A government/contractor integrated test team has been formed for the preparation,
planning, conduct,
and reporting of the F-22 Flight Test Program. This integrated test team
is composed of personnel from
the Air Force Flight Test Center (AFFTC) at Edwards AFB, Calif.; the Air
Force Operational Test and
Evaluation Center (AFOTEC) headquartered at Kirtland AFB, N. M.; Air Combat
Command (ACC),
the ultimate user of the F-22, headquartered at Langley AFB, Va.; Pratt
& Whitney; the F-22 System
Program Office (SPO) at Wright Patterson AFB, Ohio, and the Lockheed Martin
Boeing team. This
organization is defined as the F-22 Combined Test Force.
The various personnel and organizations functioning as the CTF have responsibility for:
Estimating the scope of the air vehicle flight test program;
Organizing the test team to accomplish assigned tasks;
Determining and obtaining sufficient resources (budget, schedule, materiel,
facilities, and
personnel) for successful accomplishment of the flight test program;
Develop planning and documentation that adequately describes the flight
test program;
Conduct the flight test program in a safe, efficient, and effective manner,
and
Report the flight test program status, accomplishments, significant problems,
and results.
Given the geographical locations of the various organizations involved,
the CTF does not currently
exist as a fully co-located entity. The CTF functions as a virtual co located
entity by using methods such
as frequent face-to-face meetings and video teleconferencing.
Fully co located operation of the CTF is scheduled to commence with delivery
of the first Engineering
and Manufacturing Development F-22 (the aircraft identified as company
number 4001) to Edwards
AFB in October 1997.
The combined test force will start at about 290 people and build to a maximum
of 650 in 2001.
Initially the CTF will comprise a 60/40 percent mix of contractor and Air
Force personnel. As testing
progresses, the mix will shift to 50/50. The organization will be commanded
by an Air Force officer, with
a contractor deputy. The internal organization is built around the Integrated
Product Teams (IPTs) that
produce the flight test and production data.
The Airworthiness IPT is permanent at Marietta, Ga. and is responsible
for taking the F-22s from
manufacturing through initial ground tests, first flight, air worthiness,
and ferry to Edwards.
The Air Vehicle IPT is responsible for all tests on the first three aircraft
while the Avionics IPT does
the same for the six avionics test aircraft. All other participants support
these IPTs so that test pilots
receive their assignments from flight operations but work directly for
the IPT when conducting flight tests
The major objective of the CTF during this phase is to determine the various
Integrated Product
Team (IPT) requirements and to insure that they are consistent with published
plans and are fully
traceable to Contractual Product Specifications, or are required to measure
the Military Utility of the
F-22 Weapons System.
From these requirements, detailed Test Information Sheets (TIS) are written
from which the actual
content of the test program can be verified, required supporting resources
(such as instrumentation, data
processing, personnel, facilities, equipment, etc.) can be identified,
and documented methods and
processes of operations can be defined.
Flight Test Requirements Working Groups (FTRWGS) are set up to execute
the test planning
process. The FTRWG responsibility and location were determined based on
the Lockheed Martin
Boeing assignment of Product and/or Technology IPT design responsibility.
This enhanced
communications between the various Product personnel and the Test IPT personnel,
particularly in the
early stages of test requirements identification.
The working groups are generally divided by disciplines. The groups had
to decide what had to be
tested and who are the people who will be doing the tests.
The working groups remain intact throughout the test program, and are responsible
for the test
conduct, data analysis, and reporting for their particular technical discipline.
Each of the nine F-22s to be built in the current Engineering and Manufacturing
Development (EMD)
phase will be dedicated to flight test, and each of these aircraft will
be heavily instrumented to record
flight test data.
Unlike past aircraft development programs, the Flight Test IPT was brought
in at the very beginning
of the F-22 program. On other aircraft, flight test was normally brought
in after the aircraft was built and
had to integrate flight test instrumentation where it could find room to
put it. On F-22, Flight Test worked
closely with the aircraft's designers, and the instrumentation was incorporated
in the original aircraft
design and is installed as the aircraft is being built.
With the instrumentation installed as the first F-22 entered final assembly,
Flight Test was able to start
telemetering data to the Flight Test Control Room in Marietta, Ga., in
order to begin checking out the
data processing system.
A large orange box with flight instrumentation will fly in the F-22's right
hand main weapons bay. The
box, called the instrumentation data acquisition package, acquires data
from more than thirty remote units
scattered around the airplane. The box contains a high-speed data recorder
that retains all the flight data.
It also encrypts and transmits selected parameters back to the mission
control station on the ground via
two antennas on the aircraft. The instrumentation box stays with the airplane
for its entire flight test life.
The flight test data processing requirements are split into real time data
collection for safe and efficient
test conduct and post flight data processing. The Air Force is responsible
for the real time collection,
while the contractor team is responsible for the post flight processing.
The contractor team and the Air
Force agreed to use the same software to collect and process flight test
data nearly six years ago.
A test correlation software program called Test Plan is being used by the
team to maximize the data
collected on each test flight. Developed by G&C of San Juan Capistrano,
Calif., Test Plan is expected to
increase flight test efficiency and lower testing costs.
By using this software to plan a specific test mission, flight test managers
will be able to determine if
other tests requiring the same test conditions and aircraft configuration
can be piggybacked on to the
planned flight. The program can match up data points that were originally
scheduled to be gathered
months apart and will compare the resultant flight plan against any known
limitations of the particular test
aircraft.
The program will also be of benefit in daily flight test data management.
The program will indicate
what was flown on a given day, and whether that data was acceptable.
The Flight Test IPT has put much emphasis on training. Most flight test
programs rely mostly on on
the job training to train the control room personnel, but formal training
for the controllers and pilots
separately began in November 1996.
Personnel were identified by name and discipline for who was going to be
in the control room in
Marietta when training started. This reinforces the idea that the controllers
are the pilot's 'eyes and ears'
on the flights.
Four training sessions were held at the Vehicle System Simulator (VSS)
at Fort Worth (see VSS in
the Other Testing section). The first run was basic tasks and responsibilities;
the second session
introduced anomalies (or glitches) into the scenario, but the controllers
and pilot were told what situations
would be coming up; in the third and fourth sessions, the team ran the
first flight profile, but anomalies
were introduced at unexpected times. A fifth session will be conducted
from the Mission Control Room
in Marietta and will be a full dress rehearsal of the first flight using
an F-15 as a stand in for the F-22 and
F-16s as chase aircraft.
The first flight was preceded by a series of taxi tests. The tests were
used to evaluate the aircraft's
nosewheel steering, the braking system, and the operation of the arresting
gear at various speeds up to
110 knots. The instrumentation system on the aircraft was also thoroughly
checked during these ground
tests.
First flight of the first aircraft took place on September 7, 1997 from
Dobbins ARB in Marietta, Ga.,
with F-22 Chief Test Pilot Paul Metz at the controls. Flying chase on the
first flight was fellow contractor
pilot Jon Beesley in one F-16 and Maj. Steve Rainey, who was the first
Air Force pilot to fly the F-22,
in a second F-16 chase plane.
The three aircraft taxied onto the runway. The two F-16 pilots took off
first and started a slow
360-degree turn back towards the runway. Metz held the F-22 on the runway,
making final
instrumentation checks with the mission control room team.
Metz released the brakes, simultaneously easing the twin throttles to military
power with his left hand.
The Pratt & Whitney F119 PW 100 engines spun up, and the F-22 started
down the runway. At about
140 knots, Metz pulled back slightly on the sidestick controller with his
right hand. The aircraft rotated
and took off. The landing gear remained down as the F- 22 climbed, and
Metz pointed the aircraft to the
north.
The most impressive feature of the first flight was the F- 22's rate of
climb. Even though the Raptor
climbed with its landing gear down, the F-16 chase aircraft had a tough
time keeping up with the F -22,
as the F119 engines produced a tremendous amount of thrust. The airplane
climbed out fast at around a
twenty-five-degree pitch angle in military power. The steep climb angle
is a function of wanting to
maintain a constant velocity under a fixed power setting.
The airplane reached 15,000 feet in less than three minutes. Once at that
altitude, Metz leveled off
and then cycled the engines through a series of power changes. The engine
afterburners were not used
during the first flight. Metz took the airplane to a maximum angle of attack
of fourteen degrees.
All along, Metz evaluated the handling qualities of the F-22. Handling
qualities describe the feel of an
airplane. An airplane that requires little pilot effort or is easy to maneuver,
land, fly formation, aerial
refuel, or dogfight another fighter is said to have good handling qualities.
About midway through the just under one-hour flight, Metz raised the landing
gear and took the F-22
to 20,000 feet, the maximum altitude for the flight. At this altitude,
he went through more engine transients
and evaluated the cruising performance before descending. On his way down,
Metz will fly formation on
Beesley's F- 16 to determine the F-22's handling qualities during relatively
demanding piloting tasks -
what pilots refer to as 'high gain' flying.
The profile finished with the landing gear once again lowered for two simulated
approaches at 10,000
feet. Metz will then make his final approach. The F-22ís main gear
touched down first. Metz aerobraked
to slow the aircraft to about 100 knots. The nose lowered and Metz applied
the brakes to bring the
aircraft to a full stop.
The first flight will lasted just under one hour. During its flight, the
F-22 reached a maximum speed of
250 knots and a maximum load of three Gs (three times the force of gravity).
Metz flew three times around a triangular route that took him about forty
miles north from Dobbins to
the Rome, Ga., area, and then northwest from Dobbins into Alabama. This
route was carefully
coordinated with Atlanta's Hartsfield International Airport to deconflict
with commercial traffic.
All of the test flights at Marietta are designed to confirm the basic airworthiness
of the F-22. These
test flights are designed to clear a basic flight envelope roughly equivalent
to a commercial airlinerís in
order to ferry the aircraft to Edwards.
After the first flight and two or three additional airworthiness flight
tests in Marietta, the F-22 (Aircraft
4001) will go through several months of further preparation and ground
testing before it flies again.
Engines as well as control surfaces and weapon bay doors are removed and
the aircraft is placed in a
large test frame. The aircraft is then pushed and pulled using jacks and
hydraulic pistons to simulate air
loads encountered in flight. The deflections of the airframe are measured
by strain gauges attached to
hundreds of locations inside and outside the airplane. The strain gauges
are calibrated with known loads
so they can gather accurate load data on the airplane in flight.
After this ground testing, the F-22 is put back together and sent to the
coatings facility in Marietta
(see Robotics Coatings Facility in the Manufacturing section) where it
receives a final paint job. After
painting, the airplane goes through ground vibration tests in Marietta
to measure its structural dynamic
characteristics. These tests are necessary for expanding the flight envelope
in subsequent flights at
Edwards.
Ground tests are also performed on the airplane's flutter excitation system.
This system sends
commands to the flight controls to oscillate or vibrate any of the control
surfaces on the airplane while it is
flying. The system can induce controlled pulses that simulate atmospheric
turbulence and other
disturbances. Like plucking a banjo string, the flutter exciter causes
the aircraft structure to vibrate.
The damping, or dying out of the vibrations, is measured to ensure that
the structure is free from flutter
- a large amplitude vibration that can be destructive. The system makes
certain that the aircraft is
structurally stable throughout its flight envelope.
Beesley will make the initial flight after the F-22 completes this ground
preparation and tests. His
flights further expand the flight envelope to meet the parameters that
are required to ferry the aircraft to
Edwards. These flights also make use of the flutter excitation system.
Beesley will take the aircraft up to
40,000 feet and 325 knots.
He will also shut down and then restart the engine and the auxiliary power
unit in the air. These tests
ensure that the engines will restart should they die or flame out during
some of the aggressive high angle
of attack and high-speed tests later in the program.
The first F-22 is scheduled to fly six to eight times at Marietta before
flying to Edwards in October
1997. In the last of these flights, Major Rainey will qualify the airplane
for aerial refueling at altitudes of
20,000 and 30,000 feet. The F-22's flying qualities, emergency breakaway
procedures, refueling boom
clearance, and fuel transfer rates are evaluated in these aerial refueling
flights.
Rainey will also be in the cockpit when the F-22 is ferried to Edwards.
A KC 135 tanker and two
safety chase aircraft will accompany him on this non stop flight, as will
a C-141 carrying support
equipment and personnel. The planned route will take the aircraft over
eight states in a little over four
hours. A backup three leg route without aerial refueling takes the aircraft
from Marietta to Fort Worth to
Holloman AFB in New Mexico and then to Edwards.
Whereas the testing at Marietta ensures that the F-22 can be ferried safely,
the test program at
Edwards will focus on determining that the F- 22 does what it promises.
Its performance will be
measured at all altitudes, speeds, G loadings, and angles of attack. The
flight test program concentrates
on flying the F-22 to the edges of its flight envelope.
The airplane is scheduled to break the sound barrier about five weeks after
arriving at Edwards. The
F-22's flying qualities are evaluated under a variety of conditions, including
flight with the weapon bay
doors open. The aircraft also flies with external stores. The EMD flight
test program calls for establishing
a long term average of approximately 12 flights per month on each test
aircraft.
The first F-22 will have completed about 100 flights before the second
airplane (Aircraft 4002) takes
off for the first time with Beesley at the controls in mid 1998. After
two or three flights in Georgia, the
second aircraft is ferried to Edwards where it will be used for high angle
of attack testing and, later, for
testing weapon separations from the internal bay.
Before ejecting weapons from the internal bay in the air, weapons are ejected
from the bay with the
aircraft on the ground. This ground testing covers AIM 120 ejections from
the main bay as well as pylon
and store ejections from the various wing stations. The aircraft is also
used for testing the performance of
the propulsion system and for evaluating the F-22'ss infrared signature.
The third aircraft, or Aircraft 4003, is slated to be flown for the first
time by Boeing's test pilot Chuck
Killberg. The first flight of Aircraft 4003 will not be much different
from the first flight of 4001. The
aircraft will fly a profile similar to that flown by Aircraft 4001 on its
first flight, but the landing gear will be
raised right after takeoff.
Aircraft 4003 is unique in other ways. It is the first F-22 to have an
internal structure that is fully
representative of the production aircraft and it will be used to perform
demonstrations to 100 percent of
the loads. Aircraft 4003 will be the first used to test the operation of
the M61A2 cannon. It will also be
used in acoustic surveys at Edwards. In these surveys, the engines will
be operated at various power
settings from idle through maximum power to obtain data on the resulting
structural effects and potential
physiological effects on maintenance personnel.
The fourth and fifth F-22s to roll out of the Marietta factory will never
take off. The aircraft will stay in
Marietta for static load testing and fatigue testing. (While the flying
F-22s are referred to as Aircraft
4001, 4002, 4003, etc., the two non-flying F-22s are designated 3999 and
4000). Static loads testing
on Aircraft 3999 begins after the airplane is placed into a static testing
fixture. The fixture allows loads to
be applied to various parts of the airplane at varying degrees to test
its structural strength under highly
controlled and closely monitored conditions. Generally, these loads are
applied to simulate loads
experienced in actual flight.
In steps, the static test article is taken to the aircraft's load limit
first; that is, the design limit of the
structure. In the 'ultimate test' the structure will be taken to 150 percent
of its load limit. Successful
completion clears Aircraft 4003 to demonstrate maximum loads in flight.
All of the test results are used to update structural models, also called
finite element models (FEMs).
These models are representations of the airplane that break down its structure
into discrete mathematical
units called elements. The model is used as a basis for all structural
analysis.
For fatigue testing, Aircraft 4000 is placed in a test fixture similar
to the one used for static loads tests.
The airframe is then loaded in many cycles over long periods of time to
simulate stresses associated with
expected operational use. This testing evaluates the durability of the
airframe by 'flying' it on the ground in
a flight by flight manner around the clock. The airframe accumulates a
lifetime of stresses in about eight
months of this testing. The airframe will be put through two lifetimes
to evaluate its basic durability. It will
then be subjected to two more lifetimes of extended fatigue and damage
tolerance testing.
Fatigue relates to how long it takes to form a crack, which affects when
the F-22 is required to go
through its initial inspection. Damage tolerance is related to crack growth
rates, which are used to
determine inspection periods for the aircraft. Fatigue testing takes about
two and a half years.
Afterwards, the airframe is completely disassembled and thoroughly inspected
for any cracks not
detected during the tests.
Beginning around the year 2000, F-22s will roll out of the factory at a
fairly regular rate - about one
every other month. The biggest jump in technology comes with Aircraft 4004.
It and subsequent aircraft
have a full suite of avionics and software. In some respects, this airplane
represents the first ìrealî F-22
because it contains all of the avionics that allow the pilot to use aircraft
sensors to locate, target, and
shoot enemy aircraft.
Before any software ever flies on these aircraft, it is thoroughly tested
on the ground in Seattle in
Boeing's Avionics Integration Laboratory (AIL) and in the air in 757 Flying
Test Bed (FTB). (See AIL in
the Additional Testing section and FTB in the Additional In Flight Testing
section). All of the software
and hardware goes through the integration lab for Aircraft 4004 and later
flight test aircraft. This work
includes the full weapon system integration as well.
Aircraft 4004 through 4009 will fulfill a number of functions - testing
of the Communications,
Navigation, and Identification (CNI) system, Electronic Warfare (EW), radar
integration with missiles
and the M61A2 cannon, JDAM releases, and low observables testing. Flight
testing of the dedicated
avionics aircraft will run approximately 35 months from the first flight
of Aircraft 4004 in 1999 to the end
of EMD in 2002.
All of the aircraft will be configured the same, so any aircraft can be
used to collect data for a specific
mission, which will make scheduling much more efficient.
At the end of EMD, Aircraft 4001 will go into flyable storage at Edwards.
Aircraft 4003 will be the
primary functional aircraft, and it will be used for testing any non avionics
modifications or changes to the
airframe. The planned disposition of Aircraft 4002 has not been determined.
Three aircraft will be kept
flying for follow on avionics testing, primarily the proposed Block 4 avionics
software that will include
helmet mounted cueing, AIM 9X integration, and Joint Tactical Information
Distribution System (JTIDS)
send capability.
The F-22's design will likely evolve over the course of EMD. As one example,
Aircraft 4003 will
have a single piece forward fuselage keel, which on 4001 and 4002 were
made up of 70 separate pieces
and had to be assembled. All necessary improvements and changes will be
incorporated in Aircraft 4008
and 4009, so they are essentially production quality aircraft.
Those two aircraft, along with the first two true production aircraft (4010
and 4011) will be the four
aircraft the Air Force will use for Initial Operational Test & Evaluation
(IOT&E).
During IOT&E, AFOTEC will operate the aircraft as an operational unit
would. The aircraft will also
be maintained by Air Force crew chiefs and flight line maintainers.
Dedicated IOT&E will run from mid 2002 until early 2003. At the end
of IOT&E, AFOTEC will file
a report to Congress attesting to the worthiness of the F-22 to enter full
production.
The F-22 Flight Test program will consist of the nine aircraft to be built
during the current Engineering
and Manufacturing Development (EMD) phase of the program. The nine aircraft
will be flown
approximately 2,546 flights covering 4,583 test hours in EMD.
The Aircraft numbers, the projected first flight dates for each aircraft,
and the primary function for
each are:
4001
September 1997
Flying qualities, flutter, loads, and high angle of attack; Avionics Block
1 configuration
4002
Summer 1998
Propulsion, performance, and stores separation
4003
Summer 1999
Flying qualities, flutter, loads and JDAM integration; Avionics Block 2
configuration
4004
Fall 1999
Integrated avionics, CNI, observables testing
4005
Winter 2000
Integrated avionics, radar, CNI, and armament
4006
Late Spring 2000
Integrated avionics and observables testing; Avionics Block 3 configuration
4007
Late Summer 2000
Integrated avionics and air vehicle performance
4008
Winter 2001
Integrated avionics and observables*
4009
Spring 2001
Integrated avionics and observables*
*Aircraft 4008 and 4009 will be used by the Air Force for Initial Operational
Test & Evaluation
The demonstration and validation (dem/val) phase of the program began on
October 31, 1986 and
cumulated with an intensive flight test program at the Air Force Flight
Test Center at Edwards AFB,
Calif. in late 1990. In just over three months of flight testing, the two
YF-22 prototypes demonstrated
maximum mach number, supercruise (supersonic flight without afterburner),
high angle of attack (high
alpha) maneuverability, aerial refueling, and thrust vectoring. This flight
testing helped substantially in
reducing risk going into the current Engineering and Manufacturing Development
(EMD) phase.
The supercruise capability was demonstrated on both aircraft using different
sets of engines (General
Electric YF120 GE 100 and Pratt Whitney YF119 PW 100). The high angle of
attack work
accomplished by the YF-22 was impressive and gave the team high confidence
in the F 22's stability and
flight controls.
A total of 74 flights were flown on the two YF-22s for a total of 91.6
hours. After contract award in
July 1991, another 39 flights totaling 61.6 hours were subsequently flown
on the Pratt & Whitney
powered number two prototype in a follow on dem/val flight test effort.
The YF-22 and the F22 are similar in shape, but there are a number of differences.
Externally, the
wing sweep has been reduced eight degrees (from 48 to 42 degrees). The
canopy has been moved
forward seven inches and the inlets moved back 14 inches to improve over
the side visibility for the pilot.
The shape of the wing trailing edges and the horizontal stabilizers have
been changed to improve the
aircraftís stealth characteristics, as well as for structural strength
and aerodynamics refinement.
The prominent vertical tails of the YF-22s have been reduced in size by
approximately 20 percent.
As a result of the rapid pace of the dem/val program, the team designed
the vertical stabilizers of the YF
22 larger than was necessary in order to avoid potential spin problems.
When the spin problems never
materialized, the airframe designers could reduce the size of the vertical
tails of the F-22 to make the
aircraft more aerodynamically efficient and reducing drag and weight.
The number one YF 22 prototype was taken to Andrews AFB, Md., in 1991 where
it was a part of
the Air Forceís Stealth Week informational display for Congress.
The aircraft was then brought to the
then Lockheed Aeronautical Systems Company in Marietta, Ga., where it was
used as an engineering
mockup. In March 1997, the YF-22 was shipped to Nellis AFB, Nev., where
it was part of the Air
Force's 50th Anniversary Celebration in April. In the summer of 1997, the
number one YF-22 was
retired to the Air Force Museum at Wright Patterson AFB, Ohio.
The number two YF 22 prototype was used in the follow on flight test program
in late 1991 and early
1992. Returning to Edwards after a test flight, the YF 22 experienced a
series of pitch oscillations, and
with the landing gear retracted, the aircraft hit the runway, slid, and
burned. Although no longer
flightworthy, the external damage was later repaired, and the YF-22 was
airlifted to the Rome Air
Development Center at Griffiss AFB, N. Y., where it received representative
F-22 wings and
empennage and is still being used to validate aircraft antenna patterns.
Final disposition of the number
two YF-22 has not yet been determined.
Flying a specially configured F-16, test pilots completed tests on the
first block of flight control laws
for the F-22 in 1996, more than a year before first flight of the actual
aircraft.
The flight control laws (the complex set of computer instructions that
keep a modern fighter aircraft
flying) for the F-22 were programmed in the Variable Stability In flight
Simulator Test Aircraft (VISTA),
a highly modified, one of a kind F-16D that, through a sophisticated control
system, can emulate the flight
characteristics of another airplane in flight.
A total of 21 sorties totaling 26.8 hours were flown in the NF 16D (the
official designation for the
VISTA aircraft) in two test sessions.
The first test session was devoted to comparing the baseline flying qualities
of the F-22 to proposed
or potential changes in the aircraft's pitch and roll control characteristics
for landing, air refueling, and
formation flying.
The second phase focused on two aspects of F-22 flying qualities. The first
aspect was how the
control laws performed during an engine failure, and separately, two different
failures of the hydraulic
system, including a dual hydraulic failure that resulted in the loss of
use of one horizontal tail, one rudder,
an aileron on one wing, and a flaperon on the other wing.
The second aspect considered the effects of not accurately achieving the
predictions of the F-22's
aerodynamics and structural characteristics. The so-called 'parameter variation'
test flights allowed for
relatively large changes to be made in the F-22's stability and flight
control power.
In smooth air, the various failures and parameter variations were almost
indistinguishable from the
baseline F-22. In more severe winds and turbulence, some differences could
be noted but the aircraft
remained well behaved and respectable landings could be made even with
a badly degraded aircraft as a
result of the simulated dual hydraulic failure.
The overall results of the VISTA tests were excellent.
The F-22 Flying Test Bed (FTB), a modified 757, will be used by Boeing
to integrate and flight test
the F-22 air dominance fighterís highly integrated avionics. Boeing
has the lead for testing the F-22ís
avionics system in the current Engineering and Manufacturing Development
(EMD) program.
The test bed will sport an F-22 forward fuselage (built by Lockheed Martin
in Marietta, Ga.) installed
on the 757's forward pressure bulkhead. The structure will house the Northrop
Grumman/Texas
Instruments AN/APG 77 multimode radar designed for the F-22.
A second modification will be the installation of a sensor wing on the
crown of the fuselage
immediately behind the flight deck. Electronic warfare (EW) and
Communication/Navigation/Identification (CNI) sensors will be mounted directly
on the sensor wing,
which is designed to simulate the sensor positioning found on the F-22ís
wings. The configuration will
provide high fidelity data and allow the test bed to emulate the sensor
capabilities of the F-22 in realistic,
real time operations.
The nose modification is scheduled for completion in August 1997 at Boeingís
Wichita, Kan., facility
with in flight radar testing to begin shortly thereafter. Boeing will install
the sensor wing in August 1998.
Internal modifications to the 757 include structural supports for the special
nose and sensor wing
structure and the installation of unique electrical power, liquid cooling,
and instrumentation systems.
Avionics racks, test stations racks and seating for more than 25 technicians
will be located in the FTB
cabin.
Based in Seattle, the FTB will be used to conduct in flight tests of the
F-22 mission avionics system,
in addition to the radar, starting in October 1998.