Aero Commander 720 accident near 50 NW San Juan, Puerto Rico, September 30, 1987
On September 30, 1987 at about 12:51 pm local time, a Aero Commander 720, registered N4100S, was substantially damaged in an accident near 50 NW San Juan, Puerto Rico. It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured and 1 person had minor injuries. 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 October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 30, 1987 · about 12:51 pm local time
- Place
- 50 NW San Juan, Puerto Rico
- Type
- Accident
- Injuries
- 1 person was seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Aero Commander 720
- Registration
- N4100S · no longer on the register · serial 720-660-7
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
FIFTEEN MINUTES AFTER A NORTHWEST DEPARTURE FROM SAN JUAN INTERNATIONAL ARPT THE PLT REPORTED THAT THE FLT WAS RETURNING TO LAND AFTER SECURING THE RT ENG DUE TO REPORTED PROBLEMS. UNABLE TO MAINTAIN ALTITUDE THE ACFT WAS DITCHED APRX 50 MILES NORTHWEST OF THE ARPT. DENSITY ALTITUDE WAS COMPUTED TO BE 1900 FT AT THE ARPT 1 MINUTE AFTER THE DITCHING. ACCORDING TO THE ACFT OPERATING MANUAL, AT THE DESIGNED GROSS WEIGHT WITH A PROPERLY SECURED ENGINE AT THE ABOVE COMPUTED DENSITY ALTITUDE, THE SINGLE ENGINE RATE OF CLIMB WOULD BE 212 FEET PER MINUTE. THE ACFT & LOGBOOKS HAVE NOT BEEN RECOVERED THEREFORE THE CAUSE OF THE REPORTED ENG FAILURE & MAINTENANCE INFORMATION COULD NOT BE DETERMINED & OBTAINED RESPECTIVELY.
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: commercial pilot
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instrument: airplane
- Flight time: 4,080 hours in all; 43 in this make and model; 24 in the last 90 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 7,500 lb
- Seats: 6
- Landing gear: retractable
- Engine: Lycoming GSO-480-B1A6 (piston); 0 hours total
The flight
- Departed from: 5IG San Juan PR at 12:30 pm
- Destination: FLL Ft. Lauderdale FL
- Flight plan: VFR
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 130° at 9 knots
- Visibility: 15 statute miles
- Sky: scat at 2,500 ft
- Temperature: 88°F (31°C), dew point 75°F (24°C)
- Altimeter: 29.00 inHg
- Observation at 12:52 pm from SJU, 50 miles away
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.
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.