Capt. Abdu Izzadin was sick and tired of the money-losing way his government was running Sudan Airways. So in February, the pilot hijacked his own airliner.

After flying it home from Jeddah, Saudi Arabia, with only seven passengers aboard, Izzadin parked the Boeing 737 at Khartoum Airport and refused to let anyone out.

He told reporters that Sudan Airways had become such a lousy airline that even the Sudanese avoided flying on it. He said Khartoum-bound passengers, rather than fly Sudan Airways, would crowd aboard other carriers or not fly at all. He blamed Sudan's government for mismanagement. He demanded to see Sudan's prime minister.

After three hours he despaired and let everybody go.

A self-inflicted hijacking is but one symptom of Sudan's profoundly fouled-up national economy. International economists here agree that this country, having just come through its worst economic year in history, the third straight year of sharp decline, is headed for more trouble.

"The short and medium-term prospects for Sudan are grim," said a western economist here who works closely with the Sudanese government. "The long-term prospects are also grim."

A confidential report on Sudan's economy issued late last year by an international lending agency warned that without "very generous aid" and dramatic internal economic reforms, the only likely scenario for the country is "a sharp and chaotic downward movement of the economy at great cost to the Sudanese people."

Neither generous foreign aid nor economic reform are considered likely. A U.S. government report this month on Sudan's economy predicts that "foreign assistance levels will be significantly lower" in coming years and adds that "no one" expects serious economic reform.

Last year's problems were triggered by events beyond the control of Sudan's government. Drought and famine cut farm production, Sudan's lifeblood, by 20 percent. International prices collapsed for cotton, the country's major earner of hard currency. Nearly 1 million bales of the stuff, much of it ruined by an insect infestation, piled up at Port Sudan on the Red Sea.

With little real income, Sudan all but stopped paying interest last year on its $10 billion foreign debt. It fell $1.5 billion in arrears, and the International Monetary Fund in February declared Sudan ineligible for further assistance. Most analysts here say that Sudan probably will never be able to pay off its debt without generous rescheduling by commercial banks and outright cancellation of obligations by bilateral and multilateral lenders.

International economists say the inescapable problems of natural calamity and inherited debt explain only part of the country's economic crisis. Like Capt. Izzadin, who hijacked his plane to protest the government mismanagement that has crippled his airline, these economists argue that Sudan's government is managing the country toward disaster.

The inflation rate last year jumped to more than 70 percent as the government rushed to cover its deficit and meet ballooning payroll obligations by printing money, according to the U.S. report on Sudan's economy. The report said the country's money supply increased nearly 50 percent last year even as Sudan's gross domestic product declined by 7 percent.

The past year's economic tailspin has coincided with the rule of a transitional military government that came to power last April with the overthrow of President Jaafar Nimeri. Economists say the military government, which will turn power over within weeks to an elected civilian government, did almost nothing in the economic sphere except appease striking government workers with pay increases.

The new government is likely to be headed by Sadiq Mahdi, a prowestern moderate who, in an April interview in a local newspaper, said it was a "necessity" for Sudan to maintain close relations with the United States, which is by far the country's largest donor.

The U.S. government supports Mahdi, and western diplomats here say U.S. economic aid will continue at high levels under his coalition government -- which is expected to take power on Tuesday -- unless Sudan becomes too closely allied with Libya. This year's request is for $158 million.

Libyan-Sudanese relations have improved sharply in the past six weeks, both as a result of Libyan military assistance to Khartoum for the civil war in the south, and out of Sudanese displeasure with the U.S. bombing of Libya.

Mahdi is given the best chance of any Sudanese leader to resolve the country's overriding political problem: a growing civil war between the Moslem north and the Christian and animist south.

But his campaign speeches were almost devoid of any specific plans for rebuilding Sudan's economy. Mahdi has spoken vaguely of increasing agricultural production and rehabilitating factories. When asked recently about the role of government bureaucracy in Sudan's economy, Mahdi said he wanted more, not less, bureaucratic control.

Businessmen and western economists here agree that, in most instances, government involvement in running large businesses and agricultural operations in Sudan has hindered economic growth. In recent years, many leaders across Africa have come to similar conclusions.

"From the things you hear from the politicians in this country, it is as though the past 20 years never happened," said one international economist here. "I don't see any policy directives at this point leading to any long-term solutions."

To be fair to the incoming government, analysts point out that policy directives, no matter how attuned to free-market incentives and efficient management, will be no match for the country's problems without many years of low-interest loans or grants from the outside.

Sudan, a country of a million square miles, has only 1,200 miles of paved roads. The British-built railroad -- which has 30,000 government-paid employes -- carries less freight now than it did in 1947. The rest of the country's infrastructure, says one analyst, is almost "as if the 20th century had never happened."

Sudan's one sure-fire source of hard currency, large oil deposits in the south, has been sealed off because of rebel fighting. The one major cash crop, cotton, has been eviscerated by what many commodities analysts believe will be a permanent drop in world prices. On top of all this, an estimated 2 million of Sudan's best-trained people have left the country in the past decade for jobs in the Persian Gulf states and in Europe.

"We have been decapitated by the brain drain," says Abdalla M. Jubara, a protocol officer in the Foreign Ministry.

With such dire conditions, economists say the extended family and connections made through relatives have propped up Sudanese who have lost jobs or farms or herds in the past two years.

"Families have been the group insurance that keeps the decline from being catastrophic," said an economist here. "Families have made life bearable as the collapse continues."