What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Sightseeing at 2000 ft 2000 RPM engine got very rough. Made emergency landing without incident in private strip in Vaughn, WA. 6" of 1 blade tip of prop missing. (.4) while in cruise at 2,000 feet altitude and 2,000 RPM there was a sudden loud noise and vibration. The pilot reduced power and executed an emergency landing. Post-landing examination of the aircraft revealed that approximately six inches of one propeller blade had separated from the propeller. The sensenich corporation, fixed pitch, aluminum propeller, model 76EM8S5-0-60, was submitted to the safety board's materials laboratory, Washington, DC, for further metallurgical examination. The examination revealed a flat, chordwise fracture area that contained crack arrest positions and radial marks typical of fatigue cracking. Microscopy revealed that the origin area was located within a notch at the leading edge at the flat side of the blade. The depth of the notch was about 0.008 inch. The leading edge of the blade contained sanding marks, typical of a blend repair, in the vicinity of the notch. The sanding marks did not extend into the deepest part of the notc h, directly adjacent to the fracture surface at the origin area. FAA advisory circular 43.13-1A, section 3 'repair of metal propellers,' paragraph 585(a) discusses procedures applied to the repair of aluminum propellers. Specifically, this reference addresses rounding out of nicks, scars, cuts, etc. By advising '...exercise care to remove the deepest point of the injury.' The total time on the propeller was unavailable and the party who executed the propeller dressing procedure was not known.
As the FAA filed it
(-23) SIGHTSEEING AT 2000 FT 2000 RPM ENGINE GOT VERY ROUGH. MADE EMERGENCY LANDING WITHOUT INCIDENT IN PRIVATE STRIP IN VAUGHN, WA. 6" OF 1 BLADE TIP OF PROP MISSING. (.4) WHILE IN CRUISE AT 2,000 FEET ALTITUDE AND 2,000 RPM THERE WAS A SUDDEN LOUD NOISE AND VIBRATION. THE PILOT REDUCED POWER AND EXECUTED AN EMERGENCY LANDING. POST-LANDING EXAMINATION OF THE AIRCRAFT REVEALED THAT APPROXIMATELY SIX INCHES OF ONE PROPELLER BLADE HAD SEPARATED FROM THE PROPELLER. THE SENSENICH CORPORATION, FIXED PITCH, ALUMINUM PROPELLER, MODEL 76EM8S5-0-60, WAS SUBMITTED TO THE SAFETY BOARD'S MATERIALS LABORATORY, WASHINGTON, DC, FOR FURTHER METALLURGICAL EXAMINATION. THE EXAMINATION REVEALED A FLAT, CHORDWISE FRACTURE AREA THAT CONTAINED CRACK ARREST POSITIONS AND RADIAL MARKS TYPICAL OF FATIGUE CRACKING. MICROSCOPY REVEALED THAT THE ORIGIN AREA WAS LOCATED WITHIN A NOTCH AT THE LEADING EDGE AT THE FLAT SIDE OF THE BLADE. THE DEPTH OF THE NOTCH WAS ABOUT 0.008 INCH. THE LEADING EDGE OF THE BLADE CONTAINED SANDING MARKS, TYPICAL OF A BLEND REPAIR, IN THE VICINITY OF THE NOTCH. THE SANDING MARKS DID NOT EXTEND INTO THE DEEPEST PART OF THE NOTC H, DIRECTLY ADJACENT TO THE FRACTURE SURFACE AT THE ORIGIN AREA. FAA ADVISORY CIRCULAR 43.13-1A, SECTION 3 'REPAIR OF METAL PROPELLERS,' PARAGRAPH 585(A) DISCUSSES PROCEDURES APPLIED TO THE REPAIR OF ALUMINUM PROPELLERS. SPECIFICALLY, THIS REFERENCE ADDRESSES ROUNDING OUT OF NICKS, SCARS, CUTS, ETC. BY ADVISING '...EXERCISE CARE TO REMOVE THE DEEPEST POINT OF THE INJURY.' THE TOTAL TIME ON THE PROPELLER WAS UNAVAILABLE AND THE PARTY WHO EXECUTED THE PROPELLER DRESSING PROCEDURE WAS NOT KNOWN.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.