Default. For purposes of 248.105, the failure of the owner to make any payment due under the mortgage (including the full amount of the debt if the mortgagee has accelerated the debt on the basis of a non-monetary default) within 30 days after such payment becomes due.
24 CFR § 248.101
Acquisition Loan. A loan or advance of credit made to a qualified purchaser of eligible low income housing and insured by the Commissioner under part 241, subpart E of this chapter.