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Although the Lockheed F-117A stealth fighter is
almost certainly NOT in the original fighter sequence of designations,
the end of this particular sequence is perhaps most apt for
a discussion of this unusual warplane, most of the details of which are
still
highly classified.
The F-117A number was designated in sequence with other aircraft
operating at Groom. These included the
Red Squadron - a squadron of Soviet aircraft that the US government had
"acquired". These flights where logged in the pilot's logs as YF-110,
YF-113, YF-114, etc. The pilots of the Senior Trend aircraft logged in
the
next in sequence, the YF-117A for a lack of an unclassified designator.
When Lockheed printed up the Dash 1 flight manuals, they printed F-117A
on
the front cover.
The F-117A was the first warplane to be specifically designed from the
outset for low radar observability. The Lockheed Advanced Development
Company (better known as the “Skunk Works”) began working on Stealth as
far back as the late 1950s, and low radar observability had played a
role in the design of the A-12/YF-12/SR-71 series of Mach 3+ aircraft.
During 1975, Skunk Works engineers began working on an aircraft which
would have a greatly reduced radar cross section that would make it all
but invisible to enemy radar, but would nevertheless still be able to
fly and carry out its combat mission.
The technique they came up with was known as faceting, in which the
ordinarily smooth surface of the airframe is broken up into a series of
trapezoidal or
triangular flat surfaces arranged in such a way that the vast majority
of
the radar incident on the air craft from a source will be scattered
away from
the aircraft at odd angles, leaving very little to be reflected
directly back
into the receiver. An additional reduction in radar cross section was
to
be obtained by covering the entire surface of the aircraft with radar
absorbent
material (RAM). One of the disadvantages involved in the use of
faceting on
aerodynamic surfaces was that it tended to produce an inherently
unstable
aircraft in all three axes --- pitch, roll, and yaw.
In early 1977, Lockheed received a contract from the Defense Advanced
Research Projects Agency
(DARPA) for the construction of two 60-percent scale flyable Test
aircraft
under a project named Have Blue. The name Have Blue seems to have no
specific
meaning, probably having been chosen at random from an approved list of
secret
project names. Shortly after the Have Blue contract was let, the
project was transferred over to Air Force System Command control and
became
highly “black,” with all information about it being highly classified
and
restricted to those with a need to know. Outside of a few people at
Lockheed and the Defense Department, no one knew Have Blue even
existed.
The two Have Blue aircraft were built at Lockheed in only a few months.
The
first example was intended to evaluate the type’s flying
characteristics,
whereas the second was to evaluate the radar signature. In order to
save
sometime and some money, existing off-the-shelf components were used
where
feasible.
The engines were a pair of standard production non-afterburning General
Electric J85s, mounted in enclosures sitting atop the wings. The main
landing gear was taken from a Fairchild Republic A-10, and fly-by-wire
components were scavenged from an F-16. The instrumentation and the
ejector seat were taken from a Northrop F-5.
The Have Blue aircraft had the same general shape as that which would
later become familiar with the F-117A, except that the twin rudders
were located forward of the exhaust ejectors and were angled inward
rather than outward. The inward cant was about 30 degrees. The leading
edge of the semi-delta wing was swept back at 72.5 degrees. The wing
featured two inboard trailing edge elevons for pitch and roll control.
Four spoilers (two on top of the wing and two on the bottom) were
mounted just forward of
the elevons. There were no flaps or speed brakes. The wing trailing
edge was
less deeply notched than that of the F-117A. A single cockpit with an
ejector
seat was provided.
The Have Blue aircraft employed V-type windshields (similar to those of
the
F-102/F-106). No weapons bay nor any sort of tactical equipment at all
was
fitted. The Have Blue aircraft were equipped with fly-by-wire (FBW)
flight
controls adapted from the F-16 system. However, the system had to be
modified
to handle an aircraft that was unstable about all three axes (the F-16
is
unstable only about the pitch axis).
The problem of designing a stealthy system
for airspeed measurement had not yet been solved, and the aircraft were
equipped
with a conventional pitot tube which was retracted during testing for
radar
reflections. The inertial navigation system provided enough speed data
for
test purposes when the probe was retracted.
Two prototypes were built at a cost of $37 million for both aircraft.
Lockheed workers assembled the two Have Blue aircraft in a cordoned-off
area in Lockheed’s Plant 10 facility housed at the USAF Plant 42 in
Palmdale, California. Neither aircraft ever received an official DoD
designation, or did they get a USAF serial number. However, Lockheed
did give the aircraft its own manufacturer’s serial numbers ---1001 and
1002, meaning Plant 10, aircraft numbers 1 and 2.
The first example (1001) was finished in November of 1977. In order to
keep
the project away from prying eyes, the Have Blue prototype was shipped
out
to the Groom Lake Test Facility in Nevada in high secrecy for the test
flights. Groom Lake is located in a particularly remote area of the
Nellis test range complex, and is a good location for the testing of
secret aircraft. A camouflage paint scheme was applied to make it hard
for unwanted observers at Groom Lake
to determine the aircraft’s shape.
The first flight of the Have Blue took place in January or February of
1978 (the exact date is still classified), veteran Lockheed test pilot
William M. Bill Park being at the controls. At an early stage, Bill
Park was assisted in the flight
test program by Lt. Col. Norman Kenneth (Ken) Dyson of the USAF. Flight
test
of the Have Blue initially went fairly smoothly, and the fly-by-wire
system
functioned well. The landing speed was quite high (160 knots), as
expected
because of the lack of flaps or speed brakes. However, on May 4, 1978,
Have
Blue prototype number 1001 was landing after a routine test flight when
it
hit the ground excessively hard, jamming the right main landing gear in
a
semi-retracted position. Pilot Bill Park pulled the aircraft back into
the
air, and repeatedly tried to shake the gear back down again. After his
third
attempt failed, he was ordered to take the aircraft up to10,000 feet
and
eject. Park ejected successfully, but he hit his head and was knocked
unconscious.
Since he was unable to control his parachute during descent or landing,
his
back was severely injured on impact. He survived, but was forced to
retire
from flying. The Have Blue aircraft was destroyed in the crash, and the
wreckage
secretly buried somewhere on the Nellis test range complex.
Have Blue 1002 arrived at Groom Lake shortly after the loss of number
1.
It took to the air for the first time in June of 1978, Lt. Col. Ken
Dyson
being at the controls. From mid-1978 until early 1979, Lt. Col. Dyson
flew
more than 65 test sorties, testing the response of the aircraft to
various
types of radar threats.
The Have Blue prototype 1002 proved to be essentially
undetectable by all airborne radars except the Boeing E-3 AWACS, which
could
only acquire the aircraft at short ranges. Most ground-based missile
tracking
radars could detect the Have Blue only after it was well inside the
minimum
range for the surface-to-air missiles with which they were associated.
Neither
ground-based radars nor air-to-air missile guidance radars could lock
onto
the aircraft.
It was found that the best tactic to avoid radar detection was to
approach the radar site head on, presenting the Have Blue’s small
nose-on signature. The application of the RAM was rather tricky, and
ground crews had to be careful
to seal all joints thoroughly before each flight.
RAM came in linoleum-like sheets which were cut to shape and bonded to
the
skin to cover large areas. Doors and access panels had to be carefully
checked and adjusted for a tight fit between flights and all gaps had
to be filled in with conductive tape and then covered over with RAM.
Paint-type RAM was available, but it had to be built up by hand, coat
by coat. Even the gaps around the canopy and the fuel-filler door had
to be filled with paint-type RAM before each flight. Ground crews had
to even make sure that all surface screws were completely tight, since
even one loose screw for an access panel could make the aircraft
extremely visible during radar signature tests.
Have Blue number 1002 was lost in July of 1979. During its 52nd flight,
with
Lt. Col. Dyson at the controls, one of its J85 engines caught fire. The
subsequent intense fire burned through the hydraulic fluid lines,
forcing Lt. Col. Dyson was to eject. Have Blue #1002 was a total loss,
and consequently, also secretly buried on the Nellis test range
complex. No further Have Blue aircraft were built since the general
concept had been proven.
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The F-117 is NOT a fighter jet. Because it is small and cute, everyone wanted to call it a fighter, and even gave it an "F" (fighter) designation. IT HAS NO AIR TO AIR COMBAT CAPABILITIES, AND DOES NOT CARRY MISSILES. IT DROPS BOMBS, THEREFORE IT IS A BOMBER!!
The F-117A stealth bomber had the same general
configuration of the Have Blue test aircraft, but was much larger and
heavier and was provided with an offensive military capability. The
structure of the F-117A is constructed mainly of aluminum, with some
titanium being used in the engine and in the exhaust systems. The main
facets of the outer skin are separately fastened to a rather complex
skeletal frame. Since the accurate shaping and placement of these
facets is
critical to achieving a low radar cross section (RCS), production
tooling had to be ten times more precise than the tooling used to build
conventional aircraft.
The entire outer skin of the F-117A is covered by radar absorption
material
(RAM). The exact composition of the RAM is classified, but it is
believed
to consist of a matrix of magnetic iron particles held in place by a
polymer
binder. Originally, RAM came in large flexible sheets, and was bonded
to
a metal wire mesh, which was in turn glued to the airframe of the
F-117A.
Later, when the aircraft entered service, the Air Force built a special
facility for the application of the RAM. In order to provide for
uniform and accurate application, as well as to prevent people from
coming into contact with the highly toxic solvents which make the RAM
liquid, the process is completely automated.
During the application of the RAM, the F-117A is supported spit-like
and
slowly turned as the RAM is sprayed on by computer-controlled nozzles.
Minor
touch-up s are made in the field using a hand-held spray gun.
The engines powering the F-117A are a pair of
non-afterburning General Electric F404-GE-F1D2 turbofans, derivatives
of
the afterburning F404-GE-400 turbofans that power the McDonnell Douglas
F/A-18
Hornet. They are housed in broad nacelles attached to the sides of the
angular
fuselage. The General Electric turbofans are fed by a pair of air
intakes
(one on each side of the fuselage). Two gratings with rectangular
openings
cover each intake.
The purpose of these gratings is to prevent
radar waves from traveling down the intake ducts and reaching the
whirling
blades of the turbofans, which would tend to produce large echoes. This
works
because the spacings between the grids on the grating are smaller than
the
wavelengths of most radars. The grating is covered with RAM, which
helps
reduce the reflections even further.
The small fraction of incident radar energy which does pass through the
grating is absorbed by RAM mounted inside the duct. Unfortunately,
these gratings also restrict airflow to the engines, so a Large blow-in
door is fitted atop each engine nacelle to increase airflow to the
engine during taxiing, takeoffs, or low-speed flight. Ice buildup on
the intake gratings is a persistent problem, which tends to clog the
rectangular openings and restricts the airflow even further. In order
to clear the ice, the F-117employs a electrical heating system to
remove ice during flight. A light on either side of the fuselage
illuminates the intake covers, enabling the pilot to watch the deicing
operation during night flights.
One of the more unusual aspects of the F-117
is its engine exhaust system. Like the air inlets, the exhaust outlets
are
mounted atop the wing chord plane, one on each side of the centerline.
The
engine exhausts are narrow and wide and are designed to present as low
an
infrared signature as possible and mask the rear of the engine from
radar
illumination from the back. The exhaust ducts are round at the rear of
the
turbofans, but are flattened out and become flume-like by the time that
they
reach the front of the narrow slotted exhaust outlets at the rear of
the
fuselage. At the end of each of the narrow slotted exhaust ducts, there
are
twelve grated openings, each being about six inches square. These
grated
openings help reduce unwanted radar reflection from the rear as well as
providing
additional structural strength to the exhaust ducts. The exhaust
gratings
are shielded from the rear and from the bottom by the F-117’s
platypus-bill-shaped
rear fuselage section.
The extreme rear edge of the aircraft behind the exhaust slot is
covered
with heat-reflecting tiles. These ceramic tiles help to keep the rear
of
the aircraft cool, since they tend to reflect the infrared radiation
emitted
from the exhaust, rather than absorbing it as metals tend to do. The
bypass
air from the engine is also used to help cool down the entire metal
structure
of the rear of the aircraft.
The exhaust system is complex, incorporating sliding elements and
quartz
tiles to accommodate heat expansion without changing shape. Although
the
system works fairly well, Lockheed has reported that the design of this
exhaust system was the single most difficult item in the entire F-117A
project.
A typical fighter has a head-on RCS of about five square meters, which
is technical language for saying that it seems as large on radar as a
perfectly-reflective sphere of the same cross-sectional area. However,
if critical flat surfaces or whirling turbine blades happen to be
exposed to the radar, the RCS can be much larger. Reportedly, the
combination of faceting and the application of RAM gives theF-117A an
effective radar cross section of somewhere between 0.01 and 0.001
square meters, which makes the F-117A appear to be no larger than a
small bird on a radar screen. This means that a typical radar will not
be able to detect an F-117A at a range any greater than 8-16 miles.
Directional stability and control of the F-117A
is provided by a pair of all-flying tails mounted on the aircraft’s
central
spine and oriented in a V arrangement, reminiscent of the tail of the
Beechcraft
Bonanza. Unlike most V-tails, however, they have no pitch-control
function.
Each vertical tail consists of a fixed stub, and an all-flying rudder
which
pivots around a fixed shaft. The hinge line between stub and moveable
tail
is Z-shaped rather than straight, in accord with the stealth principle
of
the avoidance of any straight edges.
Both the fixed stub and the all-flying rudder are faceted to further
reduce
radar reflectivity. On the Have Blue test aircraft, the vertical tails
were
mounted further outboard on the wings and were canted inward rather
than
outward. The purpose of the inward-canted vertical tails on the Have
Blue
was to shield the upward-facing platypus exhaust nozzles from infrared
detectors
above the aircraft. In practice, however, these tails tended to act as
reflectors for infrared radiation, bouncing the rays toward the ground
and making the aircraft more visible from below.
Originally, the basic stealth design philosophy was to have the lowest
observability from the bottom and from the front, with the upper
hemisphere having less stringent requirements. Consequently, on the
F-117A aircraft, the tails were moved back further on the fuselage so
that they are no longer directly over the exhaust. In addition, the
Have Blue tails were in effect mounted on twin booms which was a
structurally inefficient arrangement.
The leading edge wing sweep on the Have Blue
was 72.5 degrees, and the resulting low aspect ratio gave a rather poor
payload-range
performance. To improve the performance, the wing sweep was reduced to
67.5
degrees on the F-117A.The flying surfaces on theF-117A consist of four
elevons
on the wing trailing edge (two inboard and two outboard) and two
all-flying
rudders mounted in a V arrangement on the rear fuselage. The elevons
and
the rudder are all faceted to reduce their radar signature, and the
hinge
lines between the wings and the elevons sealed with flexible RAM. The
four
elevons can deflect upward or downward by 60 degrees, and the rudders
can
deflect 30 degrees left or right. The elevons act in the pitch and roll
axes,
where as the rudders act in the yaw axis. The angle of attack during
landing
is about 9 degrees. The elevons do not double as flaps, which makes the
landing speed of the F-117A rather high.
The Have Blue cockpit canopy windshield had a center bow, reminiscent
of
that of the F-102/F-106 interceptor. The F-117A replaced this
windshield with a center flat panel since a heads-up display would not
work very well with a center bow blocking the view. This resulted in a
change in the shape of the nose to a steep downward-sloping section for
good downward visibility with a sharp, pyramidal-shaped nose cap for
aerodynamics and stealth. This change made the F-117 slightly more
observable by radar than the Have Blue.
The cockpit of the F-117is covered by a large and heavy hood-like
canopy
with five separate flat transparencies(one on either side and three in
front).The visibility from the cockpit is rather limited upward,
downward, and to the rear. The canopy opens to the rear and has
serrated edges in order to limit the radar reflectivity of the joint
between canopy and fuselage when the canopy
is closed. The five flat transparent panels are specially treated to
further
reduce the aircraft’s RCS. The windshield is coated with a special gold
film
layer to prevent the pilot’s helmet from being detected by radar. This
was
found to be an important problem during early tests.
The pilot sits on a McDonnell Douglas ACES II
ejector seat, the same type of seat fitted to the F-15C/D. The cockpit
is
equipped with a Heads-Up Display (HUD). The main control panel has two
five
inch CRTs, while the main FLIR/DLIRCRT had a twelve-inch screen. For
nighttime
operations in clear weather at low altitudes, the aircraft is primarily
flow
by using the FLIR/DLIR CRT. The F-117A, like the Have Blue before it,
is
unstable about all three axes and requires a fly-by-wire system in
order
to be able to fly at all. The fly-by-wire system is similar to that in
theF-16,
and is quadruply redundant. There are four independent channels which
each
control the same function. The signals from each of the channels are
constantly
being compared with each other, and if one signal is found to differ
from
the other three, its channel is assumed to have failed and is
automatically
shutdown. In the unlikely event that all four channels manage to fail
at
the same time, the aircraft cannot be flown and the pilot would be
forced
to eject.
Since the aircraft cannot use any sort of radar navigation system, the
fly-by-wire system relies on information about airspeed and angle of
attack from four individual static pitot probes of diamond section with
pyramid-like tips mounted
in the extreme nose. Each of the four-sided pitot heads have tiny holes
on
each facet, and differential readings from each hole provide air speed,
pitch
and yaw information to the flight control system. The design of these
four
nose sensors, plus the requirement that they not produce any unwanted
radar
reflections, was one of the more difficult engineering problems the
Lockheed
team had to solve.
The F-117A also differed from the Have Blue in having a weapons bay.
Since
external hard points for bombs or fuel tanks are taboo for a stealth
attack
aircraft, all stores must be carried internally. The weapons bay is
located
in the belly on the centerline. It has two wells, each covered by an
inboard-opening door. The outer edges of the weapons bay doors have
serrated edges that are designed to reduce the radar reflection from
the joint between the doors and
the fuselage belly. The weapons bay can accompany up to 5000 pounds of
ordinance
(2500 pounds in each well). Some of the loads accommodated in the
F-117A’s
weapons bay include two laser-guided MK84 2000-pound bombs, two
laser-guided
GBU-10 Paveway II 2000-poundbombs, two laser-guided GBU-12 Paveway II
500-pound
bombs, two laser-guidedGBU-27 Paveway III 2000-pound bombs, two BLU 109
deep-penetration
bombs, or two AGM130s. The GBU-10 Paveway II laser-guided bomb consists
of a special nose and tail section attached to a standard 2000-pound Mk
84
high-explosive bomb. The tail section of the bomb consists of a set of
folding
aerodynamic surfaces which permit the bomb to glide, whereas the nose
section
includes a laser light seeker, guidance electronics, and control fins.
The GBU-24 Paveway III is a more advanced version of the Paveway II
with
a larger tail surface and a more efficient guidance system which
permits
it to be used at lower altitudes and at greater distances from the
target.
The BLU-109 deep-penetration bomb has a forged casing of hardened steel
which
permits it to pierce more six feet of reinforced concrete before
exploding.
When dropped on softer targets, theBLU-109 can bury itself deep into
the
ground before exploding, destroying its target by sending
earthquake-like
shock waves rippling through the ground.
The F-117A canal so carry up to two Mark 61 nuclear weapons, although
the
aircraft does not actually have an assigned nuclear mission. For
long-range
ferry flights, fuel tanks can be installed in the weapons bays in the
place
of bombs. The F-117A has no air-to-air capability, or at least none
that
has been announced to the general public. It has no radar, it does not
carry an internal cannon, and is not equipped to carry or launch
air-to-air missiles. The F-117A can in principle launch an infrared
homer, provided the missile can be dropped from an extendable rack so
that its seeker could acquire the target before launch. The F-117A
cannot rely on radar for navigation, weapons aiming, or weapons
delivery because the transmission of a radar signal would tend to give
away the location of the aircraft and hence defeat the whole purpose of
stealth. For low-level navigation and weapons-aiming purposes, the
F-117 aircraft is provided with forward-looking infrared (FLIR) and
downward-looking infrared (DLIR) systems. Both systems are built by
Texas Instruments.
The FLIR is mounted in a recess just ahead of the cockpit front
windshield.
It is located in a steerable turret containing a dual field of view
sensor. When not in use, the FLIR is rotated 180 degrees to keep
prevent debris damaging
the sensor. The DLIR sensor system is located in a recess mounted
underneath
the forward fuselage and to the right of the nose landing gear well.
Both
the FLIR and the DLIR recesses are covered by a RAM mesh screen to
prevent
unwanted radar reflections from the active elements. The edges of the
recesses
are serrated, with fasteners covered with RAM putty. The DLIR is
provided
with a bore-sighted laser for illuminating the target for attack by
laser-guided
weapons. Together, these systems form the infrared acquisition and
designation
system (IRADS).
The laser is slaved to the IRADS and is an integral part of the
infrared
system. The spot size of the laser on the ground is about 12-18 inches,
and
the spot is stabilized in position by the IRADS. A highly-accurate
Inertial
Navigation System (INS) backs up the sensors. This system uses an
electrostatically-suspended gyro as the primary means of guidance. The
INS guides the aircraft to the immediate target area and points the
FLIR’s wide angle field of view toward the general location of the
target. As the aircraft approaches the target, the pilot monitors the
view presented by the FLIR on the heads-up display screen. When the
specific target is identified, the pilot switches to the narrow view on
the FLIR, and locks the screen of the display onto the target. As the
target disappears underneath the aircraft, control is handed over to
the DLIR, which acquires the target and continues to track it. When the
pilot
decides to attack, he releases a laser-guided Paveway bomb.
Approximately 7 to 10 seconds before bomb impact, the DLIR’s laser is
turned
on and illuminates the target, and the bomb homes onto the reflected
infrared
laser light reflected from the target. Videotapes from the FLIR/DLIR
displays
that have been released to the public By the DOD have shown that the
F-117A
flying during a clear night can hit a target only one meter in size
from
an altitude of 25,000 feet.
A parachute braking system is provided, since the lack of flaps makes
the
landing speed quite high(160 knots, or 185 mph).The braking parachute
is
housed behind split doors atop the rear fuselage. The braking chute is
deployed
as soon as the nose wheel makes contact with the runway. The parachute
can
also double as an emergency antispin device if needed.
An in-flight refueling receptacle is added behind the pilot’s cockpit.
A
small light is mounted near the receptacle to guide the refueling boom
operator in nighttime refueling operations. Midair refueling is one of
the more difficult aspects of F-117A flight, since it is always done at
night and the F-117A pilot’s upward vision is blocked by the canopy so
that he cannot actually see the boom of the refueling aircraft.
The landing gear is of the standard tricycle
type, with single wheels and tires that retract forward. The landing
gear
doors have serrated edges that help to reduce the radar cross section.
A
set of retractable communications antenna are fitted to the upper
fuselage
just behind the pilot. These are deployed during day flights, but are
retracted
for stealth missions at night. Detachable radar reflectors can be
mounted
on the fuselage sides so that local air traffic control can track the
aircraft
when it is not in stealth mode.
Some of the reports of the F-117A being tracked by radar during Desert
Storm
may have been due to the mounting of these reflectors.In 1991,
persistent
problems with the unorthodox exhaust system led to a decision to fit a
new
type of engine exhaust system involving the use of a new bottom side to
the
shelf-like extension over which the exhaust passes. The modification
involves
the use of new heat shields, better seals, new airflow paths, and new
high-temperature thermal protection at the edge of the exhaust system.
Most of these changes were designed to improve the maintainability of
the exhaust system, which had proven to be a persistent problem.
During the production run of the F-117A, the two metallic all-moving
tail
fins were replaced with ones made of graphite thermoplastic materials.
This
change resulted from the loss of one fin and rudder from a F-117 in
1987
during a flight test. The aircraft landed safely despite the loss of
the
fin. The retrofit program was interrupted by Persian Gulf deployment,
so
most of the F-117s deployed to Saudi Arabia had the original metallic
tail
fins.
The cockpit of the F-117A has been recently updated and improved in
accordance with advances in electronics and display technology. The
original navigation system of the F-117A was the SPN/GEAS inertial
navigation system .Later, this
was replaced by a ring laser gyro and a global positioning system
receiver. To improve the pilot’s situational awareness, a Honeywell
color multi-function display was fitted which had the capability of
integrating a Harris digital moving map. Two cathode ray tube-based
multifunction displays are used to call up digital maps, target photos,
or target identification diagrams. A liquid crystal display data entry
panel allows the pilot to select from256 avionics functions. The new
cockpit equipment is designed to minimize the chance of pilot
disorientation at night time, which was suspected as the primary
cause of two accidents involving operational F-117s.
In the early 1990s, auto throttles were added to provide the capability
for arrival at a precise predetermined time over a target. This
innovation was, however, not available in time for Desert Storm. The
F-117A carries a three-digit serial number on the tail. The numbers are
assigned in sequence, beginning with 780 and ending with 844. Aircraft
780 through 784 were full-scale development (FSD) aircraft, whereas 785
through 844 were production aircraft. The presentation of these numbers
on the tail of the F-117A is sort of unusual, since the serial
numbers of Air Force aircraft are typically presented as a combination
of
the last two numbers of the fiscal year in which the aircraft was
ordered, followed by the last three digits of the aircraft’s USAF
serial number.
According to Sweetman and Goodall, the tail numbers on the F-117A are
NOT
standard USAF serial numbers, that is,780 is not a shorthand for
something
like 80-0780. They are part of a different sequence of serials that are
used
by the Defense Department for some special programs. However, Steve
Pace
claims the tail numbers ARE standard USAF serial numbers, and he
includes
a list of them in the appendix of his book. They are:
Two General Electric F404-GE-F1D2
non-afterburning turbofans,10,800 lb.s.t. each.
Maximum speed 700 mph at sea level (Mach 0.92).
Normal maximum operating speed is
648 mph at 5000 feet (Mach 0.87).
Combat radius 900 miles (unrefuelled)
Weights:30,000 pounds empty, 52,500 pounds maximum take off.
wingspan 43 feet 4 inches,
length 65 feet 11 inches,
height 12 feet 5 inches,
wing area 1140 square feet.
Up to 5000 pounds of ordinance can be carried in two internal weapons
bays
This report on the F-117 stealth fighter concludes
with an account of its developmental and operational history, or at
least that part of it which has been released to the public. The
results of the Have Blue testing were sufficiently encouraging that
William Perry, who was at that time Under-Secretary of Defense for
Research and Engineering in the Carter Administration, urged the Air
Force apply the technology to an operational aircraft.
During November of 1978, Lockheed was awarded ago-ahead contract to
begin
full-scale development of the project. This was a “Special Access”,
i.e.
black, program, and the code name Senior Trend was applied to the
project.
The Senior Trend aircraft came to be defined as a single-seat night
strike
fighter with no radar, but with an electro-optic system for navigation
and
weapons delivery. No air-to-air capability was envisaged.
The first five Senior Trend aircraft built by Lockheed were to be
preproduction full scale development (FSD) aircraft. The Senior Trend
aircraft had the same
General configuration as the Have Blue test aircraft, but was much
larger and heavier. The engines were a pair of non-afterburning General
Electric F404-GE-F1D2 turbofans. These were derivatives of the
afterburning F404-GE-400 turbofans which power the McDonnell Douglas
F/A-18 Hornet.
In early June of 1981, the first Senior Trend service test aircraft
(tail
number 780) was delivered to Groom Lake for testing. On June 18, 1981,
Lockheed test pilot Harold C. “Hal” Farley made a successful first
flight in number 780. During mid-1981 and early 1982, the other four
FSD Senior Trend aircraft joined the program. They bore tail numbers
781 through784 respectively.
The first production Senior Trend (#785) arrived at Groom Lake in April
of
1982. It differed from the pre-production Senior Trend aircraft in
having
a pair of enlarged fin/rudder assemblies, with three facets rather than
just
two. Aircraft number 785 was ready for its first flight on April 20,
with
Lockheed test pilot Robert L. Ridenauer scheduled to make the first
flight.
However, unbeknownst to anyone, the fly-by-wire system had been hooked
up
incorrectly (pitch was yaw and vice versa). Upon liftoff, Ridenauer’s
plane
immediately went out of control. Instead of the nose pitching up, it
went
horizontal. The aircraft went inverted and ended up traveling backwards
through
the air. Riedenauer had no time to eject, and the aircraft flew into
the
ground. Bob Riedenauer survived the crash but was severely injured and
was
forced to retire from flying.
The aircraft was damaged beyond repair, but some of its parts could be
salvaged. It has been generally reported that since this aircraft
crashed prior to USAF/TAC acceptance, it was not counted in the
production total. This was not the case. It was, in fact, counted in
the total production run. There were 59 production airframes and five
pre-production full-scale development prototypes. The article numbers
are 780 through 843.
When it came time for the establishment of the first operational unit
for the stealth bomber, the Air Force was faced with a problem. Groom
Lake was too small to be useful as the base for an operational unit. In
addition, there were security concerns because an operational unit
based at Groom Lake would involve many more people who could now see
things that they should not be seeing. Therefore, the USAF decided to
build a new secret base for the stealth bomber on the Tonopah Test
Range, which sits on the northwestern
corner of the Nellis complex. The Facility is not perfect from a
security
standpoint, since it is overlooked by public land and is 32 miles from
the
town of Tonopah itself. However, the security surrounding the Tonopah
Test
Range was so effective that the new base was not public reported until
1985,
after it had been operating for nearly two years.
The 4450th Tactical Group was secretly established as the initial
operator
of the stealth fighter. The cover for the 4450th was that it was a
Nellis-based outfit flying LTVA-7Ds,which was not entirely inaccurate
since the outfit did use these planes for support training. The group
received its first production stealth aircraft on September 2, 1982.
The 4450th moved to Tonopah in 1983, equipped with a partial squadron
of
stealth bombers plus a few A-7Ds. The group achieved initial
operational
capability on October 28, 1983, with a total of 14 production aircraft
on
hand. To avoid having the 4450th’s aircraft seen by curious observers,
all
flying took place at night. During the day, the aircraft were always
kept
behind closed doors inside special hangars.
The stealth bomber turned out to be quite easy
to fly, and it was concluded that no two-seat trainer version was
required.
However, there was a training simulator.
The Air Force considered using the stealth bomber in the invasion of
Grenada during Operation Nickel Grass in 1983. However, the operation
was so swift that the action lasted only a couple of days, and the
combat debut of the stealth was put off. In October of 1983, the US
government considered using the stealth fighter in are taliatory attack
on Hezbollah terrorist forces based in southern Lebanon in response to
the destruction of the Marine barracks in Beirut. In anticipation of
action, the 4450th TG at Tonopah was put on alert. Five or seven
stealth bombers were armed and had their INS systems aligned for
attacks on targets in Lebanon.
The plan was for these planes to fly from Tonopah to Myrtle Beach,
South
Carolina where they would be put insecure hangars. They would then wait
for
48 hours for the crews to rest before being given the order to take off
for
a nonstop flight to Lebanon. However, Defense Secretary Casper
Weinberger
scrubbed the mission 45 minutes before the aircraft were to take off
for
South Carolina.
On April 4, 1986, during Operation El Dorado Canyon, the United States
attacked Libya in retaliation for state-sponsored terrorism. During the
initial planning for the raid, the use of the still-secret stealth
fighter in the operation was seriously considered. However, once again,
the operation was short-lived and the stealth fighter was not used.
In spite of the extreme security, some bits and pieces of the stealth
fighter story did manage to leak to the press. In October of 1981,
Aviation Week reported
that an operational stealth "fighter" was in development. Several
people
reported catching some fleeting glimpses of a rather odd-looking
aircraft flying at night out in the western desert. More and more stuff
leaked to the
media, so that all through the 1980s it had been sort of an open secret
that
the USAF was operating a “stealth fighter” which was invisible to
conventional radar. However, questions directed to the Pentagon by the
press about the stealth fighter were met either with official denials
or by a curt “no comment”, which only served to whet peoples’ curiosity
even further.
The official designation of the rumored stealth fighter was assumed by
just
about everyone to be F-19, since that number had had not been assigned
to
any known aircraft. The novelist Tom Clancy placed the stealth bomber
(named
“F-19 Ghostrider” by him) in a key role in his techno thriller novel“
Red
Storm Rising,” published in 1986. The Testors plastic model airplane
company
marketed a kit which purported to the true configuration of the
“stealth”
fighter. In the mean time, training continued out in the Nevadadesert.
On July 11,1986, Major Ross E. Mulhare flew into a mountain near
Bakersfield, California while flying production aircraft number eight
(tail number 792). Major Mulhare seems to have made no attempt to eject
and was killed instantly, his aircraft disintegrating upon impact. A
recovery team was immediately dispatched
to the crash site, and the entire area was cordoned off. Every
identifiable
piece of the crashed plane was found and removed from the area to
prevent
them from falling into the wrong hands.
The doomed aircraft had reportedly carried a flight data recorder,
which
is sort of unusual for a USAF fighter. Even though not much was found
that
was any bigger than a beer can, the flight recorder was supposedly
recovered
intact. The cause of the crash has never been officially
revealed, but fatigue and disorientation during night flying has been
identified
as a probable cause.
On October 14,1987, while flying production aircraft number 30 (tail
number 815), Major Michael C. Stewart crashed in the Nellis range just
east of Tonopah. He too apparently made no attempt to eject, and was
killed instantly. Again, the official cause was never revealed, but
fatigue and disorientation may have both played a role. There was no
moon that night, and there were no lights
out on the Nellis range to help the pilot to distinguish the ground.
Reportedly,
the mission included certain requirements that were deleted from the
final
accident report. It is possible that Stewart was going supersonic when
he
crashed and that he had become disoriented during high-speed maneuvers
and
had simply flown his plane into the ground.
These two accidents, along with a need to better
integrate the still-secret stealth fighter into its regular operations,
forced
the Air Force to consider flying the aircraft during daytime hours.
This
would in turn force the Air Force to reveal the existence of the
aircraft.
This announcement was originally scheduled to take place in early 1988,
but
internal Pentagon pressure forced a ten-month delay.
On November 10, 1988, the long-rumored existence of the “ stealth
bomber”
was finally officially confirmed by the Pentagon, and a poor-quality
photograph was released. The stealth bomber was kept secret for over
ten years, the security
and deception being so effective that all descriptions which had
“leaked”
to the media were completely inaccurate.
On the same day, the Air Force confirmed that the official designation
of
the stealth bomber was F-117A, which surprised just about everyone. The
official designation of the stealth fighter had long been assumed by
just about everyone to be F-19, since that number had apparently been
skipped in the new fighter designation sequence which was introduced in
1962. In addition, it had always been assumed that the designation
F-111 had been the last in the old series of fighter designations which
been abandoned in 1962 when the Defense Department restarted the whole
sequence over again from F-1. This led to a seeming endless round of
rumors and speculation about aircraft designation gaps and secret
projects, which continue to the present day.
If the stealth bomber was not designated F-19, then just what was F-19?
If
the F-117A was part of the old F-sequence, then what happened to F-112
through F-116? The true answer is not yet known, but the most likely
explanation is
that the 117 number is NOT in the old F-sequence that ended in 1962 but
instead
originated from the radio call signs used by the Stealth pilots when
they
were flying out of Groom Lake and Tonopah, two of the black planes’
bases.
Those are the same airfields that secretly operated Soviet- bloc
Aircraft such as the MiG-15, MiG-19, MiG-21, and MiG-23 that the US had
“acquired” by various means from such sources as Egypt, Israel,
Romania, etc. While in
flight, these aircraft were distinguished from each other by
three-digit radio
call signs (generally 11x). After awhile, these radio call signs came
to
be sort of unofficial designations for these aircraft, and even later,
F-prefixes
began to be attached to these designations.
The F-112 to F-116 are often speculated to be Soviet aircraft such as
Su-22, MiG-19, MiG-21, MiG-23, or MiG-25. There is even a rumor that
there exists a F-116A, which is a US-built version of the MiG-25
constructed to see what kind of threat the MiG-25 could be if Russia
builds it using Western techniques. There is also thought to bean
F-118, which might be a Mig-29 that was purchased before the fall of
the USSR.
Since the stealth bomber was operating in the same general area in
Nevada,
it came to be known by the radio call sign of 117. The number 117
became
so closely associated with the stealth bomber that when Lockheed
printed
up the first Dash One Pilot Manual, it had “F-117A” on the cover. Since
the
Air Force didn’t want to pay millions of dollars to re-do all the
manuals,
the aircraft became the F-117A officially. It may have even been
initially
designated F-19 in the early stages of the project, and might well have
continued
to be known as the F-19 had this mistake not been made. A similar
mistake
was made when LBJ announced the existence of the “Blackbird”.It was
supposed to have been designated RS-71, but LBJ announced it as SR-71
and no one had the guts to tell LBJ that he had goofed. The designation
stuck. This still leaves the question of the missing F-19 unanswered.
Perhaps the F-19 refers to some other “black” project, as yet
unrevealed. Perhaps the F-19does not exist at all, the designation
having been deliberately or accidentally skipped. Shortly after the
official revelation of the F-117, an Air Force spokesman answered
questions about the “missing” F-19 by stating the F-19 designation had
been deliberately skipped to prevent confusion with the Soviet MiG-19.
Another possibility that has been mentioned by several people is that
the F-19 designation was deliberately skipped in order to let Northrop
receive the designation F-20 for its advanced version of the F-5
fighter. Apparently, Northrop thought that the F-20 designation would
make for good advertising copy for its new fighter and the Air Force
agreed. A similar thing happened during World War 2, when the
designation P-74(and perhaps P-73 as well) were not assigned so that
the Fisher Body division of General Motors could get the designation
P-75 for its Eagle heavy escort fighter(“The French 75 in World War 1
--- The Fisher P-75 in World War 2”).
The 4450th Tactical Group was disbanded in October of 1989, and the
37th
Tactical Fighter Wing was established in its place. The 37th TFW had
three
squadrons, the 415th, 416th, and 417th. The 415th and 416th squadrons
flew
production F-117As, whereas the417th flew the pre-production F-117As.
The
417th also operated some LTVA-7Dsfor chase and training, but T-38A and
AT-38B
aircraft eventually replaced them.
On December 19, 1989, just 13 months after the
Pentagon disclosed the existence of the F-117A, it was used in combat
for
the first time. This was in Operation Just Cause, the invasion of
Panama
intended to dislodge and arrest General Manuel Noreiga. At the
beginning
of the invasion, six F-117As flew to Panama from Tonopah. Their mission
was
to drop 2000-pound bombs near the Panama Defense Forces (PDF) barracks
at
Rio Hato. The purpose of these bomb drops was to stun and disorient the
PDF
troops living there so that the barracks could be stormed and the
troops
captured with minimal resistance and casualties.
The pilots were instructed to drop their bombs no closer than 50 meters
from two separate PDF barracks buildings. On the night of December 19,
two lead F-117Aseach dropped a conventional 2000-pound bomb at the
RioHato barracks. The bombing attack seems to have achieved its goal,
since the barracks were quickly taken with minimal resistance. However,
it was revealed three months later that one of the bombs missed its
target by a considerable amount. It seems that there had been some
mis-communication in the final stages of the mission planning, and the
pilot had been given the wrong coordinates for the
target.
The media jumped on this event and concluded that the F-117A had been a
failure on its first mission. On April 21, 1990, stung perhaps by the
press criticism, the Pentagon released more information on the F-117A.
More photos of better quality were released, and at Nellis AFB there
was a public display of twoF-117As. The last production F-117A was
delivered to the Air Force on July 12,1990.
It was to be in Operation Desert Storm that the F-117A was to prove its
mettle. In response to the Iraqi Invasion of Kuwait on August 2, 1990,
the 415th TFS of the 37th TFW was deployed to Saudi Arabia on August
19, 1990. The 416th TFS followed in December of 1990. In January of
1991, a portion of the wing’s 417thTFTS was also deployed to Saudi
Arabia.
In spite of the massive Coalition build up, President Saddam Hussein of
Iraq stubbornly refused to withdraw his troops from Kuwait. On January
17,
1991, the Coalition began an air offensive to eject Iraqi troops from
Kuwait.
In the early morning hours, the F-117As of the 37th TFW initiated the
air
war against Iraq. Mission planners had assigned critical strategic
Iraqi
command and control installations to the F-117A, counting on the
aircraft’s
ability to hit precisely at well-defended targets without being seen.
Other
vital targets included key communications centers, research and
development
facilities for nuclear and chemical weapons, plus hardened aircraft
shelters
on Iraqi airfields.
On the first night of the war, an F-117A dropped
a 2000-pound laser-guided GBU-27 Paveway III bomb right through the
roof
of the general communications building in downtown Baghdad. In another
attack
on the communications building next to the Tigris River, another GBU-27
PavewayIII
was dropped through an air shaft in the center of the roof atop the
building
and blew out all four walls. During the first three weeks of the air
offensive,
F-117As obliterated many hardened targets with unprecedented precision.
The
37th TFW flew 1271combat sorties and maintained an 85.5 percent
mission-capable rate. The 43F-117As of the 37th TFW dropped more than
2000 tons of precision ordinance and attacked some 40 percent of the
high-value targets that were struck by the Coalition forces. Not one
F-117A was hit, shot down, or lost to mechanical failure.
There is no evidence that the F-117A was ever detected or tracked by
Iraqi
radar installations, either ground or airborne. The F-117’s
concealment,
deception, and evasiveness proved that it could survive in the most
hostile
of environments, and its laser-guided bombs struck with extreme
accuracy.
Most of the F-117As deployed to Saudi Arabia returned home to Nellis
AFB
in April of 1991, but a few remain in Saudi Arabia. The F-117A is
currently
out of production, but the Senate Armed Services Committee expressed an
interest
in acquiring 24 additionalF-117As. However, the Air Force claimed that
the
F-117A is now "obsolete technology", and that it did not need or want
any
more of them.
In 1994,there has been some thought given to building a navalized
version
of the stealth fighter to replace the cancelled A-12 project. This
would
produce a new set of challenges for designers. The aircraft would have
to
have catapult attachment point sand arrester hooks and still be capable
of
maintaining the integrity of its stealthy exterior. Afterburning
engines
would presumably have to befitted to make carrier launchings with heavy
payloads
feasible, which would require that the complex exhaust system be
completely
redesigned. If this project is funded, it will be given the designation
F-117N.
However, no firm decision has yet been made.
Although the F-117A has been called Frisbee,
Nighthawk, and Wobblin Goblin, there is no official name for it. Pilots
often
Nickname the F-117A the “BlackJet” .F-117A number 781 is now on Display
at
the Wright-Patterson AFB Museum at Dayton, Ohio. This was one of the
five
full-scale development machines. In the interest of security, the RAM
covering
was replaced by a layer of black paint, and the narrow slotted exhaust
ports
were faired over to prevent anyone peering inside to see the details of
how
the exhaust was constructed. Two F-117A FSD aircraft are still flying,
the
other two are in storage.
The F-117A Stealth Fighter, Steve Pace, Tab Aero, 1992. F-117AStealth Fighter, Andy Sun, Concord Publications Co.,1990. F-117 Stealth in Action, Jim Goodall, Squadron/Signal Publications,1991.Lockheed F-117A, Bill Sweetman and James Goodall, Motorbooks International,1990.Joe Baugher Lockheed F-117A : Have Blue Program
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