The fact there are no federal requirements for calculations critical to landing planes in wintry weather came to light in the probe into the Dec. 8 crash of a Southwest Airlines flight at Chicago's Midway International Airport, USA Today reported.
The newspaper obtained a memo Boeing sent to airlines last week, urging them to review their calculations for safe stopping distances. The company's operations manual for the type of B-737 that crashed shows that landing at Midway that day was barely possible if everything went perfectly.
With moderate snow on the runway and a tailwind, Boeing says it would take about 5,800 feet to stop. The runway is 5,826 feet long.
Flight 1248 slid off the runway and crashed through a fence, killing a 6-year-old boy in a car.
The Federal Aviation Administration, which must sign off on each airline's operations, has also begun an evaluation of landing standards, said spokeswoman Laura Brown.