The Air Florida and Metro crashes that occurred within a half an hour of each other Jan. 13 highlighted "critical weaknesses" in the District of Columbia's ability to handle emergencies, a House subcommittee chairman asserted yesterday.

Rep. William H. Gray's (D-Pa.) comments came after more than four hours of testimony before his District subcommittee that underscored critical delays, lack of coordination, and equipment problems in the rescue efforts in response to two massive accidents that came in the midst of a blinding, rush-hour snowstorm.

Despite a rescue effort that has generally been praised as valiant considering the circumstances, a succession of witnesses yesterday revealed the following problems in the District's disaster response:

* Had more passengers from Air Florida's Flight 90 remained alive in the Potomac River after the crash, "quite a few" may not have survived the accident because rescue workers could not get them out of the icy waters fast enough, according to National Transportation Safety Board member Francis McAdams.

* Neither the U.S. Park Police helicopter that rescued five survivors nor the D.C. police helicopter that headed for the Potomac, but was turned back, was properly equipped to land on the water and pick up large numbers of survivors, according to authorities.

* The first injured passengers from the Metro wreck that killed three and injured 25 did not arrive at local hospitals until 1 hour and 50 minutes after the crash, according to preliminary information gathered by safety board investigators.

* Nearly three weeks after the two crashes, there is still disagreement among officials over who first set rescue efforts in motion. In both crashes, off-duty officers who happened to be on the scene made the calls that apparently spurred the first rescue attempts, according to testimony.

* When the federal government's Office of Personnel Management dismissed federal workers early on Jan. 13 because of the snowstorm, it ignored recommendations against such action by Metro officials, thereby contributing to the massive traffic tie-ups that complicated rescue efforts.

Gray said his subcommittee on government operations and metropolitan affairs was holding hearings so it could make "positive suggestions to improve" the area's ability to handle emergencies. The area's response to the disasters is already the subject of five other investigations, including one by a special D.C. task force created by Mayor Marion Barry and Police Chief Maurice Turner.

Yesterday, witnesses from the D.C. government, the safety board, Metro, National Airport and the Office of Personnel Management described an array of problems in the area's emergency response.

McAdams, who is heading the safety board's investigation of the airline disaster that killed 78 persons, testified that he is "not at all sure" how rescuers would have handled the job if more people had survived the crash of Flight 90 and had to be picked up from the 34-degree waters.

The most effective means of rescue would have been boats, he said, but none were available with ice breaking equipment to reach the scene. National Airport's airboat, a vessel powered by a fan-like device in the rear, could not operate because of the slush, McAdams said, and the use of more than one helicopter in such a small area would have been "extremely dangerous."

Subcommittee member Stanford Parris (R-Va.) charged that the Park Police helicopter, which is listed in a National Airport manual as the first to be called when helicopter assistance is needed in a rescue, is inadequate for the task and should be equipped with pontoons to land on water or ice.

The helicopter rescued five victims who were floating in the Potomac after the crash, but was unable to reach the sixth victim before he disappeared beneath the surface. "Perhaps if that helicopter could land on ice, instead of losing one, maybe it would have been able to get them all out," Gray said during the hearing.

In testimony on the Metro wreck, safety board member Patricia Goldman said the board's investigation showed that the crash occurred at 4:30 p.m. and that an off-duty Metro transit policeman, who happened to be on the subway car in which the victims were riding, was the first to notify Metro headquarters three minutes later and the first to advise Metro that there were serious injuries. Goldman said the train had lost radio contact with Metro Central Control because of the crash.

Metro General Manager Richard Page, however, testified that radio contact was not lost and that the supervisor operating the train notified the proper authorities.

In later testimony, D.C. Fire Chief Norman Richardson said the first ambulances arrived at the site of the wreck at 5:03 p.m. But despite repeated questioning by Parris and Rep. Michael Barnes (D-Md.) about why it took until 6:21 p.m. for the first injured passengers to arrive at local hospitals, no official was able to offer an explanation.

Safety Board member Goldman said the investigators were concerned about that issue, but had been unable to document "why people took so long."

The decision by the Office of Personnel Management to dismiss the massive federal work force early on Jan. 13 came under fire by Metro's Page and D.C. Transportation Director Thomas Downs.

Page said Metro had recommended against the early dismissal, telling OPM officials that day that it could not gear up quickly enough. Downs said he would have recommended against the move for the same reason, had he been notified. But OPM officials did not notify his office until about 1:40 p.m., the same time federal workers were told of the early dismissal.

Page said the resulting crush of passengers and "pressure" on the system may have contributed to the "human errors" that have been blamed for the crash. Downs said the massive tie-ups of traffic may have hampered rescue efforts.

OPM Director Donald Devine said Metro's recommendation was taken into account that day. But he said that "it was clear that the longer federal employes remained at the office, the more difficult and treacherous their trips home would be."