Supercruise Aviation - Article
Black Widow II, a missed opportunity!
Photo from the USAF

In the early eighties, the USAF found that there had to be a replacement for the F-15 Eagle. As the requirements for the Advanced Tactical Fighter (ATF) program was established, the relations with the Soviet Union where very poor, partly because the then U.S. president Ronald Reagan, called the Soviet Union "the Evil Empire".

In 1981 a "Request for Information (RFI)" was issued. The main things to be incorporated into the design were, Stealth, Super STOL and Supercruise. In 1983, seven companies were invited to submit concept designs. At the end of 1984 the objectives to be achieved were more and more sophisticated, the ATF had a maximum starting weight of 23,000 kg, a mission range of 1,300 kilometers, fly Supercruise at Mach 1.4 to 1.5 and a maximum runway of 610 m. As you can see in the picture, the proposals were very diverse.

In late 1985 a "Request for Proposals (RFP)" was issued. In 1986 the RFP was adjusted, so that from the two chosen designs, the companies had to make flying prototypes. Ultimately, Boeing, General Dynamics, Lockheed, Northrop and McDonnell Douglas presented proposals. Late 1986, Lockheed and Northrop's designs were chosen and got the designations YF-22 Raptor and YF-23 Black Widow II. The two companies received 50 months to make two flying prototypes and test them, to see if the prototypes met the requirements within the ATF program. Because the costs of developing the prototypes would be significant, Lockheed was working with Boeing and General Dynamics and Northrop was a collaboration with McDonnell Douglas.

The YF-23 was first in the air, on 27 August 1990 and the YF-22 just over a month later. The YF-23 was the first fly Supercruise in late November 1990. The two prototypes where tested for a half year, where all parts of the RFP were checked. On April 23, 1991 the YF-22 Raptor became the winner. Where the YF-22, especially on won, according to the USAF, was the maneuverability. The YF-23 had a better stealth characteristics and was faster. Rumor has it that the YF-22 was chosen because several senators wanted the new fighter to be produce in their States.

In evaluating the prototypes, the requirement was that 100% of the stated objectives would be achieved. The YF-22 had a score of 68%, while the YF-23 scored 100%!

Common to these developments, showed that the YF-22 had to be properly adjusted to be eventually become the F-22A production version. A large number of design elements of the YF-23, where used for the funder development of the F-22. It illustrated once more that maybe not be the best of the two won!

In 2004 the second prototype of the YF-23 Northrop Grumman was modified to join the USAF's request for a interim bomber, but this idea of the USAF is unfortunately canceled.

Both photo's are from the USAF

A general view is that the YF-23 aircraft is a lot nicer than the YF-22 or F-22A production version. The distinctive design of the YF-23 was more breaking through than the YF-22. The commentary that the YF-22 won because it was more agile then the YF-23 is doubtful. The design of the YF-23 was very unstable and in cooperation with the fly-by-wire system, you get a very agile airplane. Another component that increased maneuverability, was the design of the tail. The YF-22 uses two tail surfaces and rudder control surfaces, while the YF-23 had only two control surfaces, which were placed at an angle of 45 °.

Stealth characteristics were also better than the YF-22, especially by the above mentioned tail surface, the Radar Cross Signature (RCS) was greatly reduced. Another item which the RCS is reduced, the placement of the engines. In the YF-23 they are placed in two gondolas that smoothly progress into the wings. These gondolas are partly under the wings and partially above the wing, causing the fuselage beneath the wings to be much shallower.
The air intakes are designed so that the radar beams can not directly see the rotating parts of jet engines. The air intakes first go up and then bend inwards.

The design of the wing is determined by stealth characteristics. The angles of the leading and trailing edge are the same. This is also the case with the tails. So obliquely from above these lines are in parallel with each other.

The internal fuel tanks of the YF-23 are larger than the YF-22, because the fuselage and the wings are larger. This allows the YF-23 fly longer and further in Combat Air Patrol missions. So they can fly deeper into enemy territory, without refueling in the air. This allows aircraft to fly missions with fewer airplanes and you need fewer tankers for in-flight refueling, what was important, even then, because the KC-135's were too long over their expiration date.

The question remains, has the best design won or did the politics won?

By François van Riel