Allies’ Other Foes: the Wind, the Rain, the Sand : Climate: A Saudi expert predicts that the weather will get worse by the end of this month.

Steady 30 m.p.h. winds drove powdery sand across the desert outside this northern city on Tuesday, giving U.S. Army troops camped near here a gritty taste of what to expect in the coming weeks.

Already the fine, talc-like sand is forcing crews to take extraordinary maintenance steps and raising questions about the long-term effect on such key pieces of equipment as attack helicopters and electronic surveillance devices.

But it will soon get worse. Spring winds known as sarrayat (night comer) can whip up a desert sandstorm in a matter of minutes from any direction.

Rain also is expected to become a problem soon, creating rough going for vehicles and breeding grounds for numerous diseases, such as the insect-borne ailment river blindness, to which Western troops are unaccustomed.

U.S. commanders in Riyadh and Washington say weather considerations have been calculated into the timing for the possible start of a land war.

“We look at the calendar like anybody else does,” said Marine Brig. Gen. Richard I. Neal, deputy commander of operations for Desert Storm. “We look at the weather for the past four, five, six years. It’s all put into the equation as to what would be a good time for doing any type of operation.”

But some soldiers in the field wonder whether the impact of weeks of sand on weapons and vehicles can be measured.

“We’ve seen some problems so far that are mostly minor, but you sure don’t have any idea what’s gonna happen when the sand really kicks up,” said a staff sergeant outside an Army camp a few miles from here. He spoke anonymously because he said he had orders not to talk to reporters who are not escorted by military officers.

As he described his problems, the wind continually blew a layer of sand about a foot high across the desert floor. Occasionally, it gusted up into the air.

He said soldiers have wrapped their M-16s in T-shirts and pantyhose to protect them from the pervasive sand, a violation of regulations but a necessity in the eyes of the troops.

Nothing like the Saudi sand and weather exist at Ft. Irwin, Calif., the Mojave center that serves as the desert training ground for U.S. armored forces.

Jaber Jumah, a Saudi astronomer and weather expert, said sandstorms and rain will increase by the end of February, about the time some are predicting the start of a ground war.

“The weather we get in March and April is very windy, with lightning and rain,” Jumah said. “It comes around dusk but is very unpredictable. They are like mini-tornadoes and you don’t know the direction it will come from.”

While British and U.S. commanders maintain that their troops are prepared now for a ground war, President Bush and Defense Secretary Dick Cheney have indicated publicly that they are in no hurry for such a battle. Their apparent rationale is that the increased bomb damage resulting from a longer air war will justify launching a ground assault in poorer weather.

The bulk of the allied force is at the front. The volume of military equipment moving north along the main road out of the Saudi port of Dammam was noticeably less on Tuesday than during previous weeks. Nonetheless, the buildup is not finished.

Substantial numbers of the huge M1-A1 tanks and other heavy equipment were on the road and a convoy of 30 mine-clearing bulldozers, still painted green for camouflage in the forests of central Europe, left the port early in the morning.

Some equipment already in place has been exposed to sand for months, and the exposure is causing headaches for maintenance crews. The sand is so fine it slips through filters and permeates seals in all sorts of equipment.

M-16 rifles must be cleaned daily to remove sand from magazines and barrels. Cooling fans on communications radios are cleaned every few hours. Air filters on engines are changed every other day, instead of after the normal 30,000 miles.

“It requires a lot of extra effort to keep things clean,” Sgt. Surender Kothakota, an Army maintenance chief, told a pool reporter a few days ago. “Longer term, it could be a serious problem.”

Some of the biggest worries center on the impact of weeks of sand on Apache and Cobra helicopters. These aircraft would play an integral role in a land war by killing Iraqi tanks with their TOW missiles and providing cover fire for advancing U.S. troops.

But they are already showing signs of strain from the sand.

During training runs in the desert before the war, sand began eroding the leading edge of helicopter rotor blades. Crews tried to correct the problem by applying an epoxy tape to the edges. But here in the north, where the sand is finest, the tape must be changed after almost every flight.

Apaches and Cobras also have been equipped with special air-cleaning devices to keep the fine dust from getting into engines and causing rapid wear.

“Without the new particle separator, engine life is reduced out here in the desert,” said Lt. Col. Don Olson, commander of a helicopter squadron with the 2nd Armored Cavalry.

But others say that even the separators cannot stop all dust from being sucked into the helicopter engines.

“For now, they are performing well,” said Lt. Col. Bill Tucker, commander of an Army battalion of Apaches. “It’s going to have an effect. You can’t put a time or a date on it. It wears out moving parts of the engine. The sand collects inside the engine, causing it to get hotter and therefore it doesn’t produce as much power.”

Chief Warrant Officer Steve Snyder flies an Apache and told a pool reporter that sand and gravel kicked up by the chopper’s rotors could upset its aerodynamic structure and sensitive electronics.

“It’s a cumulative effect. It’s accelerated wear on all moving parts of the helicopter. It causes an overall loss of efficiency,” he said.

There are also dangers from losing visibility during what pilots call “brownouts,” the huge clouds of sand that helicopters kick up as they land.

“It’s easy to put the aircraft down wrong then,” said another Apache pilot, 1st Lt. John Evans.

Early last Thursday, a Cobra crashed and burned during takeoff and both pilots escaped unharmed. The helicopter may have drifted sideways during takeoff, digging a skid into the sand and overturning, according to Olson.

He would not speculate on whether weather was involved because an investigation of the cause is under way.

Pool reports cleared by the U.S. military were used in preparation of this story.