Raytheon Aircraft Company B300 accident near Mammoth Lakes, California, February 10, 2015
On February 10, 2015 at about 1:00 am local time, a 1996 Raytheon Aircraft Company B300, registered N49WC, was substantially damaged in an accident during enroute (descent) near Mammoth Lakes, California (Mammoth Yosemite airport). It was a positioning 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).
The NTSB's probable cause their words, unchanged
The airplane encountered extreme turbulence during descent.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 10, 2015 · about 1:00 am local time
- Place
- Mammoth Lakes, California · Mammoth Yosemite · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Raytheon Aircraft Company B300 UNDESIGNAT, built 1996
- Registration
- N49WC · registry record · serial FL-144
- Damage
- Substantial damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that while in a descent from 16,000 feet, at 1,500 feet per minute, slowing from 190 knots indicated airspeed to 160 knots, the airplane encountered extreme turbulence. The pilot reported one hard jolt up/down followed by about 15 seconds of light turbulence then one final hard jolt similar to the first. The weather was visual conditions and no turbulence was encountered prior to or after the event. A postflight examination of the airplane revealed that the extreme turbulence encountered resulted in substantial structural damage to both wings spars. The pilot reported there were no pre-impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
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
What happened, in order
- Turbulence encounter during enroute (descent) defining event
The NTSB's findings
- cause Environmental issues › Conditions/weather/phenomena › Turbulence › (general) › Effect on equipment
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 3,800 hours in all; 1,300 in this make and model; 110 in the last 90 days; 22 in the last 30 days; 3,009 as pilot in command; 1,900 on instruments
- Last flight review: January 14, 2015
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Co-pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 2,180 hours in all; 100 in this make and model; 18 in the last 90 days; 9 in the last 30 days; 2,035 as pilot in command
- Last flight review: June 20, 2014
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 9,205.5 hours
- Last inspection: continuous airworthiness programme, January 6, 2015; 55 hours since
- Maximum gross weight: 15,000 lb
- Seats: 11
- Landing gear: retractable
- Engine 1: Pratt & Whitney PT6A-60A (turboprop); 8,607 hours total
- Engine 2: Pratt & Whitney PT6A-60A (turboprop); 8,607 hours total
- Operator: West Coast Charters INC
The flight
- Departed from: SNA Santa Ana CA at 11:30 pm
- Destination: MMH Mammoth Lakes CA
- Flight plan: IFR
- Runway 27, 7,000 ft by 100 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 210° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 12°F (-11°C)
- Altimeter: 30.02 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.
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.