Flight Delays Up Sharply in Dec.

WASHINGTON — Flight delays increased sharply in December, partly because of harsh weather that disrupted traffic at some of the busiest airports, the Transportation Department reported today.

American Airlines, which had the best on-time performance in the three previous months, dropped to fourth as Pan American World Airways, which had been among the poorer performers previously, reported the best record in December. Overall, the 14 carriers required to submit reports said their flights arrived on time 66.4% of the time, contrasted with 76% in November and about 80% in October.