(CNN) -- Several major US airlines were reporting malfunctions with flight planning software early Monday morning, leading to delays across the country.
A spokesman for the Federal Aviation Administration said the issue involved a third-party vendor that provides weight and balance software which airlines use to determine flight plans and make fuel calculations, among other purposes.
The spokesman, Greg Martin, said the outage was "short-lived" and delays should be "minimal."
The issue is not believed to have put any passengers in danger.
Southwest Airlines, Delta Air Lines and American Airlines said the issues caused passengers to experience delays Monday.
Southwest said in a statement that they "issued a ground stop" as a result of technical issues "involving a vendor that provides aircraft weight and balance data." The ground stop was lifted 40 minutes later, according to the airline.
Delta also reported a similar issue, saying in a statement they were experiencing problems with a third-party vendor that "prevented some Delta Connection flights from being dispatched on time this morning."
The airline said no cancellations were expected due to the issue.