# NTSB MKC90LA108: Piper PA-31-350, N111AY, Dubuque, IA, May 16, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 15, 1990, 22:50 local (May 16, 1990, 03:50 UTC)
- Place: Dubuque, IA
- Coordinates: 42.500377, -90.689178 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.5004&lon=-90.6892&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report September 15, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 34980
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC90LA108
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34980/pdf
- Page: https://openairdocs.org/ntsb/MKC90LA108

## Probable cause

WEATHER EVALUATION MISJUDGED RESULTING IN UNCONTROLLED DESCENT BY THE PILOT IN COMMAND AND AIRCRAFT CONTROL NOT MAINTAINED BY THE PILOT IN COMMAND.

## Sequence of events

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

- In flight encounter with weather, approach - faf/outer marker to threshold (ifr)
  - weather condition - rain (contributing factor)
  - weather condition - turbulence (contributing factor)
  - weather condition - windshear (contributing factor)
  - weather evaluation - misjudged, pilot in command (cause)
  - missed approach - attempted, pilot in command (cause)
  - descent - uncontrolled, pilot in command (cause)
  - aircraft control - not maintained, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

WHILE ON FINAL, DURING A FULL ILS APPROACH, THE ATR RATED PLT SAID THAT HE ENCOUNTERED HEAVY RAIN, EXTREME TURBULENCE, AND A POSSIBLE WIND SHEAR AT ABOUT 600 FEET AGL. HE SAID THAT HE LOST THE LOCALIZER, STARTED A MISSED APPROACH WITH FULL POWER AND A PITCH UP ATTITUDE, BUT THE AIRCRAFT CONTINUED ITS DESCENT AND COLLIDED WITH THE TERRAIN ABOUT 1/2 MILE SHORT OF THE RUNWAY.

## Aircraft

- Registration: [N111AY](https://openairdocs.org/deregistered/N111AY-1990-08-07), registration cancelled 1990-08-07, S/N 318052125 (OpenAirDocs)
- Reported make and model: PIPER PA-31-350
- Registry model: [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350) (registry code 7103110) (OpenAirDocs)
- Category: Airplane
- Serial number: 31-8052125
- Airframe hours: 3948
- Engines: LYCOMING TSIO-540-J2BD 350 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Registered owner: A.Y. Mcdonald Co.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 19, 1989, 179 hours before
- Departed: DSM, DES MOINES, IA
- Destination: DBQ
- Flight plan: IFR
- Airport: DBQ, Dubuque, runway 31, 6,498 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; airline transport, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 10,200 total, 1,583 in this make and model, 7,673 as pilot in command, 64 in the last 90 days, 34 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Night/dark
- Wind: 330° at 20 knots, gusting 30
- Visibility: 2 statute miles
- Lowest ceiling: 300 ft overcast
- Temperature: 55 °F, dew point 55 °F
- Altimeter: 29.00 inHg
- Observed at: DBQ, 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 19900515015799A](https://openairdocs.org/incident/19900515015799A), May 15, 1990: Piper PA31350, Dubuque, IA, Substantial damage. Encountered heavy rain,turbulence, and windshear on ILS approach. Tried go around. Continued descent until impact.

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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