# NTSB NYC97LA046: Piper PA-28R-200, N57010, Thorndale, PA, January 18, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 18, 1997, 11:45 local (16:45 UTC) - Place: Thorndale, PA - Coordinates: 39.999977, -75.760566 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.0000&lon=-75.7606&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 10, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 39321 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC97LA046 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39321/pdf - Page: https://openairdocs.org/ntsb/NYC97LA046 ## Probable cause Inadequate overhaul of the crankshaft that failed to detect fatigue cracks, which resulted in a total loss of engine power when the crankshaft separated in two. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - normal - engine assembly,crankshaft - fatigue (cause) - maintenance,overhaul - inadequate, other maintenance personnel (cause) - engine assembly,crankshaft - failure,total - Forced landing, emergency descent/landing - In flight collision with object, emergency descent/landing - object - utility pole ## Analysis The pilot reported that during cruise flight the engine started to run rough followed by a total loss of engine power. The pilot performed a forced landing during which the airplane collided with a utility pole. Examination of the engine revealed that the crankshaft was separated in two with an additional crack. Review of the maintenance records revealed that the crankshaft was overhauled by Engine Components, Inc., San Antonio, Texas. During the first magnetic particle inspection, the crankshaft was considered for rejection due to heat cracks in the area of the number 3 main journal. The main and rod journals were then ground and renitrided. The crankshaft then had two additional magnetic particle inspections and was returned to service. Examination of the crankshaft revealed that preexisting fatigue cracks propagated at least 75 percent of the crank cheek wall. The accident occurred about 9 flight hours after the crankshaft inspections which were conducted in December, 1996. ## Factual narrative On January 18, 1997, about 1145 eastern standard time, a Piper PA-28R-200, N57010, was substantially damaged when it collided with a utility pole during a forced landing, near Thorndale, Pennsylvania. The certificated airline transport pilot and private pilot were not injured. Visual meteorological conditions prevailed for the local flight that departed the Chester County G.O. Carlson Airport, Coatesville, Pennsylvania. No flight plan was filed for the instructional flight conducted under 14 CFR Part 91. In a written statement submitted by the airline transport pilot, a certificated flight instructor, he stated the following: "This started as a high performance checkout. After some stalls and slow flight and VOR tracking, engine started to run rough. Switched [fuel] tanks, alternate air and check and switched magnetos. Pointed airplane toward [Coatesville] upon which the engine seized. . . ." On February 25, 1997, the engine was examined at the manufacturer, Textron Lycoming, Williamsport, Pennsylvania under the supervision of the NTSB investigator. The engine model was an IO-360-C1C. During the examination, the engine was unable to be rotated by hand. The engine was then disassembled for further examination. During the disassembly, it was revealed that the crankshaft was separated in two just aft of the number 2 cylinder connecting rod. Another crack was observed just forward of the number 1 cylinder connecting rod. On April 18, 1997, the crankshaft was examined at the NTSB office of research and engineering material laboratory division, Washington, District of Columbia. The following are excerpts from the metallurgist's factual report: "This crankshaft separated through the number 3 crank cheek intersecting the forward radius of the number 3 main journal and the aft radius of the number 2 rod journal. . . .Stereo microscope examination of [the aft] fracture revealed ratchet marks indicative of multiple fracture origins that emanated from the surface of the forward radius of the number 3 main journal. . . .Clam shell marks typical of a fatigue crack progressed away from the ratchet marks. . . .This fatigue crack propagated at least 75% of the crank cheek wall. The area outside the fatigue region contained features typical of overstress separation as well as isolated areas with mechanical damage." "In December 11, 1996, the crankshaft was overhauled by Engine Components, Inc. (ECI), San Antonio, Texas. According to the travel card for this overhaul, an initial magnetic particle inspection method found heat cracking [in] the front fillet radius of the number 3 main journal and there was a remark entered indicating possibility for rejection. The main and rod journals were then ground 0.010 inch undersize and renitrided. During the NTSB metallurgical examination a representative from ECI was contacted by phone to clarify additional information made on the work card. This representative indicated that the crankshaft passed 2 additional magnetic particle inspections on December 3, 1996 after the grinding process and on December 11, 1996 after the renitride process. The engine log book indicated that at about the same time period as the crankshaft overhaul, ECI repaired excessive fretting damage in the middle main bearing saddle of the crankcase." According to the NTSB form 6120.1/2, the airplane had accumulated about 9 hours of flight time since the overhaul of the crankshaft. ## Aircraft - Registration: [N57010](https://openairdocs.org/deregistered/N57010-1997-05-28), registration cancelled 1997-05-28, S/N 28R7435072 (OpenAirDocs) - Reported make and model: Piper PA-28R-200 - Registry model: [Piper PA-28R-200](https://openairdocs.org/model/piper-pa-28r-200) (registry code 7102811) (OpenAirDocs) - Category: Airplane - Serial number: 28R-7435072 - Airframe hours: 6975 - Engines: Lycoming IO-360-C1C 200 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Chester County Aviation - Airworthiness certificate: Standard, Utility - Last inspection: Annual, December 31, 1996, 9 hours before - Departed: 40N, COATESVILLE, PA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 12,000 total, 500 in this make and model, 11,800 as pilot in command, 400 in the last 90 days, 100 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 18 knots - Visibility: 30 statute miles - Lowest ceiling: 20,000 ft broken - Temperature: 14 °F, dew point 10 °F - Altimeter: 29.00 inHg - Observed at: LNS, 22 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 19970118000619A](https://openairdocs.org/incident/19970118000619A), Jan 18, 1997: Piper PA28R200, Thorndale, PA, Substantial damage. Aircraft made emergency landing on a road after engine quit, struck a pole on landing. 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.