# NTSB ANC96LA029: Cessna 172, N739YR, Ketchikan, AK, March 4, 1996 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: March 4, 1996, 16:33 local (20:33 UTC) - Place: Ketchikan, AK - Coordinates: 55.610984, -131.580825 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=55.6110&lon=-131.5808&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report September 19, 1996 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2803 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC96LA029 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2803/pdf - Page: https://openairdocs.org/ntsb/ANC96LA029 ## Probable cause loss of engine power for undetermined reason(s). A factor relating to the accident was: the lack of a suitable area for an emergency landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, maneuvering - reason for occurrence undetermined (cause) - Forced landing, emergency descent/landing - Ditching, emergency landing - terrain condition - none suitable (contributing factor) - terrain condition - water ## Analysis The first pilot, a certificated flight instructor, was providing a demonstration of departure stalls to the second pilot, who was occupying the left front seat. The instructor reported that he applied carburetor heat before beginning the demonstration. At the conclusion of the third stall, the first pilot added power about 1,800 feet mean sea level (MSL). The engine did not respond, and emergency procedures only restored partial power. The airplane continued to descend, and the pilot declared an emergency 'mayday' over the airplane radio. He selected an emergency landing area near the shore of an island, but noticed that the beach area contained large rocks. The pilot then intentionally ditched the airplane about 30 yards from the shore. After touchdown in the water, both pilots swam to shore and the airplane sank. A nearby float equipped airplane responded to the emergency call and picked up the two pilots. An examination of the airplane did not locate a mechanical malfunction. The reported temperature and dew point were 40 and -2 degrees, respectively, which were not conducive to carburetor icing. ## Factual narrative On March 4, 1996, about 1633 Alaska standard time, a wheel equipped Cessna 172, N739YR, was ditched following a loss of engine power, about 12 miles north of Ketchikan, Alaska. The airplane was being operated as a visual flight rules (VFR) local area instructional flight when the accident occurred. The airplane, operated by the first pilot, sustained substantial damage. The first pilot, a certificated airline transport pilot and flight instructor, was not injured. The second pilot, a noncertificated student, received minor injuries. Visual meteorological conditions prevailed. The flight originated at the Ketchikan airport about 1550. In a telephone conversation on March 5, 1996, the first pilot reported to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) that he was occupying the right front seat and was providing a demonstration of departure stalls to the second pilot who was occupying the left front seat. At the conclusion of the third stall, the first pilot added power about 1,800 feet mean sea level (MSL). The engine did not respond and emergency procedures only restored partial power. The first pilot indicated that he applied carburetor heat during the demonstration of stalls. The airplane continued to descend and the pilot declared an emergency "mayday" over the airplane radio. The pilot selected an emergency landing area near the shore of Betton Island but noticed that the beach area contained large rocks. The pilot then intentionally ditched the airplane about 30 yards from the shore. After touchdown in the water, both pilots swam to shore and the airplane sank. A nearby float equipped airplane responded to the emergency call and picked up the two pilots. After the airplane was recovered from the water, an engine examination was conducted on June 6, 1996, in Ketchikan. The examination was supervised by a Federal Aviation Administration (FAA) airworthiness inspector from the Juneau Flight Standards District Office (FSDO). The engine had been partially preserved after retrieval from the salt water. Gear and valve train continuity was established and thumb compression was evident when the engine was rotated by hand. The magnetos were internally damaged by corrosion. The vacuum pump drive was sheared. The engine oil filter was free of contaminants. Fuel and water was found in the carburetor fuel line. The carburetor inlet screen was free of contaminants. The throttle and mixture cables were attached to the carburetor. The carburetor accelerator pump and floats were undamaged. The carburetor heat assembly was crushed and the carburetor heat control cable was broken about 2 inches from the its attach point on the assembly. The FAA inspector could not determine if the broken carburetor heat cable occurred before or after impact with the water. ## Aircraft - Registration: [N739YR](https://openairdocs.org/aircraft/N739YR), registered now, S/N 17270917, built 1978 (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: 17270917 - Airframe hours: 5091 - Engines: Lycoming O-320-H2AD 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Michael C. Rhoads - Registered owner: Richard D. Trimble - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 27, 1996, 7 hours before - Departed: KTN, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 28; airline transport, flight instructor; airplane ratings: single-engine land, multi-engine land, single-engine sea, multi-engine sea; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 6,500 total, 300 in this make and model, 6,350 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 6 knots - Visibility: 65 statute miles - Lowest ceiling: 20,000 ft broken - Temperature: 39 °F, dew point -0 °F - Altimeter: 29.00 inHg - Observed at: KTN, 12 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 19960304003519A](https://openairdocs.org/incident/19960304003519A), Mar 4, 1996: Cessna 172N, Ketchikan, AK, Substantial damage. Demo departure stalls. Engine failed respond on recovery. No direct cause fround. Possible carb ice. Broken cable. 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.