# NTSB CEN24LA211: Cessna 172RG, N751DW, Chandeleur Island, LA, May 22, 2024 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: May 22, 2024, 06:53 local (11:53 UTC) - Place: Chandeleur Island, LA · sand bar - Coordinates: 29.8366, -88.839 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.8366&lon=-88.8390&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 194406 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN24LA211 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194406/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=194406 - Page: https://openairdocs.org/ntsb/CEN24LA211 ## Probable cause A fatigue failure of the engine oil pressure line, which resulted in the loss of engine oil during the flight and subsequent damage to the nose landing gear support structure during the precautionary landing. ## 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 172RG, 3 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=2072438), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md) - [Landing gear system: nose/tail landing gear](https://openairdocs.org/ntsb-findings/01023220): Aircraft › Aircraft systems · Capability exceeded (probable cause); cases with it: [Cessna 172RG, 3 cases](https://openairdocs.org/ntsb-findings/01023220/cases.md?model=2072438), [All aircraft, 185 cases](https://openairdocs.org/ntsb-findings/01023220/cases.md) - [Eng oil sys (airframe furnish): eng oil dist (airframe furn)](https://openairdocs.org/ntsb-findings/01057920): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-findings/01057920/cases.md?model=2072438), [All aircraft, 18 cases](https://openairdocs.org/ntsb-findings/01057920/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Cessna 172RG, 3 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=2072438), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 172RG, 10 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072438), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Cessna 172RG, 11 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=2072438), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The pilot reported that about an hour and twenty minutes into the flight he smelled smoke and noticed that the oil pressure was decreasing. He diverted for a precautionary landing. By that time, the oil pressure had dropped to zero and the cabin was filling with smoke. He landed on a beach, and the nose landing gear dug into the sand and collapsed. The landing gear well structure sustained substantial damage during the precautionary landing. A postaccident examination determined that the oil pressure line from the engine to the firewall fitting had fractured due to fatigue. The line was bent about 360° near mid-span, and the line was fractured within the bent segment. Airplane maintenance records revealed that the engine was overhauled and reinstalled on the airframe about a month before the accident. The mechanic noted that the oil line was inspected and reinstalled after the overhaul. The airplane had accumulated 119 hours since the engine overhaul. ## Factual narrative On May 22, 2024, about 0653 central daylight time, a Cessna 172RG airplane, N751DW, was substantially damaged when it was involved in an accident near Chandeleur Island, Louisiana. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. The pilot reported that about an hour and twenty minutes into the flight he smelled smoke and noticed that the oil pressure was decreasing. He diverted to Chandeleur Island for a precautionary landing. By that time, the oil pressure had dropped to zero and the cabin was filling with smoke. He landed on a beach, and the nose landing gear dug into the sand and collapsed. The landing gear well structure sustained substantial damage during the precautionary landing. A postaccident examination determined that the oil pressure line from the engine to the firewall fitting had fractured. The line was bent about 360° near mid-span, and the line was fractured within the bent segment. Metallurgical examination revealed that the fracture surface exhibited features consistent with fatigue. The origin was located at the exterior surface of the tube at the outside of the 360°bend. The crack progressed through the thickness of the tube wall and then circumferentially to final fracture at the opposite side of the tube. Airplane maintenance records revealed that the engine had been overhauled and was reinstalled on the airframe about one month before the accident. The mechanic noted that the oil line was visually inspected for condition, and there was no corrosion, worn areas, dents, or nicks on the line. As a result, the oil line was reinstalled on the airplane after the overhaul. The airplane had accumulated 119 hours since the engine overhaul. ## Aircraft - Registration: [N751DW](https://openairdocs.org/aircraft/N751DW), registered now, S/N 172RG1002, built 1981 (OpenAirDocs) - Reported make and model: CESSNA 172RG - Registry model: [Cessna 172RG](https://openairdocs.org/model/cessna-172rg) (registry code 2072438) (OpenAirDocs) - Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 172RG1002 - Year built: 1981 - Airframe hours: 19940.5 - Engines: Lycoming O360F1A6 180 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial observation, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 29, 2024, 119.5 hours before - Departed: HUM, Houma, LA - Destination: PQL, Moss Point, MS - Equipment: ADS-B, Stall warning system, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review March 25, 2024; seat: left; restraint: 3-point; flight hours: 6,833.4 total, 4,858.6 in this make and model, 6,773.4 as pilot in command, 130.3 in the last 90 days, 131.4 in the last 30 days, 11 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 68 °F - Altimeter: 29.99 inHg - Icing: Unknown - Turbulence: Unknown - Observed at: KPQL, 41 nm away - METAR: KPQL 221153Z 36004KT 10SM CLR 21/20 A2999 RMK AO2 SLP156 T02110200 ## Other investigations on N751DW (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 ERA09CA391](https://openairdocs.org/ntsb/ERA09CA391), Jul 4, 2009: Cessna 172RG (N751DW), Morristown, NJ, substantial damage. Probable cause: The pilot's failure to maintain clearance from a parked aircraft during taxi operations. ## Docket (8 files) The files NTSB released with the investigation on September 11, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=194406. 13.9 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17261885&FileExtension=pdf&FileName=Accident%20Report%20--%20CEN24LA211_redacted-Rel.pdf - Investigation photos (item 2, PDF, 9 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17459283&FileExtension=pdf&FileName=Investigation%20Photos%20--%20CEN24LA211-Rel.pdf - Maintenance records -- airframe (item 3, PDF, 1 page, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17440836&FileExtension=pdf&FileName=Maintenance%20Records%20--%20Airframe_redacted-Rel.pdf - Maintenance records -- engine (item 4, PDF, 1 page, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17260507&FileExtension=pdf&FileName=Maintenance%20Records%20--%20Engine_redacted-Rel.pdf - Materials laboratory factual report 24-046 (item 5, PDF, 4 pages, 2 photos, 464 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17440669&FileExtension=pdf&FileName=24-046-Rel.pdf - Conversation summary -- mechanic (item 6, PDF, 1 page, 143 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17473105&FileExtension=pdf&FileName=ROC%20--%20ICSAviation(Gill)_06Aug2024-Rel.pdf - FAA maintenance technician hdbk -- general / chap 9 (item 7, PDF, 25 pages, 4.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17451994&FileExtension=pdf&FileName=AMTG%20HDBK%20--%20Chap9_Tubing-Rel.pdf - FAA AC43.13 -- section 8-5 / oil system lines inspection (item 8, PDF, 1 page, 20 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17452004&FileExtension=pdf&FileName=FAA%20AC_43.13-1B%20--%20Section%208-5_Oil%20System%20Lines%20Inspection-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.