19961006031079A

Accident · Substantial damage

FAA accident report · Bell 47G-5 · Nunda, SD · October 6, 1996

Date: October 6, 1996 · 08:00 local
Place: Nunda, SD
Phase of flight: Autorot Descent (Rotorcraft)
Operating rules: Agricultural (Part 137)
Damage: Substantial damage
Aircraft: N7925J
NTSB investigation: NTSBCHI97LA004
Reported as: Bell 47G5
Reported engine: Lycoming VO435*
People aboard: 1
Fatal injuries: 0
Pilot’s flight hours: 2,600 total1,100 in this make and model320 in the last 90 days

N7925JRegistered now · Bell 47G-5S/N 25041 · Built 1971 Airframe modelBell 47G-5 Engine modelLycoming VO-435 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.

Aircraft engine failed during aerial application and aircraft crashed in the field. (-23) no narrative. (.4) during the second agricultural load, a total loss of engine power occurred, and the pilot made an autorotative landing, but the helicopter was damaged during the occurrence. Examination of the engine revealed failure of six bolts that attached the accessory drive gear to the crankshaft. Further examination of the attachment bolts revealed that fatigue cracking had occurred. There was evidence that inadequate pre-load torque had been applied to the assembly. The engine had approximately 400 hours since its last overhaul.

As the FAA filed it

AIRCRAFT ENGINE FAILED DURING AERIAL APPLICATION AND AIRCRAFT CRASHED IN THE FIELD. (-23) NO NARRATIVE. (.4) DURING THE SECOND AGRICULTURAL LOAD, A TOTAL LOSS OF ENGINE POWER OCCURRED, AND THE PILOT MADE AN AUTOROTATIVE LANDING, BUT THE HELICOPTER WAS DAMAGED DURING THE OCCURRENCE. EXAMINATION OF THE ENGINE REVEALED FAILURE OF SIX BOLTS THAT ATTACHED THE ACCESSORY DRIVE GEAR TO THE CRANKSHAFT. FURTHER EXAMINATION OF THE ATTACHMENT BOLTS REVEALED THAT FATIGUE CRACKING HAD OCCURRED. THERE WAS EVIDENCE THAT INADEQUATE PRE-LOAD TORQUE HAD BEEN APPLIED TO THE ASSEMBLY. THE ENGINE HAD APPROXIMATELY 400 HOURS SINCE ITS LAST OVERHAUL.

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 CHI97LA004Accident · No injuriesLimited investigationFinal reportNunda, SDfailure of maintenance personnel to properly torque the six accessory drive bolts, which resulted in fatigue failure of the undertorqued bolts.Oct 6, 1996 · Substantial damage

Other reports on N7925J · 2

Matched to the same aircraft by N-number and date.

Accident 20030715015279ALow Level Operations · Cleveland, MN(-23) On July 15, 2003, at 0735 central standard time, a Bell, BHT-47-G5, owned and operated by scott churchill, struck two powerlines while spraying herbicide (24D) in an area approximately 1.5 miles south of Cleveland, MN. VFR conditions prevailed and no…Jul 15, 2003 · Destroyed Accident 19921207056359AAerial Taxi, Other Helicopter · Belle Grade, FLDuring aerial taxi to reposition ag helicopter in ramp tail struck ramp. Lost control impacted in a spin.Dec 7, 1992 · Substantial damage