# NTSB DEN83LA081: Cessna 421C, N67943, Gunnison, CO, March 18, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 18, 1983, 16:45 local (23:45 UTC)
- Place: Gunnison, CO
- Coordinates: 38.539424, -106.919609 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.5394&lon=-106.9196&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 7 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16054
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN83LA081
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16054/pdf
- Page: https://openairdocs.org/ntsb/DEN83LA081

## Sequence of events

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

- Overrun, takeoff
  - weather condition - temperature extremes (contributing factor)
  - weather condition - snow (contributing factor)
  - weather condition - tailwind (contributing factor)
  - wrong runway - selected, pilot in command (contributing factor)
  - aborted takeoff - delayed, pilot in command (cause)
  - airport facilities,runway/landing area condition - wet (contributing factor)
- Gear collapsed, takeoff
  - terrain condition - soft (contributing factor)
  - terrain condition - high vegetation (contributing factor)

## Analysis

THE PLT BEGAN TAKING OFF ON RWY 06 WITH A WIND FROM 190 DEG AT 8 KTS. HE STATED THAT MAX POWER & RPM WERE OBTAINED. HE NOTED THAT HE OBTAINED 39 INCHES OF MANIFOLD PRESSURE & 2235 RPM AT 100 KTS IAS. REPORTEDLY, THE ACFT ROTATED PROPERLY, BUT BEGAN TO VIBRATE & SHUDDER & WOULD NOT LIFT OFF. THE PLT THEN LOWERED THE NOSE & ACCELERATED TO 110 KTS IAS. HOWEVER, AGAIN, THE ACFT WOULD ONLY VIBRATE & SHUDDER & WOULD NOT LIFT OFF. THE PLT THEN BEGAN ABORTING THE TAKEOFF. THE ACFT WENT OFF THE END OF THE RWY AT 70 TO 80 KTS & BECAME AIRBORNE FOR APRX 75 FT AS IT WENT OVER A DROP OFF IN THE TERRAIN. SUBSEQUENTLY, THE ACFT LANDED IN SOFT SOIL & HIGH GRASS WHERE THE GEAR COLLAPSED. AN INVESTIGATION REVEALED THAT THE TEMP WAS 30 DEG & SNOW WAS FALLING. THE PLT BELIEVED THE ACCIDENT RESULTED FROM COLD TEMPS ALONG WITH WATER BLOWN ONTO THE TAIL SURFACES OF THE ACFT. HE DID NOT DESCRIBE THE SURFACE CONDITION ON THE WINGS. STALL SPEED FOR THIS ACFT WAS 86 KTS AT THE MAX GROSS WT & WAS WITH WT & BALANCE LIMITS.

## Aircraft

- Registration: [N67943](https://openairdocs.org/deregistered/N67943-2013-05-02), registration cancelled 2013-05-02, S/N 421C1036, built 1981 (OpenAirDocs)
- Reported make and model: CESSNA 421C
- Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (registry code 2076016) (OpenAirDocs)
- Registry engine: [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c) (registry code 17035, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 421C1036
- Airframe hours: 684
- Engines: CONTINENTAL IO-520-N 365 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: J&K Asset Management
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, December 8, 1982
- Departed: GUC, GUNNISON, CO
- Destination: OUN, NORMAN, OK
- Flight plan: IFR
- Airport: GUC, Gunnison, runway 6, 7,198 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 2,117 total, 348 in this make and model, 1,383 as pilot in command, 59 in the last 90 days, 9 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 190° at 8 knots
- Visibility: 15 statute miles
- Lowest ceiling: 5,000 ft overcast
- Temperature: 30 °F, dew point 30 °F
- Altimeter: 29.00 inHg
- Observed at: GUC

## 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 19830318008829A](https://openairdocs.org/incident/19830318008829A), Mar 18, 1983: Cessna 421C, Gunnison, CO, Substantial damage. Aircraft shuddered on liftoff. Pilot aborted takeoff. Overran departure end into a ditch. Possible slush icing.

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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