# NTSB ANC02LA127: Piper PA-18, N723C, Ekwok, AK, September 30, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 29, 2002, 16:30 local (Sep 30, 2002, 00:30 UTC) - Place: Ekwok, AK - Coordinates: 59.170555, -157.327224 - Nearby events: https://openairdocs.org/map.md?lat=59.1706&lon=-157.3272&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 25, 2003 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL-ANC FSDO 03 - NTSB case key (mKey): 55817 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC02LA127 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55817/pdf - Page: https://openairdocs.org/ntsb/ANC02LA127 ## Probable cause A partial separation of one propeller blade during cruise flight. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Propeller failure/malfunction, cruise - propeller system/accessories,blade - separation (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency descent/landing - terrain condition - tundra ## Analysis The commercial certificated pilot was conducting a personal cross-country flight. During cruise about 700 feet agl, the airplane suddenly developed a severe vibration. He reduced engine power to idle, and then shutdown the engine. He said he landed on tundra-covered terrain. During the landing roll, the airplane nosed down and received damage to the air intake housing. After the emergency landing, the pilot discovered that about 10 inches of one propeller blade had separated from the rest of the blade. He described the separation as a straight chordwise fracture. ## Factual narrative On September 29, 2002, about 1630 Alaska daylight time, a tundra tire-equipped Piper PA-18 airplane, N723C, had an in-flight separation of a propeller blade while in cruise flight about 12 miles southeast of Ekwok, Alaska. The airplane received minor damage during a forced landing. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by the pilot. The commercial certificated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at the Ekwok Airport about 1615. No flight plan was filed, nor was one required. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on October 2, 2002, the pilot reported he was en route to Naknek, Alaska, and was in cruise flight about 700 feet agl. The airplane suddenly developed a severe vibration. He reduced engine power to idle, and then shutdown the engine. He said he landed on tundra-covered terrain. During the landing roll, the airplane nosed down, but received only minor damage to the air intake housing. After the emergency landing, the pilot discovered that about 10 inches of one propeller blade separated from the rest of the blade. He described the separation as a straight chordwise fracture. ## Aircraft - Registration: [N723C](https://openairdocs.org/aircraft/N723C), registered now, S/N 18-1150 (OpenAirDocs) - Reported make and model: Piper PA-18 - Registry model: [Piper PA-18](https://openairdocs.org/model/piper-pa-18) (registry code 7101802) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-1150 - Engines: Lycoming IO-360 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: MICHAEL P. McCRARY - Registered owner: Preston Cavner - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 7, 2002 - Departed: KEK, EKWOK, AK - Destination: 5NK, NAKNEK, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; injuries: none; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: front; flight hours: 9,000 total, 1,700 in this make and model, 9,000 as pilot in command, 0 in the last 90 days, 70 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 45° at 15 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 39 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20020929035829I](https://openairdocs.org/incident/20020929035829I), Sep 29, 2002: Piper PA18, Ekwok, AK, No damage. (-23) While flying about at 700' AGL about 10 miles east of Ekwok pilot had an inflight separation of the last 18" of the propeller blade. Aircraft began to… ## Other investigations on N723C (2) 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 ANC06CA052](https://openairdocs.org/ntsb/ANC06CA052), May 10, 2006: Piper PA-18 (N723C), Iliamna, AK, substantial damage. Probable cause: The pilot's misjudged distance and altitude, which resulted in an undershoot during final approach to a beach, and subsequent in-flight collision with water and a nose over. - [NTSB UNK64X2553](https://openairdocs.org/ntsb/UNK64X2553), Jun 28, 1964: Piper PA18 (N723C), Atlanta, GA, substantial damage 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.