Israel Aircraft Industries 1125 incident near Pine Knot, Kentucky, April 3, 2000
On April 3, 2000, a Israel Aircraft Industries 1125, registered N511WA, was involved in an incident near Pine Knot, Kentucky. It was an executive or corporate flight under general aviation rules (Part 91). No one was hurt; 4 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The partial failure of an inverter and the inadequate design of the electrical circuit breaker system.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 3, 2000
- Place
- Pine Knot, Kentucky · map
- Type
- Incident
- Injuries
- No one was hurt; 4 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Israel Aircraft Industries 1125 · all 1125s on the register
- Registration
- N511WA · registry record · serial 034
- Damage
- Not recorded
- Flight
- Executive or corporate flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While in cruise flight, the flightcrew selected "GPS" on the pilot's Electronic Horizontal Situation Indicator (EHSI). The number one inverter then began to malfunction and produce lower than normal voltage. As the voltage decreased, the vertical gyroscopes began to slow down and the displays on the Electronic Attitude Display Indicators (EADI) "blacked out," without any warning from the master caution panel. Shortly thereafter, heading warning flags appeared and the compass cards locked in position on both EHSI's. Due to the decreased voltage, the motors of the directional gyroscopes drew higher-than-normal amperage, and blew their respective internal 0.75-amp fuses. When the fuses blew, the load was decreased on the number one inverter, and the voltage output increased back to normal levels; however, because of their inaccessibility, the flightcrew could not reset the fuses. Additionally, a sensing relay, pre-set to de-energize at about 40-volts AC, did not activate to illuminate an "AC FAIL" light on the master caution annunciator panel. With the normal voltage levels restored, the vertical gyroscopes began to accelerate, and approximately 8 to 10 minutes later, the EADI displays returned. The flight landed uneventfully. After the incident, the airplane manufacturer issued an Alert Service Bulletin providing instructions to replace existing low voltage sensing relays with higher accuracy relays capable of providing a warning at higher voltages and to replace the 3-amp Directional Gyros circuit breakers on the overhead circuit breaker panel, with 0.5-amp circuit breakers, enabling disconnection of power to the EHSI's prior to their internal 0.75-amp blowing.
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
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 5,815 hours in all; 155 in this make and model; 145 in the last 90 days; 35 in the last 30 days; 4,330 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,755 hours
- Last inspection: continuous airworthiness programme, March 9, 2000; 55 hours since
- Maximum gross weight: 23,500 lb
- Seats: 10
- Landing gear: retractable
- Engine: Airesearch TFE-731-3A (turbojet); 0 hours total
The flight
- Departed from: APF Naples FL at 11:30 pm
- Destination: LUK Cincinnati OH
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: night, dark
- Wind: from 010° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 115°F (46°C), dew point 82°F (28°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 | |||
| Passengers | 2 |
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.