Upon a determination by the Secretary concerned that a member described in would be qualified for retirement under but for the fact that his disability is not determined to be of a permanent nature and stable, the Secretary shall, if he also determines that accepted medical principles indicate that the disability may be of a permanent nature, place the member’s name on the temporary disability retired list, with retired pay computed under .section 1201(c) of this titlesection 1201 of this titlesection 1401 of this title