Glide Path

by Arthur C. Clarke

  “He’ll understand,” Mac replied, rather shortly. He liked Jackson, and somewhat resented Hart’s assumption that everything had to be explained to him twice. He had to admit, however, that Hart’s suggestion was an excellent one, and the best thing that could be done in the circumstances.

  “What’s happening?” asked the Approach Controller plaintively.

  “Give me a couple of minutes, sir,” begged Hart. “Then everything will be OK.”

  He could only hope so; but an awful lot depended on Leading Aircraftsman Jackson and his bicycle.

  Perhaps Alan would have been a little happier had he known what was going on, but he could hardly bombard the ground staff with questions; if he did, it would seem that he was pressing the panic button. He was still, at this stage, more puzzled than worried. The approach system was clearly cockeyed, and this was very surprising, for he had complete confidence in Corporal Hart. Maybe he should have checked the line-up himself before he took off, but he’d been too busy with those generals. Well, they were certainly getting their money’s worth.

  C Charlie was being vectored around again for another approach, and the Traffic Director seemed to be taking his time. That was understandable; he might be holding them off while the boys in the back room found what was wrong. It was probably something that could be fixed in a couple of minutes—or else it would take hours and they’d better start looking for a diversion airfield. Alan had no idea how much gas C Charlie was carrying in its tanks; still less—and this thought was almost equally disturbing—did he know how much longer FIDO could keep up its hundred thousand gallons an hour. Suppose those walls of fire collapsed, and the fog came rolling back…

  At the moment they were still going full blast, and no one knew that better than LAC Jackson. He had grabbed one of the bikes parked against the control van, and had hurried it over to the runway as quickly as he could, pushing it ahead of him across the sodden grass. There was no hope of riding here; the tires would sink up to the rims if he attempted it.

  He knew exactly what he had to do, and why it was so important. In any event, the raw heat from the burners did not encourage him to linger near the edge of the runway. As soon as he felt its hard surface beneath him, he swung himself on to the bike and raced out into the exact center of the huge, lonely strip of concrete.

  It seemed a pity that there was not a single eyewitness of Jackson’s Ride, for it was to become one of the legends of GCD. Since Jackson himself was not a very articulate type, no one ever knew exactly what he felt as he flew like the wind along the axis of Runway 320, with the roar of the flames in his ears and the stars miraculously shining overhead. Probably he felt nothing at all; he could have had little energy for sight-seeing or introspection. For it was later calculated that he covered a distance of four thousand feet, on a wet surface, up a slight gradient, in little more than two minutes. And, be it noted, on an RAF bike, which is built for durability rather than speed.

  There was no doubt that he was feeling quite pleased with himself, though a little short of breath, when he saw the huge, elongated numbers “320” on the concrete ahead of him, and knew that he had almost reached the end of the runway. He cycled across them, and veered off onto the perimeter track—straight into the arms of the Station CO, who was still waiting anxiously amid the I ambulances and Flying Control trucks.

  “What the hell do you think you’re doing, cycling on the runway in use!” shouted the Group Captain. “Sergeant, put that man on a charge!”

  It was fortunate for Jackson that he was not struck as dumb as Billy Budd in a similar moment of monumental injustice. He was still trying to explain matters when the distant roar of C Charlie checked all further conversation.

  For there had been a witness of Jackson’s Ride, though not a human one. That witness, as Corporal Hart had planned, was the GCD system itself. The fact that it could track individual human beings had been proved conclusively during the defense exercise (though it had not, the Corporal remembered a little sourly, saved him from being scragged in his foxhole by the RAF Regiment). A large lump of manhood like LAC Jackson would give him a fine echo; his bike would give an even better one.

  The precision system picked him up first at five hundred feet—a small, distinct amoeba of light moving up the runway, approximately where Hart had expected to see him.

  “Strewth,” he said under his breath, “he’s moving!”

  Indeed, the echo had shifted appreciably between successive sweeps of the scan. Hart watched it with the utmost satisfaction, There would be no further argument about the line-up, now that LAC Jackson was tracing the runway; 320 had never been pinned down so accurately before.

  Already he was halfway to touchdown point, and now the original error was obvious. The marker that should have given them their line-up was undoubtedly missing. Presently they’d find out what had happened to the damned thing, but they had no need of it now that they had a much better way of pinpointing the runway. Maybe they should always send someone cycling along to touchdown before they made an approach. It would take a bit of time, and would annoy Flying Control, but there would never be any doubts.

  Hart had already made the necessary corrections and reset the Controller’s meters by the time that LAC Jackson was expostulating with the Station Commander. It was a close thing; he had barely finished his adjustments before C Charlie came on the screens once more, nine miles out and lined up for the approach.

  Corporal Hart relinquished his seat to the azimuth tracker, who promptly speared the oncoming blip with her electronic pin.

  “OK now, sir,” he called to the much-relieved Controller. “The calibration’s perfect.” “I’d stake my life on it,” he added beneath his breath. If anything else went wrong, it would not be in his department…

  Nor was it.

  27

  The second approach was just beginning when the telephone from Flying Control started to ring. Now what? thought Corporal Hart as he picked up the receiver. He wondered ironically if someone was going to raise hell because GCD had not asked permission to overshoot on 320.

  “GCD truck here—Corporal Hart speaking,” he answered smartly. As he listened, his face relaxed into a somewhat satisfied smirk. “Thank you,” he said at last. “Tell him we already know about it.”

  “What was that?” asked the Controller, who was just getting ready to take over C Charlie.

  “Flying Control reported our marker down, sir. The Station Security Officer ran into it.”

  “Pity they couldn’t tell us ten minutes earlier. Still, I’m glad we know what went wrong.” He pushed the transmit key. “Longstop calling C Charlie. Are you receiving me? Over.”

  “Receiving you loud and clear. Over.”

  “Remain on receive, continue on course three two zero….”

  Listening to that familiar and reassuring patter, Alan felt at ease once more. There was nothing to worry about now; he had the best Controller and the best (he had to admit it) pilot, and whatever had gone wrong on the ground had now been fixed. He still wondered what it was, but he’d find out soon enough.

  Three miles to go; there had been very few corrections. It was a simple, almost standard approach—if one forgot the bonfire at the end. Suddenly, Alan remembered a little notice that one of the trainee controllers, presumably blessed with a classical education, had pasted above the meter panel. It had read Facilisdescensus Averno, and one needed no Latin to realize that it might be all too appropriate.

  “Three degrees left; I say again, three degrees left. You are slightly above the glide path. Increase rate of descent. Two miles to go.”

  The memory of that Latin tag brought back another even more ominous phrase which some cynic had once suggested as a motto for GCD—“Nearer, My God, to Thee.” Alan’s mind dwelt upon it a little uncomfortably. Like most of his generation, he had no formal religion and had put himself down as “Church of England” when enlisting. No one had ever made any determined attempts to save his soul—no
t even Miss Hadley, who might have been expected to do so. Though she was High Church, she had never attempted to influence Alan in this direction. Having spent much of her life among non-Christian communities, she was unusually tolerant in matters of faith.

  “One and a half miles to go. Resume normal rate of descent.”

  Alan smiled, even now, as he remembered the times he had been exposed to religion in the RAF. When the Flights were drawn up for Church Parade, the Warrant Officer in charge would shout: “Fall out the Jews and Roman Catholics!” All those who considered themselves in these categories would step smartly back two paces, and the C. of E. prayers would be read. Alan often wondered if the Jews and Roman Catholics felt that six feet of parade ground gave their consciences sufficient insulation.

  He wished he could get his mind away from this subject, but he could not help thinking of the plastic tags around his neck—the two tags with his name, number, and C. of E. stamped upon them. For if the worst came to the worst, those letters would decide what happened to his body, in the absence of any other instructions for burial. But enough of that—

  “You are on the glide path, runway directly ahead, half a mile to go—go ahead and land.”

  They were almost there; everything was fine. Alan felt himself reaching for his safety belt; it was a little too tight and he’d slacken it off just as soon as they touched down.

  There was the yellow glow of the burners, blasting through the fog. It was all right—the line-up was perfect. In thirty seconds, they’d be down.

  Without any warning, the aircraft shuddered violently, as if a giant hand had slapped it. At the same instant the light from below flared up with a sudden dazzling brilliance as the concealing fog whipped away. They might have been flying above the throat of a volcano, looking straight down into the incandescent lava. It could only be imagination, but it seemed to Alan that he could feel the heat of the flames licking against his face.

  The buffeting grew more violent. Dennis seemed to be fighting with the controls, like a rider trying to curb a startled horse. He was no longer attempting to land, but, on the contrary, was gaining height—climbing to escape from the turbulence that had suddenly engulfed the aircraft. There was no doubt of what had happened; they had been caught in a manmade gale generated by the heat of the burners. Ten million horsepower, the general had calculated. How many little C Charlies would be needed to match that?

  It was over so swiftly that Alan had no time to feel any fear. His only sensation was one of surprise, coupled with an almost dispassionate annoyance that an excellent approach had been aborted at the last moment. Not until the glare of the flames had dwindled to a faint twilight luminosity, soon lost once more in utter darkness, did he consciously start taking stock of the position.

  They would have to go around again, of course. The crucial point was—could they do any better next time?

  He was about to call Dennis on the intercom when the voice of the Controller, now definitely showing signs of worry, broke through over the radio.

  “What’s the matter, C Charlie? We heard you overshoot. Couldn’t you see the runway?”

  Dennis picked up the mike dangling on his chest and threw the transmit switch.

  “C Charlie to Longstop,” he answered, as calmly as if he had done a normal overshoot on a bright summer day. “The line-up was perfect, but there’s such a hell of an updraft from the flames that I got blown off the runway. You’ll have to take me round again. I’ll be able to cope better, now I know what to expect. Over.”

  There was a long pause—much longer, it seemed to Alan, than was necessary for the Controller to digest and act upon this information. After all, he had only to tell them to continue on course three two zero and climb to three thousand feet…

  But the instruction, when it came, was quite different, and by its very unexpectedness brought back all Alan’s apprehensions with redoubled intensity.

  “Longstop to C Charlie,” said the radio. “I am not, repeat not, taking you round the circuit again, but will turn you back on a reciprocal. Change course to one four zero; I say again, one four zero. Use maximum rate of turn.”

  One four zero! They were being given a hairpin bend—or as close to that as C Charlie could manage. It would take them straight back over the airfield, retracing the line of their unsuccessful approach, but in the opposite direction. Though it was the quickest possible way of getting them into position for another approach, Alan did not like the sound of it at all. It seemed unwise to attempt so unusual a maneuver in such circumstances as these, when it was important to make everything as easy as possible for the pilot.

  Was FIDO running short of gas, as he had feared? Well, they could probably get in without it, especially since it seemed to be doing its best to blow them back into the sky. Or had something else happened to the Mark I? This was definitely not their lucky day.

  How unlucky it was only Sergeant McGregor realized. He alone knew, as he stood beside the roaring diesel in the transmitter truck, that the Mark I was finished. All the electronic circuits were working perfectly—the signals were coming in clearly, the needles of the meters were steady at their appointed places, the wave forms on the oscilloscopes showed their familiar shapes. Yet none of this compensated for the small piece of broken metal, no bigger than the last joint of a little finger, that McGregor was now holding in the palm of his hand and cursing with a quiet and desperate intensity.

  ***

  The aircraft banked violently as Collins threw them into their hairpin bend. If the horizon had been visible, it would now have become an endless slope, steep as the roof of a house, bisecting the sky ahead of them. But in this tiny enclosed world the only indication of the turn was the centrifugal pressure forcing them into their seats, and the swiftly changing numbers on the compass card as the aircraft pointed first west, then southwest, then south, and at last almost southeast, as it straightened out on 140, the exact reverse of the course they had flown on the approach.

  “And now,” said Dennis, barely anticipating Alan, “I’d like to know what the hell’s happening.” He switched from intercom to RT.

  “C Charlie calling Longstop. Steady on course one four zero. Please advise. Over.”

  Again that long pause, all too suggestive of hasty conferences on the ground. Then the carrier wave of the GCD truck’s transmitter broke through, quenching the faint mush of distant interference.

  “Longstop calling C Charlie,” said the Controller. “Continue on present course. Sergeant McGregor wishes to speak to Mr. Bishop. Over.”

  The words, though half expected, made Alan cold with apprehension. But his voice—he hoped—was steady enough as he flicked the transmit key and said, “Bishop here. Go ahead. Over.” Despite all his fears about the coming message, he found himself hoping that Mac would remember that this was hardly a private circuit, and that scores of people—including the Station Commander—would be listening to every word. The usual Australian adjectives, however merited, might not go over too well in these circumstances.

  Mac sounded breathless and—though this was hard to credit—almost on the point of tears.

  “McGregor here, sir.” (He had remembered his audience.) “The search system’s packed up, and there’s nothing we can do to fix it. The turning gear’s bugg—ah—broken, and the whole antenna’s jammed solid. We can’t move it an inch. One of the teeth snapped off in the main geardrive and chewed up the works before we could switch the motor off. The Controller’s sending you downwind and we should be able to pick you up on the precision system in a minute, so there’s no need to worry. But I thought you’d better know what’s happened.”

  “No need to worry!” That was a slight exaggeration, if ever there was one. In a single moment of tearing metal, the Mark I had become blind over three hundred and forty of the three hundred and sixty degrees of the sky. The beam of the search system could no longer sweep around the heavens giving a complete picture of everything that lay in each direction of the co
mpass. The Traffic Director’s hundred-mile-wide circle of vision had shrunk to a single useless line of light, pointing along the bearing on which the antenna had now frozen.

  But what was left might be enough; the precision system’s independent antennas were still scanning back and forth across the runway. Though the sector they could explore was only twenty degrees wide, it was the most important slice of the sky. If C Charlie could be headed into it and kept there without wandering off into the blind 95 per cent of the heavens, it could be landed.

  Alan acknowledged McGregor’s report without comment; there was nothing he could add, no helpful suggestion he could possibly make. What had happened could be rectified only by a major overhaul of the antenna-driving mechanism, and the construction of a fresh set of gears—a job that would take weeks, rather than days.

  But there was no point in looking that far ahead. The next five minutes were all that mattered now…

  Dennis had heard the whole conversation, and knew exactly what had happened. Yet his voice was perfectly normal and unperturbed as he reported: “Steady on course one four zero. Still at three thousand feet.”

  “Roger,” said the Controller, “we’re looking out for you.”

  How long had it been, thought Alan, since they had turned back on their course after overshooting the runway? Surely by now, covering two miles in every minute, they had passed back over the airfield and must now be entering the thin wedge of space being searched by the precision antennas! In his mind’s eye, he had a vivid, almost photographic image of the situation. He could picture a giant clock face centered on the airfield, with twelve at due north. The whole face of the clock was dark—except for a tiny slice pointing toward five, and not even covering the space between two successive figures.

  C Charlie was like a fly crawling over this darkened clock face. It had been aimed at the narrow illuminated section, but might already have missed it, to remain lost in the blackness that covered almost all the dial.