Q. I’m six-feet one-inch tall and will be flying from New York to San Francisco soon. Which airline should I fly on? JetBlue, Virgin American, Delta, US Air, United, or American?

A. I assume you’re asking because you’re concerned about legroom and you’ll be flying in economy. JetBlue will give you the most space for your legs. Their standard seats on all their flights offer 34 inches of space between seats (“pitch” in airline parlance) and their “even more room” seats offer 38 inches, along with priority TSA lines and boarding, for an additional fee. United’s PS Service, which flies exclusively between JFK and both San Francisco and Los Angeles, also offers extra legroom in economy class (34 inches). I find Virgin America’s economy class cramped in comparison at 32 inches. The only downside to JetBlue, really, is that they don’t yet offer WiFi on board (it’s coming later this year), whereas United, Delta, American and Virgin do. Delta’s JFK terminal (until they rebuild it) is so confusing that I tend to avoid them for now. US Air doesn’t fly JFK to the West Coast nonstop. If you like to fly on larger aircraft, American is the only airline serving the route with wide-body jets. But I’d go with JetBlue unless you can’t live without WiFi. You can check out seat maps and seat pitch at Seatguru.com.

Q. What is the maximum age for a child to share your airline seat on your lap?

A. It depends on the size of your lap. Just kidding. Lap children should be two years of age or younger, although as I’ve said in this column before, I don’t recommend carrying a child in your lap in a car going 100 miles per hour and nor do I recommend doing so on a plane landing at 100 miles per hour. Keep in mind that although lap children ride free on domestic flights, you’ll pay 10 percent of the applicable adult fare on international ones. Even if you’re flying on a free frequent flyer ticket internationally, if the equivalent business class fare is $5000 round-trip you’ll pay $500 for your lap child. It also makes for a very uncomfortable flight.

Q. Does any airline still have a Rule 240?

A. Rule 240 was a clause in airline contracts of carriage back when airlines were regulated by a government agency. It stated that, except in cases of “force majeure” (i.e., an act of God such as severe weather), airlines had to offer you any available seat on a competitor’s next flight out in the event that your original flight was canceled or severely delayed. Airlines formed after deregulation, such as Virgin America and JetBlue, never had a Rule 240, but most “legacy” carriers (American, Delta, US Airways, United, Continental, Eastern, etc.) did. Of the remaining airlines, only United and Alaska still have language similar to Rule 240 in their contracts. United now calls it Rule 24 and Alaska calls it rule 240AS. The only problem these days is that will so many airlines operating virtual monopolies at some airports, and flights being so full, there is often no alternative seat available on other airlines. To check if your airline has a Rule 240, see our recently updated list of airline contracts of carriage.

Q. What is the Department of Transportation policy governing airline delays due to mechanical failure? We were stuck at the New Orleans airport for more than 10 hours when our plane had an engine problem and would like compensation.

A. There is no D.O.T. rule concerning compensation when an airline experiences a mechanical problem. There used to be a D.O.T. rule called Rule 240 that required airlines to put you on another airline’s flight in such circumstances, if that airline would get you to your destination sooner than your original airline. Airlines often will provide some compensation, usually in the form of a travel voucher or frequent flyer miles, in such cases. It doesn’t hurt to ask.

Q. I recently had a round trip ticket purchased from US Airways, traveling from Portland, Maine to Baltimore. My travel plans changed and I was going to switch to a one way ticket from Baltimore to Portland. I called and spoke with the agent who looked at the ticket and advised me what the charges would be to change the ticket. It turned out to be more economical for me to cancel the ticket, have the value for a future flight, and re-book a one way ticket.
 
Here's the catch. The agent made a mistake. She changed the ticket, charging me a $150 change fee and a $25 service fee, then turned around and canceled the ticket. I caught the charge on receipt of my credit card statement.
 
Now I'm getting the run around at US Airways. I had to log a complaint and request a refund through the web tool and now sit and wait for someone to contact me because no phone number is provided for the customer relations group.
 
What recourse do I have? The agent made a mistake. How can I fight this?

A. If your ticket was a non-refundable ticket, than a cancellation would incur a change fee. This is the language on their website with the pertinent language underlined:

Non-refundable tickets

If a customer has already missed their flight but contacts their travel agency prior to midnight on the day of departure, the travel agent must call US Airways Reservations to document the PNR to retain value. Failure to contact US Airways and simply canceling the past segment in the GDS will result in the ticket being marked with a "no value" status. Cancellations made in the GDS prior to flight departure do not require a call to US Airways.

A change fee, per fare rules, applies to all non-refundable tickets. Any flights or flight segments canceled on or before the scheduled date of travel will retain ticket value and can be credited against the price of another ticket.

   If a reservation is canceled on/before the ticketed departure date, the value of the ticket may be applied toward future travel up to one year from the original issue date. Travel on the new ticket must be completed within one year of the original date of issue.
   If any part of the ticket is unused after the ticketed departure date and the reservation has not been canceled, the ticket has no value.
   Once the value of a non-refundable ticket has been applied towards the purchase of a new ticket, the original ticket is considered valueless.
   Any difference in fare, if greater, must be collected. No refund is given for a decrease in fare (no residual value) and residual amount cannot be applied to the change fee. All non-refundable values remain non-refundable.

Refundable tickets

All changes to refundable tickets (whether full or partially used) can be made at no charge. (Changes to passenger name are not permitted.) The value of the original reservation will be credited against the price of the new reservation.

Any difference in fare must be collected if greater and refunded if less. All non-refundable values remain non-refundable. All unused ticket segments must be canceled.

You may want to call US Airways (800-428-4322) and double-check, but fees are commonly charged by most airlines either for a change in your itinerary or canceling your itinerary. 

Q. I have noticed the last few times I have booked flights they don't have seats for my husband and me to sit together. Is this something new? How can I book flights online and make sure we can sit together?

A. What you’re experiencing is a relatively new practice. Flights are more crowded than ever thanks to capacity cuts and route eliminations, and airlines are holding back advanced seat assignments and “priority” seats for their best customers (those paying higher fares, booking at the last minute or “elite” frequent flyers) or those willing to pay for them. As a result, other passengers are finding it harder to find seats together. Once you get to the airport, or once you’re on board, you can try to find seats together either by asking the gate or check-in agent to reassign you, by asking other passengers to switch seats with you, or by paying for a “premium” seat assignment. You’ll also increase your chances of finding a seat together if you book far in advance. Another option is to pay the $10 fee levied by Southwest Airlines, which doesn’t offer seat assignments at all, to get “early bird check in.” This gives you a better chance of boarding the aircraft sooner than most other passengers, which means you’re more likely to get a seat together.