“In my haste to complete my syllabus sortie, despite of a recovering cold, I went ahead for the sortie that morning. As I climbed, I had some difficulty in clearing my ears. But when I started my descent to come back to land, I realised that I could not equalise pressure in my middle ears, despite vigorous attempts of Valsalva. As I continued descent there, I had an excruciating pain in my ears, as if it is going to burst. I called out on RT about my unbearable pain, …and landed with great difficulty.”
This is a true incidence of barotrauma of ears in a combat pilot. This is caused by the change in the ambient pressure occurring during ascent or descent, especially if one is suffering from common cold, flu or sore throat. It usually occurs during flying or under water operations (diving); and the symptoms collectively are called as “Barotrauma”. This can lead to problems in the ear (Otitic Barotrauma), sinuses (Sinus Barotrauma), in the intestine or a bad tooth (Aero-odantalgia).
Barotrauma is caused by the expansion of trapped gases in the body cavities due to changes in the pressure between ambient and semi-closed or closed cavities in the body. The applicable physical law is Boyle’s law. The law states that the volume (V) of gas in inversely proportional to its pressure (P), with temperature (T) remaining constant, i.e. P α 1/V.
Though this piece has been written with focus on aircrew, especially pilots, barotrauma is known to occur in non-pilot aircrew, passengers, especially at the extremes of ages, as well as, those who choose to fly despite of a cold or flu. Hence the information provided here may be of use to everyone who flies. It is advisable that in case of doubt about your fitness to fly or related clarifications, please consult your doctor.
1. Ernsting’s Aviation Medicine. Rainford DJ, Gradwell DP (Editors). 4th Edition. Hodder Arnold, London 2006.
2. Fundamentals of Aerospace Medicine. DeHart RL, Davis JR (Editors). 3rd Edition. Lippincott, Williams & Wilkins, Philadelphia 2002.
3. Human Performance & Limitations – JAA ATPL Theoretical Knowledge Manual. 2nd Edition. Jeppesen GmbH, Frankfurt 2001.
Acknowledgement Image courtesy Freedigitalphotos.net