NYC86MA148 · Sikorsky S-76B
Sikorsky S-76B · Accident: uncontrolled altitude deviation en route
From Laurence G Hanscom Field (BED) to Sikorsky Heliport (JSD)
Event
- NTSB case
- NYC86MA148
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 4 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Sikorsky S-76B
- Aircraft type
- Sikorsky S-76
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N5AZ
- Operator
- United Technologies
- Onboard fatalities
- Unknown
- Route
- From Laurence G Hanscom Field (BED), Bedford, MATo Sikorsky Heliport (JSD), Stratford, CT
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Uncontrolled altitude deviation
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Reason for occurrence undetermined
Approximate · Estimated position: the centre of Sutton, MA, the place the record names. Not the accident site.
NTSB narrative
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).
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record NYC86MA148
- Event ID
- 20001213X34016
- Case number
- NYC86MA148
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: c3815551ca0a0d32b47dd0cc321b90507fe2023494d0e12bd12bd64a16c592cb; retrieved 2026-09-21T04:32:31.584Z.