If you are flying this Thanksgiving, you better check the weight of your bags twice.
A three-week enforcement sweep from Oct. 19 to Nov. 6 by regulators in New York found that many of the scales the airlines use to weigh your bags weren't registering the right weight.
That could mean big penalties for you.
Most major airlines already charge passengers $15 to $20 to check a bag. But if that bag is overweight -- typically the threshold is 50 pounds -- the airlines tag on a steep penalty, ranging from $25 to a whopping $150. And often those fees are imposed each way.
The airlines collected more than $1.2 billion in such baggage fees in the first six months of this year, according to the U.S. Bureau of Transportation Statistics.
Before you panic and think that the airlines are trying to rip you off -- or at least cheat you at the scale -- note that 92.3 percent of the 741 scales at the two airports were found to be in perfect working condition. The airlines were ordered to stop using the other 57 scales, and they have since been fixed.
New York Department of Consumer Affairs Commissioner Jonathan Mintz's said that of those 57 scales that failed inspection, only 42 percent were overweighing bags.
The other good news for travelers is that this year's inspection showed more scales in working order: 92.3 percent compared to 88 percent during last year's enforcement drive.
Enforcement of the scales across the country is left up to local authorities, and no national group appears to keep a database of their accuracy.
A South Florida Sun-Sentinel analysis last month of nearly 2,000 South Florida airport scale inspections found that more than one in four resulted in failures from 2005 to mid-2008. Palm Beach International Airport had the worst record for weight-related failures, 12 percent, while Fort Lauderdale-Hollywood International and Miami International had 4 percent.
Last year, the Arizona Department of Weights and Measures, responding to a complaint by a US Airways passenger, did a surprise inspection of the airlines' scales at Phoenix's Sky Harbor International Airport. A team of inspectors tagged 31 of the 72 scales with infractions, but all but three were minor and none was to the airline's advantage.
Southwest, which has a large presence in Phoenix, shut down three of its 26 scales because they received the most serious violation from the inspectors. The problem: The scales did not start at zero. In Southwest's case, they started before zero, so any error would be in the customer's favor.
Rick Seaney, CEO of flight search site FareCompare.com and an ABCNews.com columnist, said that thanks to added baggage fees, consumers are now trying to fit the contents of two bags into one, making this a bigger issue than in past year.
"Now with the fees being so much higher than they were 18 months ago for overweight baggage, if you're going to charge that much, it behooves you to calibrate your scales properly across the board," Seaney said.
For travelers, Seaney said: "Certainly, if you are right on the dividing line, there is haggling that needs to be done, especially if you are armed with this information."