# NTSB CEN11LA413: Cessna 172N, N172NT, Bedford Park, IL, June 18, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 18, 2011, 16:35 local (21:35 UTC) - Place: Bedford Park, IL - Coordinates: 41.786109, -87.752502 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.7861&lon=-87.7525&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: 4 uninjured - Status: Completed, report October 4, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-DuPage FSDO - NTSB case key (mKey): 80861 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA413 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/80861/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=80861 - Page: https://openairdocs.org/ntsb/CEN11LA413 ## Probable cause A loss of engine power due to a fractured push rod precipitated by a stuck exhaust valve. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna 172N, 13 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2072434), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Runway/land/takeoff/taxi surface: soft surface](https://openairdocs.org/ntsb-findings/03023020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Cessna 172N, 1 case](https://openairdocs.org/ntsb-findings/03023020/cases.md?model=2072434), [All aircraft, 264 cases](https://openairdocs.org/ntsb-findings/03023020/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 172N, 11 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=2072434), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Cessna 172N, 28 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2072434), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 172N, 31 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072434), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 172N, 44 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072434), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that about 5 miles from the destination the engine started to run rough, and about 20 seconds later the engine lost power. His attempts to restore engine power were unsuccessful. The pilot subsequently performed a forced landing to a field. During the landing roll the airplane nosed over on the soft field. A postaccident examination revealed that the No.3 cylinder exhaust valve push rod had buckled and fractured near mid-length. The push rod fracture surfaces showed failure signatures consistent with overload precipitated by a stuck valve. No other engine anomalies were observed. ## Factual narrative On June 18, 2011, about 1635 central daylight time, a Cessna 172N, N172NT, was substantially damaged when it nosed over during a forced landing following a loss of engine power about 2 miles southwest of Midway Airport (MDW), Chicago, Illinois. The pilot and 3 passengers were not injured. The aircraft was registered to Woma LLC and operated by Aviation Professionals Inc. under the provisions of 14 Code of Federal Regulations Part 91, as a training and rental airplane. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The local personal flight originated from Lansing Municipal Airport (IGQ), Lansing, Illinois, about 1610. The pilot reported that about 5 miles from MDW the engine started to run rough, and about 20 seconds later the engine lost power. His attempts to restore engine power were unsuccessful. The pilot subsequently executed a forced landing to a field. However, the airplane nosed over during the landing rollout due to the soft terrain. He noted that the field was used as a water retention reservoir with 2-foot tall grass and approximately 4 inches of water and mud. A postaccident examination revealed that the #3 cylinder exhaust valve push rod had buckled and fractured near mid-length. The fracture surface was uniform in appearance and oriented approximately 45-degrees to the surface of the push rod consistent with an overload failure. At the time of the examination, the exhaust valve was free to move. However, the damage to the push rod was consistent with a stuck valve condition during operation. No other engine anomalies were observed. The accident airplane was powered by a 160-horsepower Lycoming O-320-H2AD engine, serial number L-80290-76T. Maintenance records indicated that the most recent annual inspection was completed on May 10, 2011. The engine had accumulated about 1,567 hours since overhaul, with approximately 67 hours since the annual inspection. ## Aircraft - Registration: [N172NT](https://openairdocs.org/deregistered/N172NT-2013-01-31), registration cancelled 2013-01-31, S/N 17271113, built 1978 (OpenAirDocs) - Reported make and model: CESSNA 172N - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17271113 - Airframe hours: 5832 - Engines: LYCOMING O-320 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Aviation Professionals Inc. - Registered owner: Woma LLC - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: Annual, May 10, 2011, 67 hours before - Departed: IGQ, Lansing, IL - Destination: MDW, Chicago, IL - Airport: MDW, Midway International ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 28; injuries: none; private; airplane ratings: single-engine land; medical: class 1, with waivers/limitations; last flight review November 23, 2010; seat: left; flight hours: 125 total, 58 in this make and model, 48 as pilot in command, 18 in the last 90 days, 2 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 13 knots - Visibility: 10 statute miles - Lowest ceiling: 30,000 ft broken - Temperature: 79 °F, dew point 66 °F - Altimeter: 29.80 inHg - Observed at: MDW, 2 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 20110618011909A](https://openairdocs.org/incident/20110618011909A), Jun 18, 2011: Cessna 172N, Bedford Park, IL, Substantial damage. While approaching Midway (mdw) for landing, the engine began running rough, pilot declared an emergency to mdw twr. And took initial action. The engine failed… ## Docket (4 files) The files NTSB released with the investigation on August 16, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=80861. 3.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 897 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351682&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Conversation Record -- FAA Inspector (item 2, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351687&FileExtension=.PDF&FileName=Conversation%20Record%20--%20FAA%20Inspector-Master.PDF - Airframe Log -- Excerpts (item 3, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351688&FileExtension=.PDF&FileName=Airframe%20Log%20--%20Excerpts-Redacted.PDF - Engine Log -- Excerpts (item 4, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351689&FileExtension=.PDF&FileName=Engine%20Log%20--%20Excerpts-Redacted.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.