International air passengers face tightened security on U.S.-bound flights following the alleged attempt by Nigerian Umar Farouk AbdulMutallab to bomb a Christmas Day flight heading for Detroit . U.S. travel and security authorities , international airlines and airports and aviation organizations have all moved quickly to implement a range of measures that will impact travelers ' normal routine . Which flights are affected by the new measures ? At present only flights to the United States are affected . What are the measures ? The Transportation Security Administration , which oversees the security for U.S. travel , says it has issued a directive for additional security measures to be implemented for flights as they leave their last stop before the United States . The authority has not made public the directive . But it said in a statement that passengers can expect to see extra security `` at international airports such as increased gate screening including pat-downs and bag searches . During flight , passengers will be asked to follow flight crew instructions , such as stowing personal items , turning off electronic equipment and remaining seated during certain portions of the flight . '' Individual airlines and airports will each interpret the TSA directive in their own way . But anecdotal advice suggests that passengers are not allowed to leave their seats for the bathroom or to access luggage during the final hour of any flight , nor keep blankets or pillows on their laps . Passenger Niki Yazzie , who was on a flight Saturday from Brussels , Belgium , to Dulles Airport in Virginia told CNN that passengers not allowed to leave their seats for the last hour of the flight . There have also been reported bans on the use of laptops and MP3 players . What will be the knock-on impact on air travel ? The measures , which only apply to U.S.-bound flights , are not at present as severe as those introduced after 9/11 or the revelation of the liquid bomb plot in August 2006 . CNN aviation analyst Richard Quest cautions : `` If the measures are just for U.S.-bound flights then they 're workable . If they are for all passenger flights then things will grind to a halt . It will not be as bad as the ban on liquids but it will be close . '' Can passengers expect more extensive precautions ? Quest says that the Detroit incident has exposed a hole in airport security . `` This is their worst nightmare , '' he said , `` someone following procedure and still getting through . They are trying to avoid the ultimate -- the ban on hand luggage and the physical search . But they have now been forced into the latter . '' He adds that airlines would eventually ease the severity of some of the measures . `` There 's no way a major carrier will tell its business class passengers that they ca n't have a pillow and blanket . '' American carriers tend to be the first to introduce security measures and the last to abandon them -- to the benefit of rival airlines . What are airlines telling passengers ? All are following a similar line -- check before you fly , turn up early , expect tougher security and skimp on the hand luggage . British Airways has advised that `` only one item of hand luggage is allowed for all passengers traveling to the U.S. from Heathrow , Gatwick or London City . This applies to passengers whose journey originates in London , as well as those who are transferring flights . '' It adds that holiday presents in hand luggage will need to be unwrapped -- but only for U.S.-bound flights . American Airlines meanwhile advises that `` all passengers should plan to arrive at the airport at least three hours in advance of their flight 's departure to allow extra time for check-in and the boarding process . '' Cathay Pacific states that additional security measures will include : `` Pat down check by security personnel and physical inspection of their cabin baggage and personal property prior to boarding ; and , restricting the use of cabin phones at any time during the flight . `` Passengers will be required to cooperate with cabin crew on any other inflight security measures as instructed . '' What does this mean for passengers ? After previous scares extra security measures have been introduced , only to eventually be scaled back slightly . Now , life for travelers is likely to become more complicated again . `` After this latest incident there will now be the normal fuss and furor for an airline , '' said Quest . Female passengers , for example , might have to put handbags and purses in hand luggage rather than being allowed to carry them in addition . Will travelers from certain countries be affected ? A leaked copy of the TSA 's Standard Operating Procedures , published online in early December , stated that travelers from certain nations -- Cuba , Iran , North Korea , Libya , Syria , Sudan , Afghanistan , Lebanon , Somalia , Iraq , Yemen or Algeria -- should be referred for screening . The inclusion of Yemen is notable as the country where Umar Farouk Abdulmutallab says the explosive device was acquired , according to a U.S. federal security bulletin . Quest says that while positive vetting -- where certain groups of travelers are targeted -- would not be enforceable , it may take place covertly . How long will these measures continue ? `` Patdown is here to stay on U.S.-bound flights , '' says Quest , adding that it would even apply to all family members heading for a break at Disneyworld in Orlando . `` This incident has exposed what the airline authorities hoped would not be shown up . ''
U.S. authority in charge of travel security issues new directive on measures after alleged terror bid . Airlines : Check before flying , turn up early , expect tougher security , skimp hand luggage . Comment: