"Good grief, why not?"
"Margins of error, old boy. The R.A.F.'s prepared to accept a very small calculated risk—any operational war force must be, obviously. The particular figure determining things in this case was one fatality in one hundred thousand landings where the system was in full use."
"And this small percentage of calculated error was not good enough for civil planes?" Illya asked.
"Not by a long chalk. The Air Registration Board wouldn't certify full use of any equipment until it had proved a safety standard of one fatality per ten
million
landings...Nevertheless B.E.A. started using Smith's equipment on their Tridents in 1964. This controlled the aircraft's height until the moment of touchdown. Then B.O.A.C. equipped V.C. 10's with similar gear developed by Elliott-Bendix."
"Was this used on all landings?"
"No. Mainly for fog. A limited use in fact. They were waiting for the International Civil Aviation Organization to give the final go ahead on world-wide adoption of the system in principle."
"And the principle is?"
"Plances carry the equipment in a square box housed in the cockpit. As they approach the airport, the box fixes them on a localizer beam which brings them in line with the runway to be used for the landing. Then another ground transmitter broadcasts an electronic beam down which the plane rides, as it were, to establish the correct glide path."
"And the gear in the box causes the plane's controls to adjust themselves so as to maintain the correct altitude and inclination for touchdown?"
"Dead on target, old chap. Hole in one. The pilot still has to control the sideways aspect, the roll of his wings, himself—but the height's always the most difficult part of it, after all. And even in good weather this limited use of the stuff increases the safety factor no end."
"Aren't they developing an—er—extension to the system so that the roll factor will be taken care of too?"
"They are. Have, in fact. Supposed to be installed later this year. In the meantime, our own gear—the Murchison-Spears, you know—already takes care of this."
"Is it based on the same principles?" Illya asked.
The Technical Director struck a match and sucked the flame noisily into the sodden bowl of his pipe. "Partly," he replied. "Fact is, the gear that fixes the plane on the localizer beam is a dead crib—so far as that's possible within the copyright infringement laws. But the part that adjusts the height and inclination is quite different. Instead of relying on a ground-to-air electronic beam and riding down it, the Murchison-Spears equipment works on a system more like ordinary radar."
"You mean it emits a signal and deduces information from the way that signal is echoed back—then causes the aircraft to act upon this?"
"Broadly speaking, yes. Murchison designed the altitude-and-aspect end of it—that's simple in theory but extremely sophisticated in design. And Spears—he's the hydraulics wizard—handled the part that deals with the roll factor. Basically, this is just a sensitizer at each wing-tip and something very like the old-fashioned balance-pipe between them. But again—the
means
he used to achieve this are electronically most advanced. The sensitizers—which both transmit and receive pulses, after all—are extraordinarily compact and ingenious."
"How do you yourself account for the three T.C.A. crashes here?"
The man with the pipe lit another match. For some moments he puffed away behind his private smokescreenm, then he rose to his feet and crossed the room to the window. "Very difficult question to answer," he said at last, with his back to them. "Mind, I haven't had time to go over the bits—the actual pieces of wreckage of the latest one. They're being assembled on the floor in a hangar nearby, as nearly as possible in their original relationship to one another. And that's a hell of a job when you've got perhaps several tens of thousands of segments—buckled, torn, melted, twisted, distorted and what-not."
"I can imagine."
"Nevertheless, my chaps and I have formed certain opinions—and they
are
only opinions, based on interpretation of the information supplied by other bods, and not deductions from data observed by ourselves. That'll come later."
"Any opinion, any suggestion, any hint will be valuable, sir."
"Yes. Well—for what it's worth, all my chaps underwrite what the accident investigation johnnies said: that there was no human error in any of the three prangs. And that there was nothing wrong with any of the planes. Or with their normal controls, for that matter."
"You're saying, in effect, that there
was
something wrong with the Murchison-Spears equipment?"
"No, old boy. That's exactly what I'm
not
saying. I'm saying there was
nothing
wrong with anything
else
. You can draw what deductions you want to from that. In view of the fact that the M-S gear was proved to be in perfect condition after each crash, I simply cannot say that, ergo, it must have been the gear that was at fault. Until our own investigations have been completed, I must say nothing: my mind must remain open..."
"If the gear
had
been at fault, what would you say—unofficially, of course—would have been the—er—likeliest thing to have happened to it? That could have left it in perfect condition afterwards, that is."
"Seems obvious to me, old chap. In such a case—
if
one existed!—one would have to look for a set of conditions causing false readings on the equipment. Something that caused the box to direct the aircraft as though the ground
wasn't
where it really was...if you get my meaning!"
"You mean the box could have acted as though the runway was higher or lower than it really is, for example?"
"I mean," the Director said carefully, "I'd be inclined to look for a situation in which such a thing
could
happen."
"And if such a set of conditions existed—which part of the gear would you be inclined to suspect of being affected?"
"Look—the box divides itself pretty definitely into three separate complexes, doesn't it? The bit getting it in line with the runway to start with...and after that the altitude-and-aspect gear, and finally the wing-tip equipment that controls the roll. Right?"
"We're with you."
"Right. Now it would seem unlikely that the first is in any way affected: all three crashes actually occurred
on
the runway, so the planes must have been accurately lined up, eh?...And again, no eyewitnesses have mentioned anything like a sideslip or a wingtip digging in or anything of that sort. Admittedly the last one did cartwheel—but that was apparently only after the under-carriage had been wrecked on the first impact. So it seems—shall we say?—
unlikely
that the wingtip gubbins
caused
the crashes."
"Which leaves the altitude and glide-angle equipment?"
"Exactly. You examine all the witnesses' statements. Seventy per cent of 'em say something like 'the plane seemed to fly straight into the ground'. And the survivor of the last one was trying to say something to the nurse in the ambulance. Unfortunately, she didn't speak English—but we gather he was spouting something about height, or too high, or something. All of which seems to me to suggest either wrong altimeter readings or wrong glide angles."
"Or wrong interpretation by the gear to give the
effect
of this?"
The dark man with the moustache shrugged. For the first time, he removed the pipe from his mouth. "You must appreciate my position," he said, jetting a small cloud of smoke into the air. "We make the gear, after all. As there's no evidence of faultiness after the crash, we feel it's not up to us to ferret out reasons why it
might have been
at fault—though of course we should accept any conclusive evidence found by someone else."
"I understand," Solo said. "And you can't think of any device—or set of conditions, to use your phrase—under which the part of the gear affecting height readings or glide angle could be momentarily distorted, and yet return to normal afterwards?"
The Technical Director jammed the pipe back into his mouth. "Oh, have a heart, old chap," he said. "Have a heart."
Later, Solo and Illya spent some time studying the technical drawings of the Murchison-Spears equipment—with particular emphasis on those parts of it affecting the height of the aircraft and the automatic control of this.
"I can see the principle," Solo said. "But I'm afraid the detail is a bit too..."
"No, no, Napoleon," Illya said. "It is relatively simple. Look...after the scanner tube has...Look!...Here...This is where, if it was just giving a reading, the electronic pulse would be turned into a visual indication, on a dial. See?"
"Ye-e-es. I'm with you so far. Just."
"Well, since it's
not
just giving a reading—but causing the plane to react as a pilot would after digesting that reading—the electronic information feeds in...here. In this small memory storage unit."
"Something like a computer?"
"On a far less complicated scale, yes...And then these selectors...here...and here...and here...See, the contact is made by this core of toridium. As you know, it's a metal whose coefficient of expansion is —"
"No, Illya, no!" Solo said firmly. "This is way beyond me. Let me leave the technical stuff to you. When you have an idea, tell me—and we'll act on it. Until then, you're on your own, boy!"
"Just as you like, Napoleon. I think I might have the glimmering of an idea how someone might—just might—begin to make...what did the man say?"
"A set of conditions?"
"That's it! A set of conditions! A set of conditions in which this equipment might be made to react falsely without permanently damaging it...but I'd like to brood on it before I commit myself."
"You do that. In the meantime, we'll start on the social side, as we said..."
* * *
At seven thirty, they met Helga for a drink in the airport lounge. Sheridan Rogers had still not returned to her apartment, nor had she left any message at the T.C.A. office or in the bureau at the terminal building. They gave her a half hour and left at eight o'clock—calling once again at the empty apartment on the way to Haut-des-Cagnes.
Illya, customarily a reserved companion, was abnormally quiet and worried during the short journey. Solo and Helga, torn between the extremes of failing to cheer him up and appearing too flippant in the face of his obvious distress, struck a kind of subdued bantering note in their exchanges as the car sped along the motor road to Cros-des-Cagnes and then turned inland towards the medieval village perched so picturesquely above it. From the coast, Haut-des-Cagnes presents a symmetrical aspect—a pyramid of rough, red-tiled Proven�al roofs crowned by a 14th century Grimaldi castle, beneath whose floodlit and crenellated keep the
place
clusters at night. But the visitor who ventures along either of the valleys running inland to each side of it soon sees the village in a different perspective. It is built—for a start—at the end of a spur and not on a hillock...so that a moving viewpoint presents constantly shifting profiles. At one moment, the emphasis seems to be rectangular—a line of picture-postcard houses serrating the sky at the top of a squared-up bluff; the next minute, the picture is all zig-zags—a series of slopes linked by hairpin bends, the whole complex rising to stone ramparts and punctuated by clusters of cottages clinging to the wall as tenaciously as the bougainvillea which covers them. And yet on the far side of the valley, a little higher up, an onlooker would characterize the place as a series of stepped terraces, rectangular plots and parcels of land related vertically by the swooping walls of villas and the trailing profusion of flowers hanging from their balustrades.
Illya drove about a kilometer along the road leading inland to Vence and then made a steep, climbing turn back to the right, approaching the old village from the north.
The center of social life in Haut-des-Cagnes is the
place
at the very summit of the pyramid—a small square dominated by the battlemented turret of the keep. Here a handful of expensive and chi-chi boutiques and souvenir shops vie with the three cabaret-restaurants in the laudable task of parting the tourist painlessly and as elegantly as possible from his money. And here in the summer—especially in August—an absurd and ludicrous number of cars attempt to park.
As the 404 negotiated the narrow, steep streets leading by degrees to the
place
, it became increasingly necessary to stop and allow other vehicles room for manoeuver—despite the traffic lights which in a desultory way tried to regulate the traffic coming up and down. As always, the square was full, and people on their way to the boutiques or the cafés had left their cars absolutely anywhere: they lined the constricted roadway, projected across intersections, blocked the exits from drives and garages, balked those wishing to turn and sprawled across every available inch of space in the congested village. Illya was eventually forced to turn around at the top and drive down again to a square only halfway up the ramparts. After waiting a moment here, they slid into a space vacated by a departing Belgian and climbed back to the
place
at the top via a steep stone staircase.
The party from T.C.A.—there were really three separate parties—was easy enough to identify. The alert young men and women in their crisp uniforms had taken over the three outside tables on one of the café terraces.
Helga, Illya and Solo took a table nearby and watched them curiously for a while. But the stereotyped banter, the stereotyped horseplay and the expected ploys soon palled and they began to look around at the other tourists there. Next door to their restaurant was another, and those sitting outside under the floodlit vine pergolas were separated from them only by a row of white fencing running from the junction of the two buildings. It was very warm in the soft summer darkness—a little humid, perhaps—and the shrill banalities of the holidaymakers sounded loud in the night air. On the far side of the square, beyond the massed lights of the parked cars, away from the milling convolutions of the café patrons, blue-clad men with lined faces the color of walnuts played a quiet game of
pétanque
.