# NTSB ERA22LA045: Cessna 172, N172XX, Decatur, GA, November 4, 2021 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: November 4, 2021, 09:47 local (13:47 UTC) - Place: Decatur, GA · In front of 2806 N Decatur Road - Coordinates: 33.793803, -84.277894 - Nearby events: https://openairdocs.org/map.md?lat=33.7938&lon=-84.2779&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - 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): 104203 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA22LA045 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104203/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104203 - Page: https://openairdocs.org/ntsb/ERA22LA045 ## Probable cause Oil exhaustion due to an oil leak that resulted in a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fluids: oil](https://openairdocs.org/ntsb-findings/01071020): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Cessna 172A, 1 case](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=2072404), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md) - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Cessna 172A, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2072404), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 172A, 2 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2072404), [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: [Cessna 172A, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072404), [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: [Cessna 172A, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072404), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The student pilot reported that, before takeoff, he added 1 quart of oil, bringing the oil quantity to full capacity. Shortly after takeoff, while the airplane was at an altitude of 1,500 ft mean sea level, the pilot noted that the engine began running roughly, which was followed by a total loss of engine power. He pitched the airplane to attain its best glide airspeed. He descended the airplane for a forced landing to a four-lane road, during which the airplane struck powerlines and came to rest inverted on the road. Postaccident examination of the engine found that crankcase was breached consistent with a catastrophic failure. Additionally, a substantial amount of oil was covering the exterior of the bottom fuselage skin from the engine compartment to the tailcone, fresh oil was noted in the cockpit floor area, and only a minimal amount of oil remained in the engine. Given this information it is most likely that the total loss of engine power occurred due to oil exhaustion, that was precipitated by an oil leak. At the rear portion of the engine, the oil filter adapter and its attached base had separated from the accessory case. Although it is possible that the oil leak emanated from this location, the available evidence for this investigation precluded a definitive determination of the source for the oil leak. ## Factual narrative On November 4, 2021, about 0947 eastern daylight time, a Cessna 172A, N172XX, was substantially damaged when it was involved in an accident near Decatur, Georgia. The student pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The student pilot stated that, before takeoff, he added 1 quart of oil, bringing the total quantity to 8 quarts (full capacity). The airplane departed from Dekalb-Peachtree Airport (PDK), Atlanta, Georgia. While the airplane was at an altitude of 1,500 ft mean sea level, the student pilot noted that the engine began running roughly, which was followed by a total loss of engine power. The student pilot pitched the airplane for best glide airspeed and declared an emergency with air traffic control. He subsequently attempted a forced landing to a four-lane road, but the airplane struck powerlines and came to rest inverted on the road. The accident site was located about 5 miles south-southwest of PDK. Postaccident examination of the airplane at the accident site revealed that the exterior surface of the bottom fuselage skin was coated in oil from the engine compartment to the tailcone, and a hole was noted in the crankcase above the No. 6 cylinder. Examination of the airframe and engine after recovery revealed fresh oil on the cockpit floor behind the firewall. In the rear portion of the engine, the oil filter adapter and its attached base had separated from the engine accessory case. The adapter did not appear to be safety wired, per the instructions in the manufacturer’s service bulletin. The separated portion of the oil filter, which was safety wired, exhibited impact damage. The oil suction screen contained some ferrous material, but no contamination was observed in the oil filter element. About 4 to 5 ounces of oil were drained from the oil sump, which contained metal. Examination of the accessory case revealed that the lower portion of the opening, into which the oil filter adapter threads, was fractured away. None of the smeared threads of the accessory case accepted the oil filter adapter, but some of the damaged threads of the oil filter adapter would have threaded into the accessory case. A review of the maintenance records revealed that the airplane’s last annual inspection was completed in January 2014, more than 7.5 years before the accident. The Federal Aviation Administration inspector assigned to this investigation reported that the oil filter adapter was installed “sometime in 2020,” but this installation was not documented in the maintenance records. As part of the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident report, the student pilot indicated the following: There was evidence of the spin on adapter being over torqued upon installation that cracked the accessory housing, which in turn never leaked but broke free on rotation at PDK. This dumped all eight quarts [of oil] out of a hole over an inch indiameter starving the crank and causing the [connecting] rods to seize. The spin on was installed by the [airframe and powerplant mechanic] that did the 100hr inspection. ## Aircraft - Registration: [N172XX](https://openairdocs.org/aircraft/N172XX), registered now, S/N 47123 (OpenAirDocs) - Reported make and model: CESSNA 172 (A) - Registry model: [Cessna 172A](https://openairdocs.org/model/cessna-172a) (registry code 2072404) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 47123 - Year built: 1959 - Airframe hours: 4531 - Engines: Continental O-300-C 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Roberts Christopher B - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: Annual, January 19, 2014, 181 hours before - Departed: PDK, Atlanta, GA - Destination: PXE, Perry, GA - Airport: PDK, Dekalb-Peachtree - Equipment: Auto-pilot, Handheld GPS, Satellite tracking device, Stall warning system, Video recording device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: minor; student; medical: class 1, without waivers/limitations; seat: left; restraint: lap only ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 4 knots - Visibility: 5 statute miles - Lowest ceiling: 3,100 ft overcast - Temperature: 45 °F, dew point 43 °F - Altimeter: 30.26 inHg - Observed at: KPDK, 5 nm away - METAR: KPDK 041353Z 04004KT 5SM -RA BR FEW009 OVC031 07/06 A3026 RMK AO2 SLP251 P0001 T00720061 ## 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 20211104018909A](https://openairdocs.org/incident/20211104018909A), Nov 4, 2021: Cessna 172A, Decatur, GA, Substantial damage. Aircraft N172XX, Cessna 172A ser# 47123 traveling from peach-tree dekalb (pdk)to perry,GA(pxe) crashed shortly after takeoff at the intersection of north… ## Docket (7 files) The files NTSB released with the investigation on September 7, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104203. 28.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 11.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13426839&FileExtension=pdf&FileName=6120%20Recd%2011%2029%202021_Redacted-Rel.pdf - NTSB record of conversation with pilot (item 2, PDF, 3 pages, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13432605&FileExtension=pdf&FileName=FINAL%20Record%20of%20Conversation%20w%20Christopher%20B%20Roberts%2011%204%202021%20v04%20w%20Corrctns_Redacted-Rel.pdf - Maintenance log excerpts (item 3, PDF, 3 pages, 9.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13428529&FileExtension=pdf&FileName=Maintenance%20Record%20Copies_Redacted-Rel.pdf - FAA inspector statement (item 4, PDF, 14 pages, 26 photos, 3.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13427577&FileExtension=pdf&FileName=FAA%20Inspector%20Statement%2014%20Pages-Rel.pdf - Record of NTSB conversations with FAA (item 5, PDF, 8 pages, 3 photos, 604 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13434406&FileExtension=pdf&FileName=Record%20of%20Conversations%20w%20FAA_Redacted-Rel.pdf - Investigative photographs (item 6, PDF, 5 pages, 5 photos, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13439683&FileExtension=pdf&FileName=Investigative%20Photographs_ERA22LA045-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 7, PDF, 1 page, 450 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13449555&FileExtension=pdf&FileName=Wreckage%20Release_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.