# NTSB IAD01LA108: Von Claparede Clemen Preceptor-Ultra, N66VC, Dublin, VA, September 29, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 29, 2001, 16:50 local (20:50 UTC) - Place: Dublin, VA - Coordinates: 37.235, -80.616943 - Nearby events: https://openairdocs.org/map.md?lat=37.2350&lon=-80.6169&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 26, 2003 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 53550 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD01LA108 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53550/pdf - Page: https://openairdocs.org/ntsb/IAD01LA108 ## Probable cause The pilot's failure to maintain sufficient altitude/clearance, which resulted in the airplane's collision with terrain. A factor was the downdraft. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, maneuvering - altitude/clearance - not maintained, pilot in command (cause) - weather condition - downdraft (contributing factor) ## Analysis The pilot approached a mountain ridge at a 45-degree angle, "at the same altitude as the ridge." As he flew closer to the ridge, the airplane experienced a "modest downdraft," and the pilot added power to maintain his altitude. When the pilot noticed that he would not be able to climb over the ridge, he turned the airplane back toward the valley to regain altitude. During the turn, the airplane experienced a "substantial downdraft combined with windshear." The pilot added full power; however, the airplane's altitude continued to decrease at about 2,500 feet per minute, and the airplane impacted trees. The pilot reported no mechanical deficiencies with the airplane. The winds reported at an airport 5 miles away were from 330 degrees at 11 knots, gusting to 15 knots. ## Factual narrative On September 29, 2001, at 1650 eastern daylight time, a homebuilt Preceptor-Ultra, N66VC, was substantially damaged during impact with terrain near Dublin, Virginia. The certificated private pilot and passenger were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 CFR Part 91. In a telephone interview, the pilot stated that he departed the New River Valley Airport (PSK), Dublin, Virginia, about 1630, for a local sightseeing flight. On his way back to the airport, the pilot approached a mountain ridge at a 45-degree angle, "at the same altitude as the ridge." As he flew closer to the ridge, the airplane experienced a "modest downdraft," and the pilot added power to maintain his altitude. When the pilot noticed that he would not be able to climb over the ridge, he turned the airplane back toward the valley to regain altitude. He stated that during the turn, the airplane experienced a "substantial downdraft combined with windshear." The pilot added full power; however, the airplane's altitude continued to decrease at about 2,500 feet per minute, and the airplane impacted trees. The pilot further reported that he set the altimeter to the field elevation before he took off, which was 2,030 feet. He estimated his altitude in the turn was 400-500 feet above the trees. He normally flew to the airport at 1,000 feet AGL, and stated that if he would have flown at a higher altitude, about 3,000 feet, he would not have impacted the trees. The pilot stated there were no mechanical deficiencies with the airplane. Additionally, he stated that he obtained the winds prior to his departure, which were reported to be variable from 360 to 020 degrees, at 8 knots, gusting to 15 knots. A Federal Aviation Administration (FAA) inspector examined the airplane after the accident. According to the inspector, substantial damage was observed to the cowling, fuselage, and both wings. Flight control continuity was established from the cockpit to all control surfaces, and the engine was rotated 360 degrees by the propeller. A Safety Board Meteorologist conducted a search of pilot reports (PIREPs), in-flight advisories (AIRMETs), and winds aloft forecasts (FDs) issued for the surrounding area, on the day of the accident. According to the Meteorologist, no PIREPs or AIRMETs were issued around the time of the accident. Examination of upper air data revealed that the winds aloft in the vicinity of Greensboro, NC, at 1,000 feet, were from 020 degrees at 7 knots. The winds reported in the vicinity of Sterling, Virginia, at 1,000 feet, were from 010 degrees at 17 knots. Surface observations reported at PSK, at 1641, included winds from 330 degrees at 11 knots, gusting to 15 knots, 10 miles visibility, scattered clouds at 5,000 feet, temperature 17 degrees Celsius, dew point 6 degrees Celsius, and altimeter setting 30.15 in Hg. The pilot reported 697 hours of total flight experience, 153 of which were in make and model. ## Aircraft - Registration: [N66VC](https://openairdocs.org/deregistered/N66VC-2001-11-08), registration cancelled 2001-11-08, S/N 0155, built 1999 (OpenAirDocs) - Reported make and model: Von Claparede Clemen Preceptor-Ultra - Registry model: [Von Claparede Clemens C PRECEPTOR-ULTRAPUP](https://openairdocs.org/model/von-claparede-clemens-c-preceptor-ultrapup) (registry code 05606XL) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 0155 - Airframe hours: 153 - Engines: Volkswagen 2180 75 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Clemens Von Claparede Crola - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, July 7, 2001, 19 hours before - Departed: PSK, Dublin, VA - Destination: PSK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; last flight review May 7, 2000; seat: rear; flight hours: 697 total, 153 in this make and model, 4 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 11 knots, gusting 15 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 43 °F - Altimeter: 30.14 inHg - Observed at: PSK, 5 nm away ## 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 20010929028579A](https://openairdocs.org/incident/20010929028579A), Sep 29, 2001: Dublin, VA, No damage. (-23) The pilot stated that he departed the New River Valley Airport (psk), Dublin, Virginia, approx. 1630 for a local sightseeing flight. The pilot stated he… 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.