# NTSB SEA03LA050: Hiperlight SNS-8, South Prairie, WA, March 25, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 25, 2003, 09:45 local (17:45 UTC) - Place: South Prairie, WA - Coordinates: 47.139999, -122.103889 - Nearby events: https://openairdocs.org/map.md?lat=47.1400&lon=-122.1039&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 25, 2003 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 56711 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA03LA050 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/56711/pdf - Page: https://openairdocs.org/ntsb/SEA03LA050 ## Probable cause The failure of the pilot to maintain control of the aircraft during the crosswind turn resulting in an inadvertent spin entry, followed by his intentional stall to a landing resulting in a hard landing and subsequent nose over. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - turn to reverse direction - aircraft control - not maintained, pilot in command (cause) - Hard landing, landing - flare/touchdown - stall/mush - intentional, pilot in command (cause) - Nose over, landing - roll ## Analysis The pilot /owner of the unregistered experimental homebuilt SNS-8 aircraft took the aircraft out on its first flight following maintenance work. The pilot reported that the airspeed indicator was inaccurate. After departing the private airstrip, and about 1,300 feet above ground, he attempted to level the wings out of a left turn, but the aircraft continued rolling inverted and the pilot reported that it entered into a spin, which he recovered from after roughly two rotations. The pilot then elected to execute an immediate landing in a nearby field. During his approach, he intentionally slowed the aircraft to stall speed. The aircraft impacted the ground and immediately nosed over. An FAA inspector examined the aircraft and found no malfunction with its flight controls. He also reported finding a leak in the aircraft's pitot static system. ## Factual narrative On March 25, 2003, approximately 0945 Pacific standard time, an unregistered experimental homebuilt SNS-8 aircraft, owned and being flown by a private pilot sustained substantial damage when the aircraft impacted terrain and nosed over during an off airport precautionary landing following a loss of control in flight near South Prairie, Washington. The pilot was uninjured. Visual meteorological conditions prevailed and no flight plan had been filed. The flight, which was personal, was to have been operated under 14 CFR 91, and originated from Cawley's South Prairie private airstrip (02WA) approximately 0930. The pilot reported that the aircraft had undergone repair work including re-skinning and had been trailered to South Prairie from Oregon on March 24th. The pilot took the aircraft out on its first flight following the maintenance work, departing 02WA and climbing up to approximately 1,300 feet above ground. He reported that when he attempted to level the wings out of the left turn, he could not stop the aircraft from rolling left. The aircraft rolled inverted and the pilot reported that it entered into a spin, which he recovered from after roughly two rotations. Following his recovery he elected to execute an immediate landing in a nearby field and determined that fences and other objects would interfere with the aircraft's landing roll. He then conducted an approach to the field and "...decided to slow to stall speed and ditch at very low alt[itude]...." Upon ground impact the aircraft rolled a short distance and then nosed over (refer to graphic image 1 and 2). An inspector from the Federal Aviation Administration (FAA) interviewed the pilot (refer to attached statement) and examined the aircraft. He reported finding no malfunction with the flight controls and asked the pilot about his airspeed at the time of the spin entry. The pilot responded that the airspeed indicator was inaccurate and that "...he judged his airspeed by how fast the trees were passing by the aircraft...." An operational check of the aircraft's airspeed indicator by the FAA inspector revealed a leak in the pitot static system. ## Aircraft - Registration: UNREG (not matched to a registry record) - Reported make and model: Hiperlight SNS-8 - Category: Airplane, amateur-built - Serial number: 46 - Engines: Rotax 447 36 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Kirk, Donald J. - Departed: 02WA, South Prairie, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; last flight review March 14, 2003; seat: front; flight hours: 426 total, 3 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 6 knots - Visibility: 7 statute miles - Lowest ceiling: 12,000 ft broken - Temperature: 50 °F, dew point 43 °F - Altimeter: 30.09 inHg - Observed at: TCM, 16 nm away 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.