Agusta A109A accident near Sioux Falls, South Dakota, April 9, 1988
On April 9, 1988 at about 5:15 pm local time, a Agusta A109A (helicopter), registered N33SV, was substantially damaged in an accident near Sioux Falls, South Dakota (Joe Foss Field). It was a positioning flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. 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 November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 9, 1988 · about 5:15 pm local time · cases in 1988
- Place
- Sioux Falls, South Dakota · Joe Foss Field · cases near this airport
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Agusta A109A · all A109As on the register
- Registration
- N33SV · registry record · serial 7154
- Damage
- Substantial damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 13,615 hours in all; 120 in this make and model; 50 in the last 90 days; 13,150 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,303 hours
- Last inspection: annual inspection, July 20, 1987; 5 hours since
- Maximum gross weight: 9,800 lb
- Seats: 4
- Landing gear: retractable
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: 1SD9 Sioux Falls SD at 5:10 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 350° at 23 knots, gusting 35
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 46°F (8°C), dew point 25°F (-4°C)
- Altimeter: 30.00 inHg
- Observation at 12:38 pm from FSD
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 3 |
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 N33SV the same tail number, which may have belonged to a different aircraft at the time
Connections how this case links to the rest of the register
- N33SV on the register today · the tail number may have moved to another aircraft since
- Agusta A109 11 registered today · the model family and its accident history
- Agusta 12 aircraft on the register
- Engine: Allison 250-C20B 113 aircraft carry this series today · as the NTSB recorded it
- Joe Foss Field · nearest airport
- Sanford Usd Medical Center Heliport · departed from
- Accidents and incidents in South Dakota 469 since 1982 · 69 in the last ten years
- South Dakota 2,276 aircraft registered
- Other NTSB records under N33SV 1 records · the number may have belonged to another aircraft at the time
The whole map of how records connect · these connections as data: /graph/accident/DEN88LA094.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.