April 10, 2021: The U.S. Air Force indicates the importance of little-known equipment and aircraft by the amount of money it devotes to maintaining and expanding their capabilities. One of the best examples of this is the BACN (Battlefield Airborne Communications Node) technology and the aircraft used to carry it aloft. The air force recently spent $3.6 billion just for development and testing of new hardware and software for BACN. In addition. Congress also approved the purchase of E-11A BACN to replace one lost in early 2020 in a crash landing in Afghanistan. The air force is seeking air force budget money for five more E-11As over the next five years.

One justification for the billions in additional BACN development spending is to put new, smaller, more capable and cheaper sets of BACN equipment in additional aircraft, like the aerial refueling aircraft and UAVs. This is already done, but not with full BACN capability provided by three E-11As and three EQ-4B (Global Hawk) UAVs that also carry BACN.

Most people don’t notice the E-11A because it is a twin-engine business jet filled with BACN electronics, mainly communications equipment which enables the E-11A to serve as the equivalent of a communications satellite. This lets American and allied ground and air forces communicate freely without worrying about the interference Afghanistan’s many mountains create for most types of wireless communications. Equally important, it provides an Internet-like network shared by ground troops and air force combat and non-combat aircraft. Ground troops can quickly report enemy activity and request air support or ground reinforcements. BACN connects ground forces with transports delivering supplies by parachute, army helicopters coming in to evacuate casualties, or providing AC-130 or helicopter gunship support. In effect, BACN aircraft provides Afghan and foreign troops with more effective communications than anyone else in the country, especially the Taliban and drug gangs. The bad guys can use satellite phones but these are very expensive and detectable. BACN is encrypted and designed to resist jamming.

There are only six BACN aircraft available now; three E-11As and three EQ-4Bs and these are crucial to quickly linking air controllers on the ground with warplanes in the area. Some of warplanes benefitting from BACN are those that provide airstrikes using smart bombs or missiles. Most of the airstrikes carried out in Afghanistan depend on BACN to maintain a link between the aircraft and ground troops. Because of this, the BACN aircraft operate 24/7 over Afghanistan to speed up the delivery of air support and better communications in general.

BACN capabilities are useful in any remote area where American troops are operating. The new air force development contract will provide that by putting BACN equipment on a wider variety of aircraft. Since BACN does not require any external modification to the user aircraft, the new generation of BACN could be put on a cargo pallet used by C-130 transports and rolled aboard a C-130 that would just spend hours providing an aerial platform for BACN, which never required airborne personnel to operate it. That is all done from the ground.

The need for BACN became obvious soon after American forces entered Afghanistan in late 2001. By 2005 a test version of BACN was sent to Afghanistan and it performed as predicted. By 2008 the first E-11A was in service and was soon followed by the first UAV version. In 2011 the air force assigned new designations (E-11A and EQ-4B) to the manned aircraft and UAVs that have been operating as communications satellite substitutes.

The E-11A could be carried by any twin-engine business jet but the current ones are 44-ton BD 700 business jet and the UAV BACN is carried by the RQ-4B Global Hawk UAV. This is the largest UAV in American service about the same size and capacity of most business jets. Since 2008 BACN service has been available over 98 percent of the time to provide communications relay services over Afghanistan. Both E-11A and EQ-4B carry the same BACN equipment.

The BACN software does more than just act as a communications satellite. In order to make it possible for ground troops to not only talk to others farther away (anywhere, in fact), it also enables ground troops to quickly connect with other military aircraft combat and support) overhead. This is done with software that automatically transfers the data between the normally incompatible radio equipment aircraft and ground troops use. BACN also provides communications between aircraft. BACN not only provides ground troops with unlimited communications range but also handles linking normally incompatible communications systems with each other. BACN also provides a substitute for satellite communications which, right after 2001, was in short supply for troops in Afghanistan and that was one reason for creating BACN.

The E-11A can stay in the air for over ten hours per sortie, while the EQ-4B can do more than twice that. Both fly at 12,900 meters (40,000 feet). The E-11A entered service first, followed about a year later by the EQ-4B. Currently, BACN aircraft have not been needed anywhere else, mainly because no other combat zone has the many high mountains and numerous valleys where normal military communications are often blocked. The new generation of BACN equipment will change that because BACN was found useful as more than a communications satellite. BACN created a more effective army-air force battlefield Internet and more army and air force aircraft are being equipped with encrypted digital communications meant to operate like BACN. The best example of this is the communications capabilities found in the F-35 stealth fighter. Other fighters and bombers already have dome of this network capability.

The E-11A is used when you have to get some BACN capability somewhere in an area that might require some skilled piloting. The EQ-4B is for when you want to keep the BACN capability going someplace 24/7 and you have time for the EQ-4B ground controllers to deal with the details.

BACN is not a new idea for the air force. In 2003, realizing that every aerial battlefield in the past few decades has featured several KC-135 tankers circling, waiting to refuel a thirsty warplane, the U.S. Air Force gave the tankers an additional job. By adding a few hundred kilograms (220 pounds) of electronics mounted on a cargo pallet, which KC-135s are equipped to handle, the tanker was turned into a node in a lower altitude (then BACN) aerial communications network. This solved the problem of how to connect warplanes to the new battlefield Internet when those planes do not have satellite communications capability. The aircraft use line-of-sight communications, which cannot connect with any ground station or aircraft that is over the horizon or behind a mountain. The system, called ROBE (Roll-On Beyond-line-of-sight Enhancement), was particularly useful in a mountainous areas throughput the Middle East, with Afghanistan being the worst case. After the first 20 ROBE units, costing about $900,000 each, entered service, an upgraded model was introduced in 2017. The Department of Defense and NATO have already developed standards (LINK 16) for the transfer of video, picture and data electronically between ground stations, aircraft and ships using radio or satellite communications networks. KC-135s can't use BACN because they normally fly lower, at about 6,700 meters (20,000 feet) than required to truly act as a satellite substitute. Moreover, there are some mountains in Afghanistan higher than the KC-135 “working altitude.” The air force effort to develop a much-improved version of ROBE is what the new BACN will also do. The future ROBE will also provide surveillance and EW (Electronic Warfare) function as well.