Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Southwest Airlines unexpectedly grounded 34 Boeing 737-700 aircraft on Thanksgiving Eve, Nov. 21, when the budget carrier realized that the maintenance paperwork for the relevant planes were out of compliance with Federal Aviation Administration (FAA) safety directives. The unfortunate timing coincided with one of the busiest travel days of the year for up to 25 million Americans.The issue had to do with damaged fuselage areas on the aircraft that were previously repaired. Most of the planes involved had previously been owned by other airlines. The FAA mandated that Southwest complete immediate detailed visual inspections of the nearly three dozen 737s, most of which were added to the airline’s fleet after Southwest got rid of its remaining older Boeing 737-300 aircraft sooner than originally planned.Southwest has already been under close scrutiny this year for two reasons. First of all, the airline is in the final stages of approval for its highly anticipated impending service to Hawaii, which still has not been finalized despite much hubbub.Additionally, the airline is being investigated by the Inspector General of the US Department of Transportation following Flight 1380’s in-air engine explosion in April, which led to the airline’s first-ever mid-flight fatality in nearly half a century. However, Southwest insisted that last week’s FAA-directed aircraft grounding was unrelated to the Inspector General’s investigation.A Southwest spokesperson said that the Thanksgiving Eve groundings and inspections “had minimal effect on our operation,” managing to complete 4,100 flights on the eve of the major US holiday.