# NTSB DEN89LA049: Piper PA-11, N5570H, Winnett, MT, December 23, 1988

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 23, 1988, 13:00 local (20:00 UTC)
- Place: Winnett, MT
- Coordinates: 47.109333, -108.219871 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.1093&lon=-108.2199&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report December 3, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 17653
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN89LA049
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17653/pdf
- Page: https://openairdocs.org/ntsb/DEN89LA049

## Sequence of events

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

- Loss of control - in flight, takeoff - initial climb
  - wing - ice (contributing factor)
  - aircraft preflight - inadequate, pilot in command (cause)
  - stall - inadvertent, pilot in command (cause)
  - fatigue(flight schedule), pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PILOT WAS TAKING OFF FROM A FARM STRIP WITH A 10 KT HEAD WIND. THE PLT SAID THE SUN WAS SHINING  AT THE TIME OF THE ACDT BUT THERE HAD BEEN SNOW SHOWERS IN THE AREA. HE SAID THE LIFTOFF WAS NORMAL BUT AT ABOUT 15 TO 18 FT AGL THE ACFT STALLED AND CRASHED. AFTER THE ACDT THE PLT FOUND A THIN LAYER OF ICE ON THE WINGS. HE SAID THE SUN PROBABLY MELTED SNOW ON THE WINGS, WHILE THE ACFT WAS PARKED, WHICH THEN FROZE DURING THE TAKEOFF. THE TEMP AT THE TIME OF THE ACDT WAS ESTIMATED TO BE 20-25 DEG F. THE PLT REPORTED HE HAD FLOWN 10 HRS IN THE PRECEDING 24.

## Aircraft

- Registration: [N5570H](https://openairdocs.org/aircraft/N5570H), registered now, S/N 11-1092, built 1949 (OpenAirDocs)
- Reported make and model: PIPER PA-11
- Registry model: [Piper PA-11](https://openairdocs.org/model/piper-pa-11) (registry code 7101102) (OpenAirDocs)
- Registry engine: [Continental C90 series](https://openairdocs.org/engine/continental-c90-series) (registry code 17009, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 11-1092
- Airframe hours: 3825
- Engines: CONTINENTAL C-90-8F 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Lemmon, Darrell C.
- Registered owner: Lemmon, Darrell & Robin
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 23, 1988, 174 hours before
- Departed: NONE
- Destination: NONE, RYEGATE, MT
- Airport: NONE, Farm Strip, runway 22, 3,000 × 50 ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: front; flight hours: 246 total, 175 in this make and model, 204 as pilot in command, 150 in the last 90 days, 75 in the last 30 days, 10 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 200° at 10 knots
- Visibility: 3 statute miles
- Lowest ceiling: 1,500 ft overcast
- Temperature: 25 °F

## 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 19881223060079A](https://openairdocs.org/incident/19881223060079A), Dec 23, 1988: Piper PA11, Winnett, MT, Substantial damage

## Other investigations on N5570H (2)

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.

- [NTSB DEN68D0047](https://openairdocs.org/ntsb/DEN68D0047), Jul 11, 1967: Piper PA-11 (N5570H), Sheridan, WY, substantial damage
- [NTSB SEA65D0016](https://openairdocs.org/ntsb/SEA65D0016), Feb 6, 1965: Piper PA-11 (N5570H), Decker, MT, substantial damage

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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