Eurocopter MBB-BK117-B2 accident near New York, New York, April 15, 1997
On April 15, 1997 at about 9:37 pm local time, a Eurocopter MBB-BK117-B2 (helicopter), registered N909CP, was destroyed in an accident near New York, New York (60Th Street Heliport airport). It was an executive or corporate flight under general aviation rules (Part 91). 1 person was killed, 2 people were seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Fatigue failure of the vertical fin, accelerated by the installation of blind rivets in lieu of solid rivets in the replacement of the yaw SAS mount support, which resulted in the loss of helicopter directional control and collision with the terrain (water). Factors contributing to the accident were: a lack of information regarding repair of the yaw SAS mount support in the manufacturer's maintenance manuals, and the design of the vertical fin which was susceptible to fatigue cracking. An additional factor was the lack of an adequate passenger briefing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 15, 1997 · about 9:37 pm local time
- Place
- New York, New York · 60Th Street Heliport · map
- Type
- Accident
- Injuries
- 1 person was killed, 2 people were seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter MBB-BK117-B2 MBB-BK117-
- Registration
- N909CP · registry record · serial 7189
- Damage
- Destroyed
- Flight
- Executive or corporate flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
After taking off, the helicopter climbed to approximately 30 feet, and produced a loud bang. The helicopter rotated nose right several times, descended, struck the heliport pier and continued into the East River where it submerged. The pilots were evacuated underwater; the passengers were found in the cabin unconscious and recovered by divers. The throttles were found in the flight position. The investigation revealed that the upper 3 feet of the vertical fin had failed due to fatigue fractures and had separated, along with the tail rotor assembly. About 4 1/2 years prior, the left-hand yaw SAS actuator mounting plate attached to the vertical fin developed a crack and was replaced using blind rivets in lieu of the solid rivets specified in the manufacturer's design drawings. Neither the repair nor the substitution of rivets was addressed in the manufacturer's maintenance manual. Literature from the rivet manufacturer indicated that blind rivets may be substituted for solid rivets in most applications. No specific reference by the FAA was found to allow for this rivet substitution. The investigation revealed 11 other helicopters with fatigue cracking in the vertical fin spar similar to the accident helicopter. Testing revealed that materials fastened with blind rivets are more susceptible to fatigue cracking than materials fastened with solid rivets. Passenger interviews disclosed that many were not aware of emergency exit locations, or how to operate them; life vests were available, but were not used.
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: airline transport pilot, private
- Ratings: single-engine land; instrument: helicopter; rotorcraft: helicopter
- Flight time: 9,400 hours in all; 3,900 in this make and model; 154 in the last 90 days; 53 in the last 30 days; 5,050 as pilot in command
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 4,190 hours
- Last inspection: continuous airworthiness programme, March 25, 1997; 36 hours since
- Maximum gross weight: 7,385 lb
- Seats: 8
- Landing gear: fixed
- Engine: Lycoming LTS101-750B-1 (turboshaft); 0 hours total
The flight
- Departed from: 6N4 at 9:37 pm
- Destination: HPN White Plains NY
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 200° at 12 knots
- Visibility: 10 statute miles
- Sky: scat at 25,000 ft
- Temperature: 55°F (13°C), dew point 37°F (3°C)
- Altimeter: 30.00 inHg
- Observation at 9:51 pm from LGA, 4 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | 1 | ||
| Passengers | 1 | 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.