The FAA says the airworthiness directive will make sure pilots avoid icing conditions that could hurt engine power and possibly damage the engines.
In certain conditions, ice crystals can form in the engines, reducing their power. The problem has come up with General Electric engines used on Boeing Co.'s 747-8s and 787s.
The U.S. agency says it's an "interim" action, so more could be coming later.
The directive will apply to 14 U.S. planes, including Boeing 787s flown by United Airlines.