The Federal Aviation Administration is questioning a shortage of life rafts on board some American Airlines planes, while some veteran pilots question why the agency and the airline didn't identify the issue sooner.
"We are working with American Airlines to make sure they have enough life rafts for everyone on board," said FAA spokesman Roland Herwig.
He said the agency will also look at whether or not the airline violated any federal rules and decide if the FAA should take any action.
Memos that American Airlines management sent to employees indicated the airline would restrict the number of passengers on board its 767-300 aircraft until the company could place an additional life raft on the planes.
The airline has declined to be interviewed about the issue, but provided a fact sheet that was sent to employees.
"This issue of compliance never endangered passenger safety," the document said.
The airline argues it had enough life vests and flotation cushions on board to accommodate passengers, even if there was not enough space in the rafts.
But the union that represents American's pilots disagrees with the company's assessment.
"AMR management's standard response to things like this is it's not a safety issue, but clearly it is," said Scott Shankland, a spokesman for the Allied Pilots Association.
Shankland said the union questions why airline management and the FAA did not recognize concerns about the life raft capacity on the 767s in 2007, when the airline added additional seats and renovated the cabins.
The planes fly mostly international routes to Europe and South America.
Veteran pilot and aviation safety consultant Denny Kelly said the recent US Airways water landing in New York shows why the rafts are important.
He said rafts keep passengers dry and increase their chances of survival, unlike life vests or flotation cushions that force survivors into the water.
"You can't offset the life rafts with vests or seat cushions; you just can't do it," Kelly said.
He disagreed with the airline's claim that limited raft capacity does not present a threat to safety.
"The passengers were at risk because there weren't enough life rafts," he said.
American Airlines has said it hopes to have additional rafts on board its 767-300s within a month.