As he was laying out papers and maps from the locker, there was a knock on the door.
Purple looked up and smiled, “Ah-ha. The other key member of the crew…”
The door opened and a fully uniformed, older officer walked in. Planner recognised his face, but out-of-context, he struggled to recall who he was.
But there was no such problem for Bates, “Colonel Nicholas!” he said enthusiastically.
“Hello, Rainbow Team,” Nicholas smiled. “You looked surprised.”
“I guess I am,” said Planner. “Pleasantly so!”
“Colonel Purple and myself arranged this some time ago. We knew this would be the best place to be, come the Big Event,” he said.
“Welcome back, Colonel. Glad you could make it,” beamed Purple.
* * * *
The four of them poured over the draft flight plans and timelines, finally agreeing the flight plans, of the E4-B, the airliners, the drones and chase planes.
The two Colonels took the pencil drawn plans back to the Command Room for the draft flight plans to be entered into the computer. That way they could run a variety of simulations to check the reactions of USAF and capacities at key airfields.
Soon after that the remainder of the Rainbow Team with the notable exception of Turq, entered the E4-B. There was a mix of some 30 people: 20 male, 10 female, some military, some casually dressed, a couple in suits. As they entered the Rest Room, they were handed a thick document from Captain Ochre. The team dispersed around the aircraft reading the material, making notes and highlighting sections.
Colonel Purple gave a briefing to the team in the Briefing Room, covering basic etiquette on the E-4B and the objectives of their first flight.
All the team had been trained individually on each of the computer systems and communication headsets. All the team, that is, except Bates and Planner, this was their time to learn. For the rest of the team the mission was basic familiarity and to come together as a team; to “gel”.
* * * *
Bates took the opportunity while the aircraft was on the ground to use the Large Conference Room to give a presentation on the back-story. About thirty people squeezed into the briefing room. On a back projected screen, he displayed portraits of the hijackers with short profile details as text below. He used a laser pointer to pick particular characteristics and was able to make quite a few jokes around some of the subtlety of details arranged in the back-story.
The Rainbow Team called out information from their own research of the Rainbow Actors actions and known locations to bolster the narrative.
The plane engines started up. They all found a seat: color coordinated, of course, and prepared for take off.
Due to its reduced passenger count and weight compared to a commercial 747, the E4-B felt smooth and agile on take-off.
Once airborne and at cruising altitude, Colonel Purple lead Planner and Bates into the Command Room. Lieutenant Orange, a fresh-faced, thirty year old, explained the radar picture on a large, flat-screened computer display.
Planner pulled a face when he found out that Bates did not understand anything about transponder codes or what they implied. So Orange explained it to him.
“Have you heard of IFF,” asked Orange to Bates.
Bates frowned; he had not.
“Identification Friend of Foe115. It was devised in the second world war to identified radar blips as either one of ours or one of theirs,” he explained patiently.
“Right,” Bates apologetically. “Yes, I had heard of that.”
“Well a transponder code is the same sort of thing. A radar sweeps around radiating RF waves. These waves hit an aircraft. Onboard they have a device, called a transponder, which then transmits back a particular type of radio wave. That’s interpreted by the receiving system as a four-digit code and that’s the transponder code,” said Orange. “It also provides extra data, particularly the altitude of the aircraft, most radars can’t work out height so they get the information from the aircraft itself.”
“That four digit code… that’s the same as the Squawk Code?” suggested Bates.
“Yep, same thing. So it’s just a number coming back from the aircraft. It’s those four digits that are displayed on the radar picture below the track symbol,” said Orange.
Bates nodded.
“Ok, here’s where it gets complicated. Because an enemy can spoof these numbers, there are military bands that encrypt the number,” said Orange. “So we can tell whether they are friendly, hostile or civilian. And we color code them on-screen: Blue tracks are other friendly military aircraft. Green tracks are civilian airliners. Red tracks are hostiles, tracks that are not returning any valid transponder codes, flash red and yellow.”
“So they are easy to spot,” said Bates.
“Yeah, that’s the point. Even Red tracks could just be a problem with their equipment; at least you know where they are. But no code at all, well they’re dangerous no matter what the situation. Potential for mid-air collision.”
“So how do you spot aircraft with no transponder,” asked Bates.
“Well, the computer does it. Autotracking, is the term. It used to be done by the Mark One Eyeball,” he said pointing to his eye. “Ok. When I press this button,” Orange pressed a button and all the blue tracks disappeared on his radar screen, “This is what the FAA sees: just green and red tracks. But not blue tracks and not red/yellow tracks.”
“It cuts out the military picture,” said Planner.
“Right,” said Orange and pressing another button, “but we will be seeing the military picture, we will be seeing this picture, blue tracks, red and red/yellow. As you can see, quite empty in comparison.”
“A couple of things confuse me,” sighed Bates, “how does the FAA see aircraft with no transponders?”
“Well, they don’t. If the FAA needs to track an aircraft with no transponder the track is manually selected by NORAD and passed through to them over a data gateway. The same gateway where we plan to pass dummy data during the Big Event.”
Bates nodded, “And how do military aircraft see civilian aircraft?”
“Oh we can always see them, here,” and Orange pressed a button and the green tracks reappeared. “It’s just a way of de-cluttering the screen. There’s collision detection software running continuously to alert of any hazard.”
“The clever stuff, hey, Orange, do you want to tell him?” said Planner. “About dead reckoning?”
“No, I’ll let you, Sir,” smiled Orange.
“The clever stuff, is that these tracks persist when there is no radar cover and no transponder returns,” Planner said with a smile.
“I don’t follow,” said Bates.
“The tracks exist in the database and they are updated using the last known information in the computer: speed direction altitude. The computer predicts where the aircraft is going to be using Newton’s laws of motion. Even when there is no radar cover,” said Planner.
“So this provides the space where a airliner can be replaced by a drone?” said Bates cautiously.
“Hole-in-one, Bates,” smiled Planner. “The blip on the ATC screen is just the computer’s best guess.”
“And there’s just one further thing,” said Orange.
Bates and Planner looked back at him, worried.
“It’s not so easy to see on this display, but see this light blue circle?” Orange pointed to the radar screen. “In the centre of that circle is an AWACS aircraft116. You know what an AWACS is, right?”
“It’s a flying radar?” said Bates uncertainly.
“Right, so we have an entirely separate radar picture, not shared with NORAD and the FAA, just for us on a separate communications network running at secret level. We’ll have three AWACS flying on missions many miles away, on their own training mission. Each AWACS only sees their own returns. Only we get to see the fully compiled big picture.”
“The big radar picture,” offered Planner.