Aero Commander 680FL accident near Helena, Montana, June 17, 1998
On June 17, 1998, a Aero Commander 680FL, registered N446JR, was destroyed in an accident near Helena, Montana (Helena Regional Airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 1 person was killed. The weather was instrument conditions (cloud, fog or low visibility).
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The NTSB's probable cause their words, unchanged
The pilot's failure to maintain the correct altitude while turning inbound during a procedure turn to the ILS final approach course. Factors include hilly/mountainous terrain and clouds in the area where the course reversal was performed.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 17, 1998
- Place
- Helena, Montana · Helena Regional Airport · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Aero Commander 680FL · all 680FLs on the register
- Registration
- N446JR · registry record · serial 1325-10
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The pilot of the Part 135 cargo flight was executing the 'full' ILS runway 27 approach at Helena Regional Airport in a non-radar environment. Although the approach calls for the pilot to maintain 7,000 feet until intercepting the glideslope, the aircraft impacted the terrain at 5,300 about 1.5 miles prior to reaching the point where the pilot should have crossed the Hauser NDB at an altitude of 6,741 feet. According to the approach plate, the aircraft should not have descended to an altitude below 5,400 feet until reaching the outer marker, which is located about five and one-half miles west of the impact site.
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: multi-engine land; single-engine land; instrument: airplane
- Flight time: 1,506 hours in all; 344 in this make and model; 199 in the last 90 days; 54 in the last 30 days; 1,480 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 17,972 hours
- Last inspection: approved inspection programme, May 7, 1998; 85 hours since
- Maximum gross weight: 8,500 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming IO-720-B1B (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: FCA Kallispell MT at 11:05 pm
- Destination: HLN Helena MT
- Flight plan: IFR
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 290° at 76 knots
- Visibility: 6 statute miles
- Sky: broken clouds at 2,600 ft; not recorded
- Temperature: 48°F (9°C), dew point 46°F (8°C)
- Altimeter: 29.00 inHg
- Observation at 11:56 pm from KHL, 10 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number SEA98FA100.