The Federal Aviation Administration, seeking to prevent airplane collisions, ordered altitude-reporting transponders for all aircraft operating around 14 U.S. airports. The action brought the number of major terminal control areas at which such safety devices are required to 23. The equipment will provide air traffic controllers with altitude information on all flights, including small airplanes, in terminal control areas. The new regulation applies to terminal control areas in Cleveland, Denver, Detroit, Honolulu, Kansas City, Houston, Las Vegas, Minneapolis, New Orleans, Philadelphia, Pittsburgh, Seattle, St. Louis and San Diego. Such transponders already have been required for planes flying around the nine busiest control areas--Atlanta, Boston, Chicago, Dallas, Los Angeles, Miami, San Francisco, Washington National and New York-Newark.