Quote:
Originally Posted by cactuspilot
The data does not show the position of the trim switch or the actions of the pilot or if the trim was running away. and the numerous problems and posts on here have proven very instructive to later builders to learn from the problems others have faced in this regard.
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I agree that the data doesn't show specific trim position but it does show changes in the pitch trim control and changes were made in both directions so (to me anyway) it appears highly unlikely there was any type of pitch trim runaway.
I am not going to allow anyone to accuse me of playing the blame game, but I will point out a couple things that may not be obvious to everyone looking at the data of this report.
I understand and respect Doug's policy regarding waiting for a final accident report... my understanding is this will be the only report ever published for public consumption. The ATSB got involved with the investigation to help assist with data acquisition only. The local authorities were leading the investigation, and it is my understanding that their report will never be made public (though I may be wrong).
The data indicates that the airplane lifted off after about an 8 second long take-off run (about what would be expected).
It then leveled off at 20 ft (because of instrument errors of some type, it started out indicating a Neg. 50 ft altitude for some reason but it doesn't matter, we can still see a delta increase of 20 ft)
It flew level at 20 ft (with a pretty high level of precision, that for me doesn't indicate that it was severely out of trim in pitch... you decide for your self) for about 13 seconds.
During the level flight at 20 ft it accelerated pretty much linearly to about 89 MPH (converted from Meters/Second).
During this time the pitch trim was being constantly adjusted. Fully expected since the pitch trim would be changing the entire time the airplane was accelerating. NOTE: The actual calibrated trim range is noted to be from 1 to -1 so the amount of pitch trim change indicated in the chart is a small percentage of the entire range.
At the end of the 13 seconds level at 20 altitude, the airplane made an abrupt pitch up. The stall indicator activated at the beginning of the pitch up, probably as a result of it not yet being calibrated properly.
Airplane decelerates during the steep climb until it appears to stall at about 125 ft AGL, where during the stall it both yaws and rolls abruptly to the right