Story highlights United no longer lets coach fliers with small kids board before general boarding

Airline spokesman: "We figured it would be better to simplify that process"

A passenger advocate says the move is "anti-family"

United: We'll work to accommodate families who need additional help

As families prepare for air travel this coming Memorial Day weekend, United Airlines won't be offering early boarding to families in coach with small children.

Joining a handful of other carriers, United made the policy shift in late April with little fanfare.

Previously, families with small children flying coach were allowed on aircraft before general boarding, a convenience for moms and dads trying to herd their kids across the friendly skies.

"We figured it would be better to simplify that process and reduce the number of boarding groups," said United spokesman Charles Hobart. The airline does allow passengers with children traveling in first class or business class to board early.

"I have to wonder if it will end up slowing things down because of the extra time it takes for families to board," said Brett Snyder of the blog crankyflier.com.

Kate Hanni of flyersrights.org calls the move "very anti-family."

"There are very few things a parent can count on when it comes to air travel these days, but one of those things was always the ability to board first to get your children settled in and all of their needs met before the throngs of people board the plane," said Hanni in an e-mail to CNN. "I hope United changes their mind."

"If families do need additional assistance, our gate agent will work to accommodate them," Hobart said. "That message has been communicated."

"We're not going to fly United knowing that we're going to have to put up with that extra hassle," wrote Steven Manson, a Brooklyn, New York, father of twin 4-year-old boys. "Frankly, we always look forward to the preboarding when we fly and try and position ourselves near the gate when boarding begins. It's just so helpful getting the car seat attached and everyone settled before the plane is crowded with passengers," Manson said in an e-mail to CNN.

The policy change also has roots in the merger announced in 2010 between United and Continental.

"We transitioned to a common boarding process across all aircraft," Hobart said.

As a policy, American Airlines also does not specifically allow families with children to get on aircraft before general boarding. However, the airline said it makes an announcement to all ticketed passengers before general boarding asking anyone who needs extra time or assistance to come forward.

"It would not be realistic to preboard that many families just on that sole basis alone," wrote an American Airlines spokeswoman in an e-mail to CNN. "It could easily translate into most of the passengers for the flight."

JetBlue offers families traveling coach with children under age 2 to board early, the airline said. Delta Air Lines said it also offers passengers with children an opportunity to preboard, including those with first class and business class tickets. So does Virgin America , which said it allows children under 5 to board early.

US Airways tweaked its child preboarding rules within the past year -- allowing families with kids to get on the plane after the call for Zone 2, but before the general boarding announcement. Previously the airline had allowed earlier boarding. "We're always looking for ways to make the boarding process a little more efficient and quicker for our passengers," said spokeswoman Liz Landau.

Have you had a good or bad experience trying to preboard a flight? Please share your experiences in the comments section below.