As the Air Force begins flying the first B1 bombers into the arsenal of democracy this summer, the sleek jet with the needle nose will arrive with a few accessories.

For guidance on how to fix and fly the plane, the bomber comes with 7,000 manuals totaling more than 1 million pages. Repairs will be made with 3,100 kinds of maintenance equipment, most of it specially built for the B1. A squadron of 16 B1s will need 1,577 handlers, of whom only 84 will be crew members flying the planes.

And the B1 is landing with many strings still attached to the defense industry. Manuals, equipment and legions of mechanics notwithstanding, the contractors building the bomber for more than $20 billion also will fix it -- for a price.

"There's no one else in the universe who knows how to repair these things," said Col. David L. Morris, B1 logistics director.

The same candid confession could be made for a growing list of weapons that are the most visible consequence of President Reagan's vow to rearm America.

Incapable of fixing many of its newest gadgets, the Pentagon is ceding an ever larger chunk of the $38 billion-a-year military maintenance kitty to arms makers. Almost every major system, from Army Blackhawk helicopters to Navy cruise missiles to Air Force F15 fighters, is at least somewhat dependent on industry support. Decades from now, the $1 trillion spent on military hardware in the Reagan years may seem little more than a down payment to arms contractors. If generals tend to think only of a weapon's initial price tag, arms makers count on "harvesting the contracts" with years of lucrative upkeep.

In part, the Defense Department leans on industry because of the fantastic complexity of modern weapons.

The fuel-control system alone in a modern fighter jet has more than 5,000 parts and resembles "a little petrochemical plant," as one retired general put it. For every hour an F15 is airborne, the Air Force spends an average of 53 hours maintaining the plane on the ground.

The same kind of high-technology intensity is commonplace throughout today's military. To diagnose snafus in TOW missiles arming the Cobra helicopter gunship, the Army bought a $360,000 test set consisting of three large cases of equipment so fragile that simply hauling it in a Jeep could knock it out of calibration, according to a 1983 report by the Defense Department's Logistics Management Institute.

Two skilled technicians needed two days to make a complete checkup of the TOW, which was failing three times more often than the Army had predicted. Even so, nearly half of the failures detected by test equipment were false alarms, the report said.

With similar tales plaguing all four services, the defense industry has become indispensable not only in outfitting the American war machine but also in keeping it in gear. In West Germany, the Air Force needs Honeywell, Magnavox, Northrop and Loral to keep its F15 electronic warfare system humming; back home, a contractor will help plug the B1 into the Single Integrated Operating Plan, or SIOP, the Pentagon's game plan for World War III.

The Pentagon's dependence means contractors frequently have no incentive to curtail repair costs and no competition threatening their stranglehold. Indeed, lifetime maintenance of a weapon system can easily cost the Pentagon more than the original hardware. The contractors' grip can last for generations -- as in the case of the B52 bomber, which entered the fleet three decades ago and still relies on industry technicians.

One aspect of this dependence on contractors for maintenance worries many analysts: How well will the contractor crutch hold up if the United States is at war? Rep. Jack Brooks (D-Tex.) says as many as 6,000 essential civilians work for the military on warships and abroad and cannot be counted on if shooting starts.

"A lot of the things [the Pentagon] is contracting out are the most critical in wartime. It's not that they've gone through some rational process of sorting out what's critical," a former Air Force official added. "They contract out what they're not capable of doing." An Army of Mechanics

When the 54 M1 tanks of the U.S. Army's 2nd Armored Division rumble across the farm roads and potato fields of northern Germany, life is a little different than the days when Gen. George S. Patton Jr. led the same "Hell on Wheels" outfit in World War II.

A gaggle of mechanics tags behind the M1 Abrams, lugging seven oversized valises known officially as Special Test Equipment and Breakout Boxes but nicknamed STANLEY and BOB by GIs. When something breaks on the M1, mechanics who once wielded spanners and pliers fling themselves on the turret with a tangle of plugs, wires and digital dials.

"I think because the crew cannot see what's wrong, crew frustration is sometimes a little higher than when they could say, 'The shaft's broke, sergeant!' " Maj. Raymond J. Leisner Jr., executive officer of the 2nd Armored's tank battalion, said in an interview in Garlstedt, West Germany.

The Army has both boots planted firmly in the electronic age, following the path blazed by the Air Force 15 years ago in fielding weapons less mechanical and more reliant on computers and microcircuits.

When something breaks, military mechanics are supposed to isolate the failure by using test gear built into the weapons and diagnostic tools such as BOB and STANLEY, remove the "black box" containing the offending electronic part, slap in a new box, and ship the old one to the rear for repair while the tank or fighter plane returns to duty.

"While these promises looked good on paper . . . the actual field performance has been nothing short of disaster," the Pentagon's Defense Science Board concluded in 1981.

"We swallowed a story hook, line and sinker that said, 'We've gotten so good with test equipment that we've got dumb man-smart machine,' " Lt. Gen. Leo Marquez, Air Force deputy chief of staff for logistics and engineering, said in a recent interview. "It turned out to be an incomplete promise; matter of fact, it turned out to be complete bull."

In truth, much of the ballyhooed equipment has been distressingly unreliable; even repairing the repair equipment is a Herculean job.

To cite one example among hundreds, test equipment built into the Army's Improved Hawk missile was supposed to snare 90 percent of all glitches in the system; instead, it catches about 60 percent. "The result is guesswork by mechanics" so four parts in every 10 shipped back for repair turn out to be flawless, according to the Logistics Management Institute.

Next month, the Army hopes to launch full-scale development of a $1.6 billion system designed to diagnose electronic snafus on a dozen of the service's fiercest weapons; however, the General Accounting Office last week warned that the scheme had not been adequately thought through despite 11 years of planning.

The double whammy of complex weaponry and cumbersome logistics has resulted in disturbing consequences. For one thing, costs are exorbitant as the logistics "tail" grows ever longer to support the combat "teeth." In a briefing to contractors, the Air Force said that, in 1960, 30 percent of the service's budget for tactical aircraft supported the jets. By 1980, that had soared to 70 percent, excluding petroleum costs, with concomitant decreases in the money available for development and production.

Last May, a report by the Pentagon's logistics think tank estimated that the Navy spends "several billions of dollars annually" to compensate for kinks in the tail, such as the 60 percent to 80 percent false-alarm rate for circuit boards unnecessarily hauled from ships to depots for repair.

Furthermore, complexity has bred complexity. Gen. Marquez has estimated that, when a squadron of 24 fighters moves to an unprepared base, 29 large C141 transport planes must lumber behind, carrying support equipment and mechanics. And the Air Force needs 166 different types of specialists to keep its planes aloft -- a colossal headache in planning round-the-clock war operations.

Nagging most at the logisticians is the wartime crunch. They fret that their delicate construct of computers, dust-free repair labs and ocean-spanning supply lines will collapse in the smoke and stress of battle. The situation "bodes ill for the Navy's ability to sustain wartime mission requirements," the Navy report warned.

Air Force Secretary Verne Orr, flogging the idea of more reliable weapons, had something of an awakening several years ago while watching mechanics replace the radio on an F4 Phantom jet. Because the radio failed every two or three hours, repairmen were forced to yank it from the fighter after every second flight.

"Now, the radio is under an explosive seat used to eject the pilot," Orr said. "To take it out, you bring the explosive experts out to disarm the seat, take the seat out, take the radio out -- and then reverse the process."

Orr and Marquez contend that future weapons will have radios, radars and other systems more durable and easier to reach when broken. The Army likewise promises that the next generation of helicopters will be simple to fix.

But industry has made promises in the past.

"I've been in the business for 23 years, and I don't believe anything a developer tells me," Marquez said. "I don't believe anything an engineer tells me, because they've never come through before." The Allure of New Hardware

Few weapons better illustrate the Pentagon's repair dilemma than the 300 Phalanx guns bought by the Navy for $1 billion to shoot down enemy missiles. Not only does the Navy rely on General Dynamics Corp. to fix the guns, but it also lacks the savvy to gauge "whether prices paid for repairs are fair and reasonable," according to a Pentagon audit last month.

The Pentagon traditionally gives short shrift to logistics, preferring the allure of buying new hardware. As Brig. Gen. Alfred G. Hansen, an Air Force logistician, told Congress two years ago, "I would hate to slow down a procurement of a weapon system by being obstinate about the logistical part of it."

Consequently:

* The Army has spent more than $100 million in the last five years to buy a sophisticated training device called the Multiple Integrated Laser Engagement System (MILES), which substitutes light beams for bullets. All repairs are farmed out to the contractor, Loral Electro-Optical Systems, which has 100 MILES representatives at 28 sites worldwide and collects $30 million a year for its work.

"The only people who knew the technology and were trained on the technology worked for the company, and that's why it's the way it is today," said Capt. Tim Mishkofski, an Army spokesman.

* The Navy has spent $1 billion for 300 SLQ32 radar systems, used to track enemy missiles. Because it chose not to buy the technical documents from Raytheon Co. showing how the radar works, the Navy "has had to rely solely on the prime contractor for system support," according to a Pentagon audit.

Stuck with a $90 million bill for SLQ32 repair parts in 1984 alone, the Navy reconsidered. But when the service solicited blueprints that would allow other companies to compete for repair contracts, Raytheon replied that only 11 of 53 subcontractors were willing to sell the documents -- for $45 million.

* When the Air Force began installing Delco Electronics navigation gear in cargo planes in 1975, the service had enough foresight to negotiate an option to buy technical data and equipment needed to maintain the systems itself.

But the Air Force failed to pay the necessary $1.5 million before the four-year option expired and wound up paying Delco $12.6 million for the same data and somewhat fancier equipment in 1983. Today, the Air Force is still plodding toward in-house maintenance, while Delco has earned an extra $17 million keeping the gear running.

Phalanx, MILES, Raytheon's radar and Delco's navigation gear typify a lengthening list of weapons maintained by industry. The Army this year will spend more than $7 billion on outside maintenance contracts; the Air Force will contract out the equivalent of 78,000 years of work.

Not all of those contractors fix complicated weapons, and not all weapons need fixing by the contractor. For instance, the Navy's Aegis radar has 6 million parts and relies solely on sailors for repairs at sea.

Defense officials also argue that logistical complications are part of the price of more potent weaponry, and the Pentagon contends that industry handles some maintenance jobs more inexpensively than soldiers and sailors. But internal Navy studies reveal that, without competition, private firms cost 50 percent more than in-house technicians for aviation repair. And the more complex a weapon, the more likely the arms maker is to elude competition for the maintenance harvest.

In 1974, for example, the Navy relied on contractors for 30 percent of complex repair work on computers and other aircraft electronics. By last year, that dependence had doubled to 59 percent, virtually all awarded without competition, according to congressional testimony by Rear Adm. Allen D. Williams.

Indeed, GAO investigators found that, throughout the military, fewer than 5 percent of guided-missile maintenance contracts and 1 percent of fire-control awards are competitive.

"To the extent that we've had success with high-technology systems, to a large extent it's related to the availability of contractor personnel," said Martin Binkin of the Brookings Institution. "I think there are more contractor people on Navy ships than people realize."

Aboard the four aircraft carriers at sea last month, for instance, were 101 contractor technicians. The Navy has been ambivalent about that kind of civilian support, which can cost more than $100,000 for each technician. After planning to ship out even more "tech reps" in wartime, the service recently decreed that the fleet must be scrubbed of contractors by July 1987.

"Why are we going to have a military if we're going to have civilians fight the war?" one captain asked.

Yet there seems little doubt that for the foreseeable future, the Pentagon will be incapable of fighting without its corps of contractors.

To critics, including uniformed skeptics, that dependence is dangerous and dangerously expensive. Today's Pentagon budget for operations and maintenance already is higher, after accounting for inflation, than at the peak of the Vietnam war, according to Richard Stubbing of Duke University.

And beyond the billions spent today is the question of whether a mortgage has been unwittingly levied on future defense budgets as the American armory fills up with ever more complicated guns, planes, missiles and ships. "It's as if I gave you a Mercedes for $5,000, but there's a mechanic in the back seat," said an aide to Rep. Brooks. "And as long as you drive the car, you have to drive the mechanic around, too."