EN ROUTE HERE in the Chase Manhattan-owned Gulfstream -- a jet that has taken David Rockefeller around the world five times -- Rockefeller was in a relaxed mood. He had just received a rousing reception at the Economic Club of Detroit from a blue-ribbon audience of 1,400. And while that was only half of the record turnout for ABC's Barbara Walters a few years ago, it was a bigger crowd than either Vice President Walter Mondale or GOP vice presidential candidate George Bush had drawn in recent appearances.

Rockefeller, after all, is probably the best-known name in U.S. banking. Moreover, David is one of only two left of six extraordinarily wealthy and influential siblings. The other is Laurence, who for the last 20 years has been managing Rockefeller family interests.

And now, David Rockefeller is about to give up the reins at the giant bank's annual meeting, he will yield as chairman to Willard C. Butcher, who already has taken over as Chase's president and chief operating officer. So fellow-occupants of the executive suite are turning out to hear Rockefeller's message. It is a mixture of grim assessment of the nation's and world's economic problems, and a measure of hope that, somehow, answers will be found.

As might be expected, Rockefeller -- originally for George Bush -- is a strong supporter of Ronald Reagan, and a sharp critic of President Jimmy Carter.

Sipping a scotch-and-soda and munching on nuts as the Chase jet sped eastward, Rockefeller hit out at Carter's inability to sustain "clear-cut, consistent policies either in the domestic or foreign field." The banker believes that Carter's economists were premature in announcing that the recession had ended. Rockefeller and Chase economists argue that the recession may not yet be over, although the down trend has slowed somewhat. In Detroit, Rockefeller had said that interpretation of recent economic statistics "is a bit like taking a ride on a roller coaster, and apparently Washington believes the economy should run the same way! At least it would appear that there's nobody up front steering the thing."

Like most of his peers, Rockefeller echoes the now well-orchestrated demand for better tax treatment for business. But more forthright than many, he suggests that U.S. industry also needs to take a page out of the Japanese book "and concentrate less on short-term results and more on long-term possibilities."

In dealing with the need to automate -- including the use of robots -- Rockefeller warns that "here lies a potential booby trap in the form of a two-tier society" which will leave the blacks, Hispanics and other miniorities "to grapple for a dwindling supply of unskilled jobs."

As critical as Rockefeller is of Carter's domestic policies, he is even more concerned about what he considers Carter's mismanagement of the United States' international role. Specifically, Rockefeller charged that the president has not done "what most other countries do themselves, and expect us to do -- namely, to make U.S. national interests our prime international objective."

We have confused U.S. interests, Rockefeller believes, with two other objectives: the promotion of human rights, and an effort to restrict the development of nuclear power. The first -- human rights promotion -- is, of course, desirable, Rockefeller says, while the second "is a more debatable objective."

He cited as examples the way Carter handled Brazil and Argentina. "When Carter first came to office, he hit them both on the human rights front. And Brazil, he also hit on the nuclear front in relation to its deal [for technical assistance] with the Federal Republic of Germany. So in that particular case, we annoyed both Brazil and [West] Germany in one fell swoop.

"And while I'm sure that Brazil does a number of things that we would consider less than desirable in terms of human rights, it seems to me that one has to judge them -- as any country -- on the basis of what went before the present regime, and what the likely alternative would be if they were overthrown."

As to Argentina, Rockefeller says that inasmuch as "they want to go back to democratic forms," it was foolish for the Carter administration to ban the sale of Allis-Chalmers turbines, and refuse Export-Import Bank loan assistance.

Rockefeller, who in the past has turned down numerous Washington job offers, including the Treasury more than once, plans to take over the management of Rockefeller family affairs from brother Laurence. As he noted a bit plaintively, not only is no young Rockefeller interested in banking, but the entire younger generation of Rockefellers is more interested "in the field of the arts, conservation, environment and things of that sort, than they are in business."