# NTSB CEN17LA121: Beech C90A, N1551C, Rattan, OK, February 14, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 14, 2017, 11:45 local (17:45 UTC) - Place: Rattan, OK - Coordinates: 34.238609, -95.25389 - Nearby events: https://openairdocs.org/map.md?lat=34.2386&lon=-95.2539&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Electrical system malf/failure](https://openairdocs.org/ntsb-events/332) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report August 10, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: EagleMed LLC, FAA Flight Standards, Texron Aviation - NTSB case key (mKey): 94826 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA121 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94826/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94826 - Page: https://openairdocs.org/ntsb/CEN17LA121 ## Probable cause The loss of electrical power due to the pilot’s inadvertent selection of the engine start switches and the subsequent fuel exhaustion to the left engine as the pilot attempted to locate visual meteorological conditions. Contributing to the accident were the pilot’s failure to ensure adequate fuel reserves on board for the flight in instrument meteorological conditions and the miscommunication between the pilot and medical crewmembers. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Beech C90A, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=1152911), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Electrical power system: starter-generator](https://openairdocs.org/ntsb-findings/01022435): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [Beech C90A, 1 case](https://openairdocs.org/ntsb-findings/01022435/cases.md?model=1152911), [All aircraft, 4 cases](https://openairdocs.org/ntsb-findings/01022435/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid management (probable cause); cases with it: [Beech C90A, 2 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=1152911), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Communication (personnel)](https://openairdocs.org/ntsb-findings/02063500): Personnel issues › Task performance · Other (probable cause); cases with it: [Beech C90A, 1 case](https://openairdocs.org/ntsb-findings/02063500/cases.md?model=1152911), [All aircraft, 17 cases](https://openairdocs.org/ntsb-findings/02063500/cases.md) - [Planning/preparation: fuel planning](https://openairdocs.org/ntsb-findings/02061030): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Beech C90A, 3 cases](https://openairdocs.org/ntsb-findings/02061030/cases.md?model=1152911), [All aircraft, 719 cases](https://openairdocs.org/ntsb-findings/02061030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Electrical system malf/failure](https://openairdocs.org/ntsb-events/332) (defining event); cases with it: [Beech C90A, 1 case](https://openairdocs.org/ntsb-events/332/sequence.md?model=1152911), [All aircraft, 182 cases](https://openairdocs.org/ntsb-events/332/sequence.md) - [Enroute-cruise: Fuel exhaustion](https://openairdocs.org/ntsb-events/192); cases with it: [Beech C90A, 2 cases](https://openairdocs.org/ntsb-events/192/sequence.md?model=1152911), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Beech C90A, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1152911), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot stated that the engine start and airplane power-up were normal for the air medical flight with two medical crewmembers. The engine ice vanes were lowered (as required for ground operations) and then were subsequently raised before takeoff. Takeoff and climbout were routine, and the pilot leveled off the airplane at the assigned cruise altitude. The air traffic controller informed the pilot of heavy showers near the destination airport, and the pilot "put the ice vanes down." The pilot indicated that, shortly afterward, the airplane experienced two "quick" electrical power fluctuations in which "everything went away and then came back," and "[s]econds later the entire [electrical] system failed." Due to the associated loss of navigation capability while operating in instrument meteorological conditions (IMC), the pilot set a general course for better weather conditions based on information from his preflight weather briefing. While the pilot attempted to find a suitable hole in the clouds to descend through under visual conditions, the left engine lost power. The pilot ultimately located a field through the cloud cover and executed a single-engine off-airport landing, which resulted in substantial damage to the right engine mount and firewall. A postaccident examination of the airplane and systems did not reveal any anomalies consistent with an in-flight electrical system malfunction. The three-position ignition and engine start/starter-only switches were in the ON position, and the engine anti-ice switches were in the ON position. When the airplane battery was initially checked during the examination, the voltmeter indicated 10.7 volts (normal voltage is 12 volts); the battery was charged and appeared to function normally thereafter. The loss of electrical power was likely initiated by the pilot inadvertently selecting the engine start switches instead of the engine anti-ice (ice vane) switches. This resulted in the starter/generators changing to starter operation and taking the generator function offline. Airplane electrical power was then being supplied solely by the battery, which caused it to deplete and led to a subsequent loss of electrical power to the airplane. A postaccident examination revealed that neither wing fuel tank contained any visible fuel. The left nacelle fuel tank did not contain any visible fuel, and the right nacelle fuel tank appeared to contain about 1 quart of fuel. The lack of fuel onboard at the time of the accident is consistent with a loss of engine power due to fuel exhaustion. This was a result of the extended flight time as the pilot attempted to exit instrument conditions after the loss of electrical power to locate a suitable airport. Further, the operator reported that 253 gallons (1,720 lbs) of fuel were on board at takeoff, and the accident flight duration was 3.65 hours. At maximum range power, the expected fuel consumption was about 406 lbs/hour, resulting in an endurance of about 4.2 hours.Thus, the pilot did not have the adequate fuel reserves required for flying in IMC. Both the pilot and medical crewmembers described a lack of communication and coordination among crewmembers as the emergency transpired. This resulted in multiple course adjustments that hindered the pilot's ability to locate visual meteorological conditions before the left engine fuel supply was exhausted. ## Factual narrative On February 14, 2017, about 1145 central standard time, a Beech C90A twin-engine airplane, N1551C, was substantially damaged during a precautionary landing following a loss of power on one engine near Rattan, Oklahoma. The pilot and two medical crew members on board were not injured. The airplane was registered to and operated by EagleMed LLC under the provisions of Title 14 Code of Federal Regulations Part 135 air medical flight. The pilot stated that the engine start and airplane power-up were normal. The engine ice vanes were lowered, and the de-icing system was activated as required for ground operations. The ice vanes were subsequently raised before takeoff. Takeoff and climb out were routine, and he subsequently leveled off the airplane at 7,000 ft. mean sea level (msl). The air traffic controller informed him of "heavy rain showers" near the destination airport and he "put the ice vanes down." Shortly afterward, the airplane experienced two "quick" electrical power fluctuation; "everything went away and then came back." "Seconds later the entire [electrical] system failed." Due to the associated loss of navigation capability while operating in instrument meteorological conditions, the pilot set a general course for better weather conditions based upon the preflight weather briefing. During the attempt to find a suitable hole in the clouds to descend through under visual conditions, the left engine lost power. The pilot ultimately located a field through the cloud cover and executed a single engine precautionary landing. The nose landing gear collapsed, and the airplane sustained substantial damage to the right engine mount and firewall. A postaccident examination was conducted by Federal Aviation Administration inspectors and operator personnel. The left propeller blades were bent aft and did not exhibit any curling of the blades. The right propeller blades were curled in the direction of rotation. The left- and right-wing fuel tanks did not contain any visible fuel. The left nacelle fuel tank did not contain any visible fuel. The right nacelle fuel tank appeared to contain about one quart of fuel. The three-position Ignition and Engine Start/Starter Only switches on the cockpit instrument panel were in the ON position. The Engine Anti-Ice switches were in the ON position. The cabin medical bed electrical switches corresponding to the inverter and accessories were in the ON position; the remaining medical bed switches were OFF. A postrecovery examination was conducted by the NTSB investigator-in-charge and operator personnel. No anomalies consistent with an in-flight electrical system malfunction were observed. When the airplane battery was initially checked during the exam the voltmeter indicated 10.7 volts; the battery was charged and appeared to function normally thereafter. The operator reported that 253 gallons (1,720 lbs.) of fuel were onboard at takeoff and the airplane gross weight was 7,838 lbs. The accident flight duration was3.65 hrs. Airplane performance data indicated that at maximum cruise power, the expected fuel flow would be about 632 lbs./hr., resulting in an endurance of approximately 2.7 hrs. At maximum range power, the expected fuel consumption was about 406 lbs./hr., resulting in an endurance of approximately 4.2 hrs. Both the pilot and medical crew described a lack of communication and coordination among crew members. The pilot reported that the medical crew became apprehensive as the emergency transpired. On three occasions, as the pilot maneuvered the airplane attempting to locate a hole in the clouds to descend, the medical crew member in the co-pilot seat grabbed the control wheel to keep the pilot from banking the airplane. He subsequently relinquished the control wheel as directed by the pilot. The medical crew attempted to locate the airplane by using cellphones to coordinate with the operator's operations center or by using the cellphone GPS capability. However, these efforts resulted in multiple course adjustments and ultimately failed to encounter visual meteorological conditions before fuel exhaustion on the left engine. ## Aircraft - Registration: [N1551C](https://openairdocs.org/deregistered/N1551C-2018-08-09), registration cancelled 2018-08-09, S/N LJ-1365, built 1994 (OpenAirDocs) - Reported make and model: BEECH C90A (A) - Registry model: [Beech C90A](https://openairdocs.org/model/beech-c90a) (registry code 1152911) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: LJ-1365 - Year built: 1994 - Airframe hours: 7862.1 - Engines: Pratt & Whitney Canada PT6A-21 550 horsepower turbo prop; Pratt & Whitney Canada PT6A-21 550 horsepower turbo prop - Damage: Substantial damage - Flight: Part 135 - Operator: Eaglemed LLC - Registered owner: Eaglemed LLC - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, December 20, 2016, 75 hours before - Departed: MLC, McAlester, OK - Destination: 4O4, Idabel, OK - Flight plan: IFR - Equipment: Onboard weather, Electronic primary flight display, Auto-pilot, Stall warning system, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review December 5, 2016; seat: left; restraint: 4-point; flight hours: 22,000 total, 400 in this make and model, 21,500 as pilot in command, 41 in the last 90 days, 24 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: 20° at 8 knots - Visibility: 2 statute miles - Lowest ceiling: 1,100 ft broken - Temperature: 45 °F, dew point 39 °F - Altimeter: 29.96 inHg - Observed at: MLC, 49 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 20170214006299A](https://openairdocs.org/incident/20170214006299A), Feb 14, 2017: Beech C90A, Rattan, OK, Substantial damage. On February 14, 2017, approximately 0805 central daylight time, a Hawker Beechcraft C90A airplane, N1551C, operated by eaglemed, LLC, under 14 CFR part 135,… ## Docket (19 files) The files NTSB released with the investigation on June 10, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94826. 12.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 684 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483587&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot's Statement (item 2, .PDF, 146 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483588&FileExtension=.PDF&FileName=Pilot%27s%20Statement-Master.PDF - Medical Crew Statement (item 3, .PDF, 32 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483589&FileExtension=.PDF&FileName=Medical%20Crew%20Statement-Master.PDF - Accident Site Diagram (item 4, .PDF, 85 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483590&FileExtension=.PDF&FileName=Accident%20Site%20Diagram-Master.PDF - Accident Photos (item 5, .PDF, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483591&FileExtension=.PDF&FileName=Accident%20Photos-Master.PDF - Airplane Examination Summary (item 6, .PDF, 31 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483592&FileExtension=.PDF&FileName=Airplane%20Examination%20Summary-Master.PDF - Maintenance Records -- AD Compliance (item 7, .PDF, 703 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483593&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20AD%20Compliance-Master.PDF - Maintenance Records -- Aircraft Status Sheet (item 8, .PDF, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483594&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20Aircraft%20Status%20Sheet-Master.PDF - Maintenance Records -- Airframe (item 9, .PDF, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483595&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20Airframe-Master.PDF - Maintenance Records -- Daily Flight-Maintenance Logs (item 10, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483596&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20Daily%20Flight-Maintenance%20Logs-Master.PDF - Maintenance Records -- Left Engine (item 11, .PDF, 479 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483597&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20Left%20Engine-Master.PDF - Maintenance Records -- Left Propeller (item 12, .PDF, 479 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483598&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20Left%20Propeller-Master.PDF - Maintenance Records -- Right Engine (item 13, .PDF, 245 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483599&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20Right%20Engine-Master.PDF - Maintenance Records -- Right Propeller (item 14, .PDF, 282 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483600&FileExtension=.PDF&FileName=Maintenance%20Records%20--%20Right%20Propeller-Master.PDF - Flight Manual Excerpt -- Airplane Performance (item 15, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483601&FileExtension=.PDF&FileName=Flight%20Manual%20Excerpt%20--%20Airplane%20Performance-Master.PDF - Flight Manual Excerpt -- Normal Procedures Checklist (item 16, .PDF, 105 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483602&FileExtension=.PDF&FileName=Flight%20Manual%20Excerpt%20--%20Normal%20Procedures%20Checklist-Master.PDF - Flight Manual Excerpt -- Engine Anti-Ice System (item 17, .PDF, 35 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483603&FileExtension=.PDF&FileName=Flight%20Manual%20Excerpt%20--%20Engine%20Anti-Ice%20System-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 18, .PDF, 361 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483604&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 19, .PDF, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483605&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.