This week, U.S. Defense Secretary Robert Gates recommended capping
the Pentagon's procurement of the F-22 Raptor at 187 planes. This
fifth-generation military aircraft is built by Lockheed Martin, a Maryland-based
defense contractor that employs over 145,000 people worldwide. Parts of the F-22
Raptor are also produced by Boeing Integrated Defense Systems (IDS), a unit of
the Boeing Company that recently unveiled the F-15
Silent Eagle (F-15SE) at its headquarters in St. Louis, Missouri.
Predictably, most accounts of Secretary Gates' decision regarding
the F-22 have focused on government outlays, cost overruns, and potential job
losses. And, also predictably, there has been little discussion about the technical
features and military capabilities of this military aircraft. CR4ers are more
tech-savvy than the general populace, however, and their knowledge is far from
"predictable". So, in the interest of examining "the technology behind the
news", here's a brief description of the F-22.
Defense Contractors
The F-22 Raptor is a highly-maneuverable strike fighter that
entered service with the United States Air Force (USAF) on December 15, 2005. As
of February 2009, 135 have Raptors have been built at per-unit flyaway cost of
$137.5 million (USD). Although Lockheed Martin is the prime contractor, Boeing
IDS supplies the aft fuselage, avionics integration, and wings. The St. Louis-based business unit also provides the pilot and
maintenance training systems. Other defense contractors for the F-22 Raptor include
BAE Systems, Inc. and Raytheon.
Stealth Technology
Although some details of the F-22's radar cross section
(RCR) remain classified, it's no secret that the Raptor uses stealth
technology. Unlike previous stealth warplanes such as the F-117 Nighthawk, however,
the F-22 Raptor relies less on maintenance-intensive radar absorbent materials
(RAM) and more on a low-observation profile and controlled radio and noise
emissions. Plus, unlike the B-2 Spirit, a stealth bomber that requires
climate-controlled hangars, the F-22 can be repaired right on the flight line.
Thrust Vectoring
The F-22 Raptor is equipped with dual afterburning Pratt
& Whitney F110-PW-100 turbofans that incorporate pitch axis
thrust-vectoring. For jet fighters such as the F-22, thrust-vectoring in the
pitch axis is more useful than thrust-vectoring in the yaw axis because the
pitch is used to make tight turns after the aircraft banks. Instead of
three-dimensional (3D) nozzles, flight control systems (FCS) and software is
used to achieve yaw control. This technology serves to minimize the plane's
infrared (IR) signature.
Built for Speed
According to Paul Metz, Lockheed Martin's former Raptor test
pilot, the F-22 Raptor has a top speed in excess of 1,600 mph (Mach 2.42) and a
faster climb rate than the F-15 Eagle. In supercruise mode, however, the F-22's
maximum speed is limited to Mach 1.82. This latter estimate is for a Raptor
without external weapons, air-to-air missiles that mount on rail launchers on
wing-based hardpoints. For combat missions that require higher speeds, longer
ranges, and the fullest use of stealth technology, these air-to-air missiles
are carried in internal weapons bays.
Resources:
http://www.bloomberg.com/apps/news?pid=20601087&sid=a0NQwnEqxSl4&refer=home
http://www.aerospaceweb.org/question/planes/q0216.shtml
http://en.wikipedia.org/wiki/F-22_Raptor
http://www.lockheedmartin.com/aboutus/index.html
http://www.f-16.net/f-16_forum_viewtopic-t-11888.html
http://cr4.globalspec.com/blogentry/6100
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