FAQs on the fly

What can’t I take on a plane?

Beside the obvious (explosives and weapons), the government forbids dozens of items. Different rules apply to checked and carry-on bags. For a full list, log onto the website of the Transportation Security Administration, www.tsa.gov, and click on “SimpliFLY.” Do not wrap gifts because TSA inspectors may need to unwrap them.

What is the latest no-no?

Since Jan. 1, lithium batteries have been banned from checked luggage unless they are installed in electronic equipment, such as cameras. However, some small, loose batteries can be carried aboard if they are packed in plastic bags or are in the original packaging. For details, visit safetravel .dot.gov.

What about liquids?

They are allowed in checked baggage but strictly limited in carry-ons. You can take aboard liquids and gels in 3-ounce or smaller bottles (by volume), providing they all fit inside a quart-sized, clear, plastic, zip-top bag. Exceptions include medications, baby formula and food, breast milk and juice, which you can bring aboard in “reasonable quantities,” the TSA says on its website.

Are the rules the same everywhere?

No. Each country is free to set its own rules. Check with your airline.

How much luggage can I take?

That depends on the airline. Typically in the U.S., you can take one bag plus a personal item, such as a purse or briefcase, as carry-ons. And if you check more than two bags or they weigh more than 50 pounds each, you may be charged excess baggage fees.

Am I still limited to one carry-on item in Britain?

In certain cases, yes. It depends on which airport and airline you’re using. The rules are gradually being loosened. For updates, contact your airline or visit www.baa.com (the company that operates Heathrow and seven other major British airports) or www.dft.gov.uk (Britain’s Department for Transport).

What should I wear when flying?

Comfortable clothing. Avoid laced boots or other footwear that will be hard to take off at checkpoints. Remove coats, sweaters and belts with large buckles and put them in provided bins before going through security.

How should I pack?

Entire books have been written on this topic. A couple of pointers: To ease your trip through security, pack your belongings neatly in layers, not in a jumble, so they can be seen on X-rays. The TSA’s website says that “seemingly innocent items can actually appear to be potential threats in an X-ray image, simply by the way they’re packed.” And don’t put vital medications or high-value items in checked bags; carry them with you.

How do I get the lowest airfare?

Book far ahead and shop around. For most simple domestic tickets, do the research on the Internet. Useful websites (there are dozens) include www.smarter travel.com, which rounds up daily deals; www.sidestep.com, which searches scores of websites; www.priceline.com, where you can bid on airfares (as well as hotels and car rentals); www.hotwire.com, with an array of deal strategies; and www.airfarewatchdog .com, which sends e-mail alerts on low fares. For complicated or foreign itineraries, use a travel agent. You’ll pay a fee, but you may save time and money.

What’s the best way to buy an air ticket?

Generally, on an airline’s website. Fares are often lower, and you’ll save on service fees too.

What is a nonrefundable air ticket?

One that usually cannot be returned for cash or credit. But you may be able to change it if you pay a fee, which can be $100 or more. It is generally cheaper than a refundable air ticket, which may let you make changes without penalty.

How do I get the best seat?

Choose it far ahead and study the aircraft. A popular website for advice is www.seatguru.com, which rates seat positions on window views, recline capability, proximity to the lavatory and other factors.

What happens if I get bumped?

You may be eligible for what’s called “denied boarding compensation” of up to $400, plus the value of your air ticket. The amount depends on how long you’re delayed. In the future, you may get even more money because the federal government has proposed increasing the limit.

Where can I find out about my rights as a flier?

The U.S. Department of Transportation offers an online guide called “Fly-Rights,” with information on denied boarding and other topics. You can find the guide at airconsumer.ost.dot.gov/publications /flyrights.htm

Do my frequent-flier miles have an expiration date?

Usually they do. Eighteen months to two years are typical. You can often keep your miles “alive” by making a small purchase from one of the airline’s partners. Contact your airline for details.