NTSB Factual Report

On June 7, 2007 at approximately 1645 eastern daylight time, a Piper PA-34-200, N15156, sustained substantial damage during a forced landing following an in-flight propeller separation near New Smyrna Beach Municipal Airport (EVB), New Smyrna Beach, Florida. The 14 Code of Federal Regulations Part 91 instructional flight departed Daytona Beach International Airport (DAB), Daytona Beach, Florida, at approximately 1545 for a local instructional flight. The certified flight instructor (CFI) was not injured. The student pilot and one passenger received minor injuries. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed.

The CFI reported that they were about to practice an engine failure during cruise flight at 6,000 feet mean sea level (msl). Upon shutting off fuel with the right fuel selector valve, a propeller blade separated from the right engine, and an unknown part penetrated the windshield. The CFI reported that the right engine "came almost completely apart and off in a matter of two seconds." The right engine was canted and hanging down, and altitude could not be maintained. The CFI declared an emergency and attempted to fly to EVB, which was 4 - 6 miles away. The drag on the right engine dictated a descending right hand turn. Controlled flight was maintained by using full aileron, full rudder input, and retarded power on the left engine. The CFI maintained sufficient airspeed to maintain control during the descent, but he elected to do a forced landing to a field as a result of the loss of altitude. He reported that he lowered the landing gear at 1,000 to 1,500 feet above ground level (agl), and brought the power to idle during the flare with the airspeed about 100 mph. The airplane impacted the side of a creek during the forced landing, and ended right side up in about three feet of water in the creek about 1/2 mile from EVB. The crew immediately departed the airplane and made their way to shore.

The Lycoming LIO-360-C1E6 engine was shipped to Textron Lycoming for an engine teardown inspection. The engine logbook indicated that the last engine overhaul had been accomplished on November 1, 1996, and had accumulated approximately 5,405 hour since the last overhaul. The manufacturer's recommended time between overhaul (TBO) was 2,000 hours time in service since new or previous overhaul. The engine disassembly inspection revealed no pre-impact abnormalities or mechanical malfunctions. However, most of the counterweight bushings were worn out of limits, but the counterweight bushings exhibited no signs of failure.

The Hartzell two bladed propeller hub and other components from the propeller assembly model HC-CYR-2CLGUF, serial number AU1465E, were sent to the National Transportation Safety Board's (NTSB) Materials Laboratory for examination. The propeller logbook indicated the propeller was overhauled on May 21, 2001, but the accumulated time in service since the overhaul was not determined from the maintenance records. The hub from the right engine of the airplane was a left hand rotating (counterclockwise viewed from the rear) propeller. The hub design was the same for either right or left hand rotating propellers. The locations of the grease fittings indicated that the hub was manufactured prior to 1983 when the location of the grease fitting was moved. The chamfer at the inside edge of the fitting hole indicated that the hub had been modified per applicable service bulletin HC-SB-61-213 and subsequent overhaul manual (Manual 202A) revisions.

The inspection revealed that the hub was fractured around the socket for blade #1 (designated by serial number location) through both the forward and aft halves of the hub. The fractures intersected the grease fitting holes in both the forward and aft hub halves. The examination of the fracture surface revealed a smoother faceted region on the forward half adjacent to the forward side of the grease fitting hole. The faceted region was lighter in color than the remainder of the fracture and contained features consistent with fatigue crack progression generally away from the grease fitting hole. The entire fatigue region measured about 3.1 inches in length from the grease fitting hole to near the forward centerline of the blade socket.

On September 17, 2007, Hartzell Propeller Inc., issued an Alert Service Bulletin "HC-1SB-61-297 Propeller Hub Inspection." The bulletin stated in part:

(1) There was a recent blade separation event originating in the lubrication hole located on the shoulder of the hub blade socket installed in a "left-hand" rotating propeller.

(2) This Alert Service Bulletin introduces an initial and repetitive eddy current inspection of the area around the lubrication holes on "left-hand" rotating propellers on certain aircraft models.

NTSB Probable Cause

The propeller blade separation from the propeller hub due to a fatigue fracture of the hub while in cruise flight. A factor was the embankment.