Hammond - Atlanta

The twin-engine airplane, flown by a commercial pilot, was departing on a business flight from runway 31 when the right engine lost power. According to a pilot-rated witness, the airplane was about halfway down the 6,500 ft runway at an altitude of about 100 ft above ground level when he heard a "loud pop" and then saw the airplane's right propeller slow. The witness reported that the airplane yawed to the right and then began a right turn toward runway 18 with the right engine's propeller windmilling. The witness further reported that the airplane cleared a tree line by about 150 ft, rolled right, descended straight down to ground impact, and burst into flames. Postaccident examination of the airplane's right engine revealed that the crankshaft was fractured adjacent to the No. 2 main bearing, which had rotated. The crankcase halves adjacent to the No. 2 main bearing were fretted where the case through-studs were located. The fretting of the mating surfaces was consistent with insufficient clamping force due to insufficient torque of the through-stud nuts. Records indicated that all six cylinders on the right engine had been replaced at the airplane's most recent annual inspection 8 months before the accident. In order to replace the cylinders, the through-stud nuts had to be removed as they also served to hold down the cylinders. It is likely that when the cylinders were replaced, the through-stud nuts were not properly torqued, which, over time, allowed the case halves to move and led to the bearing spinning and the crankshaft fracturing. During the accident sequence, the pilot made a right turn in an attempt to return to the airport and did not feather the failed (right) engine's propeller, allowing it to windmill, thereby creating excessive drag. It is likely that the pilot allowed the airspeed to decay below the minimum required for the airplane to remain controllable, which combined with his failure to feather the failed engine's propeller and the turn in the direction of the failed engine resulted in a loss of airplane control.

Flight / Schedule

Hammond - Atlanta

Registration

N33FA

MSN

421B-0502

Year of Manufacture

1973

Operator

Aero One

Date

October 14, 2015 at 03:48 PM

Type

CRASH

Flight Type

Executive/Corporate/Business

Flight Phase

Takeoff (climb)

Crash Site

Airport (less than 10 km from airport)

Crash Location

Hammond-Northshore Louisiana

Region

North America • United States of America

Coordinates

30.5230°, -90.4151°

Crash Cause

Human factor

Narrative Report

On October 14, 2015 at 03:48 PM, Hammond - Atlanta experienced a crash involving Cessna 421B Golden Eagle II, operated by Aero One, with the event recorded near Hammond-Northshore Louisiana.

The flight was categorized as executive/corporate/business and the reported phase was takeoff (climb) at a airport (less than 10 km from airport) crash site.

2 people were known to be on board, 2 fatalities were recorded, 0 survivors were identified or estimated. This corresponds to an estimated fatality rate of 100.0%.

Crew on board: 1, crew fatalities: 1, passengers on board: 1, passenger fatalities: 1, other fatalities: 0.

The listed crash cause is human factor. The twin-engine airplane, flown by a commercial pilot, was departing on a business flight from runway 31 when the right engine lost power. According to a pilot-rated witness, the airplane was about halfway down the 6,500 ft runway at an altitude of about 100 ft above ground level when he heard a "loud pop" and then saw the airplane's right propeller slow. The witness reported that the airplane yawed to the right and then began a right turn toward runway 18 with the right engine's propeller windmilling. The witness further reported that the airplane cleared a tree line by about 150 ft, rolled right, descended straight down to ground impact, and burst into flames. Postaccident examination of the airplane's right engine revealed that the crankshaft was fractured adjacent to the No. 2 main bearing, which had rotated. The crankcase halves adjacent to the No. 2 main bearing were fretted where the case through-studs were located. The fretting of the mating surfaces was consistent with insufficient clamping force due to insufficient torque of the through-stud nuts. Records indicated that all six cylinders on the right engine had been replaced at the airplane's most recent annual inspection 8 months before the accident. In order to replace the cylinders, the through-stud nuts had to be removed as they also served to hold down the cylinders. It is likely that when the cylinders were replaced, the through-stud nuts were not properly torqued, which, over time, allowed the case halves to move and led to the bearing spinning and the crankshaft fracturing. During the accident sequence, the pilot made a right turn in an attempt to return to the airport and did not feather the failed (right) engine's propeller, allowing it to windmill, thereby creating excessive drag. It is likely that the pilot allowed the airspeed to decay below the minimum required for the airplane to remain controllable, which combined with his failure to feather the failed engine's propeller and the turn in the direction of the failed engine resulted in a loss of airplane control.

Aircraft reference details include registration N33FA, MSN 421B-0502, year of manufacture 1973.

Geospatial coordinates for this crash are approximately 30.5230°, -90.4151°.

Fatalities

Total

2

Crew

1

Passengers

1

Other

0

Crash Summary

The twin-engine airplane, flown by a commercial pilot, was departing on a business flight from runway 31 when the right engine lost power. According to a pilot-rated witness, the airplane was about halfway down the 6,500 ft runway at an altitude of about 100 ft above ground level when he heard a "loud pop" and then saw the airplane's right propeller slow. The witness reported that the airplane yawed to the right and then began a right turn toward runway 18 with the right engine's propeller windmilling. The witness further reported that the airplane cleared a tree line by about 150 ft, rolled right, descended straight down to ground impact, and burst into flames. Postaccident examination of the airplane's right engine revealed that the crankshaft was fractured adjacent to the No. 2 main bearing, which had rotated. The crankcase halves adjacent to the No. 2 main bearing were fretted where the case through-studs were located. The fretting of the mating surfaces was consistent with insufficient clamping force due to insufficient torque of the through-stud nuts. Records indicated that all six cylinders on the right engine had been replaced at the airplane's most recent annual inspection 8 months before the accident. In order to replace the cylinders, the through-stud nuts had to be removed as they also served to hold down the cylinders. It is likely that when the cylinders were replaced, the through-stud nuts were not properly torqued, which, over time, allowed the case halves to move and led to the bearing spinning and the crankshaft fracturing. During the accident sequence, the pilot made a right turn in an attempt to return to the airport and did not feather the failed (right) engine's propeller, allowing it to windmill, thereby creating excessive drag. It is likely that the pilot allowed the airspeed to decay below the minimum required for the airplane to remain controllable, which combined with his failure to feather the failed engine's propeller and the turn in the direction of the failed engine resulted in a loss of airplane control.

Cause: Human factor

Occupants & Outcome

Crew On Board

1

Passengers On Board

1

Estimated Survivors

0

Fatality Rate

100.0%

Known people on board: 2

Operational Details

Schedule / Flight

Hammond - Atlanta

Operator

Aero One

Flight Type

Executive/Corporate/Business

Flight Phase

Takeoff (climb)

Crash Site

Airport (less than 10 km from airport)

Region / Country

North America • United States of America

Aircraft Details

Registration

N33FA

MSN

421B-0502

Year of Manufacture

1973