U.S. Federal Aviation Administration last month considered grounding 49 Southwest Airlines jets because the airline failed to carryout inspections and show the mandatory safety standard documents. The letter sent to Southwest that was made public on Monday required documents for 88 planes in question, which Southwest purchased from 16 foreign carriers, including Kenya, Colombia, Russia and Turkey, since 2013. FAA had given two years for the airline to carryout complete physical inspection of the 88 pre-owned aircraft purchased from 16 foreign countries., The airline has completed inspection on most of the planes, but has yet to provide documentation on 38 more that are still flying. Last year, the airline “discovered a small number of repairs on a few of these 88 pre-owned aircraft that had been performed but not properly classified by the previous owners due to differences in language and repair criteria,” said Southwest spokeswoman Brandy King to CNBC. An FAA official, John Posey, who oversees the airline, complained in an Oct. 29 letter to Southwest’s COO about the slow pace of Southwest’s review of the planes. “If the FAA’s concerns are not adequately addressed, the FAA may exercise remedies up to and including grounding the aircraft” until Southwest complies, the letter said. However, Southwest agreed to complete the inspections by Jan. 31, instead of a deadline of July 1, 2020 said the FAA.