20170706010589A

Accident · Substantial damage

FAA accident report · Bell 47D1 · Big Lake, MN · July 6, 2017

Date: July 6, 2017 · 16:50 local
Place: Big Lake, MN
Phase of flight: Takeoff: Departure Roll
Operating rules: Agricultural (Part 137)
Operator: 6SQG
Damage: Substantial damage
Aircraft: N153B
NTSB investigation: NTSBCEN17LA264
Reported as: Bell 47D1
Reported engine: Lycoming VO-435-A1F
People aboard: 1
Fatal injuries: 0
Other injuries: 0
Pilot’s certificate: Airline transport
Pilot’s flight hours: 16,300 total20 in this make and model20 in the last 90 days

N153BRegistered now · Bell 47D1S/N 7 · Built 1947 Airframe modelBell 47D1 Engine modelFranklin 6V4 seriesReciprocating

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

The pilot was performing agriculture spray operations and had just completed a refill operation of pestidices. After increasing engine RPM to 3,100 RPM and started to add collective, pilot felt a sudden pull and heard loud snap. When he looked around to determine what happened, he saw that the loading truck had significant damage. The pilot stated that he realized the engine was still running and shut it off. The pilot departed the aircraft with no injuries. The rotor mast had departed the aircraft and was found to the 8'OCLOCK position.

As the FAA filed it

THE PILOT WAS PERFORMING AGRICULTURE SPRAY OPERATIONS AND HAD JUST COMPLETED A REFILL OPERATION OF PESTIDICES. AFTER INCREASING ENGINE RPM TO 3,100 RPM AND STARTED TO ADD COLLECTIVE, PILOT FELT A SUDDEN PULL AND HEARD LOUD SNAP. WHEN HE LOOKED AROUND TO DETERMINE WHAT HAPPENED, HE SAW THAT THE LOADING TRUCK HAD SIGNIFICANT DAMAGE. THE PILOT STATED THAT HE REALIZED THE ENGINE WAS STILL RUNNING AND SHUT IT OFF. THE PILOT DEPARTED THE AIRCRAFT WITH NO INJURIES. THE ROTOR MAST HAD DEPARTED THE AIRCRAFT AND WAS FOUND TO THE 8'OCLOCK POSITION.

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.

NTSB CEN17LA264Accident · No injuriesLimited investigationFinal reportBig Lake, MNThe failure of the metal core assembly within a wooden main rotor blade due to undetected corrosion and fatigue, which caused the wooden blade to separate from the rotor mast.Jul 6, 2017 · Substantial damage