A better choice for concealed carry on an airplane would be the Kahr P9. It's not the smallest Kahr, but the G19 makes it look diminutive. The P9 is an inch and a half shorter in length, 1/2" shorter in height, over 1/3" thinner and almost 7 ounces lighter! The give up is 8 rounds versus the Glock's 16, but then, outside of a hollyweird movie, there aren't many all-out, running gun-battles on-board commercial air carriers.
The Kahr has a full, three-finger grip for excellent control. Clearly, where concealment matters, the company that lead - and still leads the single-stack market is superior to the Glock. The P9 is smaller even than the G26 save for grip length, and smaller, thinner, and lighter than the G43, while holding 8 rounds versus the G43's seven.
The Kahr PM9 is even smaller! The G43 is "YHUGE" next to the PM9, and they hold equal shots.
The gargantuan Sig P320 "sub-compact" doesn't even merit comparison.