Bye-Bye, (Supersonic) Blackbird

WE were only waiting for this moment to arrive. We've been doing long, lumbering loops over California, Nevada, and Oregon, in a KC-135 tanker aircraft, waiting for another plane to link up for in-flight refueling.

But it is no ordinary plane we're expecting. It is the fastest, highest-flying, air-breathing aircraft in the world. It confounds radar, averts missiles, conducts aerial espionage. And yes, it's even faster than a speeding bullet.

When the SR-71 flies at more than Mach 3, three times the speed of sound, it is in fact moving faster than a bullet fired from a .30-(06) rifle.

We've come along on a refueling run to catch a glimpse of it in flight. The US Strategic Air Command has allowed us on board for a simple reason: We may be witnessing one of the last flights of one of the most extraordinary planes that has ever taken to the skies. When the SR-71 does appear, rising up from the white clouds below us, another comic book allusion springs to mind: This is a Batmobile given wings.

Or, more accurately, a master aircraft designer's freewheeling imagination given shape and substance.

The SR-71 rises up in an instant and neatly parks in the air behind the tanker. It's a long, sleek plane, its graceful, curving, backswept delta wings bisected by two enormous, oversize engines. The engines and nose are tipped with metal lance-points; this is a machine that literally skewers the air. Its skin, coated with radar-dispersing, heat-absorbing paint, is black.

That's why it's called the ``Blackbird.'' But that nickname also catches something of the unruly, not-quite-respectable spirit of this craft. It's a thief of the air, darting back and forth across international borders, employing some of the most sophisticated electronics and optics ever devised to lay bare the secrets that many nations would rather keep hidden. This was one of the first aircraft to employ ``Stealth'' technology - a technology that is even now being introduced in the new US strategic bomber, the B-2.

But this Blackbird is an endangered species. Satellites can gather in more-detailed images, at far less cost, and with no crew. And the spread of newer, faster, more accurate missiles to a growing number of countries theoretically places the Blackbird at growing risk. Consequently, the SR-71s have been number-crunched out of the Pentagon's budget as of Oct. 1. The fleet is scheduled to be grounded and placed in mothballs. If that does happen, it will mark the end of an aviation era.

Undeniably, this is an expensive plane to operate. It rarely takes off with a full load of fuel, for safety reasons, and for that reason requires in-flight refueling. Not one, but two, KC-135 tankers are assigned the task, again for safety's sake, in case one should be unable to keep the aerial rendezvous. Even the jet fuel the SR-71 burns is unique; no other plane in the United States inventory uses it. And the airframe is nearly all titanium, among the most durable, strongest - and costliest - of metals. An extra flight crew, plus 50 to 60 technicians and mechanics, are needed to get ready for each mission. The rule of thumb among crew members is that every mission costs on the order of $1 million to fly.

But how this plane does fly! With afterburners flaring, it can cover the distance between New York and London in 1 hour, 55 minutes; between London and Los Angeles in 3 hours, 47 minutes. It holds world records for sustained altitude and speed: 85,069 feet and 2,193.7 miles per hour. Both records have withstood all challengers for over a decade.

In comparison with those records, this air-to-air refueling is a slow-motion replay. On board the tanker, Airman Peter Manson maneuvers a boom downward, thrusts a mechanical nozzle into a hole in the upper fuselage of the SR-71, and sends 25,000 pounds of jet fuel spewing into its tanks. Even though the KC-135 accelerates to near maximum speed, the SR-71 is going so slow it runs the danger of stalling. As soon as the new fuel is on board, it roars out of sight, loops over California, Nevada, Idaho, out over the Pacific, and back to Beale Air Force Base, north of Sacramento, Calif.

Beale has been home ever since the first SR-71s began operation in 1965. There are SR-71 detachments in Okinawa, Japan, and Mildenhall Royal Air Force Base in Britain, but the headquarters remains here. Despite years on the drawing boards and painstaking fabrication and assembly, the existence of the SR-71s was kept secret until the year before it went into service. In 1964, President Johnson - hoping to prove himself every bit as hawkish as his conservative Republican challenger, Barry Goldwater - took the wraps off the plane. It was supposed to have been called the RS-71, standing for Reconnaissance/Strike. President Johnson inadvertently transposed the two letters in his announcement. No one volunteered to correct the boss; the plane became the SR-71, the acronym rewritten to stand for ``Strategic Reconnaissance.''

In more common parlance, this is a spy plane, and an extraordinarily effective one. Flying at altitudes from 80,000 to 100,000 feet, it can record images of 100,000 square miles of territory in some 55 minutes. The reconnaissance gear is contained in a series of modules that snap into the plane's underside. They contain scanning or fixed-lens cameras, infrared sensors, or side-looking radars. Depending on the needs for each mission, a Blackbird can produce a photographic or electronic map of virtually any spot on earth. Blackbirds have detected missile installations, troop and weapons movements, chemical warfare plants and nuclear test sites in the Soviet Union, Vietnam, China, Nicaragua, and many of the world's trouble spots.

Some of the panels on the body are merely there for filler, to smooth out contours and avoid right-angle bends that might reflect back radar signals. Some analysts claim the plane also has the ability to project a ``ghost'' radar image of itself several miles away from its true position. Of course, the main defense of the SR-71 is its speed; by the time it is spotted on radar, it's usually gone before an adversary can respond.

Thousands of missiles have been fired at Blackbirds, notably from North Korea. None has ever found its mark; not a single one of the original 30 SR-71s has ever been lost to hostile action. (Some, however, have been lost in accidents.)

Clearly, there are plenty of adversaries who would love to claim a downed Blackbird for a trophy. The official Air Force position is that the SR-71 respects international borders and does not cross them. It's a claim met with incredulity by those who run the missions. Crews have standing orders to crash the plane rather than let it fall into enemy hands. In fact, the patches and insignias are attached to their uniforms with hook-and-loop fasteners; if they are forced to bail out, their uniforms will bear no markings of the type of plane they've been flying. The flight suits are pressurized, and more akin to a spacesuit than traditional aviation gear.

A Blackbird crew consists of only two men. (Yes, men. There never have been any women crew members.) One pilots, the other - known as the Reconnaissance Systems Officer (RSO) navigates and operates the sensing equipment. The jobs are exceptionally demanding. Slip-ups can become international incidents; major mistakes can be fatal.

``It's the most cerebral plane you'll ever fly,'' says Lt. Col. Stan Gudmundson, an RSO.

``If I'm not paying attention, I can get lost at least four times as fast as anything else in the air.... And I know that if I make a major mistake, somebody is waiting to blow me out of the air.''

All crew members are rigorously screened. During the plane's quarter-century life, less than 200 people have flown it in operations. The current flight roster is top-heavy with majors and lieutenant colonels; the lowest-ranked is a captain. Some are foregoing other career-advancing assignments, simply for the love of flying this plane.

It's an affection that seems to be widely shared, even by crews on other aircraft.

``This is probably the best tanker assignment in the Air Force,'' says Capt. Peggy Sherman, a KC-135 navigator.

``I'm so proud to work on this airplane,'' says Master Sgt. Steve Koren, the SR-71 flight superintendent. ``After eight years, I still learn something new.'' Like, for example, never to allow a pencil-mark on the titanium hull. The heat generated at high-speed flying burns the graphite from a pencil lead into the hull. Cadmium residue from conventional tools does the same; the SR-71 can only be worked on with special alloy implements.

Still, an SR-71 hangar is hardly pristine. Jet fuel slowly drips from the fuselage, forming pools underneath the plane.

``It leaks like a sieve,'' says Sgt. Kelly Godbey, a public affairs officer. In flight, however, the fuselage heats up, the metal expands, and the leaks stop. The fuel itself heats up to 350 degrees C. during a flight. It is specially blended to keep it from exploding at those temperatures. In fact, a match tossed into a pool of the leaking fuel will be snuffed out.

The plane itself gets so hot that the nose glows cherry red as it streaks through the sky. These hot-cool cycles would punish normal metals. But, says Sergeant Koren, experience has shown that the titanium actually grows stronger in these conditions. Even though the planes were only designed for 1,000 flying hours, they have gone well beyond that.

``They're constantly updating it, but the basic airframe can keep up with the technology of the '80s, and even the '90s,'' he says.

If, that is, it isn't retired. The State Department has petitioned the Defense Department to keep the Blackbirds flying. And others in the US intelligence community and on Capitol Hill have lodged similar appeals.

The outcome hinges on whatever new system - be it satellite or airplane - might provide the same intelligence that the Blackbirds now gather. But the new system is a closely guarded secret, buried with the Pentagon's so-called ``black'' (secret) budget.

Some financial analysts, poring over the Lockheed Corporation's books, have concluded that the company is receiving billions in revenue that aren't attributed to any publicly disclosed defense contract. Those billions could be the development funds for a new-generation, super-secret ``stealth'' reconnaissance plane.

In the meantime, however, nothing flies so high - nor so fast - as the Blackbird.

``It [the SR-71] truly is [a] national asset,'' says Captain Sherman. ``When we're talking about changes under Gorbachev'' and the opportunity to forget new arms-control agreements, she says, ``it seems to me it is really in the US interest to have an inspection capability.''

``Satellites are extremely predictable,'' says Colonel Gudmundson. ``They're also often not in the position you want them to be.'' Michael Krepon, a senior associate at the Carnegie Endowment for International Peace, says, ``It would be a mistake, in my judgment, to rely solely on space-based [reconnaissance] capabilities.''

The reasons, he says, are numerous: Satellites can break and aren't easily replaced. They are limited in number, and are not easily maneuverable to new areas of the world. Moreover, the US government does not release satellite intelligence data, because that would give a hint as to US intelligence-gathering capabilities. But it does release photographs taken from the Blackbirds and other planes.

``Their products can be used in the public domain,'' he says, ``and public diplomacy is becoming increasingly important.''

Ronald Lehman, head of the Arms Control and Disarmament Agency, says, ``Obviously, we would have liked to have kept them'' in the US inventory to help in verifying arms-control agreements.

``But,'' he says, ``you can't keep everything.''

``It's a unique system, no question about that,'' says Jim Curry, a spokesman for the Senate Intelligence Committee. ``But how much do we want to pay for it? If cost wasn't the problem, I don't think there's any question but that the Air Force and the Intelligence Committee would like to keep the planes flying.''

He says the matter is still being debated in secret hearings. ``I really don't know how it's going to come out,'' he concludes.