March 13,2008:
The U.S. Air Force is retiring the last of its F-117 light bombers. Long
called the "stealth fighter," the F-117 was designed from the start as a
bomber. But the aircraft is now 27 years old. It's really 1970s technology
that, after years of effort, was made to work in the 1980s. But better stuff is
out there, and the stealth technology of the F-117 is obsolete when it comes to
some of the more recent sensor developments. The new F-22 will be a direct, and
more effective, replacement for the F-117 as a light bomber. Plus, the F-22 is
also a superior fighter.
Earlier
attempts to take the F-117 out of service ran up against political opposition.
Bases would have to be closed, which means lost jobs. The air force worked out
deals to take care of that angle, and the last active duty F-117 will be retired in April, 2008. The last
class of F-117 pilots graduated two years ago.
A total of 558 pilots were
trained to operate the one seater aircraft. Ten aircraft were retired in late
2006, and another 27 in the last 15 months.
The first
F-117 flew in 1981, and 59 were eventually built. Six crashed due to non-combat
causes, and one was brought down due to the efforts of a clever Serb air
defense officer, who exploited the chinks in the F-117s stealth technology. But
starting in 1989, when an F-117 participated in the invasion of Panama, the
aircraft proved its worth. The usual bomb load for the 24 ton aircraft, was two
one-ton laser guided bombs, in an internal bomb bay. The F-117 almost always
attacked at night, and took out a disproportionate number of targets compared
to non-stealth bombers.
The
stealth technology used was such that no two F-117s were the same. As the
aircraft were produced, new techniques for applying the RAM (Radar Absorbent
Materials) were developed. The first planes had sheets of RAM glued onto the
airframe. More than halfway through the run, a new spray-on technique was
developed. This technique was changed several times before the 59th
F-117 was manufactured. Several different treatments have been used for the
wing edges, cockpit rim, access panels, and other areas. As the material
degraded or was damaged over time, several different repair techniques were
used. Access panels were another variable, as some aircraft had to have the RAM
scraped off to open them while others had treatments that provided easier (and
less destructive) access. Stealth works in various ways, and stealth aircraft
use a combination of techniques. The basic concept, however, is to make the
stealth RAM coating one-fourth of a radar wavelength thick. In this way, some
of the enemy radar beam is reflected by the surface of the RAM and more by the
metal under the RAM later. Because this second element travels a half of a
wavelength farther than the first element, it exactly cancels out the radar
wave.
The
retired F-117s are being put into storage (the "boneyard"). There, for the next
decade or so, the bombers can be recalled to service.