In a decision that is both an indication of societal trends and a response to a tragedy, the federal government on Monday ordered airlines to boost weight estimates for their passengers.
The action stemmed from the Jan. 8 crash of a twin-engine commuter plane during takeoff from Charlotte, N.C. It also reflected concern with what medical researchers have called an epidemic of obesity in America.
Under the Federal Aviation Administration order, the allowance for travelers and their carry-on items will go up by 10 pounds, to 190 pounds in summer and 195 pounds in winter.
The FAA gave airlines the option of setting their own weight allowances -- to account for differences within regions of the country -- by conducting surveys that may include putting some passengers on a scale. Passengers in Florida are likely to wear lighter clothing than those in Alaska, for example.
The weight figures are used to ensure that aircraft are not loaded too heavily.
The plane that crashed, US Airways Express Flight 5481, was loaded to near its limit, based on the weight estimates in effect at the time. Shortly after takeoff, the Beech 1900D turboprop went into an unsustainably steep climb, rolled right and then plunged into an airport hangar, killing all 21 aboard. In addition to weight and balance issues, a probe is looking at maintenance problems with the plane.
Excessive weight in adults has been linked to medical problems such as diabetes and heart disease, but now there is an aviation safety implication, particularly on small commuter planes.
"It's fair to say that operators of smaller airplanes, if they have nontypical passengers who are obviously in excess of average weight, are going to have to be more careful where they place them on the airplane," FAA spokesman Les Dorr said.
Medical researchers say 61% of U.S. adults are overweight and 27% are obese.
The FAA directive may force airlines to remove seats from some smaller aircraft; some have already done so. It is expected to have little or no effect on big jets with powerful engines, which seldom take off near their maximum allowable weights. The order applies to all air carriers.
"The FAA's new rule takes into account the larger profile of the average flier, and we have to go with it even if it means we have to accommodate fewer passengers," said Susan Coughlin, president of the industry-supported Aviation Safety Alliance.
Regional airlines, which have become important market players, lobbied the FAA to allow carriers the option of conducting their own weight surveys.
Deborah McElroy, president of the Regional Airline Assn., said variations in operational and atmospheric conditions, as well as differences in the amount of clothing worn or carried by passengers, argued for leeway.
"We were concerned that a number would simply be chosen," McElroy said. "It is important that the carriers have the flexibility to determine what the appropriate number is, given their operations."
In January, shortly after the crash, the FAA ordered a round of weight surveys. Operators of 10- to 19-seat planes were told to assess how closely their passengers reflected the FAA estimates.
"Some carriers added as much as 30 pounds to their weight estimates, while others had nowhere near that amount," McElroy said.
On average, passengers were about 21 pounds heavier than the FAA's estimates.
Nonetheless, Dorr said, the 10-pound increase in the estimate is sufficient to guarantee safety.
"We think this is a prudent short-term action," Dorr said. "The [previous] surveys were relatively limited in scope and we feel like we need more extensive data ... before we consider long-term change."
An advisory panel will be formed to conduct a study and make recommendations.