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 October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 9, 1988 · about 5:15 pm local time
- Place
- Sioux Falls, South Dakota · Joe Foss Field
- 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
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.