It’s Delta. They have new rules.
Here’s a tip-off to Slipped Disc from Piers Adams, of Red Priest:
I recently tried to book flights to America for Red Priest on Delta, only to be told that this airline no longer will allow cellos in the cabin for, specifically, flights to and from the UK. The booking agent helpfully told me that it would be OK if we flew via Paris. I have tried at length to elicit an explanation from Delta for this mind-bogglingly silly and random rule, without success. Here is the proof in black and white:
Scroll down to the bottom of the ‘Musical Instruments’ link and you will find in small print: “Not valid for travel to and from the United Kingdom”.
Sounds to us like Delta is not valid for musicians to fly by.
We’ve had trouble with them before.