Piper PA-24-250 N6090P

Summary

On 24 October 2006 at about 18:13 local time, a Piper PA-24-250 registered N6090P was involved in an incident near Sherman, Illinois, United States. One person was on board and nobody was injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

24 October 2006 at 18:13

Classification

Incident

Location

Sherman, Illinois, United States

Coordinates

40.4356, -90.0033

Aircraft

Piper PA-24-250

Registration

N6090P

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Springfield → Joliet

Aircraft damage

Not recorded

Weather

VMC

Light

Day

NTSB number

CHI07IA017

Nobody was injured.

The loose connecting rod bolt due to a loss of torque and subsequent failure of the connecting rod during cruise flight.

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

Read the full NTSB narrative

The pilot executed a forced landing when the airplane experienced a total loss of engine power during cruise flight. Examination of the engine crankshaft and attached rod components revealed that both nuts on the number three connecting rod were backed off from their original installed positions. One nut on the number four connecting rod had also backed off but had not failed. Bolt preload is related to installation torque but with many variables such as lubrication, thread deformities/variations, rough surfaces, and contamination. Torques tests showed a variance of 18-25 percent of torque values between the tightening and loosening of the nut. The breakaway torque values were within the range of the test values for properly torqued nuts; however due to the uncertainty of the readings no conclusion can be drawn as to the adequecy of the original installation torque. Also, no measurements were possible on the separated number three rod and the damaged number four nuts.

Quoted verbatim from the NTSB record.