Bell 206B accident near Englewood, Colorado, July 2, 1984
On July 2, 1984 at about 11:14 pm local time, a Bell 206B (helicopter), registered N3173L, was destroyed in an accident near Englewood, Colorado (Arapahoe County airport). It was a personal flight under general aviation rules (Part 91). 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
- July 2, 1984 · about 11:14 pm local time
- Place
- Englewood, Colorado · Arapahoe County · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206B · all 206Bs on the register
- Registration
- N3173L · registry record · serial 3677
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
WITNESSES STATED THE HELICOPTER ENTERED A 'HARD LEFT TURN' INTO A NEAR INVERTED POSITION BEFORE 'IT WENT DOWN HARD AND FAST.' INSPECTION DISCLOSED THE METAL CONNECTION FOR THE LEFT CYCLIC STICK WAS BROKEN IN HALF. (PLT WAS FLYING FROM LEFT SEAT.) EXAM OF THE CYCLIC STICK QUICK DISCONNECT LOCKING NUT REVEALED IT WAS HELD IN PLACE ON THE CONNECTOR BY 1 THREAD. PROPERLY INSTALLED, THE LOCKING NUT TIGHTENS DOWN OVER 6 THREADS ON THE CONNECTOR. WHEN BACKED OUT TO 1 THREAD, MOVEMENT OF THE CYCLIC WILL NOT NOT PRODUCE A CORRESPONDING CHANGE IN THE LATERAL CONTROL HYDRAULIC SERVOS. THE CYCLIC WAS LAST REMOVED APRX 80 HRS PRIOR TO THE ACCIDENT DURING MAINTENANCE. ON 7/17/84, BELL ISSUED OPERATIONS SAFETY NOTICE WHICH IN PART READ, 'FLIGHT CREWS ARE CAUTIONED TO ASSURE QUICK REMOVAL FLIGHT CONTROLS ARE PROPERLY INSTALLED PRIOR TO OPERATING THE HELICOPTER.' PRIOR TO THIS NOTICE, NO REQUIREMENTS EXISTED TO DO SO.
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: airline transport pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 5,000 hours in all; 101 in the last 90 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 2,770 hours
- Last inspection: annual inspection, September 20, 1983; 805 hours since
- Maximum gross weight: 3,200 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20J (turboshaft); 0 hours total
The flight
- Departed from: Englewood CO at 11:13 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 090° at 12 knots
- Visibility: 40 statute miles
- Sky: scat at 8,000 ft
- Temperature: 84°F (29°C), dew point 46°F (8°C)
- Altimeter: 30.00 inHg
- Observation at 11:25 pm from APA, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 |
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.
Other NTSB records under N3173L the same tail number, which may have belonged to a different aircraft at the time
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.