# NTSB DEN82FTE17: Cessna 172, N4899F, Boulder, CO, March 7, 1982

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Final report
- Date: March 6, 1982, 21:40 local (Mar 7, 1982, 04:40 UTC)
- Place: Boulder, CO
- Location: 40.0244° N, 105.2513° W: Placed by OpenAirDocs: center of Boulder, CO, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=40.0244&lon=-105.2513&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 2 serious
- Status: Completed, report March 6, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 70012
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN82FTE17
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/70012/pdf
- Page: https://openairdocs.org/ntsb/DEN82FTE17

## Sequence of events

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

- Loss of engine power, cruise - normal
  - miscellaneous - undetermined (cause)
- Forced landing, descent - emergency
  - emergency procedure - improper, pilot in command
- In flight collision with terrain/water, landing - flare/touchdown
  - light condition - dark night (contributing factor)
  - terrain condition - uphill (contributing factor)
  - terrain condition - rough/uneven (contributing factor)
- Nose over, landing - flare/touchdown

## Analysis

THE ENGINE LOST POWER WHILE THE AIRCRAFT WAS CRUISING AT 7500 FT MSL AT NIGHT. DURING A FORCED LANDING, THE AIRCRAFT TOUCHED DOWN ON STEEP, ROCKY SOIL. THE AIRCRAFT BOUNCED AND THEN NOSED OVER AFTER A SECOND TOUCHDOWN. DURING AN INTERVIEW ABOUT TWO HOURS AFTER THE ACCIDENT, THE PILOT REPORTED AN INDICATION OF ABOUT 1800 RPM WHEN THE ENGINE LOST POWER. DURING THAT INTERVIEW, HE INDICATED THAT HE MAY NOT HAVE USED CARBURETOR HEAT WHILE ATTEMPTING TO RESTART THE ENGINE. LATER IN A WRITTEN STATEMENT HE REPORTED THAT HE "PUSHED IN CARB HEAT" WHILE ATTEMPTING TO RESTART THE ENGINE. THE TEMPERATURE WAS 27 DEGREES FAHRENHEIT, BUT THE DEW POINT WAS NOT DETERMINED. WHEN THE FUEL SYSTEM WAS CHECKED, NO CONTAMINATION WAS FOUND. HOWEVER, DURING IMPACT, THE FIREWALL SUMP HAD RUPTURED AND THE CARBURETOR WAS BROKEN AWAY FROM THE ENGINE. AN ENGINE TEARDOWN REVEALED NO PREIMPACT MALFUNCTION OR FAILURE.

## Aircraft

- Registration: [N4899F](https://openairdocs.org/deregistered/N4899F-1982-08-29), registration cancelled 1982-08-29, S/N 17273098, built 1979 (OpenAirDocs)
- Reported make and model: CESSNA 172
- Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs)
- Category: Airplane
- Serial number: 17273098
- Airframe hours: 495
- Engines: LYCOMING O-320-H2AD 160 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: John F. Byrns
- Registered owner: John F. Byrns
- Departed: BJC, BROOMFIELD, CO
- Destination: LCC

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; flight hours: 296 total, 296 in this make and model, 249 as pilot in command, 94 in the last 90 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 270° at 8 knots
- Visibility: 20 statute miles
- Temperature: 81 °F
- Observed at: BJC, 7 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 19820306002479A](https://openairdocs.org/incident/19820306002479A), Mar 6, 1982: Cessna 172N, Boulder, CO, Destroyed. Engine quit en route at night. Crash landed in rough terrain. Failed to use carb heat. Conditions ideal for 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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