It was the year of Icarus, of disasters in the sky.

As with the mythical Greek who plummeted to his death when he flew too close to the sun and melted the wax off his wings, 11 major plane crashes last year resulted in the deaths of thousands.

Culminating with the New Year's Eve crash of a twin-engine plane carrying 1950s teen idol Ricky Nelson and six others in a wooded area of Northeast Texas, 1985 has proved the worst year in history for major plane crashes - including the worst single air disaster that has ever occurred.

The year was not even a day old when, on the afternoon of Jan. 1, an Eastern Airlines 727 hit 21,000-foot Mount Illimani in Bolivia, killing 29. It was Eastern Flight 980, bound from Asuncion, Paraguay, and minutes away from El Alto airport in La Paz.

Later, on Feb. 19, an Iberia Boeing 727 was flying low - 900 feet below normal level - over Bilbao, Spain, when it struck a television tower and crashed. All 148 aboard died in the accident.

On June 23, 329 people were killed when an Air-India 747 apparently exploded in flight off the coast of Ireland in a crash in which sabotage was suspected. Experts noted that the plane was apparently destroyed in one, huge explosion, suggested by the fact that the plane had been a normal dot on a radar scope one second and was gone the next.

On Aug. 2 another 137 died when a Delta Air Lines Lockheed L-1011 crashed in a thunderstorm while attempting to land at Dallas-Fort Worth Airport. "Wind shear," a natural phenomenon that causes down drafts, was blamed

Then, on Aug. 12, a Japan Air Lines Boeing 747 with 524 passengers and crew was flying over the mountainous Nagano prefecture, bound for Tokyo, when it vanished. The next day searchers found four survivors, one of those a 12-year-old girl who had landed in a tree. All others aboard - 520 - were killed, making the crash of Flight 123 the worst single plane accident ever.

Previously, the worst crash involving one aircraft had been in 1974, when 346 were killed in the crash of a Turkish DC-10 near Paris. The greatest number of fatalities - 582 - occurred when two Boeing 747s collided at Tenerife, Canary Islands, in 1977.

On Dec. 12, a DC-8 jetliner crashed on takeoff at Gander, Newfoundland, killing 257 military personnel and the crew.

And on Dec. 30, a two-engine, propeller Nepal army airplane crashed in jungles southwest of Katmandu, killing all 25 people aboard. The British-made Skyvan plane was on a routine flight to Dhangadi from Katmandu when it went down near Dhangadi, about 280 miles from the capital - the cause, unknown.

In the other major crashes:

31 were killed when a Midwest Express Airlines DC-9 crashed after taking off from Milwaukee's airport Sept. 6.

55 died when flames engulfed a British Airtours Boeing 737 charter during takeoff from Manchester airport in England Aug. 22.

74 were killed when a Colombian air force DC-6 flying a passenger route because of an airline strike crashed in the Amazon jungle July 24.

80 died when a Soviet airliner and military transport collided May 3 .

68 were killed when a chartered Galaxy prop-jet on a gamblers' junket crashed after taking off in Reno, Nev., Jan. 21.

At year's end, the toll was 1,728 lives lost in those 11 major air disasters, and more than 2,000 in all such accidents, according to the International Civil Aviation Organization, far surpassing the previous record of 1,299 killed in 1974.

And, though air crashes were the most reported form of calamity in 1985, starvation continued in Africa, and natural disasters also took their toll.

Possibly the worst occurred in Bangladesh on May 27, when a huge cyclone struck in the Bay of Bengal. The toll in lives was never really determined - with estimates ranging all the way from 3 ,000 to 100,000, with approximately 11,000 being the most widely accepted - but it is certain many perished. Many washed into the bay and were never accounted for.

The next came in Mexico City in September, when the earth trembled with the jolts of two earthquakes - one recorded at 7.8 on the Richter scale and the other at 7.3 .

Together, they crumbled buildings in the heart of the world's largest metropolis. The first jolt came on Sept. 19, when tremors ran through the Mexican states of Jalisco, Guerrero and Michoacan. It was followed by a second Sept. 21.(SEE CORRECTION)

Those tremors left more than 7,000 dead, 5,000 injured and more than $4 billion in property damage.

To the south, near Bogota, Colombia, the earth dealt another death blow. Nevado del Ruiz, an ancient, towering volcano that had been dormant almost 400 years, began to rumble. The sporadic, rolling growls continued for months without incident, however, and the 30,000 villagers of Armero were not alarmed. Moreover, they did not want to leave their crops.

Then, on the afternoon of Nov. 13, the mountain began to spit hot ash and pebbles. Still, most of the populace did not leave. Content in the thought that the last people to see an eruption from the old volcano were Spanish explorers in 1595, they went home to bed.

Between 10 and 11 p.m. Nevado del Ruiz exploded. A wave of rock and mud 150 feet high tore down the Lagunilla River and into the town of Armero. More than 25,000 people died in the volcanic flow. Fewer than 2,000 of those who had remained in the village survived.

The last of those was Maria Rosa Echeverri, 75. Rescuers found her, trapped in her house by the wall of mud, burning her last bit of fuel and eating her last bit of dried chocolate, 24 days after Nevado del Ruiz erupted.

In Africa a more insidious disaster continued. The African famine eased somewhat in 1985 as rains returned to much of the continent. At the height of the drought last year, the U.N. Food and Agriculture Organization had 21 countries on its emergency list. By the end of this year, the list had shrunk to six.

But Salim Lone, a spokesman for the U.N. office, said estimates of deaths from the drought range from 500,000 to more than a million since November 1984. He said only rough figures are available since many people died in remote villages. At least 18 million were still at risk of starvation by year's end.

Food shortages still haunted Ethiopia and Sudan, as well as Angola, Botswana and Mozambique.

"The drought is over, but the relief needs are not," Maurice Strong, executive coordinator of the U.N. Office for Emergency Operations in Africa, said in December.

And, there were others.

In Bhopal , India, near the Union Carbide chemical plant where a toxic gas - methyl isocyanate - leaked in December 1984, residents continued dying at a rate of about one per day from aftereffects of the gas.

In northeast China, the heaviest summer flooding in three decades killed 400 people and left 1.2 million families homeless.

Rain in July burst an earthen dam perched above the alpine resort of Stava, Italy. In 20 seconds, mud engulfed the village's hotels, packed with vacationers. Authorities said 268 people were killed. Grass now covers the site.

A landslide triggered by a 30-hour tropical deluge obliterated the Mameyes shantytown near Ponce, Puerto Rico, in October, grinding up its wood and tin shacks. About 160 people died. The government has sealed off the area and is building new housing nearby.

The deadliest typhoon to hit the Philippines in 15 years roared into the nation in October, tearing through the country's rice-producing center and leaving 63 dead in its wake. At its peak it whipped winds to 150 mph, but it weakened after hitting land.

Six hurricanes and two tropical storms struck the United States in 1985, more than any year since 1916. Preliminary estimates show more than $4 billion in damage, a record.

And, it was not a good year for spies or the U.S. Navy.

John A. Walker Jr., 48, a retired Navy communications specialist, pleaded guilty to espionage and conspiracy as a Soviet informer for 17 years. He faces a life sentence.

His former wife tipped the FBI - not knowing her son was involved too. "How can a father do this?" Barbara Walker said.

Her son, seaman Michael Walker, 22, also pleaded guilty while her husband's brother Arthur was convicted by a jury. John Walker's friend, Jerry Whitworth, awaits trial.

Diplomatic ties between devoted allies were strained when Jonathan Pollard, a civilian naval intelligence analyst, was accused of selling information to Israel. His wife, Anne Henderson-Pollard, was accused of trying to sell secrets to China.

In all, 11 spy suspects were arrested in the United States this year, but Washington appeared to have scored in the espionage game with Vitaly Sergeyevich Yurchenko, an upper echelon KGB member who defected in Rome.

Yurchenko reportedly exposed the Soviets' use of "spy dust" to track Americans in Moscow, solved the disappearance of a Soviet defector and identified one spy suspect.

Then Yurchenko defected again, to Moscow. He claimed he had been kidnapped and drugged, during "three horrible months" in the CIA's clutches, a claim that left his previous revelations laughable.