Amateur-built DHC-6 and Cessna 172N mid-air collision near Palmdale, California, August 4, 1987
On August 4, 1987 at about 7:19 pm local time, 2 aircraft, amateur-built DHC-6 (N931MA) and Cessna 172N (N737EV), were involved in a mid-air collision near Palmdale, California (Palmdale airport). No one was hurt; 11 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 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 October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 4, 1987 · about 7:19 pm local time
- Place
- Palmdale, California · Palmdale · map
- Type
- Accident · mid-air collision
- Injuries
- No one was hurt; 11 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Amateur-built DHC-6
- Registration
- N931MA · registry record · serial 169
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
- Aircraft 2
- Cessna 172N · all 172Ns on the register
- Registration
- N737EV · no longer on the register · serial 17269369
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative for the amateur-built DHC-6 final · quoted from the NTSB record
A DEHAVILLAND DHC-6, N931MA, OPERATING AS TRANSWORLD EXPRESS FLT 7591 (TWE 7591) & A CESSNA 172N, N737EV, COLLIDED ABT 10 MILES WEST/SOUTHWEST OF PALMDALE, CA AT ABT 5500 FT MSL. TWE 7591 WAS DESCENDING ON A 355 DEG MAG HEADING; N737EV WAS LEVEL AND WAS MAINTAINING A 060 DEG MAG HEADING. THE CAPT ABOARD TWE 7591 WAS FLYING THE AIRPLANE & THE FIRST OFFICER OBSVD N737EV JUST PRIOR TO IMPACT AND TOOK THE CONTROLS AND EXECUTED AN ABRUPT RIGHT TURN; THE CAPT THEN CONTINUED THE DESCENDING RIGHT TURN BUT TO NO AVAIL - THE AIRPLANE'S LEFT WING COLLIDED WITH N737EV. THE PLT OF N737EV REPORTED THAT HE DID NOT SEE TWE 7591 UNTIL THE COLLISION. THE CONVERGENCE ANGLE OF 7591 WAS 53 DEG AND 62 DEG FOR 737EV. BOTH AIRPLANES LANDED SAFELY - TWE 7591 LANDED AT WILLIAM J. FOX ARPT, LANCASTER, CA. & N737EV LANDED AT PALMDALE ARPT.
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 Cessna 172N final · quoted from the NTSB record
A DEHAVILLAND DHC-6, N931MA, OPERATING AS TRANSWORLD EXPRESS FLT 7591 (TWE 7591) & A CESSNA 172N, N737EV, COLLIDED ABT 10 MILES WEST/SOUTHWEST OF PALMDALE, CA AT ABT 5500 FT MSL. TWE 7591 WAS DESCENDING ON A 355 DEG MAG HEADING; N737EV WAS LEVEL AND WAS MAINTAINING A 060 DEG MAG HEADING. THE CAPT ABOARD TWE 7591 WAS FLYING THE AIRPLANE & THE FIRST OFFICER OBSVD N737EV JUST PRIOR TO IMPACT AND TOOK THE CONTROLS AND EXECUTED AN ABRUPT RIGHT TURN; THE CAPT THEN CONTINUED THE DESCENDING RIGHT TURN BUT TO NO AVAIL - THE AIRPLANE'S LEFT WING COLLIDED WITH N737EV. THE PLT OF N737EV REPORTED THAT HE DID NOT SEE TWE 7591 UNTIL THE COLLISION. THE CONVERGENCE ANGLE OF 7591 WAS 53 DEG AND 62 DEG FOR 737EV. BOTH AIRPLANES LANDED SAFELY - TWE 7591 LANDED AT WILLIAM J. FOX ARPT, LANCASTER, CA. & N737EV LANDED AT PALMDALE ARPT.
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 amateur-built DHC-6 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: 7,000 hours in all; 375 in this make and model; 176 in the last 90 days; 42 in the last 30 days; 6,738 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 30,907 hours
- Last inspection: continuous airworthiness programme, July 29, 1987; 31 hours since
- Maximum gross weight: 11,000 lb
- Seats: 14
- Landing gear: fixed
- Engine: P&W PT-6-20 (turboprop); 0 hours total
- Operator: Resort Commuter INC.
The flight
- Departed from: LAX Los Angeles CA at 6:55 pm
- Destination: WJF Lancaster CA
- Runway 6, 5,001 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 290° at 4 knots
- Visibility: 40 statute miles
- Sky: scat at 10,000 ft
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
- Observation at 7:23 pm from WJF, 9 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 | |||
| Passengers | 6 |
The factual record for the Cessna 172N from the NTSB's investigation tables, in plain English
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,725 hours in all; 67 in this make and model; 13 in the last 90 days; 4 in the last 30 days; 709 as pilot in command; 24 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 889 hours
- Last inspection: 100-hour inspection, July 3, 1987; 18 hours since
- Maximum gross weight: 2,300 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-320-H2AD (piston); 0 hours total
- Operator: Venco Pacific Aviation
The flight
- Departed from: OXR Oxnard CA at 6:45 pm
- Destination: LAS Las Vegas NV
- Flight plan: VFR
- Runway 7, 12,002 ft by 150 ft
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| 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.
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 LAX87FA290.