ERA09IA331

NTSB incident investigation · Cirrus Design SR22 · Elkin, NC · June 9, 2009

Incident · No injuriesIncident investigationFinal report
Date
June 8, 2009, 20:15 local (Jun 9, 2009, 00:15 UTC)
Place
Elkin, NC
Injuries
1 uninjured
Damage
Minor damage
Phase of flight
Enroute
Aircraft
N34TGCirrus Design SR22
Defining event
Enroute-cruise: Powerplant sys/comp malf/fail
Weather
Visual (VMC) · Dusk
Status
Completed · report May 6, 2010
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
Cirrus Aircraft, FAA/FSDO, Teledyne Continental Motors
Case key
73988

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

On this page

Probable cause

The NTSB’s determination of the probable cause, and any contributing factors.

A total loss of engine power due to the failure of the No. 2 piston as a result of a fatigue crack of undetermined origin.

Findings · 1

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings.

Analysis

The pilot stated that he was at a cruise altitude of 6,000 feet mean sea level when he heard a loud bang. Oil began to flow over the windshield and the pilot decided to activate the Cirrus Airframe Parachute System. The airplane descended under the parachute into a cornfield. Examination of the engine revealed the No. 2 piston had failed. Metallurgical examination of the No. 2 piston showed it had failed due to a fatigue crack that originated adjacent to the piston pin in the pin boss area. The exact location of the fatigue crack and the cause of fatigue crack initiation could not be determined due to extensive damage in the area of origin. Damage to the other components submitted for examination likely occurred as a result of the failure of the piston once the fatigue crack reached a critical size. While the pin boss is an area under high stress and it is possible that operational factors, such as improper timing, could initiate a fatigue crack, the investigation could not determine the cause of the fatigue crack.

Factual narrative

The factual narrative558 words

On June 8, 2009, about 2015 eastern daylight time, a Cirrus SR22, N34TG, experienced an engine failure near Elkin, North Carolina. The certificated commercial pilot was not injured, and the airplane sustained minor damage. The personal flight was operated under the provisions of 14 Code of Federal Regulations (CFR) Part 91, and an instrument flight rules flight plan was filed. Visual meteorological conditions prevailed at the time of the event. The pilot stated that he was in cruise flight at an altitude of 6,000 feet mean sea level (msl), when he heard a loud bang followed by a violent vibration of the airplane. He said that prior to this event, all engine instruments were in the normal operating range. He contacted air traffic control and requested to be vectored to the nearest airport, Elkin Municipal Airport. The airplane continued to vibrate violently, oil began to flow over the windshield, and forward vision was lost. The pilot decided to activate the Cirrus Airframe Parachute System (CAPS) at an altitude of 6,000 feet msl, and the airplane descended under the parachute into a cornfield. The pilot, age 63, holds a commercial pilot certificate with ratings for airplane single-engine land and instrument airplane. His certificate was updated on March 30, 2007. The pilot's most recent Federal Aviation Administration (FAA) third-class medical certificate was issued on January 16, 2009, with limitations for lenses for near vision. The pilot reported 2,531 total flight hours, with 900 flight hours in the SR22. The four seat, low-wing, fixed gear airplane, serial number (S/N) 0386, was manufactured in 2002. It was powered by a Continental IO-550-N7, 310 horsepower engine and equipped with a Hartzell three-bladed propeller. Review of the aircraft logbook revealed that the most recent annual inspection was conducted on October 30, 2008, at an airplane total time of 876.4 hours. The current Hobbs time indicated 928.9 hours. Examination of the airplane by an FAA inspector revealed that the airplane descended through trees into a cornfield. The airframe and flight control system components revealed no evidence of preimpact mechanical malfunction. The examination of the engine revealed it had a 6-inch diameter hole at the top rear of the engine case, below the right magneto. The right magneto was broken away from its mount. Fragments of the No. 2 piston were located externally on the engine case. Examination of the oil quantity revealed that the engine still had 4 quarts of engine oil remaining in the sump. The engine was removed by Precision Air Incorporated and sent to Teledyne Continental Motors to be examined under NTSB oversight. During the examination of the engine; fragments of the No. 2 piston, rings, and pin boss were found throughout the engine case and oiling system. All of these fragments were collected, and the remainder of the piston assembly was removed for further examination. The fragments, along with the No. 2 piston assembly were sentto the NTSB Materials Laboratory for examination. The metallurgical examination revealed that the No. 2 piston failed due to a fatigue crack that originated adjacent to the pin in the pin boss area. The exact location of the fatigue crack and the cause of fatigue crack initiation could not be determined due to extensive damage in the area of origin. During the examination of the engine, no other valve train abnormalities were noted within the engine.

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident.

Aircraft

Registration
N34TG
Reported as
Cirrus Design SR22
Category
Airplane
Serial number
0386
Airframe hours
928
Engine
Cont Motor IO-550 SERIES, 300 horsepower, reciprocating
Damage
Minor damage
Flight
Personal · Part 91
Operator
Obi-1 At Pensacola Inc
Registered owner
Obi-1 At Pensacola Inc
Airworthiness certificate
Standard, Normal
Last inspection
Annual · October 30, 2008 · 52 hours before
Departed
47N · Manville, NJ
Destination
SPA · Spartanburg, SC
Flight plan
IFR

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
63
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Seat
Left
Flight hours
2,531 total · 900 in this make and model · 2,500 as pilot in command · 50 in the last 90 days · 10 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Dusk
Wind
10° at 6 knots
Visibility
7 statute miles
Temperature
73 °F, dew point 66 °F
Altimeter
30.00 inHg
Observed at
UKF, 15 nm away

Docket · 19

The files NTSB released with the investigation on February 23, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 7.7 MB in all.