# NTSB CEN19FA100: Cessna 421, N424TW, Plain City, OH, March 17, 2019 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 2 · Field · Final report - Date: March 17, 2019, 17:45 local (21:45 UTC) - Place: Plain City, OH - Coordinates: 40.188331, -83.204444 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.1883&lon=-83.2044&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed - Report: Approved by Office Director - Investigation class: Class 2 - NTSB office: Central Region - Parties: CMI, Avidyne Corp, Textron, FAA FSDO - NTSB case key (mKey): 99120 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19FA100 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99120/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99120 - Page: https://openairdocs.org/ntsb/CEN19FA100 ## Probable cause A loss of airspeed indication due to icing of the airplane's pitot probe, and the pilot's loss of control while maneuvering. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ceiling/visibility/precip: freezing rain/sleet](https://openairdocs.org/ntsb-findings/03035040): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Cessna 421B, 1 case](https://openairdocs.org/ntsb-findings/03035040/cases.md?model=2076014), [All aircraft, 26 cases](https://openairdocs.org/ntsb-findings/03035040/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 421B, 11 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2076014), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Indicating/recording systems: instrument panel ](https://openairdocs.org/ntsb-findings/01023110): Aircraft › Aircraft systems · Inoperative (probable cause); cases with it: [Cessna 421B, 1 case](https://openairdocs.org/ntsb-findings/01023110/cases.md?model=2076014), [All aircraft, 22 cases](https://openairdocs.org/ntsb-findings/01023110/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Cessna 421B, 3 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=2076014), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Navigation system: pitot/static system](https://openairdocs.org/ntsb-findings/01023411): Aircraft › Aircraft systems · Inoperative (probable cause); cases with it: [Cessna 421B, 1 case](https://openairdocs.org/ntsb-findings/01023411/cases.md?model=2076014), [All aircraft, 7 cases](https://openairdocs.org/ntsb-findings/01023411/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Cessna 421B, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=2076014), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Enroute-cruise: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Cessna 421B, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2076014), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) ## Analysis The pilot departed on a short cross-country flight in the twin-engine airplane. Instrument meteorological conditions (IMC) were present at the time. While en route at an altitude of 3,000 ft mean sea level, the pilot reported that the airplane was "picking up icing" and that he needed to "pick up speed." The controller then cleared the pilot to descend, then to climb, in order to exit the icing conditions; shortly thereafter, the controller issued a low altitude alert. The pilot indicated that he was climbing; radar and radio contact with the airplane were lost shortly thereafter. The airplane impacted a field about 7 miles short of the destination airport. Examination of the airplane was limited due to the fragmentation of the wreckage; however, no pre-impact anomalies were noted during the airframe and engine examinations. Extensive damage to the pitot static and deicing systems precluded functional testing of the two systems. A review of data recorded from onboard avionics units indicated that, about the time the pilot reported to the controller that the airplane was accumulating ice, the airplane's indicated airspeed had begun to diverge from its ground speed as calculated by position data. However, several minutes later, the indicated airspeed was zero while the ground speed remained fairly constant. It is likely that this airspeed indication was the result of icing of the airplane's pitot probe. During the final 2 minutes of flight, the airplane was in a left turn and the pilot received several "SINK RATE" and "PULL UP PULL UP" annunciations as the airplane conducted a series of climbs and descents during which its ground speed (and likely, airspeed) reached and/or exceeded the airplane's maneuvering and maximum structural cruising speeds. It is likely that the pilot became distracted by the erroneous airspeed indication due to icing of the pitot probe and subsequently lost control while maneuvering. ## Factual narrative An excerpt from the FAA's Instrument Flying Handbook, FAA-H-8-83-15B, Chapter 4, under "Effects of Icing on Critical Aircraft Systems" states: In addition to the hazards of structural and induction icing, the pilot must be aware of other aircraft systems susceptible to icing. The effects of icing do not produce the performance loss of structural icing or the power loss of induction icing but can present serious problems to the instrument pilot. Examples of such systems are flight instruments, stall warning systems, and windshields. Flight Instruments Various aircraft instruments including the airspeed indicator, altimeter, and rate-of-climb indicator utilize pressures sensed by pitot tubes and static ports for normal operation. When covered by ice these instruments display incorrect information thereby presenting serious hazard to instrument flight. The airplane was manufactured in 1974 and was certified for flight into known icing conditions. On March 17, 2019, about 1745 eastern daylight time, a Cessna 421B airplane, N424TW, was destroyed when it was involved in an accident near Plain City, Ohio. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot departed on a short cross-country flight. A review of radar and radio communications information revealed that the pilot contacted air traffic control at 1717 shortly after takeoff from James M. Cox Dayton International Airport (DAY), Dayton, Ohio. At 1729, the pilot was given a frequency change. The pilot checked in on the new frequency and requested the RNAV runway 28 approach at Delaware Municipal Airport (DLZ), Delaware, Ohio, located about 55 nautical miles east-northeast of DAY. About 2 minutes later, the controller advised the pilot of weather ahead, and the pilot accepted a 15° course deviation. At 1735, the controller issued the pilot a heading of 090° and instructed him to maintain an altitude of 3,000 ft mean sea level (msl), which the pilot acknowledged. About 1 minute later, the pilot reported that the airplane was "picking up icing" and that he needed to "pick up speed." The controller issued the airplane a descent to 2,500 ft and subsequently asked if the airplane was clear of clouds; the pilot replied, "negative." About 1739, after noting that the airplane was climbing, the controller cleared the pilot to an altitude of 6,000 ft and approved deviations to the left or right as needed; the pilot acknowledged. The controller subsequently issued the pilot a low altitude alert, and the pilot advised that he was climbing. About 1740, the controller asked the pilot to report his altitude, as altitude information from the airplane was no longer being received; there were no further communications from the accident airplane. A review of recovered data from onboard avionics indicated that, about 17 minutes after takeoff, the airplane's indicated airspeed began to decay while its groundspeed, as calculated fromposition information, remained steady. About 1 minute later, fuel flow increased from 38 gallons per hour (gph) to 60 gph, consistent with an increase in engine power. At this time, the indicated airspeed had decayed to about 100 knots (kts), while the groundspeed remained about 150 kts. For the final approximate 2.5 minutes of the flight, the airplane was in a left turn. The airplane entered a climb to about 3,500 ft msl, then began descending around 5,000 ft per minute. The data recorded "SINK RATE" and "PULL UP PULL UP" annunciations, and the airplane's rate of descent was arrested about 300 ft above ground level (agl). The airplane subsequently entered two additional sets of climbs and descents, receiving the same annunciations; however, the pilot did not recover from the third descent. During this time, the airplane's groundspeed, and likely airspeed, exceeded the airplane's maneuvering speed (Va) of 150 kts, and during both the first and final "SINK RATE" annunciations, the airplane's groundspeed exceeded its maximum structural cruising speed (Vno) of 200 kts. Figure 1: Airplane's Final Flight Track The Montgomery County Coroner's Office, Dayton, Ohio, conducted an autopsy on the pilot. The autopsy noted the cause of death was "multiple blunt force injuries." The FAA Forensic Sciences Laboratory conducted toxicological testing. The specimens were were negative for ethanol and tested-for drugs; the specimens were not tested for carbon monoxide or cyanide. At 1735, the automated weather observation facility located at Union County Airport (MRT), Marysville, Ohio, about 8 miles northwest of the accident site, recorded calm wind, 3 miles visibility, broken clouds at 400 ft agl, an overcast sky at 1,200 ft agl, temperature 34°F, dew point 32°F, and an altimeter setting of 30.19 inHg. The pilot was a former Air Force pilot and test pilot with over 3,000 hours of military flight experience. The airplane impacted a field about 7 miles southwest of DLZ. Ground impact scars and the wreckage were consistent with a left-wing-low attitude at the time of impact. The wreckage path was oriented on an approximate 140° heading. From the initial impact point, the airplane crossed a two-lane road before impacting two wooden utility poles. The main wreckage came to rest at the base of the second utility pole, about 395 ft from the initial impact point. The wreckage path was about 850 ft long and the airplane was highly fragmented along the wreckage path. There was no postcrash fire. All major components of the airplane were located at the accident site; however, flight control continuity could not be confirmed due to the fragmentation of the wreckage. The cockpit and instrument panel were extensively impact damaged. The positions of the landing gear and wing flaps could not be determined based on the positions of their cockpit controls. Both engines had separated from the wings and were located in the wreckage path; the first engine was located nearthe utility poles. The engine sustained heavy impact damage and the majority of the components were separated from the engine. Due to impact damage, the crankshaft could not be rotated by hand. The camshaft, connecting rods, pistons, and valves were examined either by openings in the case or via borescope examination. The second engine was located near the end of the wreckage path and also sustained heavy impact damage, with the majority of the components separated from the engine. The crankshaft could not be rotated by hand due to impact damage. Each engine's fuel system, fuel manifold, fuel pump, fuel nozzles, and fuel screen were field examined and no pre-impact abnormalities were noted. The top set of spark plugs were removed from both engines and displayed normal combustion and wear signatures. Both engines were equipped with three-bladed propellers, which had separated from their respective engines during the accident sequence. All three blades from one propeller were separated from the propeller hub; two of the blades were located in the first field, with the other blade located across the road in the second field. The blades exhibited similar signatures, including twisting and leading-edge polishing. The second propeller's three blades remained in the propeller hub and also exhibited twisting and leading-edge polishing. Though the examinations were limited by impact damage, no pre-impact airframe, engine, or systems anomalies, were noted that would have precluded normal operation. The extensive damage to the pitot static and deicing systems precluded any functional testing. ## Aircraft - Registration: [N424TW](https://openairdocs.org/deregistered/N424TW-2021-05-08), registration cancelled 2021-05-08, S/N 421B0816, built 1974 (OpenAirDocs) - Reported make and model: Cessna 421 (B) - Registry model: [Cessna 421B](https://openairdocs.org/model/cessna-421b) (registry code 2076014) (OpenAirDocs) - Registry engine: [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c) (registry code 17035, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 421B0816 - Year built: 1974 - Airframe hours: 8339.4 - Engines: Continental GTSIO-520-C 340 horsepower reciprocating; Continental GTSIO-520-C 340 horsepower reciprocating - Damage: Destroyed - Flight: Business, Part 91 - Operator: Phoenix Flight Test - Registered owner: Classic Solutions Co Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 15, 2019 - Departed: KDAY, Dayton, OH - Destination: KDLZ, Delaware, OH - Flight plan: IFR - Equipment: Electronic primary flight display, Electronic multifunction display, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: fatal; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; seat: left; toxicology performed; flight hours: 3,000 total, 48.5 in this make and model ## Weather - Conditions: Instrument (IMC), Day - Wind: 80° at 3 knots - Visibility: 3 statute miles - Lowest ceiling: 1,600 ft overcast - Temperature: 34 °F, dew point 32 °F - Altimeter: 30.02 inHg - Observed at: KDLZ, 8 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 20190317001529A](https://openairdocs.org/incident/20190317001529A), Mar 17, 2019: Cessna 421B, Plain City, OH, Destroyed, 1 fatal. On March 17, 2019, about 1745 eastern daylight time, a Cessna 421B airplane, N424TW Impacted terrain near Plain City, Ohio. The commercial rated pilot, sole… ## Docket (14 files) The files NTSB released with the investigation on November 19, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99120. 40.3 MB in all. - Weather study (item 1, PDF, 14 pages, 3.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7950274&FileExtension=pdf&FileName=WX_CEN19FA100_Study-Rel.pdf - Attachment 1 to the weather study (item 2, PDF, 119 pages, 14.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7950522&FileExtension=pdf&FileName=WX_CEN19FA100_Attachment_1-Rel.pdf - Flight display factual report (item 3, PDF, 2 pages, 1 photo, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9331730&FileExtension=pdf&FileName=CEN19FA100_NoDataReport_Final-Rel.pdf - Aircraft performance study (item 4, PDF, 8 pages, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9480081&FileExtension=pdf&FileName=CEN19FA100_Performance_Study-Rel.pdf - Approach RNAV (GPS) rwy 28 (item 5, PDF, 1 page, 231 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9577474&FileExtension=pdf&FileName=28%20RNAV%20rwy-Rel.pdf - Google earth - flight track (item 6, PDF, 3 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9583386&FileExtension=pdf&FileName=Photo%20flight%20track-Rel.pdf - Air traffic control (item 7, PDF, 3 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9760490&FileExtension=pdf&FileName=ATC%20commuications-Rel.pdf - Toxicological report (item 8, PDF, 1 page, 304 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9571590&FileExtension=pdf&FileName=Tox_Redacted-Rel.pdf - Maintenance records (excerpts) (item 9, PDF, 5 pages, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9571177&FileExtension=pdf&FileName=N424TW%20%20annual%20mx%20records_Redacted-Rel.pdf - C421B POH (excerpt) (item 10, PDF, 3 pages, 200 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9780570&FileExtension=pdf&FileName=C421B%20POH-Rel.pdf - Fuel receipt (item 11, PDF, 1 page, 192 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9571021&FileExtension=pdf&FileName=Fuel-Rel.pdf - Pilot records (item 12, PDF, 10 pages, 244 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9586363&FileExtension=pdf&FileName=Pilot%20info_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation (item 13, PDF, 3 pages, 4.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9571299&FileExtension=pdf&FileName=Party%20Forms_Redacted-Rel.pdf - Photo (item 14, PDF, 10 pages, 8.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9587111&FileExtension=pdf&FileName=Photo%201-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.