BUFFALO, N.Y. - It's up to a pilot whether to flip a switch to get rid of ice building up on a plane, but some authorities hope to change that.
It's not as easy as it sounds.
Every time ice brings down a plane, the volume rises on how best to protect aircraft from the all-too-common and all-too-disastrous phenomenon.
And each time, the conversation fades before significant changes are made.
Authorities caution that they're still investigating why Continental Connection Flight 3407 dropped out of the sky onto a house Thursday night, killing 50 people.
But recordings show the crew was concerned about ice buildup on the windshield and wings shortly before the crash.
With planes carefully designed for aerodynamics, a buildup of ice can affect their lift and handling. A crash blamed on ice killed 68 people in 1994 in Indiana, another killed 29 people in 1997 in Detroit.
Investigators know the plane's deicing system was turned on but can't yet be sure it was working -- or whether it was activated, or when.
Planes are deiced before takeoff to remove any ice that collects beforehand. Sometimes, they must be deiced in the air as they descend and encounter the necessary mix of temperature and precipitation for ice to form.
If a midair deicing system isn't working, guidelines from the Aircraft Owners and Pilots Association Air Safety Foundation say pilots can take a number of steps.
They include changing speed, pulling the nose up or down, or trying a 180-degree turn to rid the plane of ice.
It's not known what steps the pilot in Thursday's crash might have taken if he was experiencing ice buildup.
But the plane had been approaching the airport, and investigators said Saturday that it apparently was pointing in the opposite direction when it crashed.
Pilots of turboprop planes like those in the Buffalo-area crash must turn on their deicing equipment when they notice buildup.
The NTSB wants to go a step further and require them to turn the equipment on when conditions are right for icing.
Then there's talk of an automated ice-detection system like those used in jetliners -- but some automated systems can cost upward of $500,000, according to The Wall Street Journal.
The commuter plane that crashed near Buffalo, a Q400 Bombardier, was equipped with rubber bladders that can be inflated by the pilot to crack ice on the nose, wings and tail; the wind then sweeps away the cracked ice.
Many procedures and devices can help ensure icing is not dangerous, and pilots need to keep up on the latest developments, Chealander said.
"You can design everything in the world, but if the human being doesn't use all those things constantly and focus on them constantly, then you can have tragic consequences," he said.
"I'm not trying to draw any conclusions about this accident, I'm just saying in general, we can never let up our focus on all these types of things," he added.
Once activated on the newer model that the Buffalo pilot flew, the bladders inflate and deflate every 24 seconds automatically, a system that NTSB Vice Chairman Steve Chealander called "very sophisticated."
Not mentioning the Federal Aviation Administration by name, Chealander said the NTSB's recommendations to stiffen rules on deicing have gone unheeded for years.
"We don't like the progress that's taken place right now," Chealander told The Associated Press on Saturday.
FAA spokeswoman Laura Brown said her agency has not ignored the NTSB recommendations and has issued more than 100 airworthiness directives since 1994 that address icing.
"Their concern is this is not happening quickly enough," Brown said. "As with any safety improvement that is significant, we have to go through rulemaking to get there.
"It takes time."
In 2007, the FAA proposed requiring better ways to detect ice buildup or let pilots know about conditions that could cause ice buildup -- in future airplane designs.
It also proposed methods that could help automatically detect ice or potentially icy weather and cue the pilot to turn on deicers.
The rule is in the final stages of executive review.
