March 24 (UPI) -- The U.S. Air Force's KC-46 tanker modernization program could be facing additional delays, according to a report by the U.S. Government Accountability Office.
In a 26-page report, GAO notes the project has experienced fewer engineering changes than expected, and the cost has fallen by 14 percent, or $7.3 billion. The agency adds, however, that the program is still falling behind schedule.
"The aircraft is projected to meet all performance capabilities. However, Boeing experienced some problems developing the aircraft," GAO said in its report.
Boeing, the prime contractor for the project, plans to deliver 18 tankers to the Air Force by Oct. 14, 2018. Deliveries are slated for 14 months later than initially planed.
GAO adds flight tests delays could further push back deliveries.
The KC-46 modernization program aims to replace a third of the Air Force's aging KC-135 tankers. The branch says the effort will provide enhanced cargo capacity and improved aerial refueling capabilities to support the U.S. Armed Forces and its allies.
Program leaders expect to field 179 aircraft once the modernization is complete.