# NTSB NYC00LA266: Morrison RANS-12, N91337, Warrenton, VA, September 24, 2000 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: September 24, 2000, 17:30 local (21:30 UTC) - Place: Warrenton, VA - Coordinates: 38.709037, -77.790702 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.7090&lon=-77.7907&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report July 17, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50330 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC00LA266 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50330/pdf - Page: https://openairdocs.org/ntsb/NYC00LA266 ## Probable cause The pilot's inadequate airspeed which resulted in the inadvertent stall. A factor related to the accident was the gusting wind condition. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, approach - vfr pattern - base leg/base to final - weather condition - gusts (contributing factor) - stall - inadvertent, pilot in command - airspeed - inadequate, pilot in command (cause) - In flight collision with object, landing - object - tree(s) ## Analysis As the airplane arrived in the airport area, the pilot observed a thunderstorm "moving in" from the west/northwest, at a distance of about 10 miles. As the pilot turned left base for final approach, about 150-200 feet above the ground, a gust of wind came over the trees and "flipped the airplane over." The airplane descended, impacted trees, and crashed onto the runway. The pilot additionally stated that he was at an indicated airspeed of 50-55mph when he encountered the wind gust and that the stalling speed of the airplane was 37 mph. Federal Aviation Administration (FAA) Airplane Flying Handbook, FAA-H-8083-3 stated, "After turning onto the base leg, the pilot should start the descent with reduced power and an airspeed of approximately 1.4 Vso." FAA Advisory Circular AC 61-67B stated, Stall and Spin Awareness Training, "Turbulence can cause an aircraft to stall at a significantly higher airspeed than in stable conditions. A vertical gust or windshear can cause a sudden change in the relative wind, and result in an abrupt increase in angle of attack. Although a gust may not be maintained long enough for a stall to develop, the aircraft may stall while the pilot is attempting to control the flightpath, particularly during an approach in gusty conditions. When flying in moderate to severe turbulence or strong crosswinds, a higher than normal approach speed should be maintained. In cruise flight in moderate or severe turbulence, an airspeed well above the indicated stall speed and below maneuvering speed should be used." The winds recorded at a nearby airport, about the time of the accident were from 350 degrees at 6 knots. ## Factual narrative On September 24, 2000, about 1730 Eastern Daylight Time, a homebuilt Rans-12, N91337, was substantially damaged while landing at the Warrenton Airpark, Warrenton, Virginia. The certificated private pilot was seriously injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 CFR Part 91. According to the pilot, as he arrived in the airport area, he observed a thunderstorm "moving in" from the west/northwest, at a distance of about 10 miles. He entered the traffic pattern for the north runway and did not experience any noticeable turbulence. As he was turning left base for final approach, about 150-200 feet above the ground, a gust of wind came over the trees and "flipped the airplane over." The airplane descended, impacted trees, and crashed onto the runway. The pilot additionally stated that he was at an indicated airspeed of 50-55 mph when he encountered the wind gust and that the stalling speed of the airplane was 37 mph. Federal Aviation Administration (FAA) Airplane Flying Handbook, FAA-H-8083-3 stated, "After turning onto the base leg, the pilot should start the decent with reduced power and an airspeed of approximately 1.4 Vso." FAA Advisory Circular AC 61-67B stated, Stall and Spin Awareness Training, "Turbulence can cause an aircraft to stall at a significantly higher airspeed than in stable conditions. A vertical gust or windshear can cause a sudden change in the relative wind, and result in an abrupt increase in angle of attack. Although a gust may not be maintained long enough for a stall to develop, the aircraft may stall while the pilot is attempting to control the flightpath, particularly during an approach in gusty conditions. When flying in moderate to severe turbulence or strong crosswinds, a higher than normal approach speed should be maintained. In cruise flight in moderate or severe turbulence, an airspeed well above the indicated stall speed and below maneuvering speed should be used." The winds recorded at an airport located 5 miles southwest of the accident site, at 1703, were from 350 degrees at 5 knots. At 1723, the winds were from 350 degrees at 6 knots, and at 1744, the winds were from 010 at 8 knots. ## Aircraft - Registration: [N91337](https://openairdocs.org/deregistered/N91337-2011-07-05), registration cancelled 2011-07-05, S/N 1292361, built 1993 (OpenAirDocs) - Reported make and model: Morrison RANS-12 - Registry model: [Morrison Ronald B RANS S-12](https://openairdocs.org/model/morrison-ronald-b-rans-s-12) (registry code 05601UI) (OpenAirDocs) - Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 1292361 - Airframe hours: 155 - Engines: Rotax 582 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: James R. Birnbaum - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, September 10, 2000 - Departed: 3VA3, BEALTON, VA - Destination: 9W0 - Airport: 9W0, Warrenton Airpark ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 225 total, 100 in this make and model, 10 in the last 90 days, 5 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 6 knots - Visibility: 4 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 81 °F, dew point 73 °F - Altimeter: 29.00 inHg - Observed at: CJR, 5 nm away ## Other investigations on N91337 (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 NYC98LA118](https://openairdocs.org/ntsb/NYC98LA118), May 16, 1998: Morrison Rans S-12 (N91337), Gum Spring, VA, substantial damage. Probable cause: A loose/partially disconnected engine intake fuel line which resulted in a loss of engine power, and the pilot's delayed (late) flare prior to touchdown. 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.