I'm not an aircraft accident investigator, so treat my interpretation with a very large pinch of salt. My interpretations follow each quoted extract from the accident report.
From the report :
"Witnesses observed the airplane flying at an
estimated altitude of 400 feet, then spiral to the ground."
My interpretation : Witnesses are very unreliable, especially when estimating the altitude of an aircraft. Spiral to the ground : the aircraft might have entered either a spiral dive or a spin.
From the report :
"The operator said airplanes used this area to practice stalls and simulated engine-out emergency landings."
My interpretation : There was a history of aircraft flying at very low airspeed in that area.
From the report :
"Both wings exhibited similar leading edge crush damage."
My interpretation : The aircraft hit the approximately ground wings-level, and so wasn't in a spin or spiral dive at impact.
From the report :
"Control continuity was traced from the control surfaces to the deformed cabin area."
My interpretation No pre-existing problems with the controls has been found. However, accidents have been caused by foreign objects getting caught up in the controls, the linkages, etc. and these might not be found in the wreckage.
From the report :
"The fuel selector valve was in the horizontal (on) position. Firemen who responded to the accident estimated 12 gallons of fuel spilled onto the ground. The airframe manufacturer's representative estimated another 5 gallons remained in
the two fuel tanks."
My interpretation : At the point of impact, fuel could be delivered to the engine.
"This representative noted no threads were exposed on the flap actuator, which he equated to the flaps up position. He also measured the elevator trim actuator at 1.6 inches, which he equated to less than 5 degrees tab up (nose down)."
My interpretation : Flaps were up, trim was set for the cruise.
"The engine was separated to facilitate inspection. It was slung from a hoist and the propeller rotated by hand. All cylinders' valves and pistons moved in firing order, the accessory gears rotated freely, and thumb compression was obtained on all cylinders. Spark was obtained on all leads for both magnetos when they were manually rotated. Fuel was observed in the carburetor bowl; the metal floats were intact and moved freely. "
In other words, no engine defect has yet been found.
One thing I thought would have been in the report (but isn't) is the condition of the propeller. It is one of the main ways of determining if the engine was producing power at impact.
The readings from the various instruments isn't given either. Often at impact, the needle of for example the ASI will leave an impact mark on the instrument.
I prefer the AAIBs reports, which might take quite some time to produce, but they are very complete, especially in a fatal accident. A LOT can be learnt from reading them.
May the two pilots involved Rest In Peace.
Mik
[This message has been edited by mik (edited 03 November 2000).]