# NTSB LAX83LA463: Cessna 172N, N6089F, Tulelake, CA, September 29, 1983

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: September 29, 1983, 16:30 local (23:30 UTC)
- Place: Tulelake, CA
- Coordinates: 41.799858, -121.460678 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.7999&lon=-121.4607&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 3 serious, 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 23866
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX83LA463
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23866/pdf
- Page: https://openairdocs.org/ntsb/LAX83LA463

## Sequence of events

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

- Loss of engine power, cruise
  - reason for occurrence undetermined (cause)
  - weather condition - high density altitude
  - weather condition - carburetor icing conditions
- In flight collision with object, descent
  - weather condition - downdraft
  - terrain condition - high terrain (contributing factor)
  - object - tree(s) (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - mountainous/hilly (contributing factor)

## Analysis

THE PLT REPORTED THAT HE MADE A LOW PASS OVER THE MEDICINE LAKE AREA, THEN AFTER CIRCLING FOR A FEW MINUTES, HE CLIMBED BACK TO 7500 FT, ESTABLISHED 2000 RPM & 70 KTS, & CONTINUED THE FLT. APPX 5 MIN LATER, HE NOTICED THAT THE TREES APPEARED TO BE GETTING CLOSER. HE CHECKED HIS VERTICAL VELOCITY INDICATOR & NOTED A 200 FT/MIN DESCENT. HE THEN APPLIED FULL THROTTLE, BUT DID NOT NOTICE THE RPM INCREASE & CONTINUED TO LOSE ALTITUDE. SUBSEQUENTLY, THE ACFT COLLIDED WITH A TREE & CRASHED AT AN ELEVATION OF ABOUT 6000 FT. DURING THE INVESTIGATION, THE ENG WAS EXAMINED & RUN ON A PORTABLE TEST STAND & IT OPERATED NORMALLY. THE DENSITY ALTITUDE OF THE CRASH SITE WAS ESTIMATED TO BE 8300 FT. REPORTEDLY, THE TEMP & DEW POINT IN THE AREA WERE 63 & 32 DEG, RESPECTIVELY. ACCORDING TO ICING PROBABILITY CHARTS, VISIBLE CARB ICING WAS POSSIBLE AT RATED POWER. ALSO, UPDRAFTS & DOWNDRAFTS WERE COMMON IN THE AREA & WERE REPORTED BY OTHER PLTS.

## Aircraft

- Registration: [N6089F](https://openairdocs.org/deregistered/N6089F-2013-02-11), registration cancelled 2013-02-11, S/N 17273145, built 1979 (OpenAirDocs)
- Reported make and model: CESSNA 172N
- Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17273145
- Airframe hours: 526
- Engines: LYCOMING O-320-H2AD 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Enterprise Flying Club
- Registered owner: Kent Blankenburg
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 17, 1983, 5 hours before
- Departed: Q93, ENTERPRISE, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 100 total, 17 in this make and model, 73 as pilot in command, 31 in the last 90 days, 9 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 340° at 9 knots
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: 63 °F
- Altimeter: 29.00 inHg
- Observed at: LMT

## 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 19830929068319A](https://openairdocs.org/incident/19830929068319A), Sep 29, 1983: Cessna 172N, Tulelake, CA, Substantial damage. Too low in mountain terrain. Encountered a downdraft and settled into trees.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.