Beechcraft A36 N517DJ

Summary

On 10 July 2013 at about 11:45 local time, a Beechcraft A36 registered N517DJ, operated by Dan Urquhart, was involved in an accident near Fallon, Nevada, United States. 4 people were on board and 4 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

10 July 2013 at 11:45

Classification

Accident

Location

Fallon, Nevada, United States

Nearest airport

Fallon Municipal Airport (FLX)

Coordinates

39.4992, -118.7489

Aircraft

Beechcraft A36

Registration

N517DJ

Category

Airplane

Engines

1

Operator

Dan Urquhart

Operating rule

Part 135: Air Taxi & Commuter

Phase of flight

Not recorded

Route

Fallon → Dixie Vally

Aircraft damage

Substantial

Weather

VMC

Light

Night

NTSB number

WPR13LA321

4 people had minor injuries.

A fatigue failure of the No. 5 connecting rod, which resulted in a catastrophic engine failure during the initial climb and a subsequent forced landing.

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

Read the full NTSB narrative

The pilot reported that, during climbout, when the airplane was about 1,000 ft above ground level, the engine lost power. The pilot subsequently maneuvered the airplane to attempt to land on the departure runway. The airplane touched down short of the runway in rough, desert terrain, which resulted in substantial damage to the wings, fuselage, and empennage. A postaccident engine examination revealed that the No. 5 connecting rod cap and one of its two bolts had fractured midlength; the opposite bolt was intact with the nut still fastened. Metallurgical examination revealed that the No. 5 connecting rod had failed due to a fatigue crack that had initiated on the outer surface of the nut-facing boss. The crack propagated inward until the final cross-section of the connecting rod yoke failed in overstress, which then catastrophically breeched the left side of the engine case. The fatigue crack did not show any material imperfections; however, the surface finish of the boss where the fatigue crack initiated was consistent with it having been shot peened. Although shot peening is performed to impart compressive stresses to prevent fatigue crack initiation, excessive peening times may sufficiently alter the surface to create stress concentrators. However, the configuration of the fractured rod yoke precluded any accurate surface roughness measurements and, therefore, it could not be determined if improper surface modification had occurred.

Quoted verbatim from the NTSB record.