# NTSB ERA12LA267: Piper PA-28R-200, N961JD, Eastover, SC, April 3, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 3, 2012, 14:00 local (18:00 UTC) - Place: Eastover, SC - Coordinates: 33.917778, -80.800277 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.9178&lon=-80.8003&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report October 9, 2014 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 83288 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA12LA267 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83288/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83288 - Page: https://openairdocs.org/ntsb/ERA12LA267 ## Probable cause Inadequate or loss of through bolt preload tension, which resulted in fretting between the engine halves, the subsequent failure of one cylinder through bolt, the loosening of additional cylinder retaining studs, and the fracture of the crankcase. Contributing to the accident was the wake turbulence of a departing military jet, which resulted in the pilot’s inability to completely align the airplane with the runway. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Piper PA-28R-200, 8 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=7102811), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Turbulence: wake turbulence](https://openairdocs.org/ntsb-findings/03032025): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Piper PA-28R-200, 2 cases](https://openairdocs.org/ntsb-findings/03032025/cases.md?model=7102811), [All aircraft, 47 cases](https://openairdocs.org/ntsb-findings/03032025/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible; cases with it: [Piper PA-28R-200, 12 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=7102811), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Action](https://openairdocs.org/ntsb-findings/02041000): Personnel issues › Action/decision · Pilot; cases with it: [Piper PA-28R-200, 1 case](https://openairdocs.org/ntsb-findings/02041000/cases.md?model=7102811), [All aircraft, 111 cases](https://openairdocs.org/ntsb-findings/02041000/cases.md) - [Maintenance: repair](https://openairdocs.org/ntsb-findings/02062015): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Piper PA-28R-200, 1 case](https://openairdocs.org/ntsb-findings/02062015/cases.md?model=7102811), [All aircraft, 99 cases](https://openairdocs.org/ntsb-findings/02062015/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-28R-200, 7 cases](https://openairdocs.org/ntsb-events/040/sequence.md?model=7102811), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Piper PA-28R-200, 9 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=7102811), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Piper PA-28R-200, 30 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7102811), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Aircraft wake turb encounter](https://openairdocs.org/ntsb-events/361); cases with it: [Piper PA-28R-200, 2 cases](https://openairdocs.org/ntsb-events/361/sequence.md?model=7102811), [All aircraft, 37 cases](https://openairdocs.org/ntsb-events/361/sequence.md) - [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Piper PA-28R-200, 21 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=7102811), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The pilot reported that, about 25 minutes into the second flight of the day, the engine began to run roughly. The pilot checked the magnetos and noted that all four cylinder head temperatures and all four exhaust gas temperatures were normal. He reduced engine power to 20 inches and 2,000 rpm, but the engine roughness increased, and the oil pressure dropped to 0 about 1 minute later. The pilot then completed a forced landing to a nearby National Guard base, but he could not completely align the airplane to the runway after it encountered the wake turbulence of a military jet departing in the opposite direction. The airplane landed at a 20- to 30-degree angle to the runway, veered off the right side, and struck a "runway remaining" sign before coming to a stop. After deplaning, the pilot saw engine oil covering the airplane's nose landing gear and the landing gear doors. Subsequent engine examination revealed that the No. 1 cylinder upper aft through bolt was sheared off, that the two No. 1 cylinder upper mounting studs had pulled loose from the crankcase, and that the crankcase at the No. 1 cylinder aft lower through bolt was cracked and separated; oil was leaking near it. Internal engine examinations revealed pitting and a frosty appearance of the metal on the Nos. 2 and 3 upper main bearing support webs consistent with fretting, which is typically a result of inadequate or loss of preload tension to fasteners. According to maintenance records, the engine underwent a major overhaul in 2002. In 2007, after about 490 hours of operation, a hairline crack was found in the engine case. The engine was disassembled and then reassembled with a rebuilt case. In 2010, after about 303 hours of operation, intake pipes were found loose on the Nos. 1 and 2 cylinders, and one exhaust nut was missing from the No. 1 cylinder. Five cylinder hold-down studs were also found broken on the No. 2 cylinder. The missing nut was replaced on the No. 1 cylinder, and the intake pipes were resealed. The No. 2 cylinder was removed, the studs were replaced, and the No. 2 cylinder was then reinstalled. It could not be determined when the fretting began due to the multiple opportunities during which the through bolt preload tension could have been affected. However, by the time of the accident, the fretting had progressed sufficiently that it likely resulted in excessive loads to the fractured through bolt, loosened the cylinder studs, and subsequently twisted the cylinder, which then fractured the crankcase. ## Factual narrative On April 3, 2012, about 1400 eastern daylight time, a Piper PA-28R-200, N961JD, was substantially damaged during a forced landing at McEntire Joint National Guard Base (MMT), Eastover, South Carolina. The private pilot and the passenger were not injured. Visual meteorological conditions prevailed. The airplane was not operating on a flight plan, from Barnwell Regional Airport (BNL), Barnwell, South Carolina, to Tappahannock-Essex County Airport (XSA), Tappahannock, Virginia. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, the previous evening, he added one quart of oil to the engine, and in the morning, prior to a first flight from Lakeland Linder Regional Airport (LAL), Lakeland, Florida, to BNL, he conducted a "complete" preflight inspection. After arriving at BNL, and subsequent to refueling, the pilot completed another "walk-around" inspection. The flight departed BNL about 1330, and approximately 25 minutes later, the [Lycoming IO-360-C1C] engine began to run rough. The pilot checked the magnetos, and noted that all four cylinder head temperatures and all four exhaust gas temperatures were normal. The pilot reduced power to 20 inches and 2,000 rpm, but engine roughness increased, and oil pressure dropped to 0 in about 1 minute. The pilot planned to divert to Columbia Metropolitan Airport (CAE), Columbia, South Carolina; however, the airplane had descended to 1,500 feet when he saw MMT, and he decided to divert to runway 32. Because of the rapidity at which the forced landing scenario developed, the pilot did not have time to change to the tower frequency, and as he approached the runway, he saw an F-16 take off from runway 14. After another F-16 took off from runway 14, the accident airplane was caught in its wake turbulence and rolled about 45 degrees. As the airplane continued to descend, through about 100 feet agl, the pilot was able to recover it to wings level but did not have sufficient altitude to properly align with the runway. He landed the airplane at a 20- to 30-degree angle to the runway, and it veered off the right side. To avoid a terrain drop-off, the pilot then aligned the airplane parallel to the runway but it struck a "runway remaining" sign about 50 mph before coming to a stop. After deplaning, the pilot observed engine oil covering the nose landing gear and the landing gear doors. According to the responding Federal Aviation Administration (FAA) inspector, subsequent examination of the engine revealed that the #1 cylinder, upper aft through bolt was sheared off, that two #1 cylinder upper mounting studs had pulled loose from the crankcase, and that the crankcase at the #1 cylinder aft lower through bolt was cracked, with an oil leak in that vicinity. The engine halves and through bolts were later examined at Lycoming Engines. Examination of the engine case halves confirmed that the cylinder #1 upper aft through bolt was broken. Internally, thecrankcase halves exhibited pitting and a frosty appearance of the metal on the #2 and #3 upper main bearing support webs, consistent with fretting. According to FAA 8083-30, fretting occurs when "when two mating surfaces, normally at rest with respect to one another, are subject to slight relative motion. It is characterized by pitting of the surfaces and the generation of considerable quantities of finely divided debris. Since the restricted movements of the two surfaces prevent the debris from escaping very easily, an extremely localized abrasion occurs." According to maintenance records, at airplane tachometer time 2,958, the engine underwent a major overhaul by Zephyr Aircraft Enginesthat was signed off on July 29, 2002. The overhaul included an engine crankcase overhauled by CSI, Incorporated. On January 9, 2007, at tachometer time 3,448, a hairline crack was found in the crankcase. The engine was disassembled by Zephyr and reassembled with a rebuilt crankcase supplied by CSI. On September12, 2010, about tachometer time 3,751, after the airplane arrived at Lubbock Preston Smith International Airport (LBB), Lubbock, Texas, Lubbock Aero found that one intake pipe was loose on cylinder #1, one on cylinder #2, and one exhaust nut was missing from cylinder #1. Five cylinder hold down studs were also found broken on cylinder #2. The missing nut was replaced on cylinder #1, and the intake pipes were resealed. Cylinder #2 was removed, the studs were replaced, and cylinder #2 was reinstalled followed by a successful engine run. In the June 2014 issue of Sport Aviation, the author of the "Savvy Aviator" column noted that, according to a veteran mechanic/expert witness, "who specializes in research on fastener torque and engine assembly practices,…the root cause of spun bearings, thrown rods, and separated cylinders is simply, 'a failure to achieve sufficient preload in the assembled fasteners.'" The author further noted that, "preload is the technical term for the clamping force created by tightening a fastener (typically athreaded bolt or stud) that holds assembled parts together. Having sufficient preload is the key to a strong and reliable bolted joint that will not loosen, break, or shift under the load. In order for a bolted joint to be stable under cyclic repetitive stress, the preload on the fasteners must be greater than the maximum stress that is trying to pull the joint apart. If this condition is met, the joint will not separate and the fasteners won't 'feel' the repetitive stress cycles. But if it isn't, the joint will shift under load and the fasteners will ultimately fail from repetitive stress fatigue." The author also noted that the expert identified five "obstacles to achieving proper fastener preload" during cylinder installation on an engine already mounted on an airplane: 1) The fasteners are not new. 2) The fasteners may not be adequately lubricated. 3) The lubricant is of poor quality. 4) Wrench access is limited. 5)Manufacturer instructions are incomplete. The complete article can be found in the public docket for this accident. ## Aircraft - Registration: [N961JD](https://openairdocs.org/deregistered/N961JD-2014-09-22), registration cancelled 2014-09-22, S/N 28R-7435075, built 1973 (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) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28R-7435075 - Year built: 1973 - Airframe hours: 3856 - Engines: LYCOMING I0360 SER 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 15, 2011, 53 hours before - Departed: BNL, Barnewell, SC - Destination: XSA, Tappahannock, VA - Airport: MMT, Mc Entire Jngb, runway 32, 9,010 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; seat: left; flight hours: 2,312 total, 2,017 in this make and model, 2,185 as pilot in command, 13 in the last 90 days, 6 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 75 °F, dew point 63 °F - Altimeter: 29.97 inHg - Observed at: MMT ## 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 20120403005639A](https://openairdocs.org/incident/20120403005639A), Apr 3, 2012: Piper PA-28R-200, Eastover, SC, Substantial damage. On April 3, 2012, at about 14:02 eastern standard time, a Piper (PA28R-200) aircraft, N461JD operating as 14 CFR part 91 made an emergency landing at Mc Entire… ## Docket (7 files) The files NTSB released with the investigation on August 25, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83288. 8.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 553 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40415641&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statement to FAA (item 2, .PDF, 378 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40415642&FileExtension=.PDF&FileName=Pilot%20Statement%20to%20FAA-Redacted.PDF - FAA Inspector Statement (item 3, .PDF, 36 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40415643&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF - Lycoming Mishap Report, Excerpt (item 4, .PDF, 236 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40415644&FileExtension=.PDF&FileName=Lycoming%20Mishap%20Report,%20Excerpt-Master.PDF - Engine Logs (item 5, .PDF, 5.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40415645&FileExtension=.PDF&FileName=Engine%20Logs-Redacted.PDF - Preload Article (item 6, .PDF, 660 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40415646&FileExtension=.PDF&FileName=Preload%20Article-Master.PDF - Photo 1 - Engine (item 7, .PDF, 961 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40415647&FileExtension=.PDF&FileName=Photo%201%20-%20Engine-Master.PDF 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.