The Twirly Birds, an international organization of pioneer helicopter pilots, will be hosting its annual meeting tonight at the Marriott Hotel Orange Country Ballroom at 5 p.m. The organization dates back to 1945, and full membership is restricted to licensed helicopter pilots who soloed at least 20 years ago. Associate members do not have to be rotary-wing pilots but must have made “significant” contributions to the industry for at least 20 years. Anyone who meets the membership requirements can join the meeting.