# NTSB ANC07CA023: Cessna 172, N73813, Chugiak, AK, March 10, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: March 10, 2007, 12:00 local (16:00 UTC) - Place: Chugiak, AK - Coordinates: 61.400001, -149.512222 - Nearby events: https://openairdocs.org/map.md?lat=61.4000&lon=-149.5122&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 29, 2007 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 65414 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC07CA023 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/65414/pdf - Page: https://openairdocs.org/ntsb/ANC07CA023 ## Probable cause The instructor pilot's inadequate supervision of the student while landing, which resulted in an undershoot, and subsequent in-flight collision with snow-covered terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Undershoot, approach - vfr pattern - final approach - distance/altitude - misjudged, dual student - supervision - inadequate, pilot in command(cfi) (cause) - In flight collision with terrain/water, approach - vfr pattern - final approach - terrain condition - snow covered ## Analysis The certificated flight instructor was providing primary flight instruction to the student pilot under Title 14, CFR Part 91, at the time of the accident. The flight instructor reported that while on final approach to land, he inadvertently allowed the student pilot to descend into a snow-covered area, about 40 feet short of the runway threshold. As the airplane's main wheels contacted an area of deep, hard packed snow, the airplane nosed down, and right wing struck the snow-covered terrain, sustaining substantial damage. The instructor noted that there were no preaccident mechanical anomalies with the airplane. ## Factual narrative The certificated flight instructor was providing primary flight instruction to the student pilot under Title 14, CFR Part 91, at the time of the accident. The flight instructor reported that while on final approach to land, he inadvertently allowed the student pilot to descend into a snow-covered area, about 40 feet short of the runway threshold. As the airplane's main wheels contacted an area of deep, hard packed snow, the airplane nosed down, and right wing struck the snow-covered terrain, sustaining substantial damage. The instructor noted that there were no preaccident mechanical anomalies with the airplane. ## Aircraft - Registration: [N73813](https://openairdocs.org/aircraft/N73813), registered now, S/N 17267693, built 1976 (OpenAirDocs) - Reported make and model: Cessna 172 - 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: 17267693 - Engines: Lycoming O-360 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Elmendorf Aero Club - Registered owner: United States Air Force - Airworthiness certificate: Standard, Normal - Departed: EDF, ANCHORAGE, AK - Destination: BCV, Chugiak, AK - Flight plan: Company VFR - Airport: BCV, Birchwood Airport, runway 19R, 4,010 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 31; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review June 1, 2005; seat: right; flight hours: 905 total, 558 in this make and model, 822 as pilot in command, 128 in the last 90 days, 56 in the last 30 days, 3 in the last 24 hours - Student pilot; age 31; injuries: none; student; medical: class 3, without waivers/limitations; seat: left; flight hours: 8 total, 5 in this make and model, 5 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 23 °F, dew point 5 °F - Altimeter: 29.52 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 20070310002969A](https://openairdocs.org/incident/20070310002969A), Mar 10, 2007: Cessna 172N, Birchwood, AK, Substantial damage. (-23) Certified flight instructor (CFI) was providing dual instruction. Student pilot was solely at the controls while landing the airplane under the… ## Other investigations on N73813 (1) 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. - [NTSB ANC92FA069](https://openairdocs.org/ntsb/ANC92FA069), May 9, 1992: Cessna 172 (N73813), Ruth Glacier, AK, substantial damage. Probable cause: THE FAILURE OF THE PILOTS OF BOTH AIRPLANES TO MAINTAIN AN ADEQUATE VISUAL LOOKOUT. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WAS THE FAILURE OF THE PILOT OF THE CE-172 TO BECOME AWARE OF AND TO USE… 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.