All of the single-seaters were later retired when the upgraded A-4SU began to enter service, the twin-seaters were upgraded instead and remained in service [REF].
In 1983, a third order of 8 TA-4S saw 16 stored A-4Bs from the Aerospace Maintenance and Regeneration Center (aircraft boneyard) being converted and rebuilt as the TA-4S-1 trainers (eight airframes) [REF].