Both in Joel's (Rob Morrow) dream sequence and in his waking life, when others mistake his fiancee Elaine (Jessica Lundy) for his sister, he quickly corrects them and flatly states that he has no sister. Throughout the series, no mention is ever made of Joel's having any siblings--except in Birds of a Feather (1993), when Joel and his father Herb (David Margulies) discuss Joel's sister in a matter-of-fact manner (it is not a dream or fantasy sequence) regarding a vacation during Joel's childhood.
Joel accidentally bangs his head on the airplane wing bracket when seeing Elaine off to Anchorage. It is clearly an accident as Elaine stifles a laugh but maintains composure.
In the series premiere, Joel took a bus from Anchorage to Cicely. When his fiancée visits, his desperation to find a pilot to fly her from Anchorage implies that Cicely is accessible only by air.