PROGRESSIVE AERODYNE INC SEAREY near Sebring, FL — 2016-08-23

Probable cause

A disconnected ground wire during initial climb, which degraded the fuel boost pumps’ performance and resulted in a total loss of engine power due to fuel starvation.

NTSB narrative

During initial climb on an instructional flight in the experimental amateur-built airplane, about 200 ft above ground level, the engine began running rough. The flight instructor immediately decreased the airplane's angle of attack and the engine subsequently experienced a total loss of power. The flight instructor tried to land on the remaining runway; however, the airplane landed hard and struck an embankment. Examination of the airplane revealed wiring that contained mismatched wire gauges and splices throughout the wiring harnesses. The ground wire for the master arm solenoid was disconnected from the back of the ignition switch. Without this ground wire, the battery was disconnected from the airplane's electrical system. The airplane's rectifier kept the fuel boost pumps running per the wiring diagrams; however, a postaccident engine run revealed that the rectifier was weak and only displacing 12.3 volts, rather than its nominal output voltage of 13.5 +/- 0.2 volts. It is likely that, during takeoff, the ground wire became disconnected from the ignition switch and the weak rectifier could not adequately supply the high electrical load requirements imposed by the fuel boost pumps, the landing gear motors retracting the gear, and the strobe lights. This degraded the performance of the fuel boost pumps, resulting in fuel starvation and a total loss of engine power.

Analysis

Primary failure mode

Engine power loss

First missed decision gate

Preflight inspection could have identified issues with the electrical system.

NTSB coding

• Electrical system malf/failure · Takeoff

Evidence available

• Photos
• 4 docket documents

Docket documents4

• Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1form
• FAA Inspector's Statementinterview
• Interview Summariesinterview
• Photo Arrayphotos