# NTSB CHI97LA145: Ercoupe 415-G, N94415, Colusa, IL, May 24, 1997 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 23, 1997, 19:30 local (May 24, 1997, 00:30 UTC) - Place: Colusa, IL - Location: 40.5620° N, 91.1036° W: Placed by OpenAirDocs from NTSB’s distance and direction from DOUGLAS (IL84), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=40.5620&lon=-91.1036&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report August 25, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 10577 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI97LA145 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10577/pdf - Page: https://openairdocs.org/ntsb/CHI97LA145 ## Probable cause improper installation of the rocker arm assembly by maintenance personnel which led to the failure of the rocker arm. A factor was the soft terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, climb - engine assembly,rocker arm/tappet - failure (cause) - maintenance,installation - improper, other maintenance personnel (cause) - Forced landing, emergency landing after takeoff - Nose over, landing - roll - terrain condition - soft (contributing factor) ## Analysis The pilot-in-command stated that during the initial climb after a series of touch-and-go's, 'at an altitude of 250 feet, the engine began running rough and made a clattering noise.' The CFI said he then took control of the aircraft. The pilot reported that the 'engine quite completely with the propeller stopping in the horizontal position.' The CFI next executed a forced landing in a 'freshly planted' field. The CFI said, [the] 'Aircraft touched down firmly and we rolled approximately 50 feet when the nose wheel dug in and the aircraft went over onto its back, nose first.' Postcrash investigation of the airplane showed that the exhaust valve rocker arm on the number two cylinder was broken in two pieces. Further inspection of the number two cylinder showed that the exhaust valve rocker arm had been interchanged with the intake valve rocker arm of the same cylinder. ## Factual narrative On May 23, 1997, at 1930 central daylight time (CDT), a Ercoupe 415-G, N94415, sustained substantial damage during landing rollout when it nosed over in a field after a forced engine-out landing near Colusa, Illinois. The Airline Transport Pilot (ATP) reported engine knocking during initial climb. Both pilots sustained minor injuries. The personal 14 Part 91 flight was operating in visual meteorological conditions. No flight plan was on file. The flight departed Douglas Airport (IL84), Illinois at 1845, for a local instruction flight. In a written statement by the Pilot in Command, an ATP and Certified Flight Instructor (CFI), he stated that the during the initial climb after a series of touch and go's, "at an altitude of 250 feet, the engine began running rough and made a clattering noise." The CFI said he then took control of the aircraft. The pilot reported that the "engine quite completely with the propeller stopping in the horizontal position." The CFI next executed a forced landing in a "freshly planted" field. The CFI said, [the] "Aircraft touched down firmly and we rolled approximately 50 feet when the nose wheel dug in and the aircraft went over onto its back, nose first." Post crash investigation of the airplane showed that the exhaust valve rocker arm on the number two cylinder was broken in two pieces. Further inspection of the number two cylinder showed that the exhaust valve rocker arm had been interchanged with the intake valve rocker arm of the same cylinder. The exhaust valve rocker arm differs from the intake valve rocker arm by having a drilled oil port. This oil port aids in cooling of the exhaust valve. In a telephone conference with the engine manufacturer, it was confirmed that the switched rocker arms would produce conditions which could fracture the switched rocker arm. No other anomalies were found with the airplane. ## Aircraft - Registration: [N94415](https://openairdocs.org/aircraft/N94415), registered now, S/N 5050, built 1950 (OpenAirDocs) - Reported make and model: Ercoupe (Eng & Research Corp.) 415-G - Registry model: [Engineering & Research 415-G](https://openairdocs.org/model/engineering-research-415-g) (registry code 0420310) (OpenAirDocs) - Registry engine: [Continental C85 series](https://openairdocs.org/engine/continental-c85-series) (registry code 17008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 5030 - Airframe hours: 3289 - Engines: Continental O-200A 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Richard Frankilin Law - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 1, 1997, 7 hours before - Departed: IL84 - Airport: IL84, Douglas Airport (Rla), runway 18, 2,300 × 100 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 5,712 total, 2 in this make and model, 5,591 as pilot in command, 129 in the last 90 days, 46 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 5 knots - Visibility: 15 statute miles - Temperature: 68 °F, dew point 43 °F - Altimeter: 29.00 inHg - Observed at: KUI, 1 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 19970523011929A](https://openairdocs.org/incident/19970523011929A), May 23, 1997: Univar 415G, Colusa, IL, Substantial damage. On climbout engine knocking and quit. Nosed over landing. Intake and exhaust rocker arms switched. Fractured arm. (-23) while departing Douglas Airport,… 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.