Five of the Carter administration's senior officials came under heavy political fire yesterday as they appeared before the Senate Foreign Relations Committee defending the Controversial plan to sell warplanes to Egypt, Saudi Arabia and Israel.

In a long day of generally hostile questioning, the committee's members confirmed predictions that most of them would oppose the administration's so-called package deal of plane sales.

While the administration's spokesmen tried to answer senators' criticism, the Israel embassy here and key Israeli supporters suggested that Israel might prefer Congress to reject all three proposed sales - including Israel's - rather than approve all three.

Foreign Minister Moshe Dayan said flatly on Sunday that this was not Israel's position, but a spokesman for the Israeli embassy here said yesterday, "Dayan doesn't express himself too clearly in English."

Carter administration officials have said often and repeated again yesterday that they undertsood Israel to favor all three plane sales if the alternative to all three were none. "It is our understanding that they want their planes, period," sais Hodding Carter, assistants secretary of state for public affairs.

This has been an important element in the administration's approach to the plane sale, since the White House has been calculating that support for sales of F-15s and F-16s to Israel would work in favour of the proposed sales to Egypt and Saudi Arabia. The administration has said that it considered the three sales in interconnected package.

Neither the Israel embassy or Israel's supporters here would say flatly yesterday that Israel now prefers no sales to all three of them, but they left open this possibility. The embassy spokesman noted a statement released (but not widely reported) last week by Ambassador Simcha Dinitz, who said Israel regarded the proposed sales of F15s to Saudi Arabia and F5e's to Egypt" as a potential threat," and said further that arms sales to Israel should not be linked to sales to any other Mideast nation.

Did that mean Israel favored no sales at all if the choice were all or none: "We do not give an answer to that question . . . at this stage of the game," the embassy spokesman replied.

Lobbyists active for the pro-Israel cause here said yesterday they understood that Israel officials probably did prefer nothing to all three sales.

A senior State Department official called this a new twist.

hey may have fastened on this device now," the official said, "but that is not what they have been saying."

When Dayan was asked Sunday on ABC's "Issues and Answers" if it was his "point of view that you would prefer the whole package being killed and that Israel received no planes." he replied: "No, no."

In another development yesterday, Deputy Secretary of State Warren M. Christopher and President Carter's chief lobbyist in Congress, Frank Moore, met for two hours late in the day with members of the House Committee on International Relations to discuss the sales.

Christopher told the members of Congress that there could be no change in the package of 60 F15s the United States proposes to sell Saudi Arbia, sources said, but he did not rule out other possible alterations to the three sales that might please some members of that committee. Tuesday, a majority of the panel signed a resolution of disapproval against all three plane sales.

Christopher promised to return to the House members Monday with specific answers to the many questions they raised. Some of those present said they thought Christopher was interested in a constructive compromise. Others, including some of Israel's staunchest friends, said they weren't so sure, particularly given the administration's refusal to modify the proposed sale to Saudi Arabia.

The scene in the large hearing room of the Senate Foreign Relations Committee was a classic confrontation between the executive branches's realpolitik and concerns of many senators about arming potential adversaries in the same volatile region of the world.

Sen. Muriel Humphrey (D-Minn.) summarized those feelings when she said: "Everyone pore in my being goes against seeking peace by arming people."

Arguing for realpolitik instead, Secretary of State Cyrus R. Vance, his deputy. Christopher, Secretary of Defense Harold Brown, arms control director Paul Warnke and Air Force Chief of Staff Gen. David Jones all said the package of plane sales would stabilize the Middle East by encouraging moderate Arabs without jeopardizing Israel's security.

Some of these officials' statements were unusually candid. Brown , for example, said the United States reckons that Israel will retain a decisive military superiority over its potential Arab enemies "for quite a few years to come," with these plane sales or without them - not a statement calculated to please Egypt at this stage of stalled peace talks.

Brown also all but invited Saudi Arabia to buy advanced warplanes from France - as it has threatend to do - if Congress refuses to approve the sale of U.S. F-15S.

Vance referred openly to the importance of Saudi Arabia to the dollar and to the world price of oil. And Christopher suggested that failure to approve the sale to Egypt would leave President Anwar Sadat in a markedly weaker position vis a vis more militant Arabs and potential domestic opponents.

Only George McGovern (D-S.D.) of the senators present indicated any sympathy for the administration's position. Sen. Dick Clark (D-IOWA) seemed neutral. All the others indicated varying degress of hostility to the package deal.

The administration witnesses were questioned repeatedly about the capabilities of the F-15S they proposed to sell the Saudis, and the danger they might pose to Israel. The Witnesses repeatedly tried to play down the F-15S' offensive capabilities, though on other occasions these have been officially praised. At one point Brown described the oasts of McDonnell Douglas, the F 15 producer, for its offensive capabilities as "puffer."

Under repeated questioning, Jones acknowledged that the F15 could be used against Israel both as a bomber and as interceptor. But he and other administration witnesses argued that the Saudis would be foolish to use them in these modes because they would be no match for Israeli airpower, because it would be stupidly inefficient and because Saudi Arabia has promised the United States not to use the planes against Israel.

The officials also said Saudi Arabia could not transfer the F-15s to more militant Arabs in a future war because no other Arab country has pilots trained to fly the plane.

Sen. Frank Church (D-Idaho) made an emotional plea against American participation in the arms business, nothing that in the past the United States has armed both sides in potential conflicts in India and Pakistan, Greece and Turkey, only to see those countries use American weapons against each other.

The hearings are to continue today.