# Accident 20130306003259A: Cessna 207, Akiachak, AK, March 6, 2013 - Type: FAA accident report (Accident/Incident Data System), as reported - Date: March 6, 2013, 17:25 local time - Place: Akiachak, AK - Airport: Akiachak - Damage: Substantial damage - Phase of flight: Cruise/Level Flight - Operating rules: Air taxi and commuter (Part 135) - Operator: YAAA - Location: 60.9656° N, 161.4292° W: From the FAA - Nearby events: https://openairdocs.org/map.md?lat=60.9656&lon=-161.4292&mi=10 - Aircraft: N1704U, registered now (https://openairdocs.org/aircraft/N1704U) (OpenAirDocs) - Registry model: Cessna 207 (registry code 2073602, https://openairdocs.org/model/cessna-207) (OpenAirDocs) - Registry engine: Continental IO-520 series (registry code 17032, https://openairdocs.org/engine/continental-io-520-series) (OpenAirDocs) - Reported make and model: CESSNA 207 - Reported engine: CONT MOTOR IO 520 SERIES - People aboard: 3 - Fatal injuries: 0 - Other injuries: 0 - Pilot certificates: Airline transport - Pilot flight hours: 30,000 total, 20,000 in this make and model, 200 in the last 90 days - NTSB investigation: [NTSB ANC13LA029](https://openairdocs.org/ntsb/ANC13LA029) (OpenAirDocs) - FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/) - Page: https://openairdocs.org/incident/20130306003259A ## Narrative As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^. AIRCRAFT N1704U FIFTEEN MINUTES OUT OF BET ON FLIGHT TO KLG IN CRUISE AT 1000 FEET. ENGINE MADE VERY LOUD WHINE NOISE AND STARTED LOSING POWER. PIC CALLED BET ON COMPANY FREQUENCY (130.70) TO REPORT SITUATION. PIC SET UP FOR LANDING ON SMALL POND (5.5 MILES NORTH OF AKIACHAK) WITH ENGINE PRODUCING SOME POWER. WHILE ON DOWNWIND ENGINE LOST ALL POWER AND PIC REALIZED HE WOULD NOT MAKE IT TO THE POND SO HE FOUND HIGH TUNDRA. PIC KEPT FLAPS UP TO MAKE IT TO CLEARER AREA. LEFT SIDE OF HORIZONTAL STABILIZER STRUCK SMALL TREES AND NOSE WHEEL FORK BROKE ON IMPACT WITH TUNDRA. ENGINE CASE CRACKED AT #2 JOURNAL WHEN CRANKSHAFT BROKE. NO FIRE. ELT DID NOT ACTIVATE, PIC AND PASSENGERS SAID INPACT FORCES WERE LOW. PIC AND PASSENGERS EVACUATED AIRCRAFT UNTIL PIC DETERMINED IT WAS SAFE TO RETURN FOR SHELTER. PIC AND 2 PASSENGERS UNINJURED. FLIGHT FOLLOWING IN BET RECEIVED PIC DISTRESS MESSAGES AND INITIATED RECOVERY PER MANUAL PROCEDURES. AMENDMENT- 6/7/2013- RECEIVED TEAR-DOWN REPORT FROM CONTINENTAL MOTORS: YUTE DOM ORIGINALLY THOUGHT THE CRANKSHAFT WAS BROKE BUT THE TEAR-DOWN REPORT IS DIFFERENT: EXAMINER SIGNATURE: PHILLIP GRICE DATE: MAY 15, 2013 DATE ENGINE MODEL ENGINE SERIAL NO. AIRCRAFT REGISTRATION PAGE 5-15-2013 IO520DCF 175037 N1704U GENERAL INFORMATION: EXAMINATION ENGINE RECEIVED DATE MAY 15, 2013 FACILITY CONTINENTAL MOTORS INC. RGA # 250415 MOBILE, ALABAMA ADDRESS 2039 BROAD STREET 36615 FROM ALASKAN AIRCRAFT ENGINES NTSB/FAA TAGGED YES BOX SEALED YES ENGINE INFORMATION: MAKE CONTINENTAL MOTORS INC. MODEL IO520DCF SERIAL NO. 175037 ENGINE POSITION SINGLE TOTAL TIME 3085.7 TIME SOH 1329.7 10/12/2011 BUILD DATE 08-26-1981 IN SERVICE DATE NOT REPORTED REMOVAL DATE 03-12-2013 AIRCRAFT / ACCIDENT INFORMATION AIRCRAFT MAKE CESSNA AIRCRAFT MODEL 207 AIRCRAFT SERIAL NO. 20700304 REGISTRATION NO. N1704U (INFORMATION FROM ENGINE LOG BOOK) ACCIDENT DATE MARCH 26,2013 ACCIDENT LOCATION AKIACHAK AK. SIGNIFICANT LOGBOOK INFORMATION: ONLY INSTALLATION AND REMOVAL ENTRIES IN LOGBOOK. REPORT SUMMARY: THE NUMBER ONE PISTON ECI PART NUMBER AEC648045/Z WAS FRACTURED AT THE PISTON PIN BORE, RELEASING THE NUMBER ONE ROD AND PISTON PIN ASSEMBLY AT THE SMALL END. THE UNSUPPORTED NUMBER ONE ROD AND PISTON PIN ASSEMBLY CAUSED EXTREME MECHANICAL DAMAGE TO THE REAR SECTION OF THE CRANKCASE AND CAMSHAFT. THE NUMBER ONE ROD RELEASED FROM THE CRANKSHAFT, EXHIBITED EXTREME MECHANICAL DAMAGE AND WAS FOUND IN THE OIL SUMP. THERE WERE NO SIGNS OF LUBRICATION DISTRESS. PORTIONS OF THE ECI PISTON SKIRT WERE RECOVERED FROM THE OIL SUMP AND INSPECTED IN THE CMI LAB. THE NUMBER ONE CYLINDER, PISTON, ROD, AND SUMP CONTENTS WERE RETAINED IN BONDED STORAGE UNTIL THE NTSB IIC DETERMINES DISPOSITION OF THE ENGINE AND THE PARTS. AMENDED SECTION 21 C THRU F OF THIS REPORT TO IDENTIFY NUMBER 1 PISTON. OPERATOR WILL AMEND SDR REPORT. ## The NTSB's investigation of this event (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 ANC13LA029](https://openairdocs.org/ntsb/ANC13LA029), Mar 6, 2013: Cessna 207 (N1704U), Bethel, AK, substantial damage. Probable cause: The failure of the engine’s No. 1 piston connecting rod retaining bolts due to fatigue fracturing, which resulted in a loss of engine power during cruise flight. ## Other reports on N1704U (3) Matched to the same aircraft by N-number and date. - [Incident 20081016849499I](https://openairdocs.org/incident/20081016849499I), Oct 16, 2008: Cessna 207 (N1704U), Bethel, AK, No damage. (-23) The aircraft ran out of fuel and the pilot landed on a sand bar on the kuskokwim river. No damage was incurred to the aircraft. The pilot was the only… - [Incident 19930211008469I](https://openairdocs.org/incident/19930211008469I), Feb 11, 1993: Cessna 207 (N1704U), Chefornak, AK, Minor damage. Pilot lost directional control on a direct crosswind landing on an icy runway. - [Accident 19860714032629A](https://openairdocs.org/incident/19860714032629A), Jul 14, 1986: Cessna 207 (N1704U), Ekuk, AK, Substantial damage. After touch and go to verify landing conditions, aircraft encountered downdraft on final and struck a log in grass. From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record. --- 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.