Sea of Shadows (For fans of Tom Clancy and Dale Brown)
Page 15
Shari sighed. “Have we ever flown a mission where everything on board actually worked for the entire flight?”
“Not that I know of, boss. In fact, I don’t think I’ve ever even heard of such a thing.”
“So we’re hitting the Op-Area blind?”
“Not exactly. We just got an ES cross-fix from Abraham Lincoln’s Airborne Early Warning plane.”
“Better than nothing,” Shari said. “Is it good news or bad?”
“Good news. There are at least two Kelvin Hughes Type 1007 I-band radars transmitting right-smack-dab in the middle of our Op-Area. Definitely consistent with German Type 212 subs.”
Shari’s eyebrows went up. “Two? What about the other two? Did they split off from the rest of the pack?”
Andy shook his head. “George doesn’t think so.”
George was Ensign George Freely, the plane’s Tactical Coordinator, or TACO (pronounced to rhyme with “whacko”).
“He says it’s not unusual for subs in a rotating diesel barrier to alternate their depths according to a predetermined schedule. That way, not all the subs are at periscope depth at the same time.”
“This isn’t exactly a rotating diesel barrier,” Shari said.
“True,” said Andy. “But that’s the closest tactical example that anyone can think of. Nobody’s had to deal with a roving diesel wolfpack since the Second World War.”
“I understand that,” Shari said. “But we still don’t know for a fact that the subs are sticking together. What if we get all our eggs in one basket, and some of those subs slip by us to the north?”
“They’re going to have to refuel somewhere,” Andy said. “The intel weenies think they’ll head for Tobruk, Libya. That’s the nearest port that’s seriously hostile to the good old U.S. of A.”
Shari glanced at her own fuel gauges. “Sounds like a pretty big gamble to me,” she said. “How much time will we have on station before the carrier gets there and steals our thunder?”
Andy took a swallow of coffee. “Those guys are making tracks. We’ll probably have the Op-Area to ourselves for an hour before AEW gets there.” He shrugged. “The carrier will be, what? An hour behind that? An hour and a half, maybe?”
Shari pursed her lips and nodded once. “Let’s make the most of it. I want to have those subs filleted and on a plate before the big boys even stick their toes in our Op-Area.” She pulled her headphones from around her neck and positioned the left earpiece over her ear. The other earpiece she put over her right temple, leaving her ear uncovered so that she could hear her copilot. She keyed her mike. “George, let’s get FLIR warmed up and ready to play.”
The TACO’s voice cracked in her left ear. “You got it, Lieutenant.”
Down in the belly of the plane, the Forward-Looking Infrared cameras came to life and began scanning the water below and in front of the aircraft for thermal signatures. The temperature contrast between a periscope and the surrounding water was sometimes drastic enough to make it detectable to IR. But FLIR really worked best against snorkeling submarines. A snorkel was a specially designed ventilation pipe that a submerged submarine could extend above the surface of the water to allow its diesel engines to suck in fresh air and expel exhaust gasses. In the infrared spectrum, the heat plume from a snorkeling engine was like a giant arrow pointing directly back to the submarine.
* * *
A few minutes out from the Op-Area, Shari began a slow descent that would take them down to their patrol altitude of 1,500 feet. Based on the recommendations of the TACO, they didn’t drop any sonobuoys on the first pass, giving the FLIR cameras and the APS-137 radar a chance to sweep the area for periscopes or snorkels.
When she reached the far edge of the search grid, Shari eased the yoke over into a slow turn that would bring them back around for another pass. She keyed her mike. “Did we get anything, George?”
“No joy. Just a merchant ship and a couple of yachts.”
“So much for beginner’s luck,” Shari said. “Let’s start planting the Briar Patch on this next pass.”
“Roger that,” her TACO said. “Stand by for waypoints.”
A series of coordinates popped up on Shari’s Tactical Data Display. She punched the acknowledge key on the TDD. “Got ’em.” She brought the nose around two degrees to starboard to line up on the first waypoint. The TDD beeped to tell her that her approach vector was within acceptable limits. She keyed her mike. “I’ll do the flying, Andy. You cover the numbers.”
Andy said, “Roger that, boss.” He paused, watching the numbers on the TDD for a moment, and then he keyed his mike. “All stations—waypoint Alpha coming up in five seconds … four … three … two … mark!”
On cue, one of the two Acoustic Sensor Operators sitting at display consoles near the center of the plane pushed a button.
An electrical signal triggered a small explosive charge, not much more powerful than a shotgun shell, propelling the first sonobuoy out of its launch tube. As soon as the metal and plastic cylinder was clear of the aircraft, a propeller-like set of spring-loaded fins popped open on the rear end of the buoy. Known in Undersea Warfare circles as a roto-chute, the fins caused the sonobuoy to spin like a helicopter, slowing the buoy’s rate of fall and keeping its nose pointed down toward the water.
On splashdown, the sonobuoy performed a series of automatic operations in rapid sequence. First a flotation collar inflated, keeping the buoy floating upright with four-fifths of its length extending down into the water. Next a latch snapped open in the lower end of the device, releasing a small array of sensitive underwater microphones to dangle at the end of a cable beneath the buoy. Relays clicked; a lithium battery powered up an acoustic processor and a radio transmitter, transforming the buoy into a small disposable sonar system. Almost simultaneously, an antenna popped out of the top of the buoy and began transmitting coded signals back to the aircraft.
The P-3 continued launching sonobuoys at precisely measured intervals, turning occasionally to begin another row. Buoy after buoy shot from the launch tubes, each spinning down toward a pre-selected spot in the ocean, until they formed an integrated field of sonar sensors: a Briar Patch.
In Shari’s left ear, the TACO’s voice said. “Buoy 12 won’t tune up. All other buoys are up and operational.”
“Copy,” said Shari. “How big a hole does that make in our coverage?”
“Negligible,” George said in her ear.
Andy keyed his mike. “Do you want to swing back around and re-seed buoy 12?”
“It’s a tight pattern with a lot of coverage overlap,” George said. “We can reseed, if it’ll give you a warm-fuzzy, but it’s not really necessary.”
“You’re the USW guru,” Shari said. “I’m just the bus driver.”
“Copilot concurs,” Andy said. “If you’re happy, we’re happy.”
“Roger,” said George. “Looks like we’re getting some LOFAR data now.”
LOFAR is an acronym for Low Frequency Analysis and Recording. It’s a method of acoustic processing that takes the noise detected by a sonar sensor and strips it apart into individual component frequencies. By comparing those frequencies against a catalogue of known acoustic sources, it is often possible to classify the source of a particular noise.
A skilled acoustic analyst can read a LOFAR gram the way an average person reads a newspaper. The process is largely one of elimination. Three-bladed propellers have different characteristics than four-bladed propellers. Engines with in-line cylinders generate different frequencies than V-configured engines. Four-pole electric motors make different tonals than two-pole motors. Chinese-built ventilation fans are different from French-built fans, which are different from Russian-built fans. Different hull designs have different hydrodynamic characteristics, which create identifiable sounds.
Sometimes, the majority of the contact's frequencies are common to several possible sources and the resulting classification may be ambiguous: This is a non–Russian-built Type I d
iesel submarine—probably Chinese but possibly Korean. Other times, the classification can be startlingly exact: This is a Russian-built Akula submarine hull Number 8.
From their display consoles, the two Acoustic Sensor Operators began the process of classifying the frequencies coming in from the sonobuoys.
After several minutes, George’s voice came over Shari’s headset. “All buoys are cold.”
Shari and Andy stared at each other in disbelief. “Say again,” Shari said.
“I repeat,” the TACO said, “all buoys are cold.”
“All of them?” Andy asked softly.
“Every one of them,” George said. “The only tonals we’ve got are coming from those two yachts, and that merchant ship. We have zero possible submarine contacts.”
“Have your guys go over the grams again,” Shari said. “Maybe they’re missing something.”
“They’ve been over them twice,” George said. “Then I went over them myself. Those grams are ice cold.”
Shari’s eyes went to the Tactical Data Display. “Check the numbers, Andy. First you do them, and then give them back to Nav for a cross-check. While you’re at it, get Nav to run a diagnostic on GPS. Maybe we planted the Briar Patch in the wrong spot.”
“I’ll check, boss,” Andy said. “But I’ve never seen a GPS plot that was off by more than a few inches.” He flipped a selector switch and began talking to the Navigator on another circuit.
Shari keyed her mike. “George, have your ASOs run diagnostics on their gear.”
“Already in progress,” the TACO said, “but I can tell you up front that the equipment is running sweet. Whatever’s wrong ain’t in the ARR-78s.”
“Let’s swing back and re-seed that bad buoy,” Shari said.
“That’s not it,” George said. “There isn’t enough room in the blind zone for one sub to hide, much less four.”
“Maybe all four of them aren’t down here,” Shari said.
Andy kept his eyes on the TDD and punched buttons, watching the changing numbers like a hawk. He keyed back into Shari’s intercom circuit. “That’s certainly a possibility. But AEW got solid ES cuts on at least two of their radars. Even if there are only two of them down here, there’s no way they both just happened to be sitting under the only bad buoy in this whole piece of water.”
“If anyone’s got a better explanation,” Shari said, “I’d love to hear it right now.”
“These new 212Bs are supposed to be bad-ass,” Andy said. “Maybe they’re just so quiet that we can’t detect them.”
“I can’t rule that out,” George said. “But I’ll believe it when I’ve seen the proof.”
“Could be we’re seeing it now,” Shari said. “Or not seeing it, as the case may be.”
“The Brits detected them by going active,” Andy said. “Maybe we need to drop some active buoys.”
“Not my first choice,” George said. “As soon as we start pinging, those subs are going to run like scalded dogs. If they split up, we’ll never catch them all.”
Shari stared out the window at the Mediterranean. The water was still just as blue as it had been before, but now her eyes accused the waves of concealing the location of her enemies. “It’s not like we’re having a hell of a lot of luck catching them now,” she said.
Andy looked up from the TDD. “The numbers are clean. We dropped those buoys right on top of the ES cross-fix.”
George said, “Maybe the cross-fix was wrong. Who says the AEW guys can’t screw the pooch once in a while?”
“Maybe,” Shari said, “but they’re never going to admit it. Let’s set up a rack of active buoys and try this again.”
“Yes ma’am,” George said, but his voice didn’t sound very confident.
Shari pretended not to notice. “Shoot me some waypoints.”
* * *
Active buoy number 9 was going into the water when George said, “Abraham Lincoln’s AEW is about thirty miles out. They’re still picking up Kelvin Hughes I-band radars in our Op-Area.”
“Where the hell are they?” Shari asked.
“Just a second,” George said. “I’m getting the cross-fix now.”
Shari waited without speaking; the only sound in the cockpit was the drone of the engines.
After what seemed like an hour, but was—in reality—probably more like five minutes, the accordion door at the rear of the cockpit slid open. George stepped into the cockpit and stood in the narrow strip of floor space between the pilot and copilot chairs. His disconnected comm-set was down around his neck, the cord draped around his shoulders. “Ah, boss?”
Shari looked up. George never came up to the flight deck to deliver good news. “I’m not going to like this, am I?” she asked.
“Afraid not, boss. We plotted the cross-fixes on those I-band radars we’ve been chasing. They fall right on top of those two yachts in the middle of our Briar Patch.”
“That’s nuts,” Shari said. “Go out to AEW and get them to check their ES gear.”
“I’ve already done that,” George said. “Their gear is clean. Those boats are emitting I-band radar signatures consistent with German Type 212B diesel submarines.”
“Leave it to the AEW weenies to screw up something simple like an ES cut.”
The idea dawned on Shari slowly, like some sort of vile egg hatching deep in her intestines. “AEW didn’t screw up,” she said. “They got suckered. We all got suckered.”
“Those boats are carrying decoy radar emitters,” George said softly.
Shari’s eyes shot over to Andy. “Get on the horn to the Abraham Lincoln! Tell them the subs are not in this Op-Area, and they never have been. We’ve got to get that carrier turned around and headed back toward the eastern end of the Med.”
Andy picked up the radio microphone, his face gone suddenly the color of ash. “It’s already too late, isn’t it? The subs have already gotten past us.”
“Forget about us,” Shari said. “The carrier is out of position, way out of position. Those subs have a straight shot into the Suez now.” She whistled softly through her teeth. “I doubt anybody can stop them.”
CHAPTER 17
USS TOWERS (DDG-103)
NORTHERN ARABIAN GULF
MONDAY; 14 MAY
1840 hours (6:40 PM)
TIME ZONE +3 ‘CHARLIE’
Fire Controlman Chief Robert Lowery tapped the video screen with the tip of his index finger. A bright green wedge of static interference eclipsed an arc of the SPY radar display. “This is a playback of recorded video from the Aegis display system,” he said. He looked up at the faces of the three technicians gathered on the far side of the console. “The interference lasted about two and a half minutes, which is pretty consistent with the other two times this malfunction has shown its ugly head.” He tapped the screen again. That’s pretty much all we know, except that it always appears in the same sector of the aft port-side SPY array, and that it tends to show up in the early to mid-afternoon.”
Fire Controlman Second Class Todd Burgess rubbed the back of his neck. “That’s array number four, Chief. Fish and I have run every test in the book on that damned thing. Every single module in the array is operating within design tolerances. Now we’re thinking about a couple of tricks that aren’t in the book.”
Chief Lowery glanced back down at the partially garbled radar screen. “Like what?”
Burgess nodded toward Fire Controlman Third Class Daryl Fisher. “The problem always seems to show up during the hottest part of the day. Fish thought that some of the emitter-receiver modules might be breaking down under the heat. If he’s right, we should be able to duplicate the problem by heating up the array a little bit. We have some ideas on how to do that.”
FCC Lowery cocked his head and narrowed his eyes. “Why am I suddenly certain that I don’t want to hear the rest of your idea?”
Fisher grinned. “Relax, Chief. We’re not going to burn it up. We’re just looking to crank the heat up a notch.”
The chief nodded. “I see … If you can make the problem appear by turning up the heat, then it just becomes a matter of finding out which components are breaking down under high temperature.”
“Right,” Fisher said. “We’ll have the problem localized to the array, and we can chase it down a module at a time. Plus, we can get the engineers to rig us a couple of fan units inside the array housing to blow extra air across the back sides of the modules. That might help us hold the heat down enough to keep the array from shitting all over itself while we look for the bad modules.”
“Sounds good,” FCC Lowery said. He looked at the third technician, who hadn’t said a word yet. “Gordo, these clowns may be onto something, but we can’t afford to get tunnel vision here. This could still be a processor error, or a software glitch, or God knows what. I want you to reload the entire Aegis software package from your archive disk packs.”
Fire Controlman Second Class Bruce Gordon nodded. “Will do, Chief. And the next time we get a satellite window for Internet access, I’ll log onto Navy Knowledge Online and post a note on the troubleshooting forum for SPY. It’s possible that somebody has seen this particular casualty before, and there might already be a fix for it.”
“Good idea,” the chief said. “All right guys, you’ve got your marching orders. I don’t need to tell you how serious this is. If we were joyriding off the coast of Southern California, this kind of casualty wouldn’t be much more than an inconvenience. Unfortunately, this is the Arabian Gulf, and the natives out here don’t run around in roller blades and thong bikinis. There are an awful lot of people out here who would love to stick a cruise missile up our ass while we’re not looking. We can’t afford to have our primary sensor go blind at a critical moment.”