# NTSB WPR18LA009: Barber Warren D Turbine Cubs P A 18, N181TJ, Skull Valley, UT, October 15, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 15, 2017, 10:00 local (16:00 UTC) - Place: Skull Valley, UT - Coordinates: 40.609165, -112.836387 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.6092&lon=-112.8364&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 26, 2019 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 96200 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA009 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96200/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96200 - Page: https://openairdocs.org/ntsb/WPR18LA009 ## Probable cause The activation of the wheel brakes during landing, which resulted in a nose-over. The reason for the wheel brake activation could not be determined. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: master cylinder/brake valve](https://openairdocs.org/ntsb-findings/01023243): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Barber Warren D TURBINE CUBS P A 18, 1 case](https://openairdocs.org/ntsb-findings/01023243/cases.md?model=056285P), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01023243/cases.md) - [Engine (reciprocating): recip eng wiring](https://openairdocs.org/ntsb-findings/01058597): Aircraft › Aircraft power plant · Incorrect service/maintenance; cases with it: [Barber Warren D TURBINE CUBS P A 18, 1 case](https://openairdocs.org/ntsb-findings/01058597/cases.md?model=056285P), [All aircraft, 8 cases](https://openairdocs.org/ntsb-findings/01058597/cases.md) - [Engine (reciprocating): recip eng wiring](https://openairdocs.org/ntsb-findings/01058597): Aircraft › Aircraft power plant · Inadequate inspection; cases with it: [Barber Warren D TURBINE CUBS P A 18, 1 case](https://openairdocs.org/ntsb-findings/01058597/cases.md?model=056285P), [All aircraft, 8 cases](https://openairdocs.org/ntsb-findings/01058597/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Barber Warren D TURBINE CUBS P A 18, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=056285P), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-change of cruise level: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Barber Warren D TURBINE CUBS P A 18, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=056285P), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Enroute-change of cruise level: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Barber Warren D TURBINE CUBS P A 18, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=056285P), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096) (defining event); cases with it: [Barber Warren D TURBINE CUBS P A 18, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=056285P), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The private pilot reported that he had just completed a low altitude pass and that when he applied power to initiate a climb, the engine "stumbled slightly and seemed to hesitate." The pilot applied carburetor heat due to concerns about carburetor ice and then applied full power. The engine again seemed to hesitate, and the pilot initiated a precautionary landing to an open salt flat. Shortly after touchdown, the airplane nosed over. The pilot reported that after he exited the airplane, he noted that both main wheel brakes were engaged, however neither he nor his passenger actuated the brake pedals during the landing sequence. A postaccident examination of the wheel brakes revealed no evidence of a preexisting malfunction or failure with the brakes. Examination of the engine revealed that one of the two carburetor temperature probe wires were separated from an electrical connector, consistent with a bad crimp. The disconnected wire would have prevented the carburetor air temperature from being displayed on the airplane's avionics panel. The examination revealed no additional findings or evidence of a preexisting mechanical malfunction that would have precluded normal operation. The atmospheric conditions in the area at the time of the accident were conducive to the formation of carburetor ice at glide and cruise power. It is likely that the hesitation in the engine performance reported by the pilot was the initial stages of the accumulation of ice in the carburetor, which precipitated the off-airport precautionary landing. ## Factual narrative ***This report was modified on October 31, 2018. Please see the docket for this accident to view the original report*** On October 15, 2017, about 1000 mountain daylight time, an experimental amateur-built Barber Turbine Cubs PA-18, N181TJ, nosed over during a precautionary landing near Skull Valley, Utah. The private pilot and passenger were not injured. The airplane sustained substantial damage to both wings and empennage. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight that originated from West Jordan, Utah, about 0915. The pilot reported that prior to departure, he completed a thorough pre-flight inspection. As part of that procedure, he checked the fuel system for water by sumping the fuel tanks, which resulted in no water being found. He stated that the cabin heat was on for the entire flight, due to an outside air temperature of 41° F. The pilot stated that he completed a low altitude pass at an altitude of about 250 to 300 ft above ground level and applied power to initiate the climb when the engine stumbled slightly and seemed to hesitate. He applied carburetor heat due to concerns about carburetor ice and then subsequently "applied power further to full power." The engine again seemed to hesitate, and the pilot elected to initiate a precautionary landing to an open salt flat area to investigate the problem. The pilot reported that he conducted a tail low wheel landing and when the airplane touched down, it nosed over and came to rest on its back. The pilot stated that after he exited the airplane, he noted that both main wheel brakes were engaged. He added that neither he nor his passenger applied pressure to the heel brake pedals during the landing sequence. Review of a photo provided by the pilot's mechanic revealed tire tracks, about 20 to 25 ft in length and consistent with both main landing gear tires, were present on the landing surface. The airplane was equipped with two brake master cylinders, plumbed to a central reservoir mounted between and above the master cylinders, located beneath the front seat. The master cylinder pedals were connected to the front brake pedals via a rod on each side. The master cylinders are of a design that allowed hydraulic fluid from a separate vented reservoir to gravity feed into the master cylinder or flow back into the hydraulic reservoir to compensate for fluid expansion. An internal check valve that restricts hydraulic fluid movement from the master cylinder to the reservoir actuates if the master cylinder shaft is depressed about 1/16th of an inch. Examination of recovered wreckage revealed that the left and right brake master cylinders remained secured to their respective mounts. When actuated by hand, the right brake pedal needed minimal input to actuate the brake, however, the left brake pedal needed asignificant amount of movement to actuate the brake. Both the left and right main landing gear wheels rotated freely without restriction. The hydraulic reservoir cap was removed, and residual amounts of hydraulic fluid was observed within the reservoir cavity. The vented cap was free of debris and no restrictions were noted. Evidence indicated that the hydraulic fluid drained from the reservoir through the vent following the accident while the airplane was inverted. The engine and all engine accessories remained secure to their respective mounts. All fuel lines remained attached and secure with no kinks or leaks noted. Throttle, mixture, and carburetor heat control continuity was established from the cockpit controls to the engine. The wooden propeller assembly remained attached to the crankshaft however, one of the propeller blades was separated at the propeller hub. Rotational continuity was established throughout the engine and valve train. The carburetor was equipped with a carburetor temperature probe. It was noted that one of the two wires were separated from the crimped side of an electrical connector. The wire exhibited missing shielding at the end and no wire was observed within the electrical connector. The carburetor was removed and examined. The throttle and mixture levers moved from stop to stop by hand freely. The accelerator pump functioned normally when the throttle lever was actuated. The carburetor was disassembled, and the internal floats were intact and moved freely. The needle valve and seat were intact. The airplane was equipped with a Dynon FlightDEK-D180, and when power was applied to the airframe, it functioned, however it was found that the carburetor air inlet temperature display was inoperative. No evidence of any preexisting mechanical malfunction that would have precluded normal operation of the engine was found. For further information, see the NTSB Airframe Examination Summary in the public docket for this accident. The Federal Aviation Administration (FAA) published Special Airworthiness Information Bulletin (SAIB) CE-09-35 on June 30, 2009, regarding carburetor ice prevention. The conditions encountered in this accident (ambient temperature 41o F, dew point 23o F) were in the area of icing at glide and cruise power. ## Aircraft - Registration: [N181TJ](https://openairdocs.org/deregistered/N181TJ-2021-07-12), registration cancelled 2021-07-12, S/N TC0705014, built 2009 (OpenAirDocs) - Reported make and model: BARBER WARREN D TURBINE CUBS P A 18 (NO SERIES) - Registry model: [Barber Warren D TURBINE CUBS P A 18](https://openairdocs.org/model/barber-warren-d-turbine-cubs-p-a-18) (registry code 056285P) (OpenAirDocs) - Registry engine: [Lycoming O-360-A4M](https://openairdocs.org/engine/lycoming-o-360-a4m) (registry code 42276, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: TC0705014 - Year built: 2009 - Airframe hours: 379.8 - Engines: Lycoming O-360 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, July 1, 2017, 13 hours before - Departed: U42, West Jordan, UT - Destination: U42, West Jordan, UT - Equipment: Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review September 29, 2017; seat: front; flight hours: 2,344 total, 227 in this make and model, 2,284 as pilot in command, 13 in the last 90 days, 13 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 46 °F, dew point 23 °F - Altimeter: 30.54 inHg - Observed at: KSLC, 41 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 20171015014659A](https://openairdocs.org/incident/20171015014659A), Oct 15, 2017: Barber Warren D TURBINE CUBS PA-18, Skull Valley, UT, Substantial damage. The aircraft departed U-42, and flew out to the Skull Valley area, the pilot desended to observe an object on the ground. When he applied power the engine… ## Docket (10 files) The files NTSB released with the investigation on November 28, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96200. 4.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458419&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation - Pilot (item 2, .PDF, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458420&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot-Master.PDF - NTSB Airframe Examination Summary (item 3, .PDF, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458421&FileExtension=.PDF&FileName=NTSB%20Airframe%20Examination%20Summary-Master.PDF - FAA Special Airworthiness Information Bulletin CE-09-35 (item 4, .PDF, 112 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458422&FileExtension=.PDF&FileName=FAA%20Special%20Airworthiness%20Information%20Bulletin%20CE-09-35-Master.PDF - Video Following the Accident - From Pilots Mechanic (Shelf Item) (item 5, .PDF, 194 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458423&FileExtension=.PDF&FileName=Video%20Following%20the%20Accident%20-%20From%20Pilots%20Mechanic%20(Shelf%20Item)-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 6, .PDF, 163 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458424&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Master.PDF - Record of Conversation - Pilot (#2) (item 7, .PDF, 83 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468818&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot%20(%232)-Master.PDF - Mechanic Correspondence with FAA About the Video (item 8, .PDF, 165 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468819&FileExtension=.PDF&FileName=Mechanic%20Correspondence%20with%20FAA%20About%20the%20Video-Master.PDF - Original Factual Narrative (item 9, .PDF, 102 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468820&FileExtension=.PDF&FileName=Original%20Factual%20Narrative-Master.PDF - Errata to NTSB Aiframe Examination Summary (item 10, .PDF, 77 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468821&FileExtension=.PDF&FileName=Errata%20to%20NTSB%20Aiframe%20Examination%20Summary-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.