of flights and even more preferably two flights 62 and 64 now it will be understood that the helical pattern of the flights 62 and 64 renders the shaft 24 insertable into the earth by screwing or rotating the shaft in a first direction and axially advancing the shaft likewise the shaft 24 is thereby rendered removable from the earth by rotating the shaft in second direction opposite the first direction u201c counter rotating u201d and axially withdrawing the shaft with continued reference to fig6 9 the helical assembly 60 further comprises at least one wing and preferably a plurality of wings more preferably the helical assembly 60 comprises two wings 66 and 68 one carried by each of the flights 62 and 64 the wings 66 and 68 are supported adjacent the hub 32 and are movable between an extended position and a retracted position more specifically the wings are connected in a manner that urges the wings toward the retracted position as the shaft is inserted into the earth and that urges the wings toward the extended position when the shaft is counter rotated fig6 illustrates the retracted position of the wings 66 and 68 and the diameter of the helical assembly is indicated at d 1 fig7 illustrates the extended position of the wings 66 and 68 and the expanded diameter of the.