Thứ Tư, 30 tháng 11, 2016

Ask one Pilot and Spencer: Views from an Cockpit

Pilot Spencer Marker in the cockpit

In our Ask a Pilot series, pilot Spencer Marker answers one of your aviation- questions each week. See past installments here and submit your own to whitney@johnnyjet.com.

The question

Have you ever seen (or can you see) the stars from the cockpit window once the aircraft has reached maximum altitude?

—Melissa

The answer

Hey Melissa! Thanks for writing in to "Ask a Pilot"! I often brag to my friends and family about how my office has the best view in the world! And at night, that view becomes even more spectacular! Not only can we see the stars more brilliantly than on the ground, other objects like satellites and the International Space Station become visible. As with most things in aviation, science holds the explanation for this pilot ocular superpower!

Modern passenger airplanes have a maximum cruising altitude generally between 37,000 feet to 41,000 feet (some corporate jets can reach 51,000 feet and the supersonic Concorde could reach 60,000 feet!). That is nearly eight miles above the surface of the Earth! At this altitude the densest parts of the atmosphere are below the aircraft. That means things that reduce visibility like moisture and pollution are also below airplane, resulting in a clearer view for pilots and passengers.

In addition, when the airplane is far from the lights of big cities, the lack of background light helps fainter celestial objects become more visible. This light pollution is the reason large research telescopes are located far from cities and at generally high altitudes in dry air.

Eye anatomy also has a role to play in a pilot's ability to see stars. In low light, the eye naturally secretes a fluid called Rhodopsin (commonly referred to as "visual purple"). The buildup of this fluid in the eye makes it more sensitive to light and therefore enhances night vision. So after roughly 30 minutes of sitting in a dark cockpit, a pilot's low light visual acuity is significantly enhanced. What this means is Rhodopsin in the eye allows even faintly lit objects to become visible, further enhancing a pilot's view of the night sky. Understanding eye physiology is also useful when landing at night. Pilots are careful to limit their exposure to bright lights as Rhodopsin is destroyed when exposed to light and requires an additional 30 minutes to become effective again.

Tip: To fully appreciate the stars on your next night flight, limit exposure to bright lights for at least 30 minutes to enhance your night vision. This way you can enjoy your view of the stars the same way the pilots do!

Personally, Melissa, I have had the chance to see some spectacular sights during my time on the flight deck. I've seen spectacular thunderstorms (from a safe distance, of course) with seemingly endless strokes of lightning. I've observed the serene glow of thousands of stars that make up our Milky Way galaxy and witnessed satellites passing silently overhead. One nighttime encounter stands out in my mind, however: Flying one evening from Orlando out to Los Angeles, I had frontrow seats for a meteor shower. One of the largest I had ever seen. We counted nearly 100 shooting stars as we made our way to L.A. that night. It was one of the most unforgettable experiences of my life.

Thanks for your question, Melissa! I love sharing some of my experiences on the flight deck, so I was happy to receive your question this week!

And if anyone has a burning aviation question or if there's something you'd like cleared up, drop us a line at Whitney@johnnyjet.com to get your question featured in an upcoming "Ask a Pilot" column.

Tailwinds,

—Spencer

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