F-22 Raptor Fighter USAF

The F-22 program is developing the next-generation air superiority fighter for the Air Force to counter emerging worldwide threats. It is designed to penetrate enemy airspace and achieve a first-look, first-kill capability against multiple targets. The F-22 is characterized by a low-observable, highly maneuverable airframe; advanced integrated avionics; and aerodynamic performance allowing supersonic cruise without afterburner. Almost all F-22 fighters planned to build are now delivered to USAF, while an oxygen supply issue is currently(July 2011) stopping the last few deliveries.

Stealth: Greatly increases survivability and lethality by denying the enemy critical information required to successfully attack the F-22

Integrated Avionics: Allows F-22 pilots unprecedented awareness of enemy forces through the fusion of on- and off-board information

Lt. Gen. Janet Wolfenbarger, one of the service’s top weapons buyers, just told Senators that it has narrowed down possible causes for Raptor pilots to be experiencing hypoxia like symptoms in-flight to those factors.

Now, it’s almost a no-brainer that hypoxia-like symptoms are being triggered by either contaminants entering pilots’ oxygen supplies or by the fact that said pilots aren’t receiving enough oxygen since hypoxia happens when the brain isn’t receiving enough oxygen. However, that it’s the Raptor’s crazy performance may be behind what’s feeding its pilots limited or contaminated oxygen is pretty damned interesting; it hints that the jet is pushing the limits of aerospace science. Remember, the F-22 flies higher for longer than other jets and performs maneuvers that almost no other fighter in the world can match.

“We have some recent data that we are starting to believe, we are coming to closure on that root cause,” said Wolfenbarger during a May 8 Senate Armed Services Committee hearing. “We’re realizing that we operate this aircraft differently than we operate any of our other fighter aircraft, we fly at a higher altitude, we execute maneuvers that are high-G at that high altitude and we’re on that oxygen system at those high altitudes for periods of time.”

“I’m not ready to say yet that we’re ready to declare a root cause,” she added.

Keep in mind that the Air Force has been studying this problem for years and hasn’t been able to find a cause — despite enlisting the “best minds” from DoD, NASA, academia and industry to study the issue, as Wolfenbarger reminded the Senators today. The fact that the F-22 operates at such extreme (possibly record-setting) levels beyond what other fighters — including the Navy’s F/A-18E/F Super Hornet that uses a similar On-Board Oxygen Generating System (OBOGS) as the Raptor — may explain why no one has been able to diagnose the problem.

Fresh on the heels of yesterday’s announcement by the Air Force that it thinks the hypoxia-like symptoms suffered by F-22 Raptor pilots may be caused by the jets high-altitude performance, reports are emerging that ground crew are also suffering from similar ailments when they stand near the jet while it’s engines are running. Interesting.

Supercruise: Enhances weapons effectiveness; allows rapid transit through the battlespace; reduces the enemy’s time to counter attack

The F-22's engine is expected to be the first to provide the ability to fly faster than the speed of sound for an extended period of time without the high fuel consumption characteristic of aircraft that use afterburners to achieve supersonic speeds. It is expected to provide high performance and high fuel efficiency at slower speeds as well.
For its primary air-to-air role, the F-22 will carry six AIM-120C and two AIM-9 missiles. For its air-to-ground role, the F-22 can internally carry two 1,000 pound-class Joint Direct Attack Munitions (JDAM), two AIM-120C, and two AIM-9 missiles. With the Global Positioning System-guided JDAM, the F-22 will have an adverse weather capability to supplement the F-117 (and later the Joint Strike Fighter) for air-to-ground missions after achieving air dominance.

The F-22's combat configuration is "clean", that is, with all armament carried internally and with no external stores. This is an important factor in the F-22's stealth characteristics, and it improves the fighter's aerodynamics by dramatically reducing drag, which, in turn, improves the F-22's range. The F-22 has four under wing hardpoints, each capable of carrying 5,000 pounds. A single pylon design, which features forward and aft sway braces, an aft pivot, electrical connections, and fuel and air connections, is used. Either a 600-gallon fuel tank or two LAU-128/A missile launchers can be attached to the bottom of the pylon, depending on the mission. There are two basic external configurations for the F-22:
Four 600 gallon fuel tanks, no external weapons: This configuration is used when the aircraft is being ferried and extra range is needed. A BRU-47/A rack is used on each pylon to hold the external tanks.
Two 600 gallon fuel tanks, four missiles: This configuration is used after air dominance in a battle area has been secured, and extra loiter time and firepower is required for Combat Air Patrol (CAP). The external fuel tanks, held by a BRU-47/A rack are carried on the inboard stations, while a pylon fitted with two LAU-128/A rail launchers is fitted to each of the outboard stations.

An all-missile external loadout (two missiles on each of the stations) is possible and would not be difficult technically to integrate, but the Air Force has not stated a requirement for this configuration. Prior to its selection as winner of what was then known as the Advanced Tactical Fighter (ATF) competition, the F-22 team conducted a 54-month demonstration/ validation (dem/val) program. The effort involved the design, construction and flight testing of two YF-22 prototype aircraft. Two prototype engines, the Pratt & Whitney YF119 and General Electric YF120, also were developed and tested during the program. The dem/val program was completed in December 1990. Much of that work was performed at Boeing in Seattle, Lockheed (now known as Lockheed Martin) facilities in Burbank, Calif., and at General Dynamics' Fort Worth, Texas, facilities (now known as Lockheed Martin Tactical Aircraft Systems). The prototypes were assembled in Lockheed's Palmdale, Calif., facility and made their maiden flight from there. Since that time Lockheed's program management and aircraft assembly operations have moved to Marietta, Ga., for the EMD and production phases.

The F-22 passed milestone II in 1991. At that time, the Air Force planned to acquire 648 F-22 operational aircraft at a cost of $86.6 billion. After the Bottom Up Review, completed by DOD in September 1993, the planned quantity of F-22s was reduced to 442 at an estimated cost of $71.6 billion.
A $9.55 billion contract for Engineering and Manufacturing Development (EMD) of the F-22 was awarded to the industry team of Boeing and Lockheed Martin in August 1991. Contract changes since then have elevated the contract value to approximately $11 billion. Under terms of the contract, the F-22 team will complete the design of the aircraft, produce production tooling for the program, and build and test nine flightworthy and two ground-test aircraft.

A Joint Estimate Team was chartered in June 1996 to review the F-22 program cost and schedule. JET concluded that the F-22 engineering and manufacturing development program would require additional time and funding to reduce risk before the F-22 enters production. JET estimated that the development cost would increase by about $1.45 billion. Also, JET concluded that F-22 production cost could grow by about $13 billion (from $48 billion to $61 billion) unless offset by various cost avoidance actions. As a result of the JET review the program was restructured, requiring an additional $2.2 billion be added to the EMD budget and 12 months be added to the schedule to ensure the achievement of a producible, affordable design prior to entering production. The program restructure allowed sourcing within F-22 program funds by deleting the three pre-production aircraft and slowing the production ramp. Potential for cost growth in production was contained within current budget estimate through cost reduction initiatives formalized in a government/industry memorandum of agreement. The Defense Acquisition Board principals reviewed the restructured program strategy and on February 11, 1997 the Defense Acquisition Executive issued an Acquisition Defense Memorandum approving the strategy.

The Quadrennial Defense Review Reportwhich was released in mid-May 1997, reduced the F-22 overall production quantity from 438 to 339, slowed the Low Rate Initial Production ramp from 70 to 58, and reduced the maximum production rate from 48 to 36 aircraft per year.

The F-22 EMD program marked a successful first flight on September 7, 1997. The flight test program, which has already begun in Marietta, Georgia, will continue at Edwards AFB, California through the year 2001. Low rate production is scheduled to begin in FY99. The aircraft production rate will gradually increase to 36 aircraft per year in FY 2004, and will continue that rate until all 339 aircraft have been built (projected to be complete in 2013). Initial Operational Capability of one operational squadron is slated for December 2005.

The F-15 fleet is experiencing problems with avionics parts obsolescence, and the average age of the fleet will be more than 30 years when the last F-22 is delivered in 2013. But the current inventory of F-15s can be economically maintained in a structurally sound condition until 2015 or later. None of the 918 F-15s that were in the inventory in July 1992 will begin to exceed their expected economic service lives until 2014 ... Continue to read: F-22 Raptor fighter