MIA99LA195

NTSB accident investigation · Ryan ST3KR · Lake City, FL · July 10, 1999

Accident · No injuriesLimited investigationFinal report
Date
July 10, 1999, 13:30 local (17:30 UTC)
Place
Lake City, FL
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N47306Ryan ST3KR
Weather
Visual (VMC) · Day
Status
Completed · report June 21, 2000
Report
Approved by Office Director
FAA report
19990710008849A
Case key
46814

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

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Probable cause

the improper maintenance and inspection of the propeller system, which resulted in loose and improperly torqued bolts, causing the subsequent failure of a propeller blade.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionCruise
Maintenance,annual inspection - improperOther maintenance personnelCause
Propeller system/accessories - loose part/bolt/nut/clamp/etcCause
Propeller system/accessories,blade - failure,totalCause
Forced landingEmergency descent/landing

Analysis

While at a cruise altitude of 2,500 feet msl the pilot reported that the airplane started to vibrate. He attempted to shut down the engine with no response. He elected to land at a nearby airport, and landed without incident. Examination of the airplane revealed that the propeller came loose from the flange. All of the propeller bolts were found backed out, and none of the bolts were safety wired. The pilot had just purchased the airplane. Examination of the airplane after the accident revealed that several inches of the leading edge of one blade of the propeller was missing. One of two propeller blades split in half from the center to the tip, the propeller bolts were found loose, and all evenly backed out approximately one quarter inch. No locking device or safety wires were attached to the bolt heads. The data sheet does not list the propeller for installation on this aircraft. There were no log book entries found to indicate that the propeller bolts were torqued or tracked on installation or at annual inspection.

Factual narrative

On July 10, 1999, about 1330 eastern standard time, a Ryan ST3KR, N47306, registered to an individual, received substantial damage during cruise flight, and made a forced landing at the Lake City Airport, Lake City, Florida. The airline transport-rated pilot reported no injuries. Visual meteorological conditions (VMC) prevailed in the vicinity, and no flight plan had been filed. The personal flight was being conducted in accordance with Title 14 CFR Part 91. The flight had originated at Albany, Georgia, at 1300.

At a cruise altitude of 2,500 feet msl, and about 7 to 8 miles north of Lake City, the pilot reported that the airplane started to vibrate. He attempted to shut down the engine with no response. The only response he could get was to the throttle. He elected to land at Lake City, and landed without incident. Examination of the airplane revealed that the propeller came loose from the flange. All of the propeller bolts were found backed out, and none of the bolts were safety wired. The pilot had just purchased the airplane.

According to the FAA inspector's statement, when he examined the airplane after the accident he observed, "...several inches of the leading edge of one blade of the propeller missing...broken across [the] grain and glue lines." The inspector found the propeller loose in the hub, the bolt heads and holes in the hub were, "...very worn like it has been loose for a while with power." There were no logbook entries found to indicate that the propeller bolts were torqued or tracked on installation or at annual inspection.

The FAA inspector stated the following findings, "...one of 2 propeller blades split in half from the center to the tip...the propeller bolts for [the] propeller were found loose at the hub, [and] all evenly backed out approximately one quarter inch...no locking device or safety wire were attached to the bolt heads." The data sheet does not list the propeller for installation on this aircraft.

Aircraft

Registration
N47306
Reported as
Ryan ST3KR
Category
Airplane
Serial number
1358
Airframe hours
2,847
Engine
Kinner R-56, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Gary V. Snodgrass
Airworthiness certificate
Standard, Normal
Last inspection
Annual · May 31, 1999
Departed
ABY · Albany, GA
Destination
GNV · Gainsville, FL
Airport
LRQ · Lake City, runway 28, 6,000 × 150 ft, concrete

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
58
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--w/ waivers/lim
Seat
Rear
Flight hours
30,000 total · 12 in this make and model · 240 in the last 90 days · 80 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
310° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
90 °F, dew point 72 °F
Altimeter
30.00 inHg
Observed at
GNV, 45 nm away

FAA reports on this event · 1

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