CHI07IA017 · Piper PA-24-250
Piper PA-24-250 · Incident: total loss of engine power (mechanical failure) en route
From Abraham Lincoln Capital Airport (SPI) to Joliet Regional Airport (JOT)
Event
- NTSB case
- CHI07IA017
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Piper PA-24-250
- Aircraft type
- Piper PA-24
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N6090P
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Abraham Lincoln Capital Airport (SPI), Springfield, ILTo Joliet Regional Airport (JOT), Joliet, IL
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Total loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Engine assembly, connecting rod bolt › Loose part/bolt/nut/clamp/etc
- Engine assembly, connecting rod › Fractured
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
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.
Probable cause
The loose connecting rod bolt due to a loss of torque and subsequent failure of the connecting rod during cruise flight.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI07IA017
- Event ID
- 20061106X01611
- Case number
- CHI07IA017
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates, damage. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 0cb65e11fc5f83fa163ef85bee93708cdc005fb5f22bc3954194a1127501056f; retrieved 2026-09-22T04:17:32.399Z.