IAD02FA091 · Piper PA 32R-301T
Piper PA 32R-301T · Accident: total loss of engine power (mechanical failure) en route
From Teterboro Airport (TEB) to London International Airport (CYXU)
Event
- NTSB case
- IAD02FA091
- 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
- Accident
- 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
- 2 · 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 32R-301T
- Aircraft type
- Piper PA-32
- 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
- C-GKLY
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Teterboro Airport (TEB), TETERBORO, NJTo London International Airport (CYXU), London, Ontario
- 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)
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Engine assembly, other › Failure
- Manufacturer › Maintenance, replacement, not performed
- Manufacturer › Material defect(inadequate quality of material)
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airplane was in cruise flight at 3,500 feet mean sea level when the engine lost power. The pilot then performed a forced landing to trees. Examination of the Lycoming IO-540 series engine revealed that the zinc-plated crankshaft gear attachment bolt was fractured, and that the crankshaft no longer drove the gear. Fracture surface analysis revealed intergranular separation due to hydrogen-assisted cracking. Engines had previously been built with cadmium-plated bolts, but zinc-plated bolts were being used because they were readily available, and had a "positive impact" on production. Lycoming received 8,500 zinc-plated bolts between November 1996 and July 1998. Lycoming manufactured or re-built/overhauled 1,088 engines with zinc-plated bolts, and shipped 2,667 zinc-plated bolts as spares. Two zinc-plated gear bolt failures were documented in helicopter engines in 1998, due to hydrogen embrittlement. One bolt failed at 30 hours of operation, and the other at 19 hours. Lycoming and FAA personnel believed the failures occurred due to the higher loads generated by helicopters. Based upon the two failures, Lycoming removed the bolts from its stock as a "precautionary measure" in July 1998. Bolt recalls were issued by the helicopter manufacturer and Lycoming in July 1998. The FAA issued an Airworthiness Directive (AD) in February 1999 to replace the crankshaft bolts in affected helicopter engines worldwide. In July 1999, a Piper PA-32R-301 bolt failed due to hydrogen embrittlement at 327 hours. Between March 2000 and January 2001, two bolts failed on Royal Jordanian Falcon trainer airplanes, at 292 and 179 hours. As a "precautionary measure," Lycoming replaced the crankshaft gear bolts in the five-airplane Jordanian Falcon fleet about February 2001. Lycoming and FAA personnel believed the failures did not extend beyond helicopter and aerobatic applications, although the PA-32R-301 failure occurred in 1999. In June 2002, another bolt failed on a Piper PA-32R-301, at 448 hours. The engine was examined by Lycoming and FAA personnel, and a Lycoming laboratory report stated the failure was due to hydrogen embrittlement. In September 2002, this accident occurred, and as a result of the investigation, about 2 weeks after the accident, Lycoming issued a Service Bulletin (SB) to replace bolts on certain 540-series engines. In October 2002, the FAA issued an Emergency AD to also replace the bolts. The common cause for hydrogen embrittlement is a missed or under baked condition.
Probable cause
the improper manufacturing of the crankshaft gear bolt, which resulted in the failure of the bolt due to hydrogen embrittlement, and the subsequent loss of engine power. Also causal was the engine manufacturer's failure to remove the affected bolts from fixed wing engines during the 4-year period that transpired between the initial failures and removal of the bolts from stock for installation, until the accident flight. A factor in the accident was inadequate oversight (lack of action) by the FAA during the 4-year period in which the bolts remained in serviceable engines.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record IAD02FA091
- Event ID
- 20020923X05199
- Case number
- IAD02FA091
- 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. 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: c6fdc6a57d40a7e465b7a139ad0136ce6d4da315440eb17b4ca6139e8b2f67ed; retrieved 2026-09-20T19:52:40.066Z.