MiG X Mk2 :: Nauka ~ Tehnika ~ Military

Switchblade

Above illustration by John MacNeill, used with permission.

The US Air Force has been testing the X-29 for two decades now, this very unusual looking aircraft has a pair of forward sweapt wings (FSW). The Switchblade design seems to be based on the X-29, with the added capability to change the position of the wing.

These wings gave the aircraft amazing maneuverability, no other aircraft can make tighter turns than the X-29.
The X-29 was tested from 1984 to 1992 in a joint NASA, DARPA (Defense Advanced Research Projects Agency) and U.S. Air Force Program, and made a total of 374 combined flights.

Reverse airflow-forward-swept wing vs aft swept wing. On the forward-swept wing, ailerons remained unstalled at high angles of attack because the air over the forward swept wing tended to flow inward toward the root of the wing rather than outward toward the wing tip as on an aft-swept wing. This provided better airflow over the ailerons and prevented stalling (loss of lift) at high angles of attack.

DARPA and NASA have invested millions of dollars on the program, yet not a single official US fighter aircraft uses the FSW design...but in the black world there is one: The Switchblade!

Illustrations by John MacNeill, used with permission.

On moonless nights a secret aircraft taxies out of a remote hangar complex located on the northeast corner of an Air Force base in Nevada. The security lights on the base are dimmed as the aircraft rolls out onto the active runway. Under cover of darkness the aircraft officially called the "Bird of Prey" (but nicknamed by pilots the "Switchblade") takes off on a training mission into the sprawling Nellis Bombing Range.

As far back as 1989 the buzz inside aviation circles was the Pentagon was developing a variable swing-wing aircraft to replace the aging fleet of F-111s which was retired for good in 1995. The F-111 was a medium sized bomber also capable of defending itself as a fighter and then speeding away at over 1600 miles per hour.

When reports of a new swing wing aircraft sighted near Cannon Air Force Base, New Mexico and at Langley Air Force Base, Virginia, surfaced Popular Science investigated. High ranking officials are said to have gathered in secure hangers at two air bases to be given a sneak peek at the new aircraft. In September of 1994, it was observed circling high over Amarillo, Texas, for several minutes at midday. These reports to an exclusive story on this aircraft in 1995.

New Evidence

Since then Popular Science has learned that the aircraft is not a standard variable swing-wing aircraft as first reported but instead employs a unique forward sweeping wing mechanism that enables the aircraft to become an advanced attack aircraft capable of precision weapons delivery, super maneuverability (for air combat) and MACH 3 dash capability. A new covert squadron was formed to fly these aircraft. Recently Popular Science obtained from aviation author and historian Jim Goodall the squadron patch worn by pilots that fly the supersecret Switchblade and very recently Northrop filled patents with the U.S. Patent Office, including descriptions and drawings of an advanced tactical fighter/bomber that could very well be the mystery aircraft.

Forward Thinking Design Has Roots in the Past

In the mid 1980s Grumman, in conjunction with DARPA, NASA and the USAF, created an unorthodoxed looking and flying aircraft the X-29.
The purpose of the X-29 project was to explore the super maneuverability of an aircraft designed with forward-swept wing.

An aircraft with a forward-swept wing (FSW) is very unstable and thus highly maneuverable but as pre-computer age designers found out also almost humanly impossible to control. But when a digital fly-by-wire flight control system is paired with onboard high speed computers, fly by wire digital control system, super-responsive wing actuators and flexible composite material wings, the result is a FSW aircraft can fly rings around anything in the sky including most modern fighters. Once controllable, forward swept wings have many advantages over conventional wings including, lower drag and lower stall speeds, super manueverbility as well as excellent control and roll response within high angles of attack.

The X-29 flew successfully for many years proving that not only was a FSW aircraft feasible but the design could also lead to future fighters with outstanding dogfighting and missile avoiding capabilities limited only by the pilot's tolerance to high G forces.

It is interesting to note that as much of a success the Grumman X-29 program was deemed to be, no currently acknowledged U.S. fighter is designed with a forward-swept wing including current advanced designs like the F-22 or the Joint Strike Fighter. Other countries however have realized the potential of the design and have built FSW aircraft such as Russia's SU-37.

Although an FSW aircraft could prove to be a potent fighter design, as an attack aircraft it has some major drawbacks. Foremost among them for accurate pinpoint bombing accuracy a stable platform is a must.

An FSW aircraft was designed just to be the opposite of stable, however if you could design an aircraft that could go from a stable configuration to an unstable one at the flick of a switch, then you would have a very desirable tactical attack aircraft. If it could also be made stealthy and given the ability to fly very fast,(above MACH 3) you would have a military planner's dream aircraft. This is what the Northrop design (U.S. patent No. 5,984,231) embodies.

Officially the Air Force does not have a replacement for the F-111 medium fighter/bomber but it is also a fact that in the Air Force's fifty plus years history it has never abandoned a aircraft mission type such as that of the medium bomber. Currently the USAF has three heavy bombers, the B-1B, B2 and B-52 and one small bomber, the F-117A (which can only carry two conventional bombs) unless you count the F-15E which is an 1970s era fighter adapted to fill a tactical bombing role. There is no white-world aircraft that comes close to duplicating the versatility and medium sized bomb load of the retired F-111 Aardvark.

Any F-111 aircraft follow-on had to be able to meet all the future tactical needs of the US armed forces including precision weapons delivery, air combat superiority, long range, low radar signature and high speed ingress and egress from the target area. To design an aircraft that is all things to all people is a considerable challenge. One aviation engineer likened it to "building an Indy racer that can climb rocky hills, haul two tons of cargo and still out race all the police cars sent to chase it."

Multi-mission aircraft of the past have invariably had to make design sacrifices in one area or another, never really coming close to becoming true flying Swiss Army knives. The Northrop design meets all the design criteria for an advanced multi-regime tactical bomber/fighter aircraft.

With the wings fully swept aft the aircraft can slow to drop precision weapons or land on short unimproved runways. Swept forward twenty degrees and the aircraft becomes a highly agile air combat platform. Sweep the wings fully forward and they become flush with the aircraft with the trailing edge becoming the leading edge, forming a highly swept 75 degree stealthy delta perfect for high speed getaways! Or as it is understated in the U.S. Patent 5,984231 abstract "The aforementioned apparatus may be used in a method to configure the aircraft for the desire flight regime." thus becoming the aircraft for every mission.

Northrop and Grumman have considerable expertise in designing advanced aircraft. Northrop was the chief contractor on the B-2 stealth bomber, YF-23 and the recently declassified Tacit Blue. Grumman has considerable experience in forward swept wing aircraft design as well as having built and designed the Navy's premier variable-swept winged aircraft, the F-14 Tomcat.

In hind sight, since both companies are now one, the merger of each company's unique design expertise into one advanced aircraft now seems inevitable. Could both of the dead-end YF-23 and X-29 technology research projects been white world covers for a black world project? Officially the YF-23 and X-29 projects led to dead ends, but together they may have yielded a military aircraft of exceptional capabilities.

But is this the aircraft referred to as the "Bird of Prey" on the secret squadron's patch? Look at the sword on the patch closely and compare it to the top view of the Northrop Patent 5,984,231 See any resemblance?

Rumbles from inside the Pentagon say the aircraft is now undergoing declassification review. Like the super secret F-117 before it, one day the Switchblade might fly above us in broad daylight or become the darling of military airshows, but until then it flies only at night also shrouded in the virtual darkness of the black world.
UPDATE:
ST. LOUIS, October 18, 2002 - Boeing unveiled the "Bird of Prey," a technology demonstrator that pioneered breakthrough low-observable technologies and revolutionized aircraft design, development and production.
The once highly classified project ran from 1992 through 1999, and was revealed because the technologies and capabilities developed have become industry standards, and it is no longer necessary to conceal the aircraft's existence.

Preuzeto sa ...

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Citat: Papalu 08. Feb 2010, 18:03:42

Ovaj ima samo dva krila, a onaj ima 4, po dva sa svake strane koja klize jedno preko drugog. Ovak americki je projekat aviona sa pokretnim krilima sa obrnutom strelom krila koja mogu da dodju u polozaj tako da stvore avion sa krilima neke vrste izduzenog delata krila. Ono je sasvim nesto drugo, ali oba su ocigledno neke ideje koje se vrzmaju nekome po glavi. Ne bih se ja tome smejao! Smile

Bogme ne bih ni ja. Samo kada nam jednog dana proleti neki avioncic iznad glava s 4 krila ... Smile