ERA15IA024

NTSB incident investigation · Cirrus Design SR22 · Lexington, NC · October 22, 2014

Incident · No injuriesIncident investigationFinal report
Date
October 22, 2014, 06:25 local (10:25 UTC)
Place
Lexington, NC
Injuries
1 uninjured
Damage
Minor damage
Phase of flight
Enroute
Aircraft
N242MBCirrus Design SR22
Defining event
Enroute-cruise: Loss of engine power (total)
Weather
Visual (VMC) · Dawn
Status
Completed · report April 26, 2016
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA, Continental Motors, Cirrus Aircraft
FAA report
20141022019719A
Case key
90288

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.

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Probable cause

Maintenance personnel's improper tightening of the crankcase through bolt nuts during reassembly of the engine at the last overhaul, which resulted in the failure of the crankshaft and the subsequent total loss of engine power.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Maintenance: installationPersonnel issues › Task performance · Maintenance personnelCirrus Design SR22: 5 casesAll aircraft: 371 casesProbable cause
Engine (reciprocating): recip eng cyl sectionAircraft › Aircraft power plant · Incorrect service/maintenanceCirrus Design SR22: 6 casesAll aircraft: 373 casesProbable cause
Engine (reciprocating)Aircraft › Aircraft power plant · FailureCirrus Design SR22: 6 casesAll aircraft: 497 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The commercial pilot was conducting a personal cross-country flight. The pilot reported that, while en route to his destination at a cruise altitude of about 5,000 ft mean sea level, the engine "failed." He flew the airplane toward an open field and deployed the ballistic recovery parachute. He subsequently conducted a successful landing in the field. An examination of the engine revealed that the crankshaft had fractured between the No. 2 main journal and the No. 2 connecting rod journal. An examination of the crankshaft revealed that the fracture was due to fatigue that had initiated from multiple origins at the fillet radius between the No. 2 main journal and the cheek at the aft end of the journal. The fatigue initiated from surface damage that occurred due to the No. 2 main bearing shifting. The bearing likely shifted due to the improper tightening of the crankcase through bolt nuts and subsequent insufficient clamping force of the crankcase saddle surfaces. A review of the airplane's maintenance records revealed that the engine was last overhauled 775 total flight hours before the accident, and no records were found indicating that the through bolts had been removed since that time. It is likely that maintenance personnel improperly tightened the crankcase through bolts during the overhaul.

Factual narrative

On October 22, 2014, at 0625 eastern daylight time, a Cirrus SR22, N242MB, registered to and operated by a private individual, deployed the Cirrus Airframe Parachute System (CAPS) following a total loss of engine power. The commercial pilot was not injured and the airplane sustained minor damage. Visual meteorological conditions prevailed for the personal flight conducted under Title 14 Code of Federal Regulations Part 91. The flight, operating under instrument flight rules, originated from Mc Gee Field Airport (24NC), Monroe, North Carolina, at 0600 central daylight time and was destined for Piedmont Triad International Airport (GSO), Greensboro, North Carolina. According to the pilot, while enroute to his destination, at a cruise altitude of 5,000 feet msl he contacted GSO approach and opened his flight plan. Shortly thereafter the engine "failed"; the pilot flew the airplane towards an open field and deployed the CAPS system. The airplane made a successful landing in the field. Examination of the engine revealed that the crankshaft had fractured between the number two main journal and the number two connecting rod journal. The number two bearing displayed bearing shift signatures and had completely extruded from the bearing support. The number one, two, three, and the number four bearing supports displayed fretting near the through bolt holes. There was no evidence of an oil starvation or lack of lubrication. Examination of the oil pump revealed that the drive gear was intact. The oil pump cavity contained light scratches. The oil pump gear teeth were intact and did not exhibited any anomalies. The oil pressure relief valve seat contained some metallic debris and the relief valve plate displayed signs of peened imprints around the seat area circumference. The oil filter was removed from the engine and the oil filter housing was cut open and the filter element was removed from the canister for examination. The oil filter element contained flakes and slivers from the damaged internal engine components. The oil sump drain plug was removed and the oil was drained from the sump; the amount was measured to be 8 quarts. The oil was dark in color and contained metallic debris. The oil sump was removed and sections of bearing were found in the sump along with metallic slivers and shavings. The oil pickup tube was bent and the screen was intact; metallic debris was noted on the screen. A review of maintenance records revealed that the Continental IO-550N7 engine was rebuilt by Teledyne Continental Motors on August 22, 2011. The engine accumulated 775 hours since factory rebuild and there is no record or evidence of the cylinders being removed since rebuild. The engine accumulated 200 hours since the last annual inspection dated November 8, 2013. Further review of records revealed that a 50 hour engine oil change was performed 69 hours prior to the accident on September 29, 2014. The crankshaft was removed sent to the NTSB materials laboratory forfracture analysis. An examination of the crankshaft revealed that the fracture was due to fatigue that initiated from multiple origins at the fillet radius between the second main journal and the cheek at the aft end of the journal.

Aircraft

Registration
N242MB
Reported as
Cirrus Design SR22
Category
Airplane
Serial number
0911
Built
2004
Airframe hours
2,512
Engine
Cont Motor IO-550 SERIES, 315 horsepower, reciprocating
Damage
Minor damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · November 8, 2013 · 200 hours before
Departed
24NC · Monroe, NC
Destination
GSO · Greensboro, NC
Flight plan
IFR
Equipment
Electronic multifunction display, Auto-pilot, Data recorder, Airframe parachute, Stall warning system, Onboard weather

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
47
Injuries
None
Certificate
Private
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 3, Without waivers/limitations
Last flight review
January 23, 2014
Seat
Left
Restraint
4-point
Flight hours
3,354 total · 1,650 in this make and model · 3,254 as pilot in command · 59 in the last 90 days · 16 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Dawn
Wind
310° at 4 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
41 °F, dew point 37 °F
Altimeter
29.97 inHg
Observed at
GSO, 30 nm away

Docket · 9

The files NTSB released with the investigation on March 10, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 18.3 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.