# NTSB NYC86MA148: Sikorsky S-76B, N5AZ, Sutton, MA, June 6, 1986

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Major investigation · Final report
- Date: June 6, 1986, 09:00 local (13:00 UTC)
- Place: Sutton, MA
- Location: 42.1501° N, 71.7628° W: Placed by OpenAirDocs: center of Sutton, MA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.1501&lon=-71.7628&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 4 fatal
- Status: Completed, report February 12, 1988
- Report: Approved by Office Director
- NTSB case key (mKey): 30431
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC86MA148
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/30431/pdf
- Page: https://openairdocs.org/ntsb/NYC86MA148

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Altitude deviation,uncontrolled, cruise - normal
  - reason for occurrence undetermined (cause)
  - spiral - uncontrolled
- In flight collision with terrain/water, descent - uncontrolled
  - weather condition - clouds (contributing factor)
  - weather condition - low ceiling (contributing factor)
  - weather condition - fog (contributing factor)

## Analysis

ABOUT 16 MIN AFTER TAKEOFF, WHILE CRUISING AT 6000' MSL IN IMC, THE PLT TRANSMITTED 'SIKORSKY 507' (CALL SIGN OF ACFT HEFREQUENTLY FLEW). THE ATC CTLR WAS TALKING TO ANOTHER FLT & DID NOT RESPOND. ABOUT 1 MIN LATER, RDO & RADAR CONTACT WERELOST & THE HELICOPTER CRASHED WHILE IN A STEEP/HI SPD DSCNT. AN INV SHOWED THAT DRG IMPACT, IT WAS IN A 10 DEG NOSE UP, 12 DEG RGT BANK ATTITUDE. WITNESSES, WHO HEARD THE HELICOPTER, RPRTD THE ENGS WERE RUNNING AT HI PWR BFR IMPACT. THEY DESCRIBED THE WX AS LOW OVERCAST WITH RAIN, FOG & POOR VIS. RADAR DATA SHOWED THAT JUST BFR ENTERING A DSCNT, THE HELI- COPTER WAS ON A SW HDG AT 138 KTS, WHEN ITS HDG & SPD BGN TO VARY. IT SLOWED TO 116 KTS, TURNED LEFT TO 229 DEG, THEN ENTERED A RGT DSCNDG SPIRAL & CRASHED. NO PREIMPACT PART FAILURE/MALFUNCTION WAS FND. PREV DISCREPANCIES NOTED OF N5AZ'SELEC FLT INSTRUMENT SYS (EFIS) ON 5/5/86 & 5/27/86; CAUSE OF 1ST WAS NOT FND; 2ND WAS RELATED TO A POPPED CKT BRKR. NO KNOWN EFIS PRBLM ON ACDNT FLT, BUT ACFT WAS BADLY DMGD. PLT HAD 1525 HRS IN S-76A, ONLY 30 HRS IN S-76B (WITH EFIS).

## Aircraft

- Registration: [N5AZ](https://openairdocs.org/deregistered/N5AZ-2013-01-31), registration cancelled 2013-01-31, S/N 760313, built 1985 (OpenAirDocs)
- Reported make and model: SIKORSKY S-76B
- Registry model: [Sikorsky S-76B](https://openairdocs.org/model/sikorsky-s-76b) (registry code 8143007) (OpenAirDocs)
- Registry engine: [Pratt & Whitney PT6SER TP](https://openairdocs.org/engine/pratt-whitney-pt6ser-tp) (registry code 52045, turbo-prop) (OpenAirDocs)
- Category: Helicopter
- Serial number: 760313
- Airframe hours: 107
- Engines: P&W PT6B-36 960 horsepower turbo shaft
- Damage: Destroyed
- Fire: On-Ground
- Flight: Business, Part 91
- Operator: United Technologies
- Registered owner: 1st N.H. Bank, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, May 30, 1986, 7 hours before
- Departed: BED, BEDFORD, MA
- Destination: JSD, STRATFORD, CT
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--w/ waivers/lim; toxicology performed; flight hours: 1,555 in this make and model, 98 in the last 90 days

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 60° at 6 knots
- Lowest ceiling: 100 ft
- Temperature: 61 °F, dew point 57 °F
- Altimeter: 30.00 inHg
- Observed at: ORH

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19860606021919A](https://openairdocs.org/incident/19860606021919A), Jun 6, 1986: Skrsky S76B, Sutton, MA, Destroyed, 2 fatal. Flight had an uncontrolled altitude deviation en route. Struck trees in high speed descent. Possible EFIS malfunction

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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