The cockpit of the B-lB gives you a lofty feeling, literally and otherwise. It sits a little more than sixteen feet above the ground. And strapped into America's latest air-breathing flying machine as part of a highly trained four-man crew, one feels special and just a bit awed. Even when it's resting quietly on the ramp, there's something exotic about this craft—a sense of tremendous power and capability about to be unleashed.
Forward, the pilot and copilot begin their checks. About eight feet behind them and slightly elevated, the offensive and defensive systems officers prepare to employ some of the world's most sophisticated electronic wizardry.
Connected to the forward fuselage are five air-conditioning hoses to cool the on-board computers, more than ten of them. Ground crews make their final checks and stand ready to see the aircraft on its way.
The B-lB comes to life when the hydraulic reservoirs activate its two auxiliary power units. Generators literally bang on-line. Cockpit noise is very low. Only the rush of air from the air-conditioning and cooling system is audible.
After about five minutes of power from the APUs, the four General Electric F101 dual-rotor, afterburning turbofan engines are started. In the cockpit, vertical-tape engine instruments are the only clue that the engines are running. The inertial navigation system aligns while flight control checks are being made. In a very short time, the bird is ready to roll.
The pilot's first real indication that he is in a movable object is when he moves the stick (gone is the traditional heavy bomber yoke) and the four 4,000-psi hydraulic actuators engage the split-tail hydraulic stabilators. The power in the system would rock the whole aircraft noticeably if this were not done smoothly. The combination of computerized fly-by-wire and mechanical linkage to the stabilator actuators gives fighter-like control to this mighty aircraft, which is in the 400,000-pound weight class.
Ready to taxi and take off, this former B-52 pilot realizes he has transitioned to the finest that modem technology has to offer. Everything about the B-lB is smooth and effortless. It has a blended-wing body with variable-sweep wings. Forward and side visibility through the elongated wraparound windscreen are excellent. The aircraft clips quickly along the runway and will turn on a dime.
As he lights the four afterburners, the pilot commands 120,000 pounds of thrust. It's still very quiet in the cockpit, but he can now feel the engines vibrate. The earth shakes. A ground observer can feel the vibrations peak as the aircraft becomes airborne after about 4,000 feet of takeoff roll.
Inside, it feels as if you've just "planed out" on water skis, giving you the freedom and mobility to dash in any direction. With the aircraft still accelerating rapidly, gear, flaps, and slats are retracted, and the variable-sweep wings are positioned to twenty-five degrees aft to reduce drag. The wings, like the rest of the plane's configuration devices, are manually controlled by the pilot.
The Magic Show Begins
Minutes later, the ship has reached its cruise altitude, and the "magic show" begins. The B-lB is essentially a large computer system surrounded by fuel and engines. It is mind-boggling, even to those who fly it. The "brains" of the airplane are in the back station. Four aircraft computer units control most of the major systems: navigation, bombing, fuel, regulation of center of gravity, and other functions.
Here, acronyms abound. There is the GNACU (Guidance and Navigation Avionics Control Unit), the WDACU (Weapons Delivery Avionics Control Unit), the CDACU (Controls and Displays/Defensive Avionics Control Units), and the CFACU (Critical Functions Avionics Control Unit).
What these systems don't control, the EMUX, or Electrical Multiplexer Unit, does. The EMUX system provides a means of transmitting data throughout the aircraft on redundant transmission lines as well as of managing electrical system load.
The computers control altitude, heading, and airspeed. Fuel transfer sequencing is automatic and provides center of gravity control by shifting fuel to compensate for any change in the center of lift caused by movement of the variable-sweep wings.
Another computer system, the Centrally Integrated Test System, or CITS, serves as an on-board test system for most of the aircraft functions. The CITS performs test and control functions required to verify aircraft system performance in flight.
The CITS computer notifies the pilot of everything from fuel temperature to impending failure of a critical component. It will tell the defensive systems officer of a failure long before it shows on the master caution panel of 112 lights. In the B-113, the state-of-the-art technology is nothing if not futuristic.
Currently, the 4018th Combat Crew Training Squadron is the only operational unit flying the B-lB. The squadron is in the process of training its flight instructor crews and began training crews for the first operational bombardment squadron in April. (See also "Bringing on the B-IB," p. 63 of this issue.)
All training missions are based on combat scenarios. They consist of air refueling with a KC-135, penetration on a low-level route, terrain masking, simulated weapons release, egress, and post-target recovery. A typical training mission also includes air work and traffic pattern operations.
Air refueling is made simple by the smoothness of the computerized flight controls. The air refueling receptacle is located on the nose of the aircraft, forward of the pilot. The B-lB has a universal aerial refueling receptacle/slipway installation (UARRSI) for in-flight refueling and a single-point refueling capability for ground refueling. It's also capable of reverse air refueling and fuel dumping. Filling body and wing tanks takes just a few minutes.
Into the Mission
When refueling is complete, the combat crew is ready to proceed to the designated low-level route for the mission. As the aircraft descends into the run, the wings are swept full aft to 67.5 degrees. This reduces drag and allows the aircraft to accelerate easily to near-supersonic speeds for cruise at low altitude.
Capabilities are being added to the aircraft in computer software blocks as they become available. One such capability is that of terrain following. Once the system is fully operational, the terrain-following computer will be engaged at high altitude, when the aircraft's wings are swept back. The computer, receiving inputs from the offensive radar system, directs the aircraft to descend quickly and then level off just above treetop level.
Regardless of weather or hour of the day, the computers can fly the aircraft just above treetop level, maintaining precise airspeed control and pinpoint navigation to the target. In front of the pilot is a cathode-ray tube with a presentation very similar to that of a computer video game. It gives altitude to the nearest foot, a vertical image of the terrain ahead, attitude, ground speed to the nearest knot, and distance to the next destination or target to the nearest tenth of a mile.
As the aircraft approaches the strategic training range, the offensive systems officer configures the computers for bombing, while the defensive systems officer configures his computers to defend the craft electronically. Seconds away from the target, the crew begins transmitting an electronic tone to the training range site. At "Bombs away!" the tone is cut. Site personnel score our release point by this electronic tone, and from this we can determine bombing accuracy.
During the bombing run, trackers at the site test our electronic countermeasures equipment to determine its effectiveness against enemy tracking radar. The B-lB's defensive avionics system provides protection from ground and airborne threats. It carries out radio-frequency surveillance, electronic countermeasures, tail warning functions, expendable countermeasures, and defense management.
The design environment of the B-IB is low-level. The craft possesses the agility to maneuver between hills and the sophistication to ride just above all kinds of terrain in any weather. When using afterburner thrust for dashes, the crew is often pressed into their ACES II ejection seats. As the aircraft climbs out of low-level, the wings are swept forward, and the mighty bomber lunges for the sky.
Most Important Part
Bombing run completed, aerial training is next. The flight characteristics of the B-IB are complicated—and critical to its safe operation. For pilot training, this is the most important part of the mission. Pilots of modern aircraft must be well acquainted with flight characteristics, as many of the old standards have changed. Speed is sometimes limited by skin temperature, and computers can see through previously restrictive clouds.
One major flight characteristic to be learned involves a wing sweep demonstration, during which wings are swept from twenty-five degrees to 67.5 degrees. The wings are swept aft to reduce drag and allow for high-speed flight. One problem a pilot may discover in this configuration is that he is flying too slowly with the wings back. The B-IB is a lifting body; it can easily fly without wings so long as the "smash" (knots indicated airspeed) is up. If flown too slowly, however, the center of lift comes too far forward of the center of gravity, and the aircraft will tend to tip over backward or run out of enough thrust to sustain a high angle of attack.
The other flight characteristics demonstrated are conventional and include approach to stall (which is defined as neutral stability; the B-IB tips over backward long before its wings stall), slow flight, and lazy eights (yes, bombers can perform lazy eights).
Following the aerial training maneuvers, it's back to the base for some pattern work. The B-IB handles extremely well in the pattern. With the wings in the forward position and flaps, slats, and gear extended, the B-lB can land as slowly as 155 knots, and landing roll is sometimes less than that of a T-38 trainer.
When the B-IB turns off the runway after completion of a training mission, the computer tells us the exact temperature of each brake and prints a record of all malfunctions that might have occurred during the flight. Alter shutdown, this printout and a tape from the CITS computer are available to maintenance personnel, making their job significantly faster and easier.
All in all, the mighty B-IB is a truly remarkable aircraft. It's a tribute to American technology and a genuine pleasure to fly.
Maj. Michael A. Kenny, USAF is the first instructor pilot in the B-lB. Now stationed at Dyess AFB, Tex., Major Kenny is a longtime bomber pilot, with 678 combat hours among his 3,300 hours of flying time. During his sixteen years in the Air Force, he has served as an instructor pilot in both B-52Ds and FB-111 As. He is a graduate of Squadron Officer School and has completed both Air Command and Staff College and the National Security Management courses.
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