Ask a Pilot with Spencer: Sinus Pain and Pressurization

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

The question

MANY sinus and migraine suffers have horrible head pain during the descent. The pain can be horrific. I have figured out, for me, at least if the descent is done slowly I don’t have the head, sinus, over the eye pain. If the aircraft goes to a fast descent then the head pain happens. How and why does a pilot decide to make a fast or slow descent? Many I know have given up flying as the pain can be so bad. Taking antihistamines, nose drops, saline spray all through the flight makes no difference.

—Suzan

The answer

Hi Suzan. Thank you so much for writing into Ask a Pilot this week. Your question highlights a unique aspect of aviation that many in the traveling public take for granted.

Humans are not flying organisms, nor are our bodies well-equipped to handle changes in altitude. Understanding these physiological limitations and how to mitigate them is something professional pilots are indoctrinated in from the beginning of our training. What you are describing is pain resulting from a failure to equalize pressure during a descent when air pressure increases.

Understanding how air pressure is managed in an airplane and how that affects us physiologically is something I think is valuable to discuss as I answer your question about managing our rate of descent.

Aircraft pressurization
Everyone that has traveled on an aircraft since the 1950s has heard this phrase during the flight attendant’s safety briefing: “The cabin is pressurized for your comfort.” But what exactly does that mean?

Pressurizing an airplane simply means that air is being fed into an airtight cabin, raising the internal pressure. This way, the cabin air remains breathable at altitudes that aren’t normally suitable for humans. Pressurization came about because aircraft engineers discovered that airplanes are most efficient at high altitudes; between 30- and 40,000 feet. Unfortunately, at these altitudes the air is too thin for humans to breathe.

So airplane designers began constructing aircraft that were tube-shaped and sealed to be airtight. Outside air is then compressed using the aircraft’s engines, conditioned to a proper temperature and pumped into the cabin. Like blowing up a balloon, the air pressure inside the cabin increases to a level that is suitable for passenger comfort. A valve in the back of the aircraft is installed to release a little of this air to maintain a controllable cabin pressure.

Flight crews measure cabin air pressure by noting cabin altitude. Cabin altitude is an easy way for the pilots to determine how the cabin is pressurizing by giving the crew the equivalent pressure in feet of altitude. For instance, an airplane that is flying at 40,000 feet may have a cabin altitude of 8,000 feet. This means the air pressure inside the cabin is the equivalent of a person standing on top of an 8,000-foot mountain.

So why not just pressurize the cabin to zero-feet altitude all the time? Well, that is the trade-off with aviation. Unfortunately, pressurizing a cabin to that altitude would require an aircraft structure that would be extremely heavy. And to fly, an airplane must be as light as possible. So engineers made a compromise. Flying at an 8,000-foot cabin altitude is safe for humans and doesn’t require a heavy structure to be so.

This paradigm is changing however, as the new Boeing 787 and Airbus A350 have a maximum cabin altitude of 6,000 feet, resulting in a more comfortable cabin for passengers. This is thanks in large part to their composite structure which provides extra strength while still being lightweight.

Changes in pressure
Another physiological limitation for humans in aviation comes about when we need to equalize the air-filled spaces in our bodies during rapid climbs or descents.

Most passengers are familiar with equalizing pressure by popping their ears. However, in our frontal sinuses (located in your forehead) and maxillary sinuses (located beside your nose), manually equalizing pressure is more difficult and the pain can be sharp and intense.

Descent paths
Now, to answer your question directly Suzan, pilots can choose to descend the aircraft quickly or slowly. Nonetheless, the most efficient descent path for aircraft is usually with the engines at idle. And with the gradual introduction of the NextGen Air Traffic Control system, most descents are structured this way for maximum aircraft efficiency. However, the descent can be rapid and can cause discomfort for passengers experiencing sinus problems.

Other times, pilots may be required to change altitude gradually, or in steps. This could be based on demands from Air Traffic Control. In these instances, changes in altitude from cruise to landing are interrupted by several step-downs which allow time for sinus pressure to equalize. Unfortunately, this scenario is increasingly becoming the exception.

To sum up
Thank you for reaching out to be included in this week’s Ask a Pilot. I am truly sorry for your inflight discomfort. Professional aviators such as myself often pride ourselves on making the flight as comfortable as possible for our passengers. While we do our best to operate the airplane in a way that is pleasant for everyone, sometimes the physiology of flying can make for an uncomfortable journey. There are options, and consulting with a doctor could get you back in the air, comfortably and confidently.

Thanks again for your question! If you have stories of inflight discomfort, post in the comments below! And if anyone have a burning aviation question or something you would 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