# NTSB DEN89FA217: Piper PA-31T2, N63XL, Louisville, CO, September 15, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: September 15, 1989, 13:36 local (19:36 UTC)
- Place: Louisville, CO
- Coordinates: 39.960651, -105.139137 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.9607&lon=-105.1391&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report April 15, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 17608
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN89FA217
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17608/pdf
- Page: https://openairdocs.org/ntsb/DEN89FA217

## Probable cause

FAILURE OF THE PILOT TO MAINTAIN ADEQUATE AIRSPEED, WHILE MANEUVERING FOR SPACING IN THE TRAFFIC PATTERN, WHICH RESULTED IN AN INADVERTENT STALL AT LOW ALTITUDE.

## Sequence of events

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

- Loss of control - in flight, approach
  - maneuver - initiated, pilot in command
  - airspeed - inadequate, pilot in command (cause)
  - stall - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PLT & 2 MECHANICS WERE ON A MAINT TEST FLT. AS THE ACFT WAS ON A STRAIGHT-IN APCH TO RWY 11 FROM THE WEST, THE PLT WAS ADVISED OF TRAFFIC AHEAD & TOLD TO SLOW HIS SPEED AS MUCH AS POSSIBLE. THE PLT ACKNOWLEDGED. ABOUT 15 SEC LATER, THE CTLR TOLD THE PLT (OF N63XL) TO MAKE A 360 DEG TURN TO THE LEFT FOR SPACING. SHORTLY THEREAFTER, WITNESSES OBSERVED THE ACFT ENTER A STEEP BANK (TURN), THEN GO INTO A STEEP SPIRALING, NOSE DOWN, DESCENT & CRASH. NO PREIMPACT MECHANICAL MALFUNCTION OR FAILURE OF THE ACFT OR ENGS WAS FOUND.

## Aircraft

- Registration: [N63XL](https://openairdocs.org/deregistered/N63XL-1991-01-30), registration cancelled 1991-01-30, S/N 31T8166037 (OpenAirDocs)
- Reported make and model: PIPER PA-31T2
- Registry model: [Piper PA-31T2](https://openairdocs.org/model/piper-pa-31t2) (registry code 7103127) (OpenAirDocs)
- Category: Airplane
- Serial number: 31T8166037
- Airframe hours: 996
- Engines: P&W PT6A-135 620 horsepower turbo prop
- Damage: Destroyed
- Fire: On-Ground
- Flight: Part 91
- Registered owner: Widefield Homes, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, September 15, 1989
- Departed: BJC, BROOMFIELD, CO
- Airport: BJC, Jefferson County, runway 11, 9,000 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; commercial, airline transport, flight instructor; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 27,000 total, 3,500 in this make and model, 100 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 80° at 14 knots
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 25 °F
- Altimeter: 30.00 inHg
- Observed at: BJC, 1 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 19890915035119A](https://openairdocs.org/incident/19890915035119A), Sep 15, 1989: Piper PA31T2, Denver, CO, Destroyed, 3 fatal. Stalled in a steep turn after advised to make a 360 degree turn on final for traffic spacing.

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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