Pursuant to a congressional request, GAO examined: (1) increases in demand for heavy airframe maintenance; (2) air carriers' efforts to comply with new federal requirements for repairing aging aircraft; and (3) the Federal Aviation Administration's (FAA) oversight of air carriers' compliance with the new rules. GAO found that: (1) the demand for airframe repair and maintenance during the 1990 through 1994 compliance period will be much greater than FAA initially believed when it gave carriers 4 years to comply with airworthiness directives; (2) unverifiable data, extensive and unforeseen repairs, and additional maintenance work loads contributed to FAA underestimating the amount of repair work needed; (3) carriers noted that about 2,600 aircraft would be affected by structural or corrosion airworthiness directives by 1995, about twice the number affected by the structural airworthiness directives alone; (4) although carriers could begin repairing their oldest aircraft immediately, limited replacement parts, hangar space, and airframe mechanics delayed such work; (5) although 13 of 17 air carriers had written plans for complying with FAA rules, the lack of action by 9 carriers shows that they may not comply by the deadline; and (6) FAA did effectively oversee aging aircraft repairs.

RCED-91-91A Aircraft Maintenance: Additional FAA Oversight Needed of Aging Aircraft Repairs (Vol. I)