Amateur-built EXEC 90 accident near Lutz, Florida, June 21, 1999
On June 21, 1999 at about 11:30 pm local time, a amateur-built EXEC 90 (helicopter), registered N4359N, was substantially damaged in an accident near Lutz, Florida (Tampa North Aero Park airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The excessive cyclic input by the non-qualified passenger during the autorotative landing following a reported loss of engine power. A factor in the accident was the inadequate preflight of the helicopter by the unqualified pilot for his failure to detect corrosion at each ignition pack during the helicopter preflight, resulting in the loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 21, 1999 · about 11:30 pm local time
- Place
- Lutz, Florida · Tampa North Aero Park · map
- Type
- Accident
- Injuries
- 1 person was seriously injured; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built EXEC 90
- Registration
- N4359N · registry record · serial 5042
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The non-certificated pilot preflighted the helicopter and after engine start, one of the magnetos was intermittent. Manipulation of the magneto switch corrected the problem; the flight then departed and flew about 5 miles away. While returning, the non-rotorcraft rated passenger began flying the helicopter and while descending over the airport about 300 feet, the engine quit. The passenger lowered full collective, maintained 60 mph, then when the helicopter was 20 feet agl, he flared using a 45 degree flare angle. The tailboom contacted the ground first, followed by the main rotor blades contacting the tailboom. The helicopter then landed hard. The passenger stated after takeoff, the pilot performed 3 or 4 simulated loss of engine power with power recoveries and while performing another, the engine quit at 100-150 feet. He took the controls from the pilot and with the main rotor tachometer indicating 0, performed an autorotative landing but the helicopter landed hard. The engine was started postaccident and found to operate normally. Examination of the engine systems revealed no evidence of preimpact failure or malfunction. The pilot stated that he found corrosion at the wiring connections at each ignition pack. Preflight examination of the ignitions packs is required.
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
- Flight time: 25 in this make and model; 16 in the last 90 days; 3 in the last 30 days
- Medical certificate: None
- Seat: left
The aircraft
- Airframe total time: 125 hours
- Last inspection: annual inspection, January 25, 1999; 25 hours since
- Maximum gross weight: 1,425 lb
- Seats: 2
- Landing gear: fixed
- Engine: Rotorway RI 162 (piston); 0 hours total
The flight
- Departed from: X39 at 11:00 pm
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: broken clouds at 25,000 ft; scat at 12,000 ft
- Temperature: 82°F (28°C), dew point 72°F (22°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
Other NTSB records under N4359N 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.