# NTSB ANC97LA068: Hammer Avid Flyer, N525BB, Chitina, AK, May 4, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 3, 1997, 19:00 local (May 4, 1997, 03:00 UTC) - Place: Chitina, AK - Coordinates: 61.449035, -143.150024 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.4490&lon=-143.1500&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 29, 1998 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 3001 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC97LA068 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3001/pdf - Page: https://openairdocs.org/ntsb/ANC97LA068 ## Probable cause improper overhaul of the engine, which resulted in a seized piston and resultant loss of engine power. Rough terrain in the emergency landing area was a related factor. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, takeoff - initial climb - maintenance,overhaul,major - improper, other maintenance personnel (cause) - engine assembly,piston - improper (cause) - engine assembly,piston - seized (cause) - Forced landing, emergency landing after takeoff - In flight collision with terrain/water, emergency landing - terrain condition - rough/uneven (contributing factor) ## Analysis The pilot was departing in a homebuilt airplane from a remote airstrip. After departure, the airplane climbed to about 250 feet above the ground, and then the engine suddenly lost power. The pilot performed a 180 degree turn back toward the runway, but landed in rough terrain, just short of the runway. The engine was overhauled 5 hours before the accident, and one piston was replaced with an oversize piston. Following the accident, an examination of the engine revealed the oversize piston was seized in the cylinder. The seized piston was found to be the same size as the cylinder bore. ## Factual narrative On May 3, 1997, about 1900 Alaska daylight time, a wheel equipped homebuilt, experimental Hammer, Avid Flyer airplane, N525BB, crashed during the initial takeoff climb from the Chitina Airport, Chitina, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight to McCarthy, Alaska, when the accident occurred. The airplane, operated by the pilot, sustained substantial damage. The certificated private pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. On May 4, 1997, at 1222, the pilot reported in a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), that he just departed runway 13 at Chitina and climbed to about 250 feet above the ground. The engine, a Rotax 618, suddenly quit. The pilot made a 180 degree turn to return to the runway. The pilot performed an emergency landing short of the runway into low brush. The airplane received damage to the fuselage and wingtips. On November 20, 1997, the pilot reported the engine was last overhauled 5 hours before the accident at a facility in Birchwood, Alaska. During the overhaul, one of the engine's two pistons was replaced with an oversize piston. The piston cylinder was also bored oversize. The second engine piston was not replaced, and remained standard size. After the accident, the pilot sent the engine to an overhaul facility in San Leandro, California. The examination revealed the oversize engine piston was found seized in the cylinder. Measurement of the oversize piston revealed it was the same size as the cylinder bore, both measuring 2.998 inches. ## Aircraft - Registration: [N525BB](https://openairdocs.org/deregistered/N525BB-2014-12-03), registration cancelled 2014-12-03, S/N 525 (OpenAirDocs) - Reported make and model: Hammer AVID FLYER - Registry model: [Hammer Robert HULLER](https://openairdocs.org/model/hammer-robert-huller) (registry code 05616YG) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 525 - Airframe hours: 260 - Engines: Rotax 618 75 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Robert Hammer - Last inspection: Continuous airworthiness, March 20, 1997, 5 hours before - Departed: CXC - Destination: 15Z, MCCARTHY, AK - Airport: CXC, Chitna, runway 13, 2,850 × 75 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 1,718 total, 405 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 100 statute miles - Lowest ceiling: none - Temperature: 50 °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). - [Accident 19970503007689A](https://openairdocs.org/incident/19970503007689A), May 3, 1997: Amtr AVIDFLYER, Chitina, AK, Substantial damage. Engine quit on takeoff. Turned back. Landed short into bushes. Oversize piston siezed. Recent repair. Cyl same bore 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.