LUANDA, ANGOLA -- There is a billboard that greets arrivals at the airport here. On it, the word "Welcome" is misspelled in both English and Portuguese.

Beneath the sign, at noon on a recent Saturday, a gaggle of fidgety foreigners stood waiting. They had been waiting since 5 a.m. for a flight to the southern city of Lubango on TAAG, the national airline. They were supposed to wait in the VIP lounge, but a backed-up VIP toilet had persuaded them to come outside to the edge of the runway.

In front of them on the runway was an intermittent parade of one-legged soldiers. At least they were one-legged when they passed left to right on crutches. Later, when they passed right to left, they limped on two legs and carried their crutches. Soldiers pick up imported legs at the airport on Saturdays.

Beyond the prosthetic procession was a gleaming white American-made Learjet. It belongs to Jose Eduardo dos Santos, president of this Marxist country, and is a gift of American oil firms operating here. Parked near the jet were four new Soviet-made Antonov jet planes. They were being loaded with Soviet-made artillery to be flown south for the fight against rebels who receive U.S.-made weapons from the CIA.

"Wellcome," as the official billboard says at the airport, to the dismal ironies of the People's Republic of Angola.

It is Marxism through the looking glass: a nation of long waits and one-legged warriors, of oil billions and superpower meddling, of socialist ideals and backed-up VIP toilets.

Angola's standard currency is a can of beer. The standard way of making a living is to plot esquemas -- schemes to get cans of beer to barter for water, fuel, clothing and food.

Nearly everyone, it seems, is a schemer. Schemers shop in black markets. Three of the largest such markets in Luanda are called (roughly translated from the Portuguese): "Keep Your Mouth Shut," "Sorry, Senhor dos Santos," and "Prices Are So High, You Have To Trade Your Knickers."

Angola's currency, the kwanza, is almost worthless. It is a mythical currency sneered at by black market traders.

Many government officials, however, believe in the myth. They have access to well-stocked government shops where a few kwanzas go a long way. In those shops kwanzas buy imported luxuries and real money -- cans of beer to trade at the "Keep Your Mouth Shut" market.

"It is an absurd and difficult life," said a European here. "There, of course, is an elite that lives well within the system."

The "absurd" system referred to by the diplomat has evolved here in the 12 years since Angola's independence from Portugal; it is a function of the country's mineral wealth and its paucity of skilled people, of its centralized Marxist government and its civil war.

Angola seems to exist in a world apart from the rest of black Africa. A key difference is money: Unlike most African nations, Angola has some.

It has diamonds, iron ore and vast reserves of a low-sulfur oil that burns cleanly in American automobiles. Most of the oil is sold to American consumers; the largest producer here is a subsidiary of Chevron. In Africa, only Nigeria pumps more oil, but it has 105 million people. Angola has about 8.8 million people.

Oil, which this year is projected to pour about $2 billion into the government's coffers, cushions the economic realities that have been so sobering to Angola's poor neighbors.

Elsewhere in Africa, lack of home-grown food and of foreign exchange to buy imported food has forced farm reform. These less fortunate countries had to pay farmers a price that motivated them to grow surplus food.

These less-fortunates also were forced to devalue their currency so it bore some relation to its real worth on the world market. To reschedule unpayable debts, the less-fortunates had to bend "African socialism" to the flinty free-market dogmas of the International Monetary Fund and the World Bank.

Angola has been rich enough to avoid all this. Its farmers produce almost no surplus food -- they have no incentive to do so -- but Angola usually can afford to ship in food from Europe.

Angola's debts are mounting, but manageable. Most of the money is owed to Soviet Bloc allies, who do not condition rescheduling on free-market reform.

OF COURSE, there is more than money behind Angola's other-worldliness. The 12-year devolution to the beer-can economy would not have been possible without a nation of unskilled people, a centralized government and war.

Before independence in 1975, about 300,000 Portuguese held nearly all the professional, managerial and skilled jobs. When the Portuguese panicked at independence and evacuated, they left behind a newly hatched nation that did not know how anything worked.

Into the vacuum rushed the People's Movement for the Liberation of Angola (MPLA), a Marxist movement with a rather narrow base among Kimbundu-speaking people of Luanda and the nearby Kwanza valley. It also is supported and, to a significant degree, administered by Angola's mixed-race mestizos who assumed new prominence with the departure of the Portuguese.

With the help of Cuba and the Soviet Union, the MPLA defeated but did not destroy rival guerrilla groups.

The MPLA came up with what proved to be a coma-inducing prescription for the problems of a country that had almost no skilled people. It centralized all decision-making in 57 people of the Central Committee. Many of those new power brokers, as President dos Santos later said, had no suitable qualifications, experience or competence.

This unskilled, narrowly based and rigidly centralized government has been locked, since its creation, in a civil war that appears unwinnable.

The opponent is the National Union for the Total Independence of Angola (UNITA), a formidable guerrilla army that draws its local support from Angola's largest tribe, the Ovimbundu. UNITA, prowestern in its ideology, also is supported by South Africa and the United States.

Fighting has razed Angola's central plateau region. What was once the country's breadbasket is now seeded with land mines. The ranks of the one-legged -- about 50,000 soldiers, women and children -- grow daily. Half the urban population is said to be on the brink of famine. The building blocks of any developing country -- transportation, communications, health care, education -- are in ruins.

It is an inefficient, expensive way to run a nation. Most other African countries could not afford it.

But Angola is a rich African country. What it cannot afford to buy from the Soviets, it can obtain with money borrowed at reasonable terms. With the countryside wrecked, there is little infrastructure to maintain. With worthless kwanzas, paying civil servants is cheap.

And for the MPLA elite living here in Luanda, where there are no land mines, the system is far from absurd.

Consider foreign air travel. Those with the right connections can buy airline tickets with kwanzas. It is a world-class bargain. A $1,300 round-trip ticket to Lisbon is available for about 40,000 kwanzas -- a sum that for the non-elite in Luanda's black markets would fetch a case of beer and five grapefruit.

About 23,000 Angolans took advantage of this air-travel bargain last year for holidays in Portugal. Diplomats here say that number is a rough estimate of the number of elite who embrace a beer-can economy.

While in Portugal, many Angolans take out what amounts to illegal insurance policies for the future of their children. Portuguese law allows them to obtain citizenship for their children, if they can prove that one of the child's grandparents was a Portuguese citizen. This requirement can be met by many senior members of the Angolan government.

Dual nationality is a crime here. But several thousand of Luanda's elite are known to be breaking the law. They have identity cards that ensure their children of a European haven if the MPLA were to collapse.

"The tragic thing is they do not need economic reform. The elite live well without it. They have oil," said one jaded diplomat here.

There are growing indications, however, that even Angola cannot afford both endless war and beer-can economics.

Dos Santos last week told MPLA planners that Angola will seek membership in the IMF. He said the country must take advantage of western financial assistance by committing itself to economic reform.

Just as in other, poorer African countries, penury appears to be the prime mover toward change in Angola.

Last year's fall in oil prices cut the country's purchasing power in half. Angola could not afford to import the food that keeps its cities alive. The government this month is appealing for international aid to feed about 1 million city people.

This is an embarrassing development for any African government. Marxist Ethiopia, even at the height of its famine in 1984-85, managed to buy food for its cities.

There has been high-level talk about economic reform in Angola for several years. Yet it remains unclear how willing Luanda's elite will be to accept reforms that might curtail Portuguese vacations and end access to shops where worthless money is worth a lot.

If the price of oil continues to recover, as it has this year, the food crisis may pass. As before, a deluge of oil money may make free-market reform seem silly -- the sort of thing done by poor African countries.

WHAT HAPPENED to the foreigners waiting at the airport for the flight to Lubango?

They had waited 8 1/2 hours when, unknown to them, a phone rang at the home of Jose Fernandes, general director of TAAG, the Angolan airline.

On the line was the general director's brother, Carlos Fernandes, the minister of transport. He was in Lubango and wanted a plane to come take him home.

A plane departed within the hour. Some things do work in Angola.