Sorry, yes it is for adding range, I should not have made a definitive statement. I also made another error, the refueling was not to limit but to increase competition! I went back and found the old thread on this, post 37 has the best info. viewtopic.php?t=1374815
Most people don't realize it, but the inflight refueling requirement was ADDED during the bidding process to the current 747-200 AF1 project.
During the original AF1 bidding proposal process, the 747-200 was competing with the DC-10 for AF-1. The DC-10 didn't meet the range requirement and the 747 did. In order to keep the DC-10 in the competition, the Air Force added inflight refueling (IFR) to the request for proposal (RFP) requirements, to keep McD in the competition, even though the 747 could meet the range requirement without IFR. After the 747 won the contract award, Boeing offered to eliminate the IFR capability from their aircraft and refund the cost of the system (tens of millions). The Air Force refused, and that is why IFR exists today on VC-25 (747-200).
I worked at Boeing Military Airplane Co in Wichita KS at the time, and worked on AF-1 in engineering. This inflight refueling story is documented in a book written by Chuck Fisher, the Boeing pilot who flew the B-52 that lost its tail over Colorado and landed in Arkansas. The book is titled "High, Low, Joker and the Game" by Charles Fisher and Steve Conway. In Chapter 24, the book states that the contract stipulated that the aircraft must have a 10,000 mile range. The 747's range exceeded the requirement substantially. The Douglas DC-10 was the only competition, didn't have that range. In a moment typical of government bureaucracy, the Air Force elected to require $40 million worth of refueling equipment so the DC-10 could meet the range requirement.
Boeing won the contract. Since the 747, with fuel capacity of 312,000 lb, can easily fly 12,000 miles without refueling, the requirement for the IFR system should have been removed from the contract. In one of those bureaucratic snafus that everyone tries to ignore, the specification remained. Once committed to contract language, the IFR system became a bureaucratic priority of the worst kind. It said in paragraph 2028 of the spec sheet that the aircraft will be equipped with IFR systems. Fisher said that reasonable and practical men should have been able to resolve this problem in some mutually acceptable manner. However neither Boeing or the AF were reasonable or practical.
This was in 1987 and his title was Chief of Safety. Later in the chapter Chuck goes on to say that he retired over disagreements with the design of the IFR system being designed for AF1. They wanted to use a single walled fueling line, similar to KC-135s. Chuck was concerned that these planes had explosion proof avionics and electrical items which were military certified. AF1's avionics were not. Chuck wanted a triple walled fuel line with a nitrogen detection system. He retired in 1988 after disagreeing with Boeing over the IFR design. I remember going to his retirement reception.
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