(CNN) -- Few people expect luxury while flying, but these days, even the basics seem to be in bad shape.
It's not uncommon to find your tray table broken, the in-flight entertainment system not working and your seat cushion worn -- all of which can make you think, how old is this plane anyway?
It won't be an issue for passengers who board the shiny new Boeing 787 Dreamliner when it enters commercial service -- perhaps sometime next year if everything goes smoothly during its testing period.
(Most Americans likely won't see the plane for a few years after that. Most Dreamliners have been ordered by airlines outside the United States.)
The fuel-efficient aircraft will boast all-new interiors with state-of-the-art lighting, bigger windows, roomier overhead bins, higher humidity levels in the passenger cabin and "more personal space," according to Boeing.
But for now, the reality for many U.S. air travelers is that most of their journeys take place on planes that have been in service for a decade or more and show it, though in ways that have no impact on their safety -- like worn interiors, broken creature comforts and less than spotless conditions.
That doesn't stop some passengers from wondering if interior wear and tear translates to something more ominous.
"It's inevitable you draw the link, even subconsciously sometimes, between whether a plane is cosmetically well maintained with whether it's safe," said Joe Brancatelli, who flies dozens of times a year and runs JoeSentMe.com, a Web site for business travelers.
"That is a very tenuous link, it's more psychological than reality, but people make that link."
In fact, it has been a while since most Americans have experienced that new plane smell.
The average age of the fleet of the seven large U.S. passenger airlines -- including American, Alaska, Continental, the merged Delta and Northwest, Southwest, United and US Airways -- is about 14 years old, according to The Airline Monitor.
It found American and Delta/Northwest had the oldest fleets, at about 16 years on average. As of the end of 2008, a small percentage of the merged Delta/Northwest's planes dated back to the late 1960s.
U.S. fleets are among the oldest in the world, said Richard Aboulafia, an aviation analyst at the Teal Group in Fairfax, Virginia.
"I'm not really sure that people should read that much into that," Aboulafia said. "From a safety standpoint, a lot of the older planes were built tougher and with proper maintenance, there's no reason why a plane can't stay safe for 25 to 30 years."
The U.S. and most of the developed world have superb standards and maintenance regulations, the result of decades of experience that have made the system incredibly safe, Aboulafia said.
It's also important to remember that a plane may be 20 years old, but its engines and other major systems could have been recently manufactured or upgraded, said Todd Curtis, a former airline safety analyst with Boeing and the founder of AirSafe.com.
There's less pressure on the airlines to upgrade the interior, unless it's a safety issue or a redesign that will save money.
Last week, Delta announced it will spend $1 billion through mid-2013 to improve the planes it already owns, rather than invest in new aircraft. The upgrades will include adding in-seat audio and video on demand in economy class on dozens of planes and installing full flat-bed seats in BusinessElite on 90 trans-oceanic aircraft.
'Creaking like a haunted mansion'
For many air travelers, the noises a plane makes can be interpreted as a disturbing sign of its age.
"There's a strange whistling in the cabin," wrote a poster recently on Flightsfromhell.com, recalling a tense journey on what appeared to be an old plane. "The engines sounded like they were at full throttle the whole trip... [and] the whole plane made a horrible 'crunching' sound on touch-down."
The aircraft then "limped up to the gate creaking like a haunted mansion. Nothing specifically bad happened on the flight, but we were all pale and shaking once we got off," the poster wrote.
Curtis, who has been around airplanes most of his adult life, said he's also sensitive to unusual noises while flying, but explained that most creaks and squeaks air travelers worry about are routine.
"Every aircraft, even brand new, is designed to be somewhat flexible -- it's not a piece of rock. It's a flexible machine that's designed to bend ever so slightly under certain kinds of stresses. So you might have structural creaking going on because parts of the fuselage or the wings are flexing during flight," Curtis said.
"You could also have equipment inside the aircraft, for example, the furnishings, the overhead bins, the seats, etc., which could have the creaky, squeaky stuff going on."
Which means that even the new Boeing Dreamliner likely won't be immune to making noises.
Some travelers may also not be eager to fly it right away precisely because it's new.
"They'd rather wait for stuff that gets shaken down and they know it works," Brancatelli said. "It's like anything, do you really want to be in a restaurant the first night it's open?"
The plane is the first major airliner to be made mostly of composite materials, making it lighter and more fuel-efficient. This also means the plane's testing will be quite rigorous to see how the material will behave in service, Aboulafia said.
Last month, United announced it has requested 25 Dreamliners, though the airline won't take delivery until 2016 at the earliest.
Boeing is touting the new plane's sweeping arches, wide aisles and larger lavatories as features that will make travelers more comfortable, but experts said economy class passengers likely won't see much relief when it comes to personal space. It will be up to each airline to decide the seat configuration, which is likely going to be similar to what travelers see now.
"The one issue I worry about in any airplane, I don't care what it is, is leg room, and frankly, if you're flying in coach, they're going to pack them in to make money," Curtis said.