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Old July 25th 18, 05:31 AM posted to rec.aviation.soaring
Frank Whiteley
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Default Ventus 3F - Fatal

On Tuesday, July 24, 2018 at 10:20:10 PM UTC-6, Frank Whiteley wrote:
On Tuesday, July 24, 2018 at 2:56:46 PM UTC-6, wrote:
On Tuesday, July 24, 2018 at 10:13:02 AM UTC-4, Jonathan St. Cloud wrote:
On Tuesday, July 24, 2018 at 1:23:25 AM UTC-7, wrote:
One last time... FLARM does not need, nor does it record airspeed, for a simple reason: airspeed cannot be used to calculate closure rates between your aircraft and others, or ground obstructions. It works entirely from GPS fixes. It only uses a pressure sensor to enhance altitude data, but does not strictly need it. To my knowledge, no FLARM devices have inputs for airspeed.

Read the manual, folks. It's all documented there, in great detail.

Alarm doesn't record airspeed, but some flight computers do. I know the LXNav records airspeed, flap position ...etc. perhaps this brand new glider had a modern flight computer?


Some that record lose the last few(up to 15) seconds of the file because the data has not been written to memory. If power is disconnected in the crash this data may be lost.
UH


That is quit correct, the 15 seconds or so of buffered data may be lost. Those who listen to satellite radio experience this buffer effect when driving through tunnels.

I looked at Renny's OLC logs and his tracker logs. He appears to have accumulated something around 7 hours in the glider. The only thing that appeared oddly interesting about the day in question was that he didn't climb out nor get very far away from Moriarty like the other pilots that day. It could have been he wasn't feeling well, had other plans later that day, or was experimenting with something. I wonder if he may have been experimenting with aft-CG, now that he had some time in the glider. If he wasn't comfortable with how it was handling, it might explain the local nature of the flight, but might also explain an inadvertent departure. I didn't go after the PowerFlarm tracks in time to get a copy, but I know who did. Having helped the FAA and NTSB with a post accident glider fatality, I have some idea of their approach and maybe the limits of what they do. I also know that they will take issue with local coroners and investigations if warranted. Yet, sometimes they don't get all of the information and that the real cause may never be officially revealed or discovered, sometimes under 20 years later, because they never interviewed all concerned.

Frank Whiteley


until 20 years later