# NTSB CHI91FA108: Piper PA-30, N8290Y, Thief River Fls, MN, March 18, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: March 17, 1991, 19:49 local (Mar 18, 1991, 01:49 UTC)
- Place: Thief River Fls, MN
- Coordinates: 48.109626, -96.1707 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.1096&lon=-96.1707&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 4 fatal
- Status: Completed, report January 27, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 14896
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI91FA108
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14896/pdf
- Page: https://openairdocs.org/ntsb/CHI91FA108

## Probable cause

IMPROPER IFR PROCEDURE OF THE PILOT, WHILE INTERCEPTING THE ILS LOCALIZER, BY NOT MAINTIANING THE MINIMUM DESCENT ALTITUDE (MDA) FOR THAT SEGMENT OF THE APPROACH.

## Sequence of events

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

- In flight collision with terrain/water, approach - iaf to faf/outer marker (ifr)
  - ifr procedure - not followed, pilot in command (cause)
  - minimum descent altitude - not maintained, pilot in command (cause)

## Analysis

DURING ARRIVAL, THE PLT WAS ADZD THAT THE 1745 CST WX WAS 500' BKN, 1000' OVC, VIS 3-1/2 MI WITH FOG.  HE MADE AN ILS RWY 31 APCH, BUT AT 1928 CST, HE RPRTD A MISSED APCH.  HE STATED THAT HE HAD SEEN 'THE LIGHTS' & REQUESTED ANOTHER APCH.  THE ACFT WAS VECTORED FOR A 2ND ILS.  WHEN IT WAS ABOUT 5 MI FROM THE OUTER MARKER (FAF), THE PLT WAS CLRD FOR THE APCH & TO CHANGE TO AN ADZY FREQ.  HOWEVER, ABOUT 3 MI SE OF THE FAF, THE ACFT FLEW INTO LEVEL TERRAIN, WHILE STILL ON A WESTERLY HDG.  MIN DSCNT ALT (MDA) FOR THIS SEGMENT OF THE APCH WAS 2700' MSL; THE ARPT ELEV WAS 1116').  NO PREIMPACT PART FAILURE OR MALFUNCTION OF THE AIRFRAME OR ENG WAS FOUND.  THE 1945 CST WX AT THE ARPT HAD DETERIORATED TO 200' OVC & 1/4 MI VIS WITH FOG.

## Aircraft

- Registration: [N8290Y](https://openairdocs.org/deregistered/N8290Y-1994-05-18), registration cancelled 1994-05-18, S/N 301428 (OpenAirDocs)
- Reported make and model: PIPER PA-30
- Registry model: [Piper PA-30](https://openairdocs.org/model/piper-pa-30) (registry code 7103002) (OpenAirDocs)
- Category: Airplane
- Serial number: 30-1428
- Engines: LYCOMING IO-320 160 horsepower reciprocating
- Damage: Destroyed
- Flight: Business, Part 91
- Operator: June I. Steiger
- Departed: BZN, BOZEMAN, MT
- Flight plan: IFR
- Airport: TVF, Thief River Regional, runway 31, 6,503 × 150 ft

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 61; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 2,400 total

## Weather

- Conditions: Instrument (IMC), Night/dark
- Wind: calm
- Lowest ceiling: 200 ft broken
- Temperature: 34 °F, dew point 28 °F
- Altimeter: 29.00 inHg
- Observed at: TVF

## 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 19910317009269A](https://openairdocs.org/incident/19910317009269A), Mar 17, 1991: Piper PA30, Thief River Fal, MN, Destroyed, 4 fatal. Descended below dh on second ILS approach after missed approach. Impact in open field,rebounded over a railroad.

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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