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CHI87FA015

1986-11-04 · BECKER, Minnesota, United States · Fatal · 1 aircraft · Status: Completed

N4247S has since been reassigned. It is now registered to a different aircraft (AVIONS MUDRY ET CIE CAP 10B, built 1982), which was not involved in this event.

Aircraft involved

Factual narrative

THE HELICOPTER (HEL) WAS BEING USED ON AN EXTERNAL LOAD OPN TO PSN A 2500 LB VENTILATOR TO THE ROOF OF A BLDG. ON THE NEXT TO LAST LOAD, THE PLT RADIOED THAT HE NOTED A MOMENTARY ILLUMINATION OF THE FUEL BYPASS ADVISORY LIGHT. HE ELECTED TO CONT THE OPN & RETURNED TO THE STAGING AREA TO PICK UP THE 2500 LB LOAD. WHEN THE LOAD WAS APRX 8' FM THE ROOF TOP, WITNESSES NOTED THE LOAD (& HEL) BGN TO SETTLE. THE PLT RLSD THE LOAD AS THE ROTOR RPM BGN DECREASING & MNVRD AWAY FM THE ROOF. THE HEL HOVERED MOMENTARILY OVR AN ELEVATED CONVEYOR, THEN THERE WAS AN ADNL LOSS OF RPM. AS THE HEL DSCNDD, THE MAIN & TAIL ROTORS HIT THE CONVEYOR & THE HEL FELL APRX 150' & CRASHED IN A NOSE DOWN ATTITUDE. THE FWD FUEL BLADDERSPLIT OPEN DRG IMPACT. THE AFT FUEL BLADDER CONTAINED A USABLE, BUT UNDETERMINED, AMOUNT OF FUEL. DIRT WAS FND IN THE FUEL BLADDERS & FUEL FILTERS, BUT NO FUEL BLOCKAGE WAS NOTED. FUEL X-FEED SELECTOR & VLV WERE FND IN THE OPEN PSN. THE FLT MANUAL LIMITS THE USE OF X-FEED FOR EMERGENCY & CRUISE FLT ONLY; BOOST PUMP MUST BE ON WHEN UNUSED TANK IS EMPTY. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1986_CHI87FA015.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.