# NTSB DEN89FA208: Piper PA-24-180, N7835P, Grantsville, UT, September 7, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: September 6, 1989, 18:15 local (Sep 7, 1989, 00:15 UTC)
- Place: Grantsville, UT
- Coordinates: 40.670825, -112.759033 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.6708&lon=-112.7590&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report September 5, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 17606
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN89FA208
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17606/pdf
- Page: https://openairdocs.org/ntsb/DEN89FA208

## Probable cause

IMPROPER IN-FLIGHT PLANNING/DECISION BY THE PILOT, BY ENTERING A BOX CANYON WITH INSUFFICIENT ALTITUDE TO ASSURE A SAFE EXIT.  CONTRIBUTING FACTORS WERE:  BOX CANYON, RISING TERRAIN, AND HIGH DENSITY ALTITUDE.

## Sequence of events

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

- In flight collision with terrain/water, maneuvering
  - in-flight planning/decision - improper, pilot in command (cause)
  - light condition - dusk
  - terrain condition - blind/box canyon (contributing factor)
  - terrain condition - rising (contributing factor)
  - proper altitude - not maintained, pilot in command (cause)
  - weather condition - high density altitude (contributing factor)
  - stall/mush

## Analysis

THE PLT & PASSENGER TOOK OFF ON A LOCAL FLT AT 1801 MDT. WHEN THE ACFT DID NOT RETURN, A SEARCH WAS INITIATED. THE ACFT WAS FOUND THE NEXT MORNING WHERE IT HAD CRASHED & BURNED ON THE SIDE OF A BOX CANYON. ENTRANCE TO THE CANYON WAS FROM THE SOUTHEAST. THE ACFT CRASHED ON STEEP TERRAIN ON THE WEST SIDE OF THE CANYON. IMPACT WAS ON A SOUTHERLY HEADING. IMPACT MARKS (FRAGMENTED & GOUGED ROCKS) WERE FOUND ABOUT 50 FT UPSLOPE FROM WHERE THE MAIN WRECKAGE CAME TO REST. MUCH OF THE WRECKAGE WAS DEMOLISHED BY FIRE. AN EXAM OF THE RGT WING REVEALED CHORDWISE CRUSHING OF ITS LOWER SKIN. BOTH PROP BLADES WERE BENT & TWISTED; THE TIPS OF BOTH PROPS WERE TORN OFF. NO PREIMPACT MECHANICAL PART FAILURE OR MALFUNCTION WAS FOUND. DENSITY ALTITUDE AT THE CRASH SITE WAS APRX 7000 FT.

## Aircraft

- Registration: [N7835P](https://openairdocs.org/deregistered/N7835P-2013-09-20), registration cancelled 2013-09-20, S/N 24-3055, built 1962 (OpenAirDocs)
- Reported make and model: PIPER PA-24-180
- Registry model: [Piper PA-24](https://openairdocs.org/model/piper-pa-24) (registry code 7102402) (OpenAirDocs)
- Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 24-3055
- Airframe hours: 4187
- Engines: LYCOMING O-360-A1A 180 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Calvin, Joe B.
- Registered owner: Calvin, Joe B
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 2, 1989, 8 hours before
- Departed: UT29, TOOELE, UT
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 1,967 total, 135 in this make and model, 95 in the last 90 days, 21 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: 320° at 11 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 39 °F
- Altimeter: 29.00 inHg
- Observed at: SLC, 28 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 19890906033989A](https://openairdocs.org/incident/19890906033989A), Sep 6, 1989: Piper PA24, Grantsville, UT, Destroyed, 2 fatal. Flew into box canyon at low altitude. Unable to clear rising terrain. Indicates tried to turn and hit canyon wall.

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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