Transportation Secretary Elizabeth Hanford Dole is planning to require increased security training for airline personnel and to seek federal research funds for an explosives-detection system at U.S. airports as part of the Reagan administration's response to terrorist hijackings and bombings, sources said yesterday.

The department's Federal Aviation Administration has summoned U.S. and international airline officials, pilot representatives and airport operators to a meeting Thursday to outline the administration program and to get reaction. The Transportation and State departments, responding to a directive from President Reagan, also are reviewing procedures at international airports served by U.S. carriers to see if security is adequate, and considering whether there is a role for armed air marshals on U.S. international flights.

Dole's program, still in development, comes as the aviation community and the government are trying to determine ways of assuring the public that flying is safe despite the June 14 hijacking of a Trans World Airlines flight from Athens, the possible sabotage that led to the deaths of 329 people in an Air-India crash on Sunday, and recent bombings at airports in Tokyo and Frankfurt, West Germany.

The Air Transport Association also said yesterday that its members -- most of the major U.S. airlines -- have tightened security. The ATA also called for nations to review and tighten their airport safeguards and to enforce international agreements "to prevent terrorists from harming world commerce."

"Our airlines have taken additional measures to protect passengers, crew, cargo and aircraft, including intensified screening procedures," said Richard F. Lally, ATA's director of security. "We know that passengers will understand if they are subjected to some additional inconvenience resulting from the current situation."

Increased training for airline personnel in preventing a hijacking or reacting to it is high on Dole's list. The training most airlines give pilots lasts less than an hour. There is also concern that ground personnel are not adequately security-conscious.

A screening system to detect explosives in checked baggage and cargo has long been a desire of the aviation-security community, but nothing better than a trained dog's nose has been developed.

However, Thomas Ashwood, vice president of the Air Line Pilots Association, said yesterday that "we're close to getting a workable explosives-detection device" and urged that money be directed toward research and development of it rather than for expansion of the air-marshal program, as some in Congress have urged. "We need more skymarshals like a hole in the head," Ashwood said.

Secretary of State George P. Shultz wrote the foreign ministers of India, Canada and Japan expressing "our shock and indignation" over the Air-India crash and "ghoulish claims of responsibility" by a Sikh separatist group that claims to have put a bomb on the plane.

"We will cooperate in every way possible with the Air-India investigation to determine if these passengers and crew were, in fact, the victims of a terrorist attack," the State Department said.

Dole is planning to speak Thursday in Montreal at a meeting of the council of the International Civil Aviation Organization, and is expected to call for increased international efforts in airport security and in prosecution of terrorists.