# NTSB SEA86LA061: Piper PA-15, N4521H, Mount St.Helens, WA, February 20, 1986

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: February 19, 1986, 17:30 local (Feb 20, 1986, 01:30 UTC)
- Place: Mount St.Helens, WA
- Coordinates: 47.300701, -122.310104 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.3007&lon=-122.3101&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 40357
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA86LA061
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40357/pdf
- Page: https://openairdocs.org/ntsb/SEA86LA061

## Sequence of events

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

- In flight encounter with weather, maneuvering
  - weather condition - high wind
  - wind information - not understood, pilot in command (cause)
  - weather condition - gusts
  - judgment - poor, pilot in command (cause)
  - aircraft performance,climb capability - exceeded (cause)
- In flight collision with terrain/water, maneuvering

## Analysis

THE PILOT WAS ATTEMPTING TO FLY INSIDE A VOLCANIC CRATER AROUND THE LAVA DOME ABOVE 6000 FEET M.S.L.. THE AIRCRAFT HAS A 75 HORSEPOWER ENGINE. HIGH WINDS ENTERING THE CRATER FROM THE NORTHEAST FLOWING ACROSS THE LAVA DOME CREATED A DOWNDRAFT THAT THE AIRCRAFT COULD NOT OUTCLIMB. BOTH OCCUPANTS WERE RESCUED THE FOLLOWING DAY.

## Aircraft

- Registration: N4521H (not matched to a registry record)
- Reported make and model: PIPER PA-15
- Category: Airplane
- Serial number: 15-295
- Airframe hours: 2
- Engines: CONTINENTAL A-75 75 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Departed: KLS, KELSO, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; private; airplane ratings: single-engine land; medical: class 3, expired; seat: front; flight hours: 75 total, 2 in this make and model, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 20 statute miles
- Lowest ceiling: none

## 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 19860219004809A](https://openairdocs.org/incident/19860219004809A), Feb 19, 1986: Piper PA15, Mount St Helens, WA, Destroyed. Wingtip struck lava dome after encountering a downdraft. Aircraft impacted inside the dome.

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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