Dear Concerned., Thanks for writing to us., While yawning your ears popping may be due to unresolved Eustachean Catarrh.Your insertion tubes in the ear indicates that you have had middle-Ear infection filled with fluid instead of normally present air. The ENT Surgeon has inserted a Gromet/Plastc Tube to prevent irregular rupture of ear drum/to drain the fuid/to make your hearing better. The un operated ear may be having this popping out problem. You can open the block in Eustachean Tube by (a) Yawning Method(b) Chewing Method(c)Swallowing Method(d)Valsalva Maneuvre-By Closing both nostrils and by blowing into them. Usually during the descent of AirCraft this type of popping occurs with pain .The passengers are asked to do the above procedures. As the Surgery of Gromet Insertion has been successful you are absolutely fit to fly provided you produce a Fit to Fly Certificate issued by the treating ENT Doctor. In addition, you may have to fill out an Indemnity Form given by the Airlines prior to flying. Wishing you a happy flying and speedy recovery., Best regards., Dr Lt Cdr ASN Bhushan., Ex-Navy.