24 C.F.R. § 905.515
(2) Within 60 days of the date of HUD's approval of the transaction or, if HUD sets conditions on its approval, within 60 days of the date that the PHA satisfies such conditions (as evidenced by documentation retained in the PHA's file and available to HUD upon request), but in no event longer than 120 days after the HUD approval, unless the time has otherwise been extended by HUD in writing, the PHA must submit: