The chaotic scene at the airport seemed to sum up the contradictions and paradoxes of postrevolutionary Algeria under Chadli Bendjedid, who will become the first Algerian president to pay an official visit to the United States when he arrives there today.

Angry at the sight of a bureaucrat bypassing travelers waiting to go through passport control, a middle-class Algerian began shouting angrily: "Who does he think he is? We are Algerians, too!" People behind him joined in with cries of "We've had enough," and within seconds the long line was in uproar.

Then a plainclothed immigration officer who had been ushering privileged travelers to the front of the line decided to assert his authority. He snatched the passports of the "troublemakers," ignoring the tearful pleas of mothers and the crying of young children.

It looked as if the unfortunate protesters were going to miss their flight to Paris. The mutiny had been quelled and the immigration officer was wearing a satisfied little smile. Then, just as all seemed lost, he quietly handed the passports back, allowing their owners to board the plane.

The small incident brought out some of the traits of Bendjedid's Algeria: the frustration of a population with glaring inefficiency and privilege, the occasional vindictiveness of a pampered bureaucracy, and the tactical flexibility of a ruling class anxious not to provoke a social explosion.

More than two decades after Algeria won its independence from France following a war of national liberation, people here seem fed up with political slogans and charismatic leaders. Revolutionary promises to make the country "a beacon of socialism" for the Third World seem irrelevant, even ludicrous, in view of today's harsher economic conditions and the diplomatic setbacks experienced by the Nonaligned Movement to which Algeria belongs.

Both western and Algerian observers credit Bendjedid, a former Army colonel who came to power in 1979 after the death of Houari Boumedienne, with sensing this new mood and charting a more moderate, pragmatic course for his country.

Bendjedid's visit to Washington, according to this analysis, is the logical outcome of Algeria's gradual drift away from revolutionary positions both at home and abroad.

"When Bendjedid took over, he seemed a colorless character," a western diplomat here said. "People thought he would just be the head of a committee, wielding power on behalf of people behind the scenes. But he has turned out to be a skillful politician with a mind of his own."

Thanks to its oil wealth, Algeria has so far managed to avoid the social upheavals experienced by its neighbors Morocco and Tunisia, the two other former French colonies of north Africa. It nevertheless faces a formidable array of longterm problems -- including one of the highest rates of population increase in the world, economic distortions caused by heavy-handed central planning and a surge of Islamic fundamentalism.

Algeria's population has increased from about 10 million at the time of independence in 1962 to 21 million today -- of whom roughly 70 percent are concentrated along the Mediterranean coast. Demographers estimate that the population could rise to between 30 million and 35 million by 2000 -- a rise that would bring significant political and social consequences.

Planning Minister Ali Oubouzar says Algeria must reinvest 40 percent of its gross national product in order to meet its target of providing an extra 170,000 jobs a year, a statistic that implies continued austerity for most Algerians despite the oil wealth.

"We have had to choose between consumption and development. We have decided to develop. We can consume later," said Oubouzar, a former guerrilla fighter who traces his political career back to the congress of the National Liberation Front, now Algeria's sole legal political party, in the valley of the Soummam in 1956.

It was this conference, held during fierce fighting with the French, that marked out Algeria's postindependence socialist course. Twenty years later, in 1976, socialism was formally enshrined as Algeria's basic and "unalterable" orientation in a National Charter drafted by the autocratic Boumedienne and endorsed in a nationwide referendum.

Asked what life is like in Algeria, a clerk shrugs his shoulders in a gesture of resignation. "Too many people," he replies simply. A taxi driver talks about "a human time bomb." A middle-class Algerian who recently returned to his homeland after 15 years abroad says he is depressed by the pessimistic outlook of his countrymen.

"Nobody believes in the revolution anymore. In the old days, at least we had ideals and there was still hope of change for the better. Now even that's gone," he said.

Reform of Algeria's top-heavy economic system has come slowly. Bendjedid and his advisers have succeeded in shifting economic priorities away from heavy industry to investment in agriculture and irrigation. "Socialism" has been redefined to include a large dose of private enterprise. The central planning mechanism, however, remains the basic motor of the economy.

In an interview before leaving for Washington, Bendjedid bridled at a suggestion that the 1976 National Charter would be "changed." The correct phrase, he said, was "enriched and developed," to take account of changed economic and social conditions. It is a formula that says a lot about Bendjedid's cautious style of leadership.

In the historic center of Algiers -- Algers le blanche, as the town is known because of its white-brick facades that stand out against the sparkling blue of the Mediterranean -- is the Rue Larbi Ben Mehidi. Named after a National Liberation Front leader executed by the French in 1957 after a nationalist insurrection in Oran, it reflects the moods and mores of a postrevolutionary society.

The country's skewed age structure is reflected in the enormous numbers of young men with apparently nothing to do. The occasional old or middle-aged man wearing a traditional white turban or red fez is outnumbered 10 to 1 by young men and teen-agers in jeans and denims. This is a layer of society, now numerically predominant, that never experienced colonial rule.

Enormous efforts have been made to beautify the "European" end of the street near the old colonial buildings. Smart, glass-plated town maps designed in Paris have been installed along the sidewalks, along with French-style telephone booths and signs proclaiming "Long live cleanliness." A large board marked "M" points downward into the undug earth: the outward sign of a so far nonexistent metro system.

Another sign provides a reminder of Algeria's past closeness to the Soviet Bloc by proclaiming that the capital city is twinned with Moscow, Prague, and Sofia in addition to Tunis and Marseilles. Sauntering nearby in the sunshine is a party of Russian tourists, identifiable by their blonde hair, ill-fitting clothes, and bulky camera equipment -- a Third World equivalent of the American in Paris.

Farther down the street, toward the Casbah, the attempt to keep Algiers tidy has long since been abandoned. White paving stones are littered with huge piles of uncollected garbage between which children play football or roll tin cans on the end of metal rods.

The supply of goods in the souk compares unfavorably with neighboring Morocco, and the prices are many times more expensive. Green peppers cost $5 a pound. Private peasants are free to demand whatever price the market will bear.

Various official explanations have been put forward for Algeria's chronically inefficient agricultural system, which meets less than half the country's total food needs. Questioned about the shortfall, Bendjedid traced the problem back to colonial times when the population was relatively small and agricultural production largely export-oriented. He conceded, however, that progress had been delayed by "red tape" and lack of investment.

High on a hill overlooking the old town is a gigantic war memorial, a tribute to the 1 million Algerians who, according to the government, lost their lives in the eight-year struggle for independence. (The official French figure is about 400,000). On the adjoining hillside, slums have been cleared to make way for modern apartment and government buildings.

Since Bendjedid came to power, the government has made an attempt to crack down on some of the more blatant examples of corruption among the so-called "BMW class" -- high state functionaries who could afford expensive imported cars. He has also reached out a conciliatory hand toward such defeated political opponents as Ahmed Ben Bella, Algeria's first president, who was overthrown by Boumedienne.

Examples of petty corruption still abound accepted as an almost inevitable consequence of a centrally planned society.

With taxis practically impossible to come by, since licenses are confined to veterans, western businessmen and tourists are preyed on by unscrupulous people who lie in wait outside the major hotels offering their services at exorbitant prices.

One recent visitor was amused to discover the staff of his hotel routinely charging telephone calls to the room of the Polisario Front -- Algerian-backed guerrillas fighting against Morocco for control of Western Sahara -- on the grounds that it was paid for by the government anyway.

The price structure and foreign exchange rates are so chaotic that western diplomats serving in Algiers find it cheaper to buy their Algerian wine in Denmark and import it back here.

Bendjedid's tactic in overhauling the economy, as in foreign affairs, has been to move one step at a time. In a recent speech, he called on Algerians to stop considering the state "like a milk cow" and promised to take measures to boost private enterprise. In the next breath, however, he warned that he would not allow the private sector to develop to a point at which it would "endanger the revolution."

A similar approach has been taken toward Islamic fundamentalists encouraged by the example of Iran. Alarmed by fundamentalist activity at Algiers University and violent clashes between fundamentalist and other students in 1982, the government cracked down by arresting several dozen leaders. They were released under a 1984 amnesty.

According to the French press, a new batch of Islamic activists went on trial this month in the town of Medea. But the trial is expected to a long one, with Algerian officials hesitant about creating martyrs.