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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 1969 Lockheed engineers showed up at the EG&G RCS facility at Groom Lake with a very crude prototype model of the first stealth plane, the Have Blue. Special Projects team members T.D. Barnes, Cowen Dawson, and Bobby Luker had the distinction of mounting the prototype on the pylon for its first RCS evaluation. Barnes reports the prototype showing up like a barn on the radar screens and script charts when the radar array beamed on the prototype. Lockheed, "the Customer" departed with the data and returned a couple months later with the modified prototype. Once again the Special Projects team conducted a RCS evaluation of the plane on the pylon. This time the radar return was much smaller. This sequence of painting the prototype with radar beams and recording the return continued until a bird landing on the prototype produced a greater return than the plane. Eventually it was the pylon pole producing too much ground clutter so a pylon was constructed from a block of Styrofoam. By the end of the RCS evaluations and Lockheed modifications it was necessary to mark the prototype with a medal tag to identify it on the script charts and readouts. 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 the F-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 the F-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 from 256 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.
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:
79-1780/1784,
Lockheed F-117 AFSD80-1785/1791
Lockheed F-117A81-1792/1798
LockheedF-117A82-1799/1807
Lockheed F-117A83-1808
Lockheed F-117A84-1809/1812
LockheedF-117A85-1813/1824
Lockheed F-117A84-1825/1828
Lockheed F-117A85-1829/1836
LockheedF-117A86-1837/1840
Lockheed F-117A87-1841/1844
Lockheed F-117A
However, it is rather odd that all of these different fiscal year numbers are in
exact sequence! In addition, note that 1825/1828 falls in an earlier fiscal year
than 1813/1824.
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 Nevada
desert.
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 the 417th 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 Rio Hato 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 miscommunication 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 Paveway III 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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