You can contribute by submitting additional or updated information.
| Date: | Tuesday 4 November 1986 |
| Time: | 16:45 |
| Type: |  Sikorsky S-58ET |
| Owner/operator: | North American Helicopter Service |
| Registration: | N4247S |
| MSN: | 58-1493 |
| Total airframe hrs: | 4136 hours |
| Engine model: | P&W PT6T-6 |
| Fatalities: | Fatalities: 1 / Occupants: 1 |
| Other fatalities: | 0 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Becker, MN -
 United States of America
|
| Phase: | Manoeuvring (airshow, firefighting, ag.ops.) |
| Nature: | External load operation |
| Departure airport: | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
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 over 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 forward 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. CAUSE:
Ex German Air Force H-34G-III 80+51
Accident investigation:
 |
|
Sources:
NTSB: https://www.ntsb.gov/ntsb/brief.asp?ev_id=20001213X35123
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 24-Oct-2008 10:30 | ASN archive | Added |
| 20-Jul-2010 11:47 | TB | Updated [Operator, Other fatalities, Nature, Damage, Narrative, ] |
| 21-Dec-2016 19:23 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency, ] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2025 Flight Safety Foundation