# NTSB CEN22LA089: Lancair IV, N994PT, Iron Mountain, MI, December 25, 2021 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: December 25, 2021, 08:25 local (14:25 UTC) - Place: Iron Mountain, MI · wooded area. - Coordinates: 45.845545, -88.113173 - Nearby events: https://openairdocs.org/map.md?lat=45.8455&lon=-88.1132&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 104465 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA089 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104465/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104465 - Page: https://openairdocs.org/ntsb/CEN22LA089 ## Probable cause The total loss of engine power after takeoff for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: task monitoring/vigilance](https://openairdocs.org/ntsb-findings/02021520): Personnel issues › Psychological · Pilot; cases with it: [Thomas Sullivan LANCAIR IV-P, 1 case](https://openairdocs.org/ntsb-findings/02021520/cases.md?model=05635FM), [All aircraft, 330 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md) - [Engine (turbine/turboprop)](https://openairdocs.org/ntsb-findings/01057200): Aircraft › Aircraft power plant · Unknown/Not determined (probable cause); cases with it: [Thomas Sullivan LANCAIR IV-P, 1 case](https://openairdocs.org/ntsb-findings/01057200/cases.md?model=05635FM), [All aircraft, 67 cases](https://openairdocs.org/ntsb-findings/01057200/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 (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Thomas Sullivan LANCAIR IV-P, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05635FM), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Thomas Sullivan LANCAIR IV-P, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05635FM), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Thomas Sullivan LANCAIR IV-P, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05635FM), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that he took off at a reduced winter takeoff power setting. Once airborne and established on a climb, he retracted the landing gear and flaps, added climb power in increments, and then noticed a failure displayed on the generator control unit annunciator. About the same time, the pilot noticed the engine was quieter and the airspeed was decreasing. Onboard data indicated that, upon reaching 650 ft above ground level, about 50 seconds after the takeoff roll was initiated, the engine power reduced to idle with a simultaneous decrease in fuel flow. Several seconds later, a generator control unit failure warning illuminated, and the voltage began to slowly decrease, consistent with the generator turning off. The airplane continued to descend straight ahead and impacted trees and terrain about one nautical mile from the departure end of the runway. Both wings, the empennage, and the engine separated from the fuselage. Following the accident, the condition lever was in an aft position. The pilot stated that, due to the altitude at the time he identified the loss of engine power, he did not take any actions to feather the propeller or restart the engine. A postaccident examination of the engine and related systems revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The recorded engine data is consistent with a reduction in commanded engine power and ultimately an in-flight shutdown. While it is possible that the condition lever came back with the flap activation and was not noted by the pilot, investigators were not able to determine when or how the condition lever was moved aft. ## Factual narrative On December 25, 2021, about 0825 central standard time, an experimental Lancair IV-TP, N994PT, was substantially damaged when it was involved in an accident near Iron Mountain, Michigan. The pilot and passenger sustained minor injuries. The airplane was operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. The pilot reported that he took off at a reduced winter takeoff power setting. Once airborne and established on a climb, he retracted the landing gear and flaps, added climb power in increments and input rate of climb (165 knots) on the autopilot and then noticed a generator control unit (GCU) annunciator display a failure. About the same time the pilot noticed the engine seemed quieter and the airspeed was decreasing. The pilot further increased the throttle lever, confirmed that the No. 1 fuel pump was switched on and the left fuel tank was selected, and then determined that the engine had shut down. The pilot lined up with a clearing in the trees to his left; however, the airplane struck a small tree on approach to the clearing. The contact with the tree separated about half the outboard section of the right wing. The airplane touched down in rough, snow-covered terrain and came to rest with the engine and engine mount separated from the firewall. The pilot and passenger exited the wreckage from the entry door. The pilot stated that due to challenging terrain and poor options for a forced landing site he did not perform any other emergency procedures such as turning the fuel pump off, pulling the condition lever to idle cut-off, or feathering the propeller. Photographs taken by law enforcement following the accident show the condition lever in an unlatched position towards the idle cut off detent. An onboard GPS and avionics unit captured data from the accident flight. Data showed that, at 0824:02 about 12 seconds after liftoff, torque and N1 (gas generator speed) reduced from 86.9% and 93.6% to 72.5% and 89%, respectively, with a simultaneous decrease in fuel flow (FF) from 62.2 gallons per hour (gph) to 53.7 gph and inter-turbine temperature (ITT) from 1114°F to 1011°F. About one second later indicated air speed (IAS) accelerated past 127 knots and the flap system indicated movement to a retracted position. At 0824:07 the autopilot was engaged and over the next 9 seconds heading (HDG) and IAS modes were selected, and IAS set to 165 knots. During this time the torque decreased and stabilized at 41.5% for several seconds with a concurrent decrease in N1 to 84.8%, FF to 40.3 gph and ITT to 900°F. At 0824:21 all parameters are consistent with an engine shutdown. Six seconds later, the GCU FAIL light (governor control unit) illuminated. During the last 22 seconds of the flight, the airplane turned 54° to the left and lost about 490 ft of altitude while slowing from 117 knots (kts) to 96 kts. During this time, the engine torque and N1 were 0% with propeller speed slowing to 1270 rpm. 0824:49 markedthe last datapoint with the autopilot engaged, with the fuel pressure at 35.6 PSI and voltage at 24.9 volts. The Garmin G3X data was recovered from records with a resolution of 1 time per second (1 Hz). Based on Garmin data, the airplane had a recorded total fuel quantity of 118 gallons at the time of startup, consisting of 60 gallons in the left wing tank and 58 gals in the right wing tank. The last recorded data point indicated 57 gallons in the left tank and 60 gals in the right tank, totaling 117 gals. Fuel pressure was consistent from startup to the last record data point, varying from 30 to 35 psi. No data was able to be recovered from the turbine start limiting management system. Figure 1 Accident Sequence 1. 8:24:02 - Engine starts to spool back. 2. 8:24:03 - Flaps retracted. 3. 8:24:07 - Autopilot engaged. Pilot starts data input in to autopilot (IAS). 4. 8:24:16 - Data entry complete, desired IAS set to 165kts. 5. 8:24:20 - Engine is flamed out. 6. 8:24:27 – GCU FAIL illuminates 7. 8:24:49 – End of recording 8. Accident location Postaccident examination of the airframe fuel system did not reveal any anomalies that would have restricted fuel flow to the engine. The fuel filter located at the bottom of the header tank was impact damaged and the filter media was not recovered. Fuel lines were examined and found to be continuous with no anomalies or blockages noted. The fuel strainer was removed from the engine-driven fuel pump and examined; and some small particles of unknown origin were noted in the housing. The engine-driven fuel pump and fuel control unit (FCU) were removed for functional testing at an overhaul facility. External damage was noted to both units consistent with the impact sequence. A solenoid, throttle linkage arm, and condition lever rod were replaced with serviceable parts on the FCU, and hardware was replaced on the fuel pump. Both units were installed onto a test engine, and leak tests were normal. The FCU was bled, and the engine started and ran at a lower power setting. It was then shutdown and bled again. The engine was started a second time and operated at rated power with the fuel pump both on and off with no anomalies noted. The engine power was manipulated from low to high several times with no anomalies noted. The engine was shut down and the units were sent to the manufacturer for disassembly. Although internal wear to the engine-driven fuel pump was noted, the FCU was unremarkable, and no anomalies were detected that could have resulted in a loss of engine power. ## Aircraft - Registration: [N994PT](https://openairdocs.org/aircraft/N994PT), registered now, S/N LIV-407, built 2016 (OpenAirDocs) - Reported make and model: LANCAIR IV (P) - Registry model: [Thomas Sullivan LANCAIR IV-P](https://openairdocs.org/model/thomas-sullivan-lancair-iv-p) (registry code 05635FM) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: LIV-407 - Year built: 2016 - Airframe hours: 599 - Engines: Walters M601D 724 horsepower turbo prop - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: AAIP, March 2, 2021, 69 hours before - Destination: 7FL6, Daytona Beach, FL - Flight plan: IFR - Airport: IMT, Ford Airport, runway 010, 6,501 × 150 ft, asphalt - Equipment: Electronic multifunction display, Electronic primary flight display, Stall warning system, ADS-B, Angle of attack indicator, Auto-pilot, Data recorder ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: minor; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review September 19, 2021; seat: left; restraint: 3-point; flight hours: 4,053 total, 599 in this make and model, 4,011 as pilot in command, 22 in the last 90 days, 6 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 13 knots, gusting 21 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 25 °F, dew point 14 °F - Altimeter: 29.62 inHg - Observed at: KIMT, 2 nm away - METAR: KIMT 251354Z AUTO 33013G21KT 10SM CLR M04/M10 A2962 RMK AO2 PK WND 32026/1334 SLP045 T10441100 ## 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 20211225021609A](https://openairdocs.org/incident/20211225021609A), Dec 25, 2021: Thomas Sullivan LANCAIR IV-P, Spread Eagle, WI, Substantial damage. The pilot of N994PT filed an IFR flight plan from iron mountain, Michigan (kimt) to spruce creek, Florida (7FL6) on December 25, 2021. Pilot received IFR… ## Docket (9 files) The files NTSB released with the investigation on August 30, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104465. 22.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 10.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13088307&FileExtension=pdf&FileName=6120%20PRINTED_redacted-Rel.pdf - On scene photos (item 2, PDF, 5 pages, 4.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13089598&FileExtension=pdf&FileName=on%20scene%20photos-Rel.pdf - Airframe and engine examination (item 3, PDF, 11 pages, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13586418&FileExtension=pdf&FileName=Airframe%20and%20Engine%20Examination-Rel.pdf - Garmin G3X data - tabular (item 4, CSV, 287 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13314170&FileExtension=csv&FileName=log_20211225_081125_KIMT-Rel.csv - Fuel control unit and fuel pump functional test observations - FAA (item 5, PDF, 1 page, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13586454&FileExtension=pdf&FileName=FAA%20run%20exam%20observations_Redacted-Rel.pdf - Photos from fuel control unit and fuel pump functional test observations - FAA (item 6, PDF, 3 pages, 730 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13586001&FileExtension=pdf&FileName=FAA%20PHOTOS%20from%20run-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 7, PDF, 1 page, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13585460&FileExtension=pdf&FileName=wreckage%20release%20signed_Redacted-Rel.pdf - Fuel pump and fcu exam summary (item 8, PDF, 4 pages, 3 photos, 202 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15728404&FileExtension=pdf&FileName=Examination%20Summary%20--%20CEN22LA089-Rel.pdf - Emails discussing systems and recollection of procedures (item 9, PDF, 5 pages, 421 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15994730&FileExtension=pdf&FileName=Email%20discussing%20systems%20and%20such_Redacted-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.