Is it possible to have a Hangout on Air and also include them using a phone number? This is possible when the Hangout is not On Air but would be a great feature to have available.
Dori, Google Community Manager
At this time it's not possible to have phone participants in an HOA. From what I understand, part of this limited functionality has to do with the fact that phone participants wouldn't know they were being broadcast publicly or recorded.
This is a feature request that we've received in the past and that the team is aware of.