Meyer LEGACY N29MM

Summary

On 28 July 2014 at about 14:53 local time, a Meyer LEGACY registered N29MM was involved in an accident near Lolo Pass, Idaho, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

28 July 2014 at 14:53

Classification

Accident

Location

Lolo Pass, Idaho, United States

Coordinates

43.6496, -116.4305

Aircraft

Meyer LEGACY

Registration

N29MM

Category

Airplane

Year built

2009

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Richland → Baker

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR14FA316

1 person died.

The fatigue fracture of an engine connecting rod, which resulted in a catastrophic engine failure and a forced landing in unsuitable terrain.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The commercial pilot was conducting a personal cross-country flight in an amateur-built, experimental airplane when he transmitted a distress call. Two pilots in other aircraft near the accident airplane's location relayed the pilot's "mayday" call to air traffic control and he was subsequently heard stating that he had low engine oil pressure and that oil was covering the windshield while he was flying over wooded mountainous terrain. The pilot attempted a forced landing, but the airplane struck trees and then impacted the terrain. Postaccident examination of the engine revealed a hole in the top of the engine case near the No. 2 cylinder. An engine teardown revealed that the Nos. 1 and 2 cylinder connecting rods had fractured. The examination of the fracture surfaces determined that the No. 1 connecting rod fracture was initiated by a fatigue crack and was the catalyst for the engine failure. In addition, partial surface decarburization and surface corrosion pits were observed around the surface of the connecting rod shaft. It is likely that the decarburization and corrosion pits decreased the connecting rod's surface hardness, served as fatigue initiation sites, and led to the premature failure of the No. 1 connecting rod. Although some fatigue cracks were observed on the No. 2 connecting rod, most of the facture surfaces exhibited overstress failure; therefore, the No. 2 connecting rod likely failed after the No. 1 connecting rod fractured. Although the cause of the decarburization was not determined based on the available evidence, it typically results from a manufacturing deficiency. Toxicology testing of the pilot detected metoprolol and rosuvastatin in his tissue samples, and he had a history of high blood pressure and cholesterol; however, it is unlikely that the pilot's medical conditions or the medications he was using to treat them impaired his ability to safely operate the airplane.

Quoted verbatim from the NTSB record.