# NTSB DEN87LA080: Cessna 170B, N2323D, Boulder, CO, April 3, 1987

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 3, 1987, 12:50 local (19:50 UTC)
- Place: Boulder, CO
- Coordinates: 40.039512, -105.369728 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.0395&lon=-105.3697&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report May 19, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 17187
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN87LA080
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17187/pdf
- Page: https://openairdocs.org/ntsb/DEN87LA080

## Analysis

AN 85 HOUR PRIVATE PLT WAS FLYING FOR PROFICIENCY IN HIS CESSNA 170. AT THE LAST LANDING OF THE FLT, AN APPARENTLY NORMAL TOUCHDOWN WAS COMPLETED. DURING THE LANDING ROLL, THE ACFT SWERVED TO THE LEFT AND THE PLT CORRECTED TO THE RIGHT. THE ACFT CONTINUED TO TURN RIGHT WITH AN INCREASED RATE OF TURN. THE PLT WAS UNABLE TO CORRECT THIS TURN AND THE ACFT DEPARTED THE RWY TO THE RIGHT. THE LEFT MAIN GEAR ENCOUNTERED SOFT FILL DIRT AND THE ACFT NOSED OVER.

## Sequence of events

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

- Loss of control - on ground/water, landing - roll
  - compensation for wind conditions - inadequate, pilot in command (cause)
  - ground loop/swerve - inadvertent, pilot in command (cause)
- Nose over, landing - roll
  - terrain condition - soft (contributing factor)

## Aircraft

- Registration: [N2323D](https://openairdocs.org/aircraft/N2323D), registered now, S/N 20475, built 1952 (OpenAirDocs)
- Reported make and model: CESSNA 170B
- Registry model: [Cessna 170B](https://openairdocs.org/model/cessna-170b) (registry code 2072306) (OpenAirDocs)
- Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 20475
- Airframe hours: 4400
- Engines: CONTINENTAL O-300-A 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Steven J. Varlese
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 18, 1986
- Airport: IV5, Boulder Municipal, runway 8, 4,100 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 85 total, 35 in this make and model, 60 as pilot in command, 23 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 140° at 6 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 57 °F, dew point 25 °F
- Altimeter: 29.00 inHg
- Observed at: BJC, 9 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 19870403079029A](https://openairdocs.org/incident/19870403079029A), Apr 3, 1987: Cessna 170, Boulder, CO, Substantial damage. Lost control and ground looped the tail wheel aircraft on the landing roll. Left the runway and overturned in dirt.

## Other investigations on N2323D (2)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB CEN13CA138](https://openairdocs.org/ntsb/CEN13CA138), Jan 20, 2013: Cessna 170B (N2323D), Erie, CO, substantial damage. Probable cause: The pilot’s failure to maintain control of the airplane while taking off in gusting wind conditions.
- [NTSB LAX76FUG65](https://openairdocs.org/ntsb/LAX76FUG65), Jun 27, 1976: Cessna 170B (N2323D), Upland, CA, substantial damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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