# NTSB ERA21LA070: Piper PA24, N7639P, Nashville, TN, December 12, 2020 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: December 12, 2020, 12:50 local (18:50 UTC) - Place: Nashville, TN - Coordinates: 36.047712, -86.947019 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.0477&lon=-86.9470&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Fuel related](https://openairdocs.org/ntsb-events/190) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA/ FSDO - NTSB case key (mKey): 102407 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA21LA070 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102407/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102407 - Page: https://openairdocs.org/ntsb/ERA21LA070 ## Probable cause The pilot’s failure to use carburetor heat during the approach, which resulted in a loss of engine power due to carburetor icing. ## 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: [Piper PA-24-180, 2 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=7102403), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Decision related to condition (probable cause); cases with it: [Piper PA-24-180, 3 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=7102403), [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. - [Approach: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Piper PA-24-180, 1 case](https://openairdocs.org/ntsb-events/190/sequence.md?model=7102403), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Piper PA-24-180, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=7102403), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The private pilot had completed most of a cross-country flight and about 7 miles from the destination airport during the approach, the engine lost all power. Despite several troubleshooting actions, the pilot was unable to restore engine power. He subsequently completed a forced landing in a field where the airplane touched down hard resulting in substantial damage to the fuselage and both wings. A postaccident examination of the airplane and engine found no evidence of mechanical malfunctions or failures that would have precluded normal operation and the fuel tanks were not breached. A carburetor icing probability chart revealed that serious icing was to be expected at glide power. The pilot had not used carburetor heat within the preceding 30 minutes prior to the loss of engine power, and he could not recall using carburetor heat after the loss of engine power. Additional examination of the airplane found about 7 gallons of fuel in the left fuel tank, which was the reported tank selected at the time of the engine failure. About 1/4 to 1/8 of a cup of fuel was found in the right tank, which was the tank the pilot switched to after the engine failure. Trace amounts of fuel were located throughout the fuel lines and carburetor. Given that sufficient fuel was found in the tank that was selected when the loss of power occurred, it is likely that the accumulation of carburetor resulted in a total loss of engine power. In addition, after the loss of engine power, the fuel selector was switched to a tank that was found to have an unusable amount of fuel, which further reduced the possibility that engine power could be restored. ## Factual narrative On December 12, 2020, about 1250 central standard time, a Piper PA-24-180 airplane, N7639P, was substantially damaged when it was involved in an accident near Nashville, Tennessee. The commercial pilot incurred minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he departed with 54 gallons of fuel for the cross-country flight and switched tanks every 30 minutes while en route. During the approach, about 7 nautical miles from the destination, the pilot reported that he observed a “significant drop in manifold pressure and change in engine noise, best described as a steady roll-back.” He reported that at the time of the loss of total engine power, the airplane was still in a “cruise configuration” with the mixture leaned, the rpm was 2,400, and the manifold pressure was 23 inches. The pilot pitched the airplane for best glide speed, began looking for an open area to land, and started troubleshooting the loss of power. He reported that he switched the fuel selector from the left tank to the right tank, moved the mixture and propeller levers full forward, turned on the boost pump, and engaged the engine starter; however, none of the actions restored power. The pilot continued his approach to a field that had trees and a house in the flight path. Just prior to impact the pilot reported that he could feel the onset of an aerodynamic stall as the airplane cleared the top of the house. He subsequently lowered the nose, and the airplane touched down hard and skidded to a stop in the field. Examination of the airplane by a Federal Aviation Administration (FAA) inspector found that the fuselage and both wings sustained substantial damage. Flight and engine control continuity was established. A total of about 7 gallons of fuel was drained from the left fuel tank, and 1/8 to 1/4 cup was drained from the right fuel tank. There was no debris or discoloration noted with the fuel, and no damage to the fuel tanks or evidence of fuel leakage was discovered at the accident site. An engine examination found that when the propeller was manually rotated, all cylinder valves operated normally, and thumb compression was found on each cylinder. Magneto spark and timing was confirmed. When the carburetor was disassembled, 4-5 teaspoons of fuel remained in the float bowl. The main fuel line was disconnected from the carburetor inlet and about 5 to 6 drops of fuel was observed to drain from the line. There was no evidence of fuel at the inlet side of the electrical fuel pump nor was there any remnants of fuel discovered at the outlet side of the engine driven fuel pump. The carburetor heat lever was found in the off position. The pilot reported postaccident that he had not turned on the carburetor heat in the 30 minutes before the loss of engine power and could not recall using the carburetor heat after the loss of engine power. He also estimated that each fuel tank should have been about 1/3to 1/2 full about the time of the loss of power. He reported the total flight time was about 2 hours and 20 minutes. Data downloaded from the engine monitoring instrument was consistent with what the pilot reported. Review of the FAA Carburetor Icing Chart found that the airplane was at risk of serious icing at glide power given the atmospheric conditions reported near the accident site. The airplanes pilot’s operating handbook (POH) stated that the total fuel capacity was 60 gallons, with 2 gallons of unusable fuel for the left- and right-wing fuel tanks. The following emergency procedure was provided for a loss of engine power during flight (see figure 1). Figure 1- Excerpt from the POH referencing the engine power loss during flight emergency procedure ## Aircraft - Registration: [N7639P](https://openairdocs.org/aircraft/N7639P), registered now, S/N 24-2851, built 1961 (OpenAirDocs) - Reported make and model: PIPER PA24 (180) - Registry model: [Piper PA-24-180](https://openairdocs.org/model/piper-pa-24-180) (registry code 7102403) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-2851 - Year built: 1961 - Airframe hours: 3639.6 - Engines: Lycoming O-360-A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 16, 2020, 50 hours before - Departed: EDN, Enterprise, AL - Destination: JWN, Nashville, TN - Flight plan: IFR - Equipment: Electronic flight bag or handheld device, Angle of attack indicator, ADS-B, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; injuries: minor; private, military, commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review April 23, 2020; seat: left; restraint: lap only; flight hours: 1,873 total, 36 in this make and model, 1,699 as pilot in command, 42 in the last 90 days, 26 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 52 °F - Altimeter: 29.84 inHg - Observed at: JWN, 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 20201212021979A](https://openairdocs.org/incident/20201212021979A), Dec 12, 2020: Piper PA-24-180, Nashville, TN, Substantial damage. On 12/12/2020 N7639P departed enterprise municipal airport (kedn), Alabama. Prior to departing the area the pilot in command (PIC) completed two practice… ## Other investigations on N7639P (1) 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. - [NTSB MIA85LA118](https://openairdocs.org/ntsb/MIA85LA118), Mar 14, 1985: Piper PA-24-180 (N7639P), Zephyrhills, FL, substantial damage ## Docket (9 files) The files NTSB released with the investigation on September 29, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102407. 16.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12533272&FileExtension=pdf&FileName=NTSB%206120.1%20Report_Redacted-Rel.pdf - NTSB memo for record (FAA inspector) (item 2, PDF, 2 pages, 163 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12533100&FileExtension=pdf&FileName=NTSB%20Memo%20for%20Record%20(FAA%20Inspector)-Rel.pdf - Record of conversation (pilot) (item 3, PDF, 2 pages, 167 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12532711&FileExtension=pdf&FileName=Record%20of%20Conversation%20(Pilot)-Rel.pdf - Photo array (item 4, PDF, 1 page, 12.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12533090&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf - Carb ice probability chart (item 5, PDF, 1 page, 362 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12532989&FileExtension=pdf&FileName=ERA21LA070_Carb%20Ice%20Probability%20Chart-Rel.pdf - Excerpts from the pilota��s operating handbook (item 6, PDF, 5 pages, 570 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12533156&FileExtension=pdf&FileName=Excerpts%20from%20the%20Pilot%E2%80%99s%20Operating%20Handbook-Rel.pdf - NTSB memo for record (jpi data) (item 7, PDF, 1 page, 223 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12533376&FileExtension=pdf&FileName=NTSB%20Memo%20for%20Record%20(JPI%20Data)-Rel.pdf - Jpi data set (item 8, CSV, 209 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12532278&FileExtension=csv&FileName=JPI%20Data%20Set-Rel.csv - Release of aircraft wreckage, NTSB form 6120.15 (item 9, PDF, 1 page, 477 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12532701&FileExtension=pdf&FileName=Wreckage%20Release%20-%20Redacted-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.