Amateur-built SD3-60 incident near Madison, Wisconsin, June 3, 1988
On June 3, 1988 at about 11:25 pm local time, a amateur-built SD3-60, registered N383MQ, was involved in an incident near Madison, Wisconsin. It was a flight of an unrecorded kind under scheduled airline rules (Part 121). No one was hurt; 21 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FAILURE OF THE RIGHT OUTBOARD FLAP POSITION SIGNALLING CABLE DUE TO CHAFFING INITIATED BY IMPROPER INSTALLATION/RIGGING BY A MANUFACTURER'S VENDOR.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 3, 1988 · about 11:25 pm local time
- Place
- Madison, Wisconsin · map
- Type
- Incident
- Injuries
- No one was hurt; 21 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built SD3-60
- Registration
- N383MQ · registry record · serial SH3706
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
WHILE ON A STABILIZED FINAL APPROACH, THE PILOT EXPERIENCED AN UNCOMMANDED RIGHT ROLL WHEN THE FLAP SETTING WAS INCREASED FROM FIVE TO FIFTEEN DEGREES. THE CONDITION WAS ALLEVIATED WHEN THE FLAPS WERE RESET TO FIVE DEGREES. POST FLIGHT INSPECTION REVEALED THAT THE RIGHT OUTBOARD FLAP POSITION SIGNALLING CABLE HAD FAILED. INSPECTION OF THE OPERATOR'S FLEET FOUND TWO ADDITIONAL AIRCRAFT WITH CHAFFED/FRAYED FLAP POSITION SIGNALLING CABLES. ALL CHAFFED/FRAYED CABLES WERE INSTALLED ON AIRCRAFT WHICH THE OPERATOR HAD PURCHASED AS A SERIES. ON THIS SERIES OF AIRCRAFT THE FLAPS AND CONTROL RIGGING WERE INSTALLED BY THE VENDOR WHICH MANUFACTURES THE WINGS, RATHER THAN THE MANUFACTURER OF THE AIRFRAME, AS IS NORMALLY THE CASE.
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, private
- Ratings: single-engine land; rotorcraft: helicopter
- Medical certificate: Class 1
- Seat: left
The aircraft
- Airframe total time: 3,413 hours
- Last inspection: continuous airworthiness programme, May 26, 1988; 50 hours since
- Maximum gross weight: 27,453 lb
- Seats: 39
- Landing gear: retractable
- Engine: P&W PT6A-65AR (turboprop); 0 hours total
- Operator: Simmons Airlines
The flight
- Departed from: ORD Chicago IL at 10:40 pm
- Destination: MSN Madison WI
- Flight plan: IFR
- Runway 36, 9,000 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 010° at 8 knots
- Visibility: 10 statute miles
- Sky: scat at 24,000 ft
- Temperature: 73°F (23°C), dew point 37°F (3°C)
- Altimeter: 30.00 inHg
- Observation at 11:00 pm from MSN, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 3 | |||
| Passengers | 18 |
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.