# NTSB SEA94LA093: Cessna 210D, N3820Y, Cobalt, ID, March 30, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 30, 1994, 07:45 local (14:45 UTC) - Place: Cobalt, ID - Location: 45.0930° N, 114.2317° W: Placed by OpenAirDocs: center of Cobalt, ID, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=45.0930&lon=-114.2317&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report October 19, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 41904 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA94LA093 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41904/pdf - Page: https://openairdocs.org/ntsb/SEA94LA093 ## Probable cause THE PILOT SELECTED UNSUITABLE TERRAIN FOR LANDING. FACTORS IN THE ACCIDENT WERE: THE WET RUNWAY AND RISING TERRAIN THAT PRECLUDED A GO-AROUND. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Overrun, landing - roll - airport facilities,runway/landing area condition - wet (contributing factor) - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause) - terrain condition - rising (contributing factor) - go-around - not possible, pilot in command (contributing factor) ## Analysis AFTER LANDING ON THE 2300-FT TURF STRIP, THE PILOT WAS UNABLE TO STOP THE AIRPLANE BEFORE OVERRUNNING THE UPWIND END INTO A CREEK. THE PILOT REPORTED THAT THE GRASS WAS COVERED WITH A HALF-MELTED COAT OF FROST RENDERING THE BRAKES INEFFECTIVE; THE TEMPERATURE WAS 35 DEGS F. RISING TERRAIN AT THE UPWIND END PRECLUDED A GO-AROUND. THE PILOT ALSO REPORTED THAT HE HAD NOT FLOWN INTO THE AIRSTRIP FOR SEVERAL YEARS. ## Factual narrative On March 30, 1994, approximately 0745 hours mountain standard time (mst), a Cessna 210D, N3820Y, registered to and being flown by Marvin D. Gregersen, a certificated commercial pilot, was substantially damaged when it overran the upwind end of the east runway at the Taylor private airstrip 23 miles west of Cobalt, Idaho. The pilot and three passengers were uninjured. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was personal in nature, was to have been operated in accordance with 14CFR91, and originated from Boise, Idaho, at 0645 hours. The pilot reported that he touched down at the intended point on the 2300 foot turf strip, landing eastbound and slightly uphill. He reported that the sun had just come up, that the winds were calm, and the temperature was approximately 35 degrees Fahrenheit. He also indicated that there was melting frost on the runway surface, that he was unable to stop the aircraft using brakes and retracted flaps, and that rising terrain precluded a go around. The aircraft subsequently overran the upwind end of the runway. The pilot reported no mechanical malfunction with the aircraft or its brakes, and told the investigator that it had been several years since he had last flown into the Taylor airstrip. ## Aircraft - Registration: [N3820Y](https://openairdocs.org/deregistered/N3820Y-2014-10-02), registration cancelled 2014-10-02, S/N 21058320, built 1964 (OpenAirDocs) - Reported make and model: CESSNA 210D - Registry model: [Cessna 210D](https://openairdocs.org/model/cessna-210d) (registry code 2073414) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 21058320 - Airframe hours: 4486 - Engines: CONTINENTAL IO-520-A5B 285 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Gregersen, Marvin, D. - Registered owner: Gregersen, Marvin, D. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 20, 1994, 32 hours before - Departed: BOI, BOISE, ID - Destination: COBALT - Airport: Taylor Ranch, runway 9, 2,300 × 150 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 3,845 total, 2,166 in this make and model, 3,845 as pilot in command, 49 in the last 90 days, 28 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 36 °F - Altimeter: 30.00 inHg ## 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 19940330007269A](https://openairdocs.org/incident/19940330007269A), Mar 30, 1994: Cessna 210D, Cobalt, ID, Substantial damage. Overran short frosty grass strip on landing. Stopped in a creek. Braking nil. Rising terrain precluded go around. 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.