Lockheed Corp. and the Department of Defense are engaged in a large, joint lobbying effort to convince the House of Representatives to buy 50 more C5 air transports, according to a detailed computer printout obtained from Lockheed.

The printout shows that Lockheed and the Pentagon mapped out an elaborate plan to try to enlist at least 40 of Lockheed's subcontractors as well as various government officials--from high-ranking military officers to the president--to contact more than 260 members they hope will support the controversial $5.35 billion purchase.

The Pentagon said yesterday that Maj. Gen. Guy L. Hecker, Air Force director of legislative liaison, is in charge of the joint effort.

Air Force Lt. Gen. Kelly H. Burke, who is responsible for the proposed C5 program, said yesterday: "You're just wrong if you think this is a highly unusual happening. Anytime you get competing views, it's customary for government to work with those contractors whose views are congruent with the president's. . . .

"I do not want to sound platitudinous, but all you're seeing is democracy in action. This is the way the system is supposed to work."

Some congressmen said yesterday they have been contacted by either Lockheed or by a high-ranking military leader. Notes in the Lockheed printouts indicated that many proposed contacts have been made, but just how many is uncertain.

For example, the printouts suggested that Pentagon and Air Force officials ask President Reagan to call House Minority Leader Robert H. Michel. An aide to Michel said yesterday that no such call was received from the White House.

By contrast, on June 2, the printout shows that the Air Force was assigned to "Get Altus AFB Cmdr. to call Rep. Dave McCurdy," a freshman Democrat whose Oklahoma district includes the Altus Air Force Base, where C5 pilots train. Later, the printout notes that a phone call was made to the base commander, but that Gen. J. R. Allen, chief of the Military Airlift Command, "will talk to McCurdy."

McCurdy said yesterday that Allen visited him and explained the Air Force position on the C5. He said that a statement in the printout that he is "not committed" is correct.

According to the printouts, the plan proposed that Lockheed ask various legislators to "work" different groups in the House, such as "liberals," "freshmen" and "moderates."

Rep. Thomas B. Evans Jr. (R-Del.), who Lockheed wanted to line up moderates, was visited on June 3 by two Lockheed executives, an Evans aide said. Emphasizing that Evans believes the C5 purchase to be in the national interest, the aide said the congressman agreed to serve in "a core group of 20 to 25 members" who would help "in getting Lockheed's story across."

Earlier this year, the Senate barred funding for the 50 Lockheed C5s, which Lockheed would build in Georgia, and instead voted to fund the purchase of wide-bodied aircraft. The measure was a defeat for Lockheed, but a victory for its rival, the Boeing Co. of Seattle, which wants to build new military 747s or modify surplus 747 commercial airliners. The House is expected to take up the legislation after the July 4 recess.

The printouts covered a 19-day period ending June 14 and were released by the Military Procurement Project, a nonprofit Pentagon watchdog group. They were authenticated by Lockheed.

Lockheed said the printouts were "apparently obtained by opponents of the C5 in the hope that publication might undermine efforts to secure congressional passage of the Defense Department's airlift enhancement proposals . . . . These working papers reflect what we said we would do and what the Air Force and DOD said they would do to make sure that congressmen and their staffs have accurate information on the issues involved."

The most active contractor -- one of many with political action committees that contribute to House candidates -- listed in the printouts was General Electric Co., which would build the C5's engines. GE was slated to contact 60 legislators.

Next were Colt Industries Inc., and its Menasco Inc., subsidiary, which would supply other components and together were listed to contact 46.

Among others listed to make contacts for Lockheed were: Marsh & McLennan Cos., a leading insurance broker; Miller & Chevalier, a Washington law firm, and William T. Kendall, who was a member of Reagan's transition congressional liaison team and was President Ford's liaison with the Senate.

The printouts disclose other efforts on behalf of the C5s, such as drafting "Dear Colleague" letters for legislators to consider sending.

The printouts begin with an "action" directive on May 26, stating that Lockheed should try to "get major contractors on board and working." They end with a "status" report on June 14, marked: "CLOSED. Working hard."

The Defense Department said that the actions taken for the C5s were proper and "necessary to ensure that both the Congress and the public have the information they need to act on defense budget requests."

A few of the persons who contacted legislators are registered lobbyists but most are not.

The department said that "there is no violation" by Lockheed of regulations on contractor lobbying issued by Defense Secretary Caspar W. Weinberger in October.

Lockheed said that in working with the Pentagon for the C5s it spent no federal funds provided for overhead costs.