# NTSB FTW85FA265: Aerospatiale AS35OD, N148BH, Dallas, TX, June 26, 1985

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 26, 1985, 11:40 local (16:40 UTC)
- Place: Dallas, TX
- Coordinates: 32.669212, -96.759635 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.6692&lon=-96.7596&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21560
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW85FA265
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21560/pdf
- Page: https://openairdocs.org/ntsb/FTW85FA265

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - rotor drive system,engine to transmission drive - failure,total (cause)
  - maintenance,inspection - inadequate, company maintenance personnel (cause)
- Forced landing, descent - emergency
- Loss of control - in flight, maneuvering
  - emergency procedure - not possible, pilot in command (contributing factor)
- In flight collision with object, maneuvering
  - object - tree(s) (contributing factor)

## Analysis

THE ENG TO TRANSMISSION SHORT SHAFT BECAME DISCONNECTED IN FLT. THIS RESULTED IN COMPLETE LOSS OF PWR TO THE MAIN ROTOR ASSEMBLY. HOWEVER, THE TAIL ROTOR ASSEMBLY WAS STILL BEING POWERED BY THE ENG. UPON COLLECTIVE PITCH APPLICATION TO STOP THE DESCENT THE ACFT YAWED ABOUT 90 DEGS TO THE RIGHT AND ALSO ROLLED ABOUT 70 DEGS TO THE RIGHT AND IMPACTED THE TRUNK OF A LARGE TREE. THIS IMPACT RESULTED IN DISINTEGRATION OF THE HELICOPTER. INVESTIGATION REVEALED THAT COTTER PINS HAD NOT BEEN INSTALLED IN THE BOLTS WHICH CONNECT THE FORWARD END OF THE SHORT SHAFT TO THE FLEXIBLE COUPLING AT THE TRANSMISSION. IT ALSO REVEALED THAT A REQUIRED 30 HR RECURRING INSPECTION HAD NOT BEEN COMPLETED AND WAS 15.9 HRS OVERDUE. THE COMPLETION OF THIS REQUIRED INSPECTION WOULD HAVE REVEALED THAT THE COTTER PINS WERE MISSING.

## Aircraft

- Registration: N148BH (not matched to a registry record)
- Reported make and model: AEROSPATIALE AS35OD
- Category: Helicopter
- Serial number: 1274
- Airframe hours: 1256
- Engines: LYCOMING LTS-101-600A2 531 horsepower turbo shaft
- Damage: Destroyed
- Flight: Positioning, Part 91
- Registered owner: Cia Machinery, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, May 25, 1985, 55 hours before
- Departed: DAL, DALLAS, TX
- Destination: LANCASTER, TX

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter; medical: class 2, valid medical--w/ waivers/lim; seat: right; toxicology performed; flight hours: 7,044 total, 166 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 14 knots
- Visibility: 15 statute miles
- Lowest ceiling: 3,000 ft broken
- Temperature: 86 °F, dew point 68 °F
- Altimeter: 29.00 inHg
- Observed at: DAL, 16 nm away

## 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 19850626027969A](https://openairdocs.org/incident/19850626027969A), Jun 26, 1985: Snias AS350D, Dallas, TX, Destroyed. Struck trees during autorotation after power failure. Short shaft disconnected at transmission end. Uncomplied ADS.

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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