# NTSB CHI08LA160: Piper PA-44-180, N159WM, Battle Creek, MI, June 8, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 8, 2008, 13:15 local (17:15 UTC) - Place: Battle Creek, MI - Coordinates: 42.311943, -85.25222 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.3119&lon=-85.2522&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 24, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration, Hartzell Propeller, Piper - NTSB case key (mKey): 68220 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08LA160 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68220/pdf - Page: https://openairdocs.org/ntsb/CHI08LA160 ## Probable cause The in-flight separation of the tip of a propeller blade due to metal fatigue that resulted from an inadequate inspection and repair. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Propeller system: propeller blade section](https://openairdocs.org/ntsb-findings/01046111): Aircraft › Aircraft propeller/rotor · Fatigue/wear/corrosion (probable cause); cases with it: [Piper PA-44-180, 1 case](https://openairdocs.org/ntsb-findings/01046111/cases.md?model=7104402), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/01046111/cases.md) - [Propeller system: propeller blade section](https://openairdocs.org/ntsb-findings/01046111): Aircraft › Aircraft propeller/rotor · Failure (probable cause); cases with it: [Piper PA-44-180, 1 case](https://openairdocs.org/ntsb-findings/01046111/cases.md?model=7104402), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/01046111/cases.md) - [Maintenance: repair](https://openairdocs.org/ntsb-findings/02062015): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Piper PA-44-180, 1 case](https://openairdocs.org/ntsb-findings/02062015/cases.md?model=7104402), [All aircraft, 99 cases](https://openairdocs.org/ntsb-findings/02062015/cases.md) - [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [Piper PA-44-180, 8 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md?model=7104402), [All aircraft, 440 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Piper PA-44-180, 4 cases](https://openairdocs.org/ntsb-events/040/sequence.md?model=7104402), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Piper PA-44-180, 2 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=7104402), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) ## Analysis The twin-engine airplane sustained substantial damage due to a separated propeller blade tip impacting the airplane's nose during cruise. The tip separation exhibited signs of fatigue failure. Witness marks consistent with tool file marks made during a leading edge repair were found at the area of the origin of fatigue. According to maintenance information published by the propeller manufacturer, a 10x magnifying glass should be used to examine repairs to ensure damage, file marks, and any course surface finish are removed prior to returning the propeller back to service.. The airplane accumulated a total time of 1,997 hours. ## Factual narrative On June 8, 2008, at 1315 eastern daylight time, a Piper PA-44-180, N159WM, sustained substantial damage due to a separated propeller blade tip impacting the airplane's nose during cruise near Battle Creek, Michigan. The airplane landed without further incident at the W K Kellogg Airport (BTL), near Battle Creek, Michigan. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 instructional flight was not operating on a flight plan. The certified flight instructor (CFI) and the commercial pilot receiving dual instruction were uninjured. The local flight originated from BTL about 1230. The flight was returning to BTL at the time of the accident. CFI's report, in part, stated: A large BANG was heard and felt 8 to 10 miles south east of the airport. At that point we scanned the gauges and saw no sign of problems. When we looked out the windscreen; however we saw a large depression in the nose section of the aircraft. Initially we thought we had ... a bird strike. N159WM was a 2002, Piper PA-44-180, which was a twin engine, four seat airplane with serial number 4496159. The airplane was powered by two Lycoming engines. Each engine drove its own Hartzell propeller. The propeller blade was a model FJC7666A-2R that was installed in a model HC-C2YR-2CLEUF hub assembly. The serial number of the blade with the tip separation was J73543. The airplane accumulated a total time of 1,997 hours. The outboard section of the remaining propeller blade was cut away and sent to the National Transportation Safety Board's Materials Laboratory. A Senior Materials Engineer examined the propeller section and produced Materials Laboratory Factual Report number 08-097. The report referred to repair data from the propeller manufacturer's website indicating that a 10x magnifying glass should be used to examine repairs to ensure damage, file marks, and any course surface finish are removed prior to returning the propeller back to service. The laboratory report, in part, stated: Fatigue features emanated from a fatigue origin area located at the leading edge near the flat side of the blade ... . ... Angled file marks consistent with a leading edge repair were observed between the leading edge and the flat side of the blade ... . ## Aircraft - Registration: [N159WM](https://openairdocs.org/aircraft/N159WM), registered now, S/N 4496159, built 2002 (OpenAirDocs) - Reported make and model: Piper PA-44-180 - Registry model: [Piper PA-44-180](https://openairdocs.org/model/piper-pa-44-180) (registry code 7104402) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 4496159 - Airframe hours: 1997 - Engines: Lycoming LO-360-A1H6 180 horsepower reciprocating; Lycoming O-360-A1H6 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Western Michigan University - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, May 1, 2008, 47 hours before - Departed: BTL, Battle Creek, MI - Airport: BTL, W K Kellogg ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 26; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review February 1, 2007; seat: right; flight hours: 650 total, 200 in this make and model, 580 as pilot in command, 114 in the last 90 days, 24 in the last 30 days, 1 in the last 24 hours - Student pilot; age 26; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review February 1, 2007; seat: left ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 15 knots, gusting 22 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 72 °F - Altimeter: 29.88 inHg - Observed at: BTL, 10 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20080608838749A](https://openairdocs.org/incident/20080608838749A), Jun 8, 2008: Piper PA44180, Battle Creek, MI, Substantial damage. (-23)Pilot and CFI heard a loud bang, saw the damage on the nose, thought they hit a bird and felt a large vibration. All engine instruments were normal, the… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.