Possible Clues:

• It may go up in an airplane
• Check about a thousand for something that might be shared on a plane
• Hand support for what 9 across might do about the millenium
• Limb perch
• Check about starting to mend part of chair
• Where to place elbow - or gun
• It may have a cup holder
• Chair side support
• Support introduction of refreshments during morning break
• Many stay around to provide support for member