# NTSB ERA18LA195: Eagle DW1, N8805X, Ider, AL, July 18, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 18, 2018, 14:00 local (19:00 UTC) - Place: Ider, AL - Coordinates: 34.714168, -85.680831 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.7142&lon=-85.6808&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 20, 2020 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 97838 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA18LA195 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97838/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97838 - Page: https://openairdocs.org/ntsb/ERA18LA195 ## Probable cause Fatigue failure of the No. 2 cylinder studs/through bolts and the fracture of the crankcase, which resulted in a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Eagle EAGLE DW-1, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=3230203), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Object/animal/substance: fence/fence post](https://openairdocs.org/ntsb-findings/03022047): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Eagle EAGLE DW-1, 1 case](https://openairdocs.org/ntsb-findings/03022047/cases.md?model=3230203), [All aircraft, 313 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Eagle EAGLE DW-1, 3 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=3230203), [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: [Eagle EAGLE DW-1, 4 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=3230203), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Eagle EAGLE DW-1, 4 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3230203), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The commercial pilot was conducting an aerial application flight. He stated that while maneuvering at 1,500 ft, he heard a "deep knock" in the engine; the entire windshield became covered with oil, and the engine lost power. The pilot made a forced landing to a service road, during which the airplane struck a barbed-wire fence with the right wings before coming to rest in a field. Postaccident examination of the engine revealed the No. 2 cylinder had separated from the cylinder mounting deck. Two fractured sections of the left crankcase that included part of the No. 2 cylinder bore were found in the engine cowling. All but one of the No. 2 cylinder base studs and through bolts remained in the cylinder bore and were fractured. The fractured surfaces exhibited signatures consistent with fatigue. The fatigue failure of the No. 2 cylinder studs and through bolts and the fracture of the crankcase led to the loss of engine power. ## Factual narrative On July 18, 2018, about 1400 central daylight time, an Eagle DW-1, N8805X, was substantially damaged when it made a forced landing following a total loss of engine power while maneuvering near Ider, Alabama. The pilot was not injured. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations as a Part 137 aerial application flight. Visual meteorological conditions prevailed, and no flight plan was filed.The pilot stated that he was maneuvering at 1,500 ft when the engine stopped producing power after he heard a "deep knock" in the engine followed by the entire windshield getting covered with oil. The pilot made a forced landing to a service road and the airplane struck a barbed-wire fence with the right wings before coming to rest upright on the edge of a soybean field. The airplane sustained substantial damage to the upper and lower right wings, the outboard section of the left wings, and the fuselage. Two of the three propeller blades were displaced aft. Postaccident examination of the airplane revealed a large hole in the left side of the engine cowling and a large amount of oil over the entire nose and windshield. The No. 2 cylinder had separated from the cylinder mounting deck. Two fractured sections of the left crankcase that included part of the No. 2 cylinder bore were found lying in the engine cowling. All but one of the No. 2 cylinder base studs and thru bolts remained in the cylinder/crankcase bore and were fractured. Photographs of the fractured studs/bolts were reviewed by the National Transportation Safety Board's Materials laboratory. The fractured surfaces exhibited signatures consistent with fatigue A review of the engine maintenance logbook revealed that all six cylinders were replaced in September 2015 at a total engine time of 1,334.0 hours. At the time of the accident, the engine had accrued 1,582.43 hours and 248.43 hours since the No. 2 cylinder was installed. In the June 2014 issue of Sport Aviation, the author of the "Savvy Aviator" column noted that, according to a veteran mechanic/expert witness, "who specializes in research on fastener torque and engine assembly practices,…the root cause of spun bearings, thrown rods, and separated cylinders is simply, 'a failure to achieve sufficient preload in the assembled fasteners.'" The author further noted that, "preload is the technical term for the clamping force created by tightening a fastener (typically a threaded bolt or stud) that holds assembled parts together. Having sufficient preload is the key to a strong and reliable bolted joint that will not loosen, break, or shift under the load. In order for a bolted joint to be stable under cyclic repetitive stress, the preload on the fasteners must be greater than the maximum stress that is trying to pull the joint apart. If this condition is met, the joint will not separate, and the fasteners won't 'feel' the repetitive stress cycles. But if it isn't, the joint willshift under load and the fasteners will ultimately fail from repetitive stress fatigue." The pilot held a commercial pilot certificate with a rating for airplane single-engine land. His last Federal Aviation Administration second-class medical was issued on December 30, 2017. The pilot reported a total flight time of 2,214.4 hours. Weather reported at Huntsville International Airport (HSV), Huntsville, Alabama, about 53 miles northwest of the accident site, at 1353, was: wind from 310° at 6 knots, visibility 10 miles, scattered clouds at 3,600 ft, scattered clouds at 25,000 ft, temperature 32° C, dew point 24°, and an altimeter setting of 29.97 inches Hg. ## Aircraft - Registration: [N8805X](https://openairdocs.org/deregistered/N8805X-2022-02-05), registration cancelled 2022-02-05, S/N DW-1-0036-81 (OpenAirDocs) - Reported make and model: Eagle DW1 (NO SERIES) - Registry model: [Eagle EAGLE DW-1](https://openairdocs.org/model/eagle-eagle-dw-1) (registry code 3230203) (OpenAirDocs) - Category: Airplane - Serial number: DW-1-0036-81 - Airframe hours: 4432.93 - Engines: Lycoming IO-540 260 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, March 23, 2018, 23 hours before - Departed: Ider, AL - Destination: Ider, AL - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review December 20, 2017; seat: center; restraint: 4-point; flight hours: 2,214.3 total ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 6 knots - Visibility: 10 statute miles - Temperature: 90 °F, dew point 75 °F - Altimeter: 29.96 inHg - Observed at: HSV, 53 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 20180718011619A](https://openairdocs.org/incident/20180718011619A), Jul 18, 2018: Eagle Aircraft Co EAGLE DW-1, Ider, AL, Substantial damage. N8805X is an Eagle DW1 aircraft. On 07/18/2018 at 1400 local time, N8805X was conducting aerial spraying activities near Ider, AL. N8805X just finished… ## Docket (5 files) The files NTSB released with the investigation on October 30, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97838. 11.2 MB in all. - Written Statement - Pilot (item 1, .PDF, 201 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477358&FileExtension=.PDF&FileName=Written%20Statement%20-%20Pilot-Master.PDF - Maintenance Records -Engine (item 2, .PDF, 6.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477359&FileExtension=.PDF&FileName=Maintenance%20Records%20-Engine-Master.PDF - Photos (item 3, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477360&FileExtension=.PDF&FileName=Photos%20-Master.PDF - Materials Laboratory Report (item 4, .PDF, 288 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477362&FileExtension=.PDF&FileName=Materials%20Laboratory%20Report-Master.PDF - Sport Aviation Article June 2014 (item 5, .PDF, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477364&FileExtension=.PDF&FileName=Sport%20Aviation%20Article%20June%202014-Master.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.