Lake LA-4 accident near Coeur D'Alene, Idaho, May 15, 1999
On May 15, 1999 at about 7:30 pm local time, a Lake LA-4, registered N152WB, was substantially damaged in an accident near Coeur D'Alene, Idaho (Coeur D'Alene airport). It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The fatigue failure of a repair weld on one of the engine pylon mount straps and the resultant reduction in directional control. Factors include an inadequate repair of the strap, variable wind speeds and sudden wind shifts.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 15, 1999 · about 7:30 pm local time
- Place
- Coeur D'Alene, Idaho · Coeur D'Alene · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Lake LA-4 · all LA-4s on the register
- Registration
- N152WB · registry record · serial 268
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While landing in variable, shifting winds, both the dual student and the instructor had trouble maintaining directional control of the aircraft. After touchdown, the aircraft started turning toward the right side of the runway, and the instructor could not get it to straighten out using maximum left brake and full left rudder. He therefore added power to get airflow over the rudder to increase its efficiency, but the aircraft continued to turn sharper, eventually departing the right side of the runway and impacting the segmented circle at the base of the wind sock. It was later discovered that an improper repair weld on one of the engine pylon mounting straps had failed from fatigue, allowing the engine pylon to twist out of alignment with the longitudinal axis of the aircraft.
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: flight instructor, commercial pilot
- Ratings: single-engine land; single-engine sea; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 4,286 hours in all; 52 in this make and model; 75 in the last 90 days; 23 in the last 30 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 1,367 hours
- Last inspection: annual inspection, August 11, 1998; 48 hours since
- Maximum gross weight: 2,400 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-360-A1A (piston); 0 hours total
The flight
- Departed from: COE at 4:30 pm
- Flight plan: none
- Runway 19, 5,400 ft by 75 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: at 10 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 3,500 ft; not recorded
- Temperature: 55°F (13°C), dew point 34°F (1°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number SEA99LA063.