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Accidents · NTSB DCA84AA034 · Preliminary: the investigation is not finished

Beech C-99 and Rockwell 112TC mid-air collision near San Luis Obispo, California, August 24, 1984

On August 24, 1984 at about 6:18 pm local time, 2 aircraft, Beech C-99 (N6399U) and Rockwell 112TC (N112SM), were involved in a mid-air collision near San Luis Obispo, California (San Loui Obispo airport). 17 people were killed. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.

Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.

What the record shows

Date
August 24, 1984 · about 6:18 pm local time · cases in 1984
Place
San Luis Obispo, California · San Loui Obispo · cases near this airport · map
Type
Accident · mid-air collision
Injuries
17 people were killed.
Weather
visual conditions (good weather)
Aircraft 1
Beech C-99 · all C-99s on the register
Registration
N6399U · registry record · serial U-187
Damage
Destroyed
Flight
Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
Aircraft 2
Rockwell 112TC
Registration
N112SM · registry record · serial 13020
Damage
Destroyed
Flight
Instructional flight · general aviation rules (Part 91)

The NTSB's narrative for the Beech C-99 final · quoted from the NTSB record

AT ABOUT 1118, A BEECH C-99 (WINGS WEST FLT 628), N6399U, & A ROCKWELL 112TC, N112SM, COLLIDED IN MIDAIR ABOUT 8 MI WEST-NORTHWEST OF THE SAN LOUI OBISPO COUNTY ARPT. THE ROCKWELL 112TC HAD DEPARTED PASO ROBLES, CA & WAS DESCENDING TOWARD THE SAN LOUI OBISPO COUNTY ARPT. THE BEECH C-99 HAD DEPARTED SAN LOUI OBISPO & WAS CLIMBING ON A FLT TO SAN FRANCISCO. THEY COLLIDED HEAD-ON AT ABOUT 3400 FT MSL IN CLEAR WX. THE C-99 CREW HAD JUST CONTACTED LOS ANGELES ARTCC. AT THAT TIME, THE AIRCREWS OF BOTH ACFT WERE GOVERNED BY THE 'SEE-AND-AVOID' CONCEPT WITH REGARD TO EACH OTHER. AN INVESTIGATION REVEALED THAT THE STANDARD DEPARTURE & INSTRUMENT APCH PROCEDURES SHARED A COMMON TRACK. THE C-99 WAS DEPARTING ALONG THE DEPARTURE TRACK. JUST PRIOR TO THE COLLISION, THE 112TC CREW HAD CONTACTED UNICOM & REPORTED AT THE DOBRA INTERSECTION WHICH WAS ON THE ILS APCH COURSE. AFTER COLLIDING, BOTH ACFT CRASHED ON OPEN TERRAIN & BURNED. THE CONTROLLER HAD ONLY SECONDS TO APPRAISE RADAR DATA & ISSUE A SAFETY ADVISORY. WINGS WEST REQD 1 RADIO ON COMPANY FREQ.

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 NTSB's narrative for the Rockwell 112TC final · quoted from the NTSB record

AT ABOUT 1118, A BEECH C-99 (WINGS WEST FLT 628), N6399U, & A ROCKWELL 112TC, N112SM, COLLIDED IN MIDAIR APRX 8 MI WEST-NORTHWEST OF THE SAN LOUI OBISPO COUNTY ARPT. THE ROCKWELL 112TC HAD DEPARTED PASO ROBLES, CA & WAS DESCENDING TOWARD THE SAN LOUI OBISPO COUNTY ARPT. THE BEECH C-99 HAD DEPARTED SAN LOUI OBISPO & WAS CLIMBING ON A FLT TO SAN FRANCISCO. THEY COLLIDED HEAD-ON AT ABOUT 3400 FT MSL IN CLEAR WX. THE C-99 CREW HAD JUST CONTACTED LOS ANGELES ARTCC. AT THAT TIME, THE AIRCREWS OF BOTH ACFT WERE GOVERNED BY THE 'SEE-AND-AVOID' CONCEPT WITH REGARD TO EACH OTHER. AN INVESTIGATIONREVEALED THAT THE STANDARD DEPARTURE & INSTRUMENT APCH PROCEDURES SHARED A COMMON TRACK. THE C-99 WAS DEPARTING ALONG THE DEPARTURE TRACK. JUST PRIOR TO THE COLLISION, THE 112TC CREW HAD CONTACTED UNICOM & REPORTED AT THE DOBRA INTER- SECTION WHICH WAS ON THE ILS APCH COURSE. AFTER COLLIDING, BOTH ACFT CRASHED ON OPEN TERRAIN & BURNED. THE CONTROLLER HAD ONLY SECONDS TO APPRAISE RADAR DATA & ISSUE A SAFETY ADVISORY. WINGS WEST REQD 1 RADIO TO BE TUNED TO COMPANY FREQ.

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 for the Beech C-99 from the NTSB's investigation tables, in plain English

Pilot

  • Certificate: airline transport pilot, commercial pilot
  • Ratings: multi-engine land; single-engine land; instrument: airplane
  • Flight time: 4,110 hours in all; 873 in this make and model; 271 in the last 90 days; 91 in the last 30 days
  • Medical certificate: Class 1 (valid medical--no waivers/lim.)
  • Seat: unk

The aircraft

  • Last inspection: inspection type not recorded; 0 hours since
  • Maximum gross weight: 11,300 lb
  • Seats: 17
  • Landing gear: retractable
  • Engine: P&W PT6A (turboprop); 0 hours total
  • Fire on the ground
  • Operator: Wings West Airlines, INC.

The flight

  • Departed from: San Luis Obispo CA at 7:00 am
  • Destination: San Francisco CA
  • Flight plan: IFR
  • Runway 0
  • A second pilot was aboard

Weather at the time

  • Light: daylight
  • Wind: from 240° at 3 knots
  • Visibility: 15 statute miles
  • Sky: clear
  • Temperature: 75°F (24°C), dew point 0°F (-18°C)

Injuries

FatalSeriousMinorNone
Crew2
Passengers13

The factual record for the Rockwell 112TC from the NTSB's investigation tables, in plain English

Pilot

  • Certificate: commercial pilot
  • Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
  • Flight time: 4,858 hours in all; 73 in this make and model; 251 in the last 90 days; 93 in the last 30 days
  • Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
  • Seat: unk

The aircraft

  • Last inspection: inspection type not recorded; 0 hours since
  • Maximum gross weight: 2,850 lb
  • Seats: 4
  • Landing gear: retractable
  • Engine: Lycoming TO-360 (piston); 0 hours total
  • Fire on the ground

The flight

  • Departed from: Paso Robles CA at 7:00 am
  • Flight plan: none
  • Runway 0
  • A second pilot was aboard

Injuries

FatalSeriousMinorNone
Crew2

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.

Connections how this case links to the rest of the register

Aircraft
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Analytics

The whole map of how records connect · these connections as data: /graph/accident/DCA84AA034.json.

The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.

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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.