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Prop Rotation, Stall and Accident Report
Joe-
The 2008 accident report is a lesson all builders should study.
Looks like a General Motors LS1 engine was installed with a -12 degree thrust angle on an SE5A replica. Original specs called for zero thrust angle. 2000ft AGL on the second test flight was an inopportune time to discover the effects of this discrepancy.
First test flight indicated upward pitch despite forward stick deflection. In response, the horizontal stabilizer was adjusted before the second test flight. The resulting deterioration of performance in air (on left turn, loss of ~ 10 mph airspeed at full power, uncontrolled descent of 100 fpm, and eventual right wing drop/stall) indicated an airframe issue, not an engine issue. Also illustrates the design concept of "outside the performance envelope".
Curious whether original SE5A naturally stalls with right or left wing drop, or straight ahead, and if that has to do with the direction of prop rotation. For auto engine installations where rotation is opposite original, is it possible to predict which wing the replica will drop on a stall?
This precautionary tale should be required on the test pilot/builder checklist
discussed elsewhere on the forum.
-pete
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