Brazil is replacing its four KC-137 aerial refueling aircraft with two KC-767 tankers from Israel that are based on the Boeing 767-300ER airliner. The elderly KC-137s were obtained in 1987 and are similar to the American KC-135. The new Israeli tankers are similar to the new American PC-46A, which is based on the Boeing-767-200 (which is a little shorter and eight tons lighter than the 300ER). Israel has an arrangement with Boeing to rebuild 767s as refueling or cargo aircraft.
The four engine KC-135 carries 90 tons of fuel and can transfer up to 68 tons per sortie. Typically, American aerial tankers have to service B-52s, which carry over 140 tons of jet fuel and fighters like the F-15 (over five tons). Brazil does not operate anything like the B-52 and its tankers mainly refuel fighters. The KC-135 can also carry cargo and passengers, as well as fuel, as can the two KC-767s.
The KC-46A is based on the Boeing 767-200. The 767 has been in service since 1982, and over 800 have been manufactured so far. Boeing developed the KC-767, at a cost of nearly a billion dollars, on its own. Boeing also developed the original KC-135 tanker in the 1950s, and has since built over 2,000 of these.
The KC-46A was selected by the U.S. Air Force to replace KC-135s, partly because it is about the same size as the KC-135 (wingspan is 50.3 meters/156 feet, 6.8 percent larger than the KC-135). Thus the new tanker can use the same basing and repair facilities as the 135. The KC-46A can carry up to 94 tons of fuel. It can also carry up to 114 passengers or 18 cargo pallets or 58 patients (24 on litters).