# NTSB CEN19LA152: Rand Robinson KR2, N886MJ, Poplar Grove, IL, May 26, 2019

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Class 3 · Limited · Final report
- Date: May 26, 2019, 17:00 local (22:00 UTC)
- Place: Poplar Grove, IL
- Coordinates: 42.342777, -88.896667 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.3428&lon=-88.8967&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Central Region
- Parties: FAA FSDO
- NTSB case key (mKey): 99482
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA152
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99482/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99482
- Page: https://openairdocs.org/ntsb/CEN19LA152

## Probable cause

The loss of engine power due to vapor lock of the throttle body injection system.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Performance/control parameters: powerplant parameters](https://openairdocs.org/ntsb-findings/01062050): Aircraft › Aircraft oper/perf/capability · Design (probable cause); cases with it: [Jones Mark S RAND ROBINSON KR-2S, 1 case](https://openairdocs.org/ntsb-findings/01062050/cases.md?model=05606SN), [All aircraft, 81 cases](https://openairdocs.org/ntsb-findings/01062050/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Jones Mark S RAND ROBINSON KR-2S, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05606SN), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md)
- [Landing-landing roll: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Jones Mark S RAND ROBINSON KR-2S, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05606SN), [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: [Jones Mark S RAND ROBINSON KR-2S, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=05606SN), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md)

## Analysis

Shortly after departure, the pilot smelled oily smoke and noted a loss of engine oil pressure and an increase in oil temperature. The engine lost power, and the pilot performed a forced landing to a corn field. During the landing, the nosewheel dug into the field and the airplane nosed over, resulting in substantial damage to the wings and vertical stabilizer. An examination of the engine revealed no mechanical anomalies that would preclude normal operations. The source of the oil leak was not identified. The pilot later reported that, after researching and consulting with other pilots who operated the engine type installed on the accident airplane, he believed that the loss of engine power was the result of vapor lock in the throttle body injection (TBI) system. His research indicated that other airplane owners provide “blast cooling” on the TBI to fix the issue. The pilot said that the vapor lock issue likely started at the same time as the engine heated up due to the extra lean mixture. He added that the rear seal might leak and spray oil on the exhaust pipe. He stated that enriching the mixture might have corrected the issue inflight.

## Factual narrative

On May 26, 2019, about 1700 central daylight time, a Rand Robinson KR2 airplane, N886MJ, was substantially damaged when it was involved in an accident near Poplar Grove, Illinois. The pilot received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, shortly after departure, the airplane did not accelerate as expected. He smelled oily smoke, saw the oil pressure reading below normal, and noted an increase in oil temperature. The engine began losing power, so the pilot performed a forced landing to a corn field. During the landing, the nosewheel dug into the field and the airplane nosed over, resulting in substantial damage to the wings and vertical stabilizer. The airplane was examined by inspectors from the Federal Aviation Administration. Examination and borescope of the engine did not locate the source of the oil leak. The pilot later stated that he believed the engine experienced a vapor lock in the throttle body injection (TBI) system. His research with the online Corvair engine community revealed that this is an issue with high air temperatures. Other airplane owners provided “blast cooling” on the TBI to fix the issue. The pilot said that the vapor lock issue likely started at the same time as the engine heated up due to the lean mixture. He added that the rear seal might leak and spray oil on the exhaust pipe and stated that enriching the mixture might have corrected the issue.

## Aircraft

- Registration: [N886MJ](https://openairdocs.org/aircraft/N886MJ), registered now, S/N 9425-886 (OpenAirDocs)
- Reported make and model: RAND ROBINSON KR2 (S)
- Registry model: [Jones Mark S RAND ROBINSON KR-2S](https://openairdocs.org/model/jones-mark-s-rand-robinson-kr-2s) (registry code 05606SN) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 9425-886
- Year built: 2004
- Airframe hours: 667.7
- Engines: General Motors Corp Corvair 100 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, July 20, 2018, 31 hours before
- Departed: C77, Poplar Grove, IL
- Destination: FEP, Freeport, IL
- Airport: C77, Poplar Grove
- Equipment: Angle of attack indicator, Handheld GPS

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 57; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review June 2, 2017; seat: left; restraint: 4-point; flight hours: 623 total, 29 in this make and model, 623 as pilot in command, 23 in the last 90 days, 10 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 55 °F
- Altimeter: 30.04 inHg
- Observed at: KRFD, 13 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 20190526017189A](https://openairdocs.org/incident/20190526017189A), May 26, 2019: Jones Mark S RAND ROBINSON KR-2S, Poplar Grove, IL, Substantial damage. All times are approximate. Alt and time data derived from aprs system tracking for KC9DAH transmitter operating in the aircraft at the time. 1550: Aircraft…

## Docket (3 files)

The files NTSB released with the investigation on November 3, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99482. 2.6 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12115615&FileExtension=pdf&FileName=6120_1__Redacted-Rel.pdf
- Additional information (item 2, PDF, 3 pages, 197 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12116431&FileExtension=pdf&FileName=Pilot%20Information_Redacted-Rel.pdf
- Summary of FAA findings (item 3, PDF, 1 page, 167 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12884404&FileExtension=pdf&FileName=Summary%20of%20FAA%20input-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.

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