The NTSB has sent an “urgent safety recommendation” asking the FAA to prohibit airlines from using credit for the use of thrust reversers when calculating landing distances. Although the recommendation would prohibit reverser credit on all runways, “its practical effect would be felt on planned landings only on contaminated runways, which is when the credit is included in stopping-distance calculations,” the Safety Board said. The recommendation follows several overrun mishaps on wet runways, including the December 8 accident in which a child was killed when the car he was in was hit by a Southwest 737 that overran the runway on landing at Chicago Midway Airport. The NTSB noted that the FAA does not allow the use of reverse-thrust credit when determining “dispatch” landing distances and that the agency permits thrust-reverser credit for calculating “en route operational landing distances for some transport-category aircraft” and not others.