# NTSB NYC90FA199: Piper PA-31T2, N85HB, Mattapan, MA, August 24, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: August 24, 1990, 06:33 local (10:33 UTC)
- Place: Mattapan, MA
- Location: 42.2723° N, 71.0870° W: Placed by OpenAirDocs: center of Mattapan, MA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.2723&lon=-71.0870&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report October 10, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 36546
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC90FA199
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/36546/pdf
- Page: https://openairdocs.org/ntsb/NYC90FA199

## Probable cause

THE PILOT'S IMPROPER IN-FLIGHT PLANNING/DECISION, WHICH RESULTED IN HIS FAILURE TO  MAINTAIN CONTROL OF THE AIRCRAFT.  FACTORS RELATED TO THE ACCIDENT WERE:  FAILURE OF THE LEFT FUEL CONTROL UNIT,  AND THE ADVERSE WEATHER CONDITIONS.

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, approach - iaf to faf/outer marker (ifr)
  - fuel system,fuel control - failure,partial (contributing factor)
  - powerplant - overtorque
  - propeller feathering - performed, pilot in command
- Loss of control - in flight, maneuvering - turn to landing area (emergency)
  - weather condition - low ceiling (contributing factor)
  - weather condition - fog (contributing factor)
  - in-flight planning/decision - improper, pilot in command (cause)
  - aircraft control - not maintained, pilot in command (cause)
- In flight collision with object, descent - uncontrolled
  - object - residence (cause)

## Analysis

THE PLT NOTED AN OVER TORQUE CONDITION IN THE LEFT ENG AS THE ACFT WAS ON AN ILS APCH. HE MADE A GO-AROUND & INITIATED ANOTHER APCH WITH THE ENG SHUT DOWN. HE WAS UNABLE TO MAINTAIN ALT & THE ACFT BEGAN A DECENT THAT WAS NOT ARRESTED. SUBSEQUENTLY, IT CRASHED INTO 2 HOMES, APRX 6 MI FROM THE ARPT. AN EXAM OF THE LEFT ENG REVEALED THE DRIVE SHAFT FROM THE FUEL PUMP TO THE FUEL CONTROL WAS SHEARED AT THE PLASTIC COUPLING. FURTHER EXAM REVEALED THE TWIN BEARINGS THAT SUPPORTED THE DRIVESHAFT HAD FAILED. ALSO, THERE WAS EVIDENCE THE DRIVE SHAFT HAD SHIFTED & SUBSEQUENTLY AN OVERTORQUE CONDITION RESULTED.

## Aircraft

- Registration: [N85HB](https://openairdocs.org/deregistered/N85HB-2014-11-26), registration cancelled 2014-11-26, S/N 31T-8120021, built 1980 (OpenAirDocs)
- Reported make and model: PIPER PA-31T2
- Registry model: [Piper PA-31T](https://openairdocs.org/model/piper-pa-31t) (registry code 7103124) (OpenAirDocs)
- Registry engine: [U/A Canada PT6A-27-28](https://openairdocs.org/engine/u-a-canada-pt6a-27-28) (registry code 61504, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 31T-812021
- Engines: P&W PT6A-28 620 horsepower turbo prop
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Michael D. Spear
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, June 20, 1990, 0 hours before
- Departed: OB6, CHATHAM, MA
- Flight plan: IFR
- Airport: BOS, General Edward Lawrence Logan, runway 4R, 10,005 × 150 ft, macadam

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 2,926 total, 536 in this make and model, 2,715 as pilot in command, 92 in the last 90 days, 30 in the last 30 days

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 50° at 7 knots
- Lowest ceiling: 300 ft overcast
- Temperature: 63 °F, dew point 63 °F
- Altimeter: 30.00 inHg
- Observed at: BOS, 6 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 19900824036289A](https://openairdocs.org/incident/19900824036289A), Aug 24, 1990: Piper PA31T, Mattapan, MA, Destroyed, 3 fatal. Over torque left engine ILS approach. Missed. Second try below VMC. Crashed into 2 homes. Fuel pump shaft broke.

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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