True or False ?

Each of the statements below appeared in claims made by proponents of DAVYJ. Try to decide whether they are true.

Each is followed by some hints that may be helpful.

DAVYJ WILL BE HIGHER THAN SERFR. DAVYJ can be flown at a higher altitude than SERFR due to its distance from the airport. Because today’s airplanes prefer a slightly flatter approach for quiet flight (BSUR is 30 years old!), DAVYJ flies a tiny bit lower than BSUR did.

Hint: Compare the red line of average SERFR altitudes as flown with the green dotted line that shows expected DAVYJ mid-range values in the plot of altitudes relative to distance from airport. Where do they intersect?

“in absolute terms, the old flight path affected less people, especially in high elevation communities”

Hint: look at Census population density maps, particularly for neighborhoods further from the coast.

“SLV, on the other hand, is not overflown by either the new or old ground tracks , has never had a noise issue, and there’s no reason to think that it ever will”

Hint : look at the distribution of flight traffic in the heatmaps for July 2014 and July 2015. The FAA estimated 50% of flights were vectored in both cases. What neighborhoods does vectored traffic overfly?

DAVYJ WILL NOT BE ANY MORE CONCENTRATED THAN BSUR WAS. Despite persistent common misconceptions, BSUR was as busy and concentrated as SERFR is today. The only difference is SERFR is louder, so people naturally perceive it as more concentrated.

Hint: Compare the flight count density heatmaps for July 2014 and July 2015. Also compare the histograms of flight density counts. Do they look the same?

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