Bell 407 and Aerospatiale AS-355-F1 mid-air collision near Vermilion 331, October 5, 1998
On October 5, 1998 at about 2:06 pm local time, 2 aircraft, Bell 407 (N403PH) and Aerospatiale AS-355-F1 (N5792H), were involved in a mid-air collision near Vermilion 331. 1 person was killed and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the failure of both pilots to see and avoid each other's aircraft during cruise flight. Factors were the failure of both pilots to use a known safety advisory recommendation and the failure of both operators to implement the recommendation as a company operating procedure.
the failure of both pilots to see and avoid each other's aircraft during cruise flight. Factors were the failure of both pilots to use a known safety advisory recommendation and the failure of both operators to implement the recommendation as a company operating procedure.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 5, 1998 · about 2:06 pm local time
- Place
- Vermilion 331
- Type
- Accident · mid-air collision
- Injuries
- 1 person was killed and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Bell 407 · all 407s on the register
- Registration
- N403PH · registry record · serial 53177
- Damage
- Destroyed
- Flight
- Positioning flight · general aviation rules (Part 91)
- Aircraft 2
- Aerospatiale AS-355-F1 · all AS-355-F1s on the register
- Registration
- N5792H · no longer on the register · serial 5132
- Damage
- Destroyed
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative for the Bell 407 final · quoted from the NTSB record
The Bell 407 collided with an Aerospatiale AS-355-F1 while both helicopters were in cruise flight at 1,000 AGL over open ocean in the Gulf of Mexico. Both aircraft were being flown single pilot and were positioning flights between offshore platforms. The pilot of the Bell initiated an autorotation to the water and was rescued. The pilot of the Aerospatiale was fatally injured during the collision/water impact sequence and his helicopter impacted the water and sank into the ocean. Physical evidence on the recovered Bell wreckage indicated that the main rotor blades of the Aerospaciale struck the nose section of the Bell, removing the windshield, chin bubble and anti-torque pedals. The Bell's direct flight course was about 265 degrees. The Aerospatiale's direct course was about 155 degrees. The Bell pilot did not see the Aerospatiale until just before impact. The Helicopter Safety Advisory Conference (HSAC) had published a Recommended Practice (RP) in 1993 for standardized vertical separation of helicopters when flying in the offshore environment. Excerpts are: 'Helicopters operating enroute to and from offshore locations, below 3,000 feet, weather permitting, should use [the following] enroute altitudes; Magnetic Heading of 0 to 179 degrees - 750 feet or 1,750 feet, or 2,750 feet, Magnetic Heading of 180 to 359 degrees - 1,250 feet or 2,250 feet.' These recommended altitudes, if used, provide a minimum of 500 feet vertical clearance. Both operators, who are participating members in HSAC, did not have the HSAC-RP No. 93.1 included in their respective operations manuals. The RP's are recommended and not mandatory.
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 Aerospatiale AS-355-F1 final · quoted from the NTSB record
The Aerospatiale AS-355-F1 collided with a Bell 407 while both helicopters were in cruise flight at 1,000 AGL over open ocean in the Gulf of Mexico. Both aircraft were being flown single pilot and were positioning flights between offshore platforms. The pilot of the Bell initiated an autorotation to the water and was rescued. The pilot of the Aerospatiale was fatally injured during the collision/water impact sequence and his helicopter impacted the water and sank into the ocean. Physical evidence on the recovered Bell wreckage indicated that the main rotor blades of the Aerospaciale struck the nose section of the Bell, removing the windshield, chin bubble and anti-torque pedals. The Bell's direct flight course was about 265 degrees. The Aerospatiale's direct course was about 155 degrees. The Bell pilot did not see the Aerospatiale until just before impact. The Helicopter Safety Advisory Conference (HSAC) had published a Recommended Practice (RP) in 1993 for standardized vertical separation of helicopters when flying in the offshore environment. Excerpts are: 'Helicopters operating enroute to and from offshore locations, below 3,000 feet, weather permitting, should use [the following] enroute altitudes; Magnetic Heading of 0 to 179 degrees - 750 feet or 1,750 feet, or 2,750 feet, Magnetic Heading of 180 to 359 degrees - 1,250 feet or 2,250 feet.' These recommended altitudes, if used, provide a minimum of 500 feet vertical clearance. Both operators, who are participating members in HSAC, did not have the HSAC-RP No. 93.1 included in their respective operations manuals. The RP's are recommended and not mandatory.
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 Bell 407 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,586 hours in all; 956 in this make and model; 81 in the last 90 days; 65 in the last 30 days
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 1,168 hours
- Last inspection: approved inspection programme, September 16, 1998; 71 hours since
- Maximum gross weight: 5,000 lb
- Seats: 7
- Landing gear: fixed
- Engine: Allison 250C47B (turboshaft); 0 hours total
- Operator: Petroleum Helicopters INC.
The flight
- Departed from: NONE Vermilion 331A GM at 1:57 pm
- Destination: NONE E. Cameron 321A GM
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 150° at 35 knots, gusting 40
- Visibility: 20 statute miles
- Sky: broken clouds at 7,000 ft; scat at 2,000 ft
- Temperature: 81°F (27°C), dew point 75°F (24°C)
- Altimeter: 29.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
The factual record for the Aerospatiale AS-355-F1 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: instrument: helicopter; rotorcraft: helicopter
- Flight time: 3,667 hours in all; 90 in this make and model; 120 in the last 90 days; 21 in the last 30 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 5,816 hours
- Last inspection: 100-hour inspection, September 25, 1998; 28 hours since
- Maximum gross weight: 5,600 lb
- Seats: 6
- Landing gear: fixed
- Engine: Allison 250C20F (turboshaft); 0 hours total
The flight
- Departed from: NONE Cameron LA at 12:57 pm
- Destination: NONE Vermilion 370 GM
- Runway 0
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.