased the engine rpm. The pilot also reported that as they started to return to base, they heard the engine "rev up" followed by the low rotor rpm alarm. The pilot executed an autorotation, after the rotor rpm recovered and entered the normal operating range; the pilot decided that they would perform a precautionary landing. A parking lot security camera caught the night image of the helicopter's landing. The video shows the parking lot and helicopter lights. As the helicopter approaches the parking lot, a spark/light shower is displayed as the helicopter's main rotor blade contacts a light pole. The helicopter subsequently makes a hard landing, coming to rest on its side. The helicopter was recovered for examination. An initial examination by a Federal Aviation Administration (FAA)Inspector, failed to identify any pre-impact abnormalities with the helicopter. The magneto, governor controller, clutch actuator, engine/rotor tachometer and drive-belts were removed and shipped to the helicopter manufacturer for further examination. On May 21, 2008, the NTSB, technical representatives from the airframe manufacturer, and the Operator inspected the components at the Robinson Helicopter factory. The governor, clutch actuator, tachometer, and drive belts all passed either a visual or electronic test inspection. A visual inspection of the magneto revealed that the exterior of the magneto was absent any damage, but was lightly covered with an "oil-like" liquid. The magneto was bench tested and produced regular sparks beginning at 196 rpm’s. The magneto's signals to the governor box were clear and equal, with only a very slight overlap between both signals. The magneto was disassembled; the light oil-like substance was present on the inside of the magneto. The inspection also revealed "whiskers" (residue/corrosion) on the magneto contacts; which were black instead of the normal silver color. The technical representative noted that the magneto should have produced a regular spark at 150 rpm, and that the residue/corrosion could send extra impulse signals to the governor box; producing an indication that the engine is revving. He also noted that because there was only a slight overlap of the electrical signals and since the magneto passed the other test items; it could not be determined whether or not the over-speed/revving condition was caused by the magneto. A review of the engine maintence record reveals that the 100-hour inspection was completed on April 3, 2008. The logbook entry noted that during the inspection, the magnetos were "checked and timed." ## Aircraft - Registration: [N402PD](https://openairdocs.org/deregistered/N402PD-2013-01-31), registration cancelled 2013-01-31, S/N 11554, built 2007 (OpenAirDocs) - Reported make and model: Robinson R44 - 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: 11554 - Airframe hours: 1207 - Engines: Lycoming IO-540 reciprocating - Damage: Substantial damage - Flight: Public aircraft - local, Part 91 - Operator: Topeka Police Department - Registered owner: City of Topeka - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 3, 2008, 4 hours before - Departed: Topeka, KS - Destination: Topeka, KS - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; injuries: minor; private; medical: class 2, without waivers/limitations; last flight review March 21, 2007; seat: left; flight hours: 611 total, 466 in this make and model, 499 as pilot in command, 72 in the last 90 days, 18 in the last 30 days, 1 in the last 24 hours - Co-pilot; age 42; injuries: minor; private; medical: class 2, with waivers/limitations; last flight review December 2, 2007; seat: right; flight hours: 186 total, 116 in this make and model, 81 as pilot in command, 101 in the last 90 days, 45 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 130° at 3 knots - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 45 °F, dew point 32 °F - Altimeter: 30.01 inHg - Observed at: KTOP ## 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 20080405014369A](https://openairdocs.org/incident/20080405014369A), Apr 5, 2008: Robsin R44RAVENII, Topeka, KS, Substantial damage. (-23) At approximately 2309 hrs on April 5, 2008, a Topeka police helicopter (N402PD/Robinson R-44) departed billard field (top) in Topeka, KS. The pilot… ## Docket (11 files) The files NTSB released with the investigation on October 27, 2008, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=67761. 23.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40302157&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40302158&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Reports and Records (item 3, .PDF, 24 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40302159&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - NTSB Summary of Component Examination (item 4, .PDF, 190 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40294637&FileExtension=.PDF&FileName=NTSB%20Summary%20of%20Component%20Examination-Redacted.PDF - NTSB Report of Examination (item 5, .PDF, 233 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40294635&FileExtension=.PDF&FileName=NTSB%20Report%20of%20Examination-Redacted.PDF - Other Pertinent Forms and Reports (item 6, .PDF, 147 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40459397&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-Master.PDF - Other Pertinent Forms and Reports (item 7, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40302160&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-Master.PDF - Engine Maintenance Log (item 8, .PDF, 20.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40302162&FileExtension=.PDF&FileName=Engine%20Maintenance%20Log-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 9, .PDF, 65 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40459398&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 10, .PDF, 41 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40459399&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Master.PDF - Photo: N402PD (item 11, .PDF, 498 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40302165&FileExtension=.PDF&FileName=Photo%3A%20N402PD-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.