Problems on US aircraft have prompted the Federal Aviation Administration (FAA) to take a zero-tolerance approach to unruly passengers with a fine of up to $US35,000 and possible jail time. The FAA on Wednesday signed an order introducing a stricter policy against unruly airline passengers that will remain in effect until March 30 "in the wake of recent troubling incidents". "Flying is the safest mode of transportation and I signed this order to keep it that way,'' FAA administrator Steve Dickson said. READ: US joins countries requiring pre-flight COVID testing. The agency said it had seen a disturbing increase in airline passengers who have disrupted flights with threatening or violent behavior stemming from a refusal to wear masks and from recent violence at the US capital. It has taken more than 1300 enforcement actions against unruly passengers in the last 10 years, including recent cases where passengers allegedly interfered with or assaulted flight attendants who instructed them to wear masks. The upgraded policy means that people disrupting US flights will no longer receive a warning or counseling about their anti-social behavior. Instead, the agency will pursue legal action against any passenger who "assaults, threatens, intimidates or interferes with airline crew members". "Passengers who interfere with, physically assault, or threaten to physically assault aircraft crew or anyone else on an aircraft face stiff penalties, including fines of up to $US35,000 and imprisonment,'' it said "This dangerous behavior can distract, disrupt, and threaten crewmembers’ safety functions." Airlines can also take action against passengers by putting them on "no-fly" lists and Alaska  Airlines recently banned 14 rowdy passengers flying to Seattle from  Washington DC after the assault on Capitol Hill. READ: Alaska bans 14 after rowdy behavior on Washington flight. Unions representing flight attendants had warned the mob mentality of some passengers was unacceptable and threatened the safety and security of other passengers and crew members.       .