# NTSB IAD01LA008: Conn Sonerai II, N188P, Manassas, VA, October 21, 2000 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: October 21, 2000, 14:07 local (18:07 UTC) - Place: Manassas, VA - Location: 38.7085° N, 77.5154° W: Placed by OpenAirDocs from NTSB’s distance and direction from Washington Manassas Harry P. Davis Field (HEF), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=38.7085&lon=-77.5154&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 4, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50510 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD01LA008 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50510/pdf - Page: https://openairdocs.org/ntsb/IAD01LA008 ## Probable cause Fuel starvation of the engine, caused by the fracturing of the fuel pump switches during a turbulence encounter. ## Analysis The pilot encountered turbulence while passing over a mountain range, en route to his destination airport. During the turbulence encounter, the pilot's knee came in contact with the instrument panel, and broke the right and left fuel pump toggle switches. Erratic fuel pressure indications were observed from the fuel pressure gauge. The pilot declared an emergency and as he prepared for a landing at a nearby airport, the engine lost power. About 1 mile from the end of the runway, the airplane encountered a downdraft, which caused the airplane to descend 600 feet. When the pilot realized he would not make the runway, he performed a forced landing in an open field. Examination of the airplane revealed the right fuel pump switch was 'completely shattered' and the left fuel pump switch was partially broken in the 'on' position. ## Factual narrative On October 21, 2000, about 1407 Eastern Daylight Time, a homebuilt Sonerai II, N188P, was substantially damaged during a forced landing at the Manassas Regional/Harry P. Davis Field Airport (HEF), Manassas, Virginia. The certificated private pilot received minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 CFR Part 91. According to the pilot, he departed the Winchester Regional Airport (OKV), Winchester, Virginia, and was en route to Washington Executive/Hyde Field Airport (W32), Clinton, Maryland. Shortly after departure from OKV, he crossed the Blue Ridge Mountains at 3,300 feet and encountered severe turbulence and heavy winds. The pilot reported the winds were from the northwest and paralleled his route of flight. He stated the turbulence was "the worst he had ever seen." In a period of 1-2 seconds, the airplane was thrown from 4,500 feet to 2,700 feet and back to 3,600 feet. During the turbulence encounter, the VSI indicated a descent of more than 5,000 feet per minute, and the pilot recalled "pulling at least 4 G's." The pilot reported that as he encountered the turbulence, his right knee came in contact with the dashboard and broke the right and left fuel pump switches. He stated that the right fuel pump switch was "totally shattered," and the left fuel pump switch was partially broken in the "ON" position. The pilot reported that during normal operations, the fuel pump switches would light up when the fuel pumps were operational. After he encountered the turbulence, the right switch did not illuminate, and the left switch was lit intermittently. He also observed erratic fuel pressure indications from the fuel pressure gauge. The pilot stated that he declared an emergency with Dulles Approach Control while at 2,400 feet, and was instructed to contact the Manassas Regional Airport control tower. Shortly after he was cleared to land at Manassas, the left fuel pump light extinguished, and the engine lost power. About 1 mile from the end of the runway, the airplane encountered a downdraft, which caused the airplane to descend from 800 to 200 feet. When the pilot realized he would not make the runway, he landed in an open field. The pilot reported that he received a weather briefing prior to the flight and no wind or turbulence advisories were issued. He additionally stated that he had accumulated 1,600 hours of total flight experience. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed the right fuel pump switch was broken and the left fuel pump switch was partially operational. Additionally, the inspector observed about 4 gallons of fuel in the fuel tank. According to the inspector, fuel was provided to the engine through the operation of the right and left fuel pumps. According to weather data provided by the National Weather Service (NWS), no weather advisories were issued for the route of flight concerning turbulence. The surface observation at HEF, at 1355, was: wind calm, visibility 10 statute miles, sky clear below 12,000 feet, temperature 26.0 degrees C, dew point temperature 12 degrees, altimeter 30.16 inches of mercury. Additionally, the Sterling, VA upper air sounding for 1200Z indicated a strong surface based inversion to 2,090 feet, and decreasing temperatures above. Wind speeds were recorded with the inversion at 32 knots from the northwest to west, and decreasing above the inversion. It should be noted that the NWS does not report mountain wave turbulence unless the area covers more than 5,000 square miles. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - weather condition - turbulence,clear air (cause) - Loss of engine power, emergency landing - fluid,fuel - starvation (cause) - electrical system,electric switch - fractured (cause) - Forced landing, emergency landing ## Aircraft - Registration: [N188P](https://openairdocs.org/deregistered/N188P-2001-04-14), registration cancelled 2001-04-14, S/N 744 (OpenAirDocs) - Reported make and model: Conn SONERAI II - Registry model: [Conn Robert R SONERAI II](https://openairdocs.org/model/conn-robert-r-sonerai-ii) (registry code 056593F) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 744 - Airframe hours: 1600 - Engines: Volkswagen T835 60 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Haim Primo - Airworthiness certificate: Special, Experimental (Special) - Departed: OKV, WINCHESTER, VA - Destination: W32, CLINTON, MD - Airport: HEF, Manassas Regional Airport, runway 34L, 3,702 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 1,600 in this make and model, 40 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 176 °F, dew point 131 °F - Altimeter: 30.00 inHg - Observed at: HEF, 1 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 20001021039079A](https://openairdocs.org/incident/20001021039079A), Oct 21, 2000: Amtr SONERAI2, Manassas, VA, No damage. (-23) Pilot flying from winchester, VA. To hyde field, MD was crossing mountains at 3200 ft hit turbulance, pilot was talking to dulles approach. Pilot hit… 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.