Diamond DA 20-C1 N166SE

Summary

On 23 March 2012 at about 16:20 local time, a Diamond DA 20-C1 registered N166SE, operated by O Toole Aviation LLC, was involved in an accident near Beaver Falls, Pennsylvania, United States. 2 people were on board and one was seriously injured, one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

23 March 2012 at 16:20

Classification

Accident

Location

Beaver Falls, Pennsylvania, United States

Nearest airport

Beaver County Airport (BVI)

Coordinates

40.7725, -80.3914

Aircraft

Diamond DA 20-C1

Registration

N166SE

Category

Airplane

Engines

1

Operator

O Toole Aviation LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Beaver Falls → Beaver Falls

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA12LA246

1 person was seriously injured.

The operator’s maintenance personnel’s improper adjustment of the engine's fuel system, which resulted in a total loss of engine power.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.