Aircraft noise dissipates with altitude but regulatory floors fail where tours fly low

Evidence

Noise impact falls off dramatically the higher a plane goes, which is why flight charts are full of markings requiring pilots to stay 2,000 feet above sensitive bird-nesting areas, 4,000 feet above wilderness hiking or canoeing areas, 14,500 feet above the most scenic parts of the Grand Canyon—so high that pilots are required to use oxygen masks there. (So why is the Grand Canyon still noisy? Because commercial tour operators are allowed to fly lower.) — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 1637

Categorization

• XREF: Connects to Hempton’s One Square Inch of Silence thesis about regulatory carve-outs eroding protected natural quiet. — connects to: Altitude-based flight regulations exist to shield wilderness from plane noise; Overcast skies protect Olympic Park’s quiet by deterring scenic flights — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 70; Olympic National Park’s quiet stems from lacking roads and air tourism — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 59 (+3 more)
• QUESTION: Worth chasing: what exactly are the Grand Canyon tour altitude exemptions and who granted them?
• corroborated: 2 independent passages support this claim — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 1637

Broader Connections

• Overcast skies protect Olympic Park’s quiet by deterring scenic flights #contradicts (0.70) — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 70
• Background noise may prevent us from hearing an otherwise audible forest sound #qualifies (0.60) — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 1010
• Olympic National Park’s quiet stems from lacking roads and air tourism #corroborates (0.55) — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 59