The distress emote being what it is, should be one of the emotes able to be used during flight. If you are being chased by a dragon, and are trying to call for help from your group or clan or bystander, it doesn't seem practical to be required to land while being chased/attacked. While the 4 call could be used in it's place, it's not the same message. 4 call says, "Don't hurt me" or, "I surrender". Distress says, "HELP!" and projects a LOT further and louder.
Just a quality of life tweak I think would help a lot.
EDIT: this would also go for drakes in full sprint.