Hey guys, hot tip:
Bring a volume controller.
This is the Westone one that I use.
Set the aeroplane headset amp to full, then limit your volume using this little guy. Only a few bucks, and you'll have perfect impedance matching. No more hiss! More accurate volume control.
I never fly without one.
Yup. I've used a shure one before. UE also has one too. It works like a charm.