Beaver Falls, PA, USA
N166SE
DIAMOND AIRCRAFT IND INC DA 20-C1
According to the flight instructor, while on final approach, he perceived that the airplane was low on the desired glidepath. He said that he issued corrective instructions to the student twice before taking the flight controls. The instructor moved the throttle forward to increase power, and the engine stopped producing power. He selected a forced landing site, issued a Mayday call to the tower, and attempted an engine restart. However, he had to conduct a power-off landing on a roadway. Before ground contact, the airplane struck wires, and, during the accident sequence, the nose gear and tail section of the airplane separated. During the examination of the wreckage, the engine was started, and it ran continuously on the airframe using the airplane's own fuel system. However, when the power was reduced to idle, the engine did not respond as expected to subsequent throttle and mixture inputs. After the initial run, the operator's director of maintenance was asked to produce the tools and documents used to calibrate the fuel system at installation. He produced instructions and gauges that resembled those used at the manufacturer’s factory, but no calibration stickers were displayed on the gauges. The gauges were installed, and, during a subsequent engine run, both the metered and unmetered fuel pressure readings were below factory specifications. The fuel system was removed and flow tested at the engine manufacturer's facility. The fuel pump and fuel control assembly were intact, and bench testing demonstrated their ability to function, but both were found with several parameters outside of their respective calibrated specifications. The fuel manifold and nozzles were also tested and found to exhibit a normal flow vs. pressure indication on the test bench. The fuel pump was found adjusted "down" and flowed less than the required fuel flow specifications. The throttle body and mixture control unit were found adjusted to a position that allowed more than the required fuel flow at three specific settings. The combination of both the fuel pump and throttle body mixture control adjustments resulted in an idle fuel flow rate 2.5 times the maximum required. When the throttle was advanced quickly to full throttle, the fuel flow rate was 40 percent of the required rate. This significant transition in fuel flow rates likely resulted in a momentary "cavitation" of the fuel pump, which allowed air to enter the system and resulted in a total loss of engine power.
HISTORY OF FLIGHT On March 23, 2012, about 1220 eastern daylight time, a Diamond DA20-C1, N166SE, was substantially damaged during a forced landing following a total loss of engine power while on final approach to land at Beaver County Airport (BVI), Beaver Falls, Pennsylvania. The certificated flight instructor sustained minor injuries, and the student pilot was seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight operated by Aviation Certification and Education Solutions (ACES), Inc., and conducted under the provisions of Title 14 Code of Federal Regulations Part 91. In a telephone interview, the flight instructor stated that the purpose of the flight was for his student to conduct a navigation exercise. The instructor followed the student as she conducted her preflight, and the instructor noted that there was approximately 13 gallons of fuel in the 26-gallon tank. After completing the approximate 45-minute round-trip flight, that included a landing and takeoff at an intermediate stop, the airplane entered a left downwind for landing on Runway 10 at BVI. While on final approach, the instructor perceived that the airplane was low on the desired glidepath based on the Precision Approach Path Indicator (PAPI) lights. He said that he issued corrective instructions to the student twice before taking the flight controls. The instructor increased the throttle, and the engine stopped producing power. He selected a forced landing site, issued a Mayday call to the tower, attempted an engine restart, but completed a power-off landing to a roadway. Prior to ground contact, the airplane struck wires, and during the accident sequence the nose gear and tail section of the airplane separated. PERSONNEL INFORMATION The instructor held a commercial pilot certificate with ratings for airplane single-engine land, multiengine land, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single-engine, multiengine, and instrument airplane. His most recent Federal Aviation Administration (FAA) third-class medical certificate was issued May 10, 2007. The instructor reported 593 total hours of flight experience, 206 hours of which were in the accident airplane make and model. The student pilot was issued a third class medical certificate on August 22, 2011. She reported 30 total hours of flight experience, all of which were in the accident airplane make and model. AIRCRAFT INFORMATION According to FAA records, the airplane was manufactured in 2004, and issued a standard airworthiness certificate on June 16, 2004. The most recent annual inspection was completed December 6, 2011, at 1756.8 total aircraft hours. At the time of the accident, the airplane had accrued 1,825.7 total aircraft hours. Examination of maintenance records revealed that the engine was removed for overhaul on October 4, 2011, and reinstalled December 6, 2011, at the time of the annual inspection. At the time of the engine installation, calibration of the fuel system was required and performed by the operator's Director of Maintenance (DOM). METEOROLOGICAL INFORMATION At 1147, the weather reported at BVI included clear skies and wind from 110 degrees at 3 knots. The temperature was 23 degrees C, and the dewpoint was 8 degrees C. ADDITIONAL INFORMATION On March 28, 2012, an engine examination and test run were conducted under the supervision of FAA aviation safety inspectors. The engine was started and ran continuously on the airframe using the airplane's own fuel system. However, when the power was reduced to idle, the engine did not respond as expected to subsequent throttle and mixture inputs. After the initial run, the operator's DOM was asked to produce the tools and documents used to calibrate the fuel system at installation. He produced factory instructions and gauges that resembled those used at the Diamond Aircraft factory, but no calibration stickers were displayed on the gauges. The gauges were installed, and during a subsequent engine run, both the metered and un-metered fuel pressure readings were below factory specifications. The fuel system was removed, and flow-tested at the engine manufacturer's facility in Mobile, Alabama, under the supervision of an NTSB investigator. According to the examination report: "The fuel pump and fuel control assembly were intact and demonstrated the ability to function, but both were found with several parameters outside of each of their respective calibrated specifications. The fuel manifold and nozzles exhibited a normal flow vs. pressure indication on the test bench." The fuel pump was found adjusted "down" and flowed less than the required fuel flow specifications. The throttle body and mixture control unit were found adjusted to a position that allowed more than the required fuel flow at three specific settings. The combination of both the fuel pump adjustments and throttle body mixture control adjustments resulted in an idle fuel flow rate 2.5 times the maximum required. When the throttle was advanced quickly to full throttle, the fuel flow rate was 40 percent of the required rate.
The operator’s maintenance personnel’s improper adjustment of the engine's fuel system, which resulted in a total loss of engine power.
Source: NTSB Aviation Accident Database
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