Amateur-built 107 accident near Cascade, Idaho, October 14, 1982
On October 14, 1982 at about 8:18 pm local time, a amateur-built 107 (helicopter), registered N6676D, was destroyed in an accident near Cascade, Idaho. It was a flight of an unrecorded kind under external-load helicopter rules (Part 133). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 14, 1982 · about 8:18 pm local time
- Place
- Cascade, Idaho · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built 107
- Registration
- N6676D · registry record · serial 6
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
DURING A LOG SLINGING OPERATION A LOUD BANG WAS HEARD & THE ACFT WAS OBSERVED TO RAPIDLY DESCEND VERTICALLY TO THE GROUND WITH NUMEROUS SMALL FRAGMENTS FALLING IN THE SAME VICINITY. THE #5 SYNCHRONIZATION SHAFT WAS FOUND TO BE FRACTURED AT THE FORWARD END ABOUT 9 INCHES AFT OF THE CONNECTION ASSY TO THE #4 SHAFT. THIS RESULTED IN AN OUT OF SYNCHRONIZATION CONDITION BETWEEN THE FORWARD & AFT ROTOR BLADES AS WELL AS A LOSS OF POWER TO THE FORWARD ROTOR. A FATIGUE FRACTURE ORIGINATED IN THE AFT MOST RING OF RIVET HOLES. THE FATIGUE CRACKS PROPOGATED FROM MULTIPLE ORIGINS WITHIN THOSE RIVET HOLES WHERE A "STEP" WAS FOUND AT THE BASE OF THE HOLE & CLOSEST TO THE INSIDE DIAMETER OF THE SHAFT.ALL RIVET HOLES IN THE FORWARD END OF THE SHAFT HAD TOPOGRAPHIC FEATURES SIMILAR TO THOSE PRODUCED IN A STEEL PLATE BY DELIBERATELY DRILLING HOLES WITHOUT COMPLETE PENETRATIONS.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: rotorcraft: helicopter
- Flight time: 6,800 hours in all; 4,300 in this make and model; 303 in the last 90 days; 80 in the last 30 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Airframe total time: 2,343 hours
- Last inspection: inspection type not recorded; 5 hours since
- Maximum gross weight: 22,000 lb
- Seats: 3
- Landing gear: fixed
- Engine: Ge CT-58-140 (turboshaft); 0 hours total
- Operator: Columbia Helicopters, INC.
The flight
- Departed from: Cascade ID at 2:15 pm
- Destination: Cascade ID
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 30 statute miles
- Sky: not recorded; clear
- Temperature: 156°F (69°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.