Piper PA-32R-301T incident near Alton, Illinois, August 15, 2007
On August 15, 2007 at about 11:00 am local time, a Piper PA-32R-301T, registered N3120T, suffered minor damage in an incident near Alton, Illinois (St. Louis Regional Airport). It was a business flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The component manufacturer's inadequate fabrication of the transient voltage suppressor.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 15, 2007 · about 11:00 am local time
- Place
- Alton, Illinois · St. Louis Regional Airport · map
- Type
- Incident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-32R-301T · all PA-32R-301Ts on the register
- Registration
- N3120T · registry record · serial 3257417
- Damage
- Minor damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
After the pilot initiated a descent, smoke began to emanate from under the left side of the instrument panel of the Piper PA-32R-301T. The primary flight display (PFD) then "blanked out" and the 10-amp PFD circuit breaker opened. The pilot declared an emergency, diverted to the closest airport, and landed uneventfully. The airplane had accrued 526 total hours of operation. Examination revealed a Transient Voltage Suppressor (TVS) had failed. The following month, the National Transportation Safety Board was advised of another TVS failure on an airplane that had accrued 132.5 total hours of operation. Research conducted by Safety Board investigators indicated that failures of the same part number TVS were occurring on multiple makes and models of airplanes, some of which had only approximately 20 total hours of operation. Review of manufacturer-supplied information revealed that the maximum ratings and electrical characteristics were compatible with the affected electrical systems; however, testing of failed TVS revealed that the TVS displayed instances of "shorting," "reverse leakage," "breakdown voltage," and "excessive leakage," damaged dies with some separated from the base disc, holes in the center of the die and/or in the silicon near the center of the die, and molten solder internally and/or physical damage to the individual sub assembly. As a result, the manufacturer implemented high-temperature reverse bias testing of all TVSs prior to delivery to reduce the probability of failure and advised their customers to remove from service any TVS with the same date codes as the failed units. Additionally, the airplane manufacturers and the Federal Aviation Administration took corrective actions to remove and replace faulty TVSs.
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, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane; rotorcraft: helicopter
- Flight time: 4,500 hours in all; 650 in this make and model; 240 in the last 90 days; 80 in the last 30 days; 4,450 as pilot in command; 4,300 on instruments
- Last flight review: February 10, 2007
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 526 hours
- Last inspection: 100-hour inspection, July 6, 2007
- Maximum gross weight: 3,600 lb
- Seats: 6
- Landing gear: retractable
- Engine: Lycoming TIO-540-S1AD (piston); 0 hours total
- Operator: Dutchman Leasing LLC
The flight
- Departed from: ARR Aurora IL at 10:00 am
- Destination: STL St. Louis MO
- Flight plan: IFR
- Runway 29, 8,101 ft by 150 ft
Weather at the time
- Light: daylight
- Visibility: 7 statute miles
- Sky: clear
- Temperature: 73°F (23°C), dew point 70°F (21°C)
- Altimeter: 29.87 inHg
- Observation at 12:05 pm from ALN
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.
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.