10/29/15 Lookout Accident - Lessons Learned

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10/29/15 Lookout Accident - Lessons Learned

Postby jjhildebrand1 » Fri Nov 06, 2015 3:49 pm

Below are the TakeAways from David Platt's accident, that were communally discussed (open-forum discussion/meeting at Ed and Janel’s home) on November 4, 2015. What follows are the generic/applicable-at any-site TakeAways and in parentheses are the specific David Platt accident TakeAways. It became apparent during the discussion, amongst the 20-30 attending members, that no one really knows what happened and that these TakeAways are reflections of possible scenarios that could’ve caused the accident. To re-iterate, what is presented below is based on analysis of what could've lead to the accident.

As is usual with accidents in any sport or industry is that they are often due to a culmination of events lining up in a specific pattern rather than a singular event. For more insight on this, please see James' Reason Swiss-Cheese model of error causation. Furthermore, root cause analysis can provide insight as well. Please take the below information and integrate into your flying, and risk management models, as you see fit and hopefully a bit more clarity will result regarding David’s tragic accident.

1. Flying near (<300' AGL) terrain (The accident initiation occurred between 150' to 250' AGL near Lookout’s north point and north ridgeline area toward the southeast). When flying in the “danger zone” of less than 300-400’ AGL, one must always consider a quickly-executed reserve toss should things go badly. “Going badly” is a subjective term for each of us and depends our own skills, preparedness, mental state, and weather conditions.

2. Possibly shifting wind conditions (Wind conditions prior to the accident were reported from the north between 10-15 mph at times, including possible wind shifts from time to time from the northwest. This could've caused turbulence, or horizontal rotor patterns, induced from the north point/north ridgeline). Rotor is most prevalent in low-moderate wind conditions where thermal strength and base wind strength is not high.

3. Along-terrain / parallel-to-terrain wind flow patterns (Along the front range, including Lookout, winds that flow parallel to the foothills [north or south flow] can produce turbulent conditions due to the air undulating and mixing around terrain features such as ridges, points, valley, and even smaller features such as treelines and rock outcroppings). It doesn’t take dramatic wind strengths to result in very turbulent conditions.

4. EN-D glider (Higher-level gliders, relative to the next level down, are more reactive, dynamic, aggressive, and even violent during the onset and recovery from an emergency event. In general, they also take longer to “start flying” again after an event, even under guidance of skilled hands.)

5. Wingovers near terrain (Wingovers can be insidious and they allow the wing to enter compromising and vulnerable attitudes given the right turbulence conditions. The wing is especially vulnerable to collapses and tucks when the energy is not adequately [slowly] bled off at the end of a wingover cycle when the wing pitches back [high angle of attack] and less loaded, likely more pronounced in higher-level wings that retain energy more efficiently.)

6. Thermal-induced turbulence (Pilot reports from the timeframe of the accident indicated that thermal-related conditions were not benign. Some pilots reported that although the lift was not that strong, the sink surrounding the lifting parcels was quite dramatic. This could’ve resulted in strong vertical shear layers between lifting and sinking parcels.)

Other safety-related tidbits to keep in mind, as we continually evaluate our own flying…

Mental state and fatigue: According to industrial safety studies and in many ways, flying, the four main causes of accidents are fatigue, frustration, rushing, and complacency. Regarding fatigue, there are many factors that can result in us being tired, worn out, and not on our A-game. When we’re tired, studies show that reaction time degrades and judgement can be impaired.

Wing-induced turbulence: When flying behind, or downwind, of any wing, especially wings that have high wing-loading, be prepared to encounter turbulence caused by induced wingtip vortices. Light wind and light/no thermal conditions allow the vortex to stay intact and thus more sharp and severe.

Stay positive everyone, and stay safe.
, ) jake

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