MIA07LA140

NTSB accident investigation · Cessna 208B · Cross City, FL · September 5, 2007

Accident · No injuriesLimited investigationFinal report
Date
September 5, 2007, 05:33 local (09:33 UTC)
Place
Cross City, FL
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N702PACessna 208B
Weather
Visual (VMC) · Night
Status
Completed · report May 6, 2009
Report
Approved by Office Director
Parties
Cessna, Pratt & Whitney of Canada, Paragon, FSDO/FAA, TSB of Canada
FAA report
20070905022629A
Case key
66579

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

A total loss of engine power during cruise flight due to the fracture and separation of the compressor turbine blades for undetermined reasons. Contributing to the accident was the unsuitable terrain for a forced landing.

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.

Loss of engine power(total) - mech failure/malfCruise
Reason for occurrence undetermined
Compressor assembly,blade - separation
Forced landingEmergency descent/landing
In flight collision with objectEmergency landing
Object - tree(s)

Analysis

The pilot stated that he was on a repositioning flight to Tampa, Florida. He was cruising at 11,000 feet msl when, with no warning or spool down time, the engine failed. The engine indications instantly went to zero. The pilot declared an emergency to the air traffic controller and was advised that the nearest airport was 29 miles away. He maneuvered the airplane toward the airport and went through the engine failure procedures. The attempts to restart the engine were unsuccessful. The pilot configured the airplane for best glide speed. After gliding for 22 miles, the airplane's altitude was about 300 feet msl. The pilot slowed the airplane to just above stall speed before impacting small pine trees pulling back on the yoke and stalling the airplane into the trees. The engine was examined at Pratt and Whitney of Canada, with Transportation Safety Board of Canada oversight. The engine compressor turbine blades were fractured at varying heights from the roots to approximately half of the span. Materials analysis determined the blade fractures to display impact damage and overheating. The primary cause of the blade fractures could not be determined. There were no other pre-impact anomalies or operational dysfunction observed to any of the engine components examined. Impact damage to the blade airfoils precluded determination of the original fracture mechanism.

Factual narrative

On September 5, 2007, about 0533 eastern daylight time, a Cessna 208 B, N702PA, registered to and operated by Paragon Air Express, Inc, as a Title 14 Code of Federal Regulations Part 91 positioning flight, impacted trees during a forced landing following loss of engine power, near Cross City, Florida. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed. The commercial rated pilot was not injured and the airplane incurred substantial damage. The flight originated from the Mobile Downtown Airport (BFM), Mobile, Alabama, earlier that day, about 0430.

The pilot stated he was on a repositioning flight to Tampa, Florida. He was cruising at 11,000 feet msl when, with no warning or spool down time, the engine failed. The engine indications instantly went to zero. The pilot declared an emergency to the air traffic controller and was advised that the nearest airport was Cross City Airport (CTY), Cross City, Florida, 29 miles away. He maneuvered the airplane toward the airport and went through the engine failure procedures. The attempts to restart the engine were unsuccessful. The pilot configured the airplane for best glide speed. After gliding for 22 miles, the airplane's altitude was about 300 feet msl. The pilot slowed the airplane to just above stall speed before impacting small pine trees pulling back on the yoke and stalling the airplane into the trees. He was able to exit the airplane without assistance. The airplane came to rest eight miles east of the CTY.

A review of Pratt &Whitney of Canada (P&WC) record's determined the engine was overhauled by Pratt & Whitney Engine Services (PWES), Bridgeport, WV on August 1, 2001. New compressor turbine blades were installed at that time. The engine's maintenance records indicated at 5,451 total hours a hot section inspection was completed on June 18, 2005 by PWES Atlanta, GA. On February 2, 2007, at 6,964 total hours, the power section was removed due to a light propeller strike and replaced with a rental unit. The original power section was repaired and reinstalled at 7,165 total hours, completed on March 27, 2007. The maintenance was performed by PWES, Addison, TX. At the time of the accident the engine's Gas Generator section had accumulated 7,507 total hours and the Power section had accumulated 7,279 total hours.

The operator was granted by the FAA, a time between overhaul extension to 4,600 hours in 2005 and was operating on an approved engine condition trend monitoring (ECTM) program in accordance with P&WC Service Bulletin 1703. The aircraft was not equipped with an automated engine parameter data recording system. Review of the ECTM data following the last hot section inspection revealed no deviations dictating a need for maintenance action.

The engine was examined at Pratt and Whitney of Canada, with Transportation Safety Board of Canada oversight. The engine compressor turbine blades were fractured at varying heights from the roots to approximately half of the span. Materials analysis determined the blade fractures to display impact damage and overheating. The primary cause of the blade fractures could not be determined. The blades' microstructure indicated that the blades had been exposed to excessive temperatures. The compressor turbine guide vane ring and all adjacent and downstream components displayed extensive mechanical damage due to contact with the separated compressor turbine blade debris. There were no other pre-impact anomalies or operational dysfunction observed to any of the engine components examined.

Aircraft

Registration
N702PA
Reported as
Cessna 208B
Category
Airplane
Serial number
208B0702
Airframe hours
7,844
Engine
Pratt and Whitney of Canada PT6A-114A, 675 horsepower, turbo prop
Damage
Substantial damage
Flight
Positioning · Part 91
Operator
Paragon Air Express, Inc
Registered owner
Paragon Air Express, Inc
Airworthiness certificate
Standard, Normal; Standard, Utility
Last inspection
Continuous airworthiness · August 16, 2007 · 53 hours before
Departed
BFM · Mobile, AL
Destination
TPA · Tampa, FL
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
44
Injuries
Minor
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
May 7, 2007
Seat
Left
Flight hours
11,732 total · 5,470 in this make and model · 180 in the last 90 days · 60 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night
Wind
60° at 4 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
81 °F, dew point 61 °F
Altimeter
29.95 inHg
Observed at
CTY, 8 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.