development / production / upgrade / life extension
Last update 06-11-2014
Northrop N-156 family program
The US Air Force was engaged in a run to obtain higher and higher performances and armament load from its new fighters up to the sixties, with the consequences of increasing complexity, increase in airframe weight, spiralling maintenance costs and necessity for long runways.
studies on lightweight fighters begun in the mid fifties with the N-102
"Fang" project, which was not built. This had no resemblance to the
Northrop N-102 Fang mock-up with fictitious serial 22777
lightweight engines with enough power were a problem, solved wth the
availability of General Electric's J-85 beginning 1955. A new project
was started with the designation N-156 and implied a family of
consisting in a ground based fighter (N-156F), a carrier-borne
(N-156N) and a trainer (N-156T, later TZ-156).
small escort aircraft carriers, for which the N-156N was foreseen, were
used only as aircraft transport carriers the development of this version was stopped by the end of the 50's.
US Air Force needed at the time a new supersonic trainer to replace the Lockheed T-33A; it issued in
May 1955 an operational requirement for what was to be selected and designated Northrop T-38A.
Northrop went on with development of the fighter version as a private venture, although
the US Air Force was not interested in the proposal for its own use, but the aircraft
might have been of interest to allied nations. Official presentation to the USAF of both the single- and double-seater was in January 1956.
Construction go-ahead (with company funding) was
given early 1958. On 27-05-58 (rather unusually) an research and development contract with the US Department of Defense was formalized in July 1959, allocating almost USD 50m (32m
to Northrop and 18m to General Electric) for 3 aircrafts and 1 static
test airframe to Norair, the division of the new Northrop Corporation now
responsible for building aircrafts and missiles.
Mock-up with fictitious 56 (Fiscal Year) 156
(project number) serial. Photo: Northrop
first prototype roll-out followed at Hawthorne on 31-05-59. Representatives
of forty allied nations attended to the ceremony.
production discussions were held with European aircraft builders:
Fokker of the Netherlands, SABCA of Belgium and FIAT of Italy but their
governments selected the Lockheed F-104G as their new fighter.
Discussions were also held with Australia and the United Kingdom
Northrop - USAF trials
First flight of the first prototype, serial 59-4987, took place on 30-07-59
(without any Air Force insignia and markings) at Edwards AFB, where the
aircraft had been transferred, going supersonic on the first flight despite the low thrust
of the installed General Electric YJ-85-1 engine.
The first protoype showing its extremely clean lines at Edwards AFB in company of the first and
second YT-38A prototypes and test pilots at Edwards AFB; note no
nationality and US Air Force
markings painted on aircraft as the fighter had not been yet accepted by the USAF.
The second protoype at an Edwards AFB open-day with Sidewinders and a full load of tanks. No nationality
or US Air Force markings were painted as the type had not been accepted by USAF. Photo: unknown
Flight tests proceeded smoothly, a
USAF project test pilot flying the aircraft from the third flight for
preliminary evaluation. No cannon armament was originally fitted, but tests with 20mm underwing podded cannons took place.
First prototype with GAM-83 Bullpup missile underwing. Photo: Northrop
Non US (French) air-to-air and air-to-ground missiles (quite unusual!) were taken in consideration as
armament in 1960: Nord AA.20 (a-a) AS.20 (a-g), Nord AA.25, AS.25 and AS.30, without follow on.
The first prototype with nose probe, Nord AS.30 underfuselage, AS.20 underwing
and AIM-9 Sidewinder missiles at wingstip in 1962.
powerful General Electric YJ-85-5, with afterburner, replaced the
early version after 32 test flights; the second prototype was foreseen to fly in January 1960.
Intensive armament trials took place: live 250/500/750 pounds bombs and napalm canisters were dropped, 2.75 inch rockets were fired, AIM-9B Sidewinder air-to-air missiles were carried on the wingtips, a "special missions" (nuclear) bomb mock-up under the fuselage.
Air Force tests at Edwards AFB were concluded with great satisfaction in
August 1960, but this did not lead to an Air Force
change of mind. No order for its own use was placed and it
seemed the the programm was going to be stopped, so the
construction of the third prototype remained incompleted.
interest in the aircraft was renewed when the Kennedy administration
beginning 60's decided to suppy it allies with a low-cost fighter under the Military
Assistance Program FX; a competition was held involving the Freedom
Fighter, the Douglas A-4 Skyhawk and the Lockheed F-104H, a simplified version of the Lockheed F-104G, this last being preferred by the Air Force.
The Northrop F-5A was anyhow selected as
the winner, officially announced on 23-04-62, receiving the USAF designation Northrop F-5A Freedom Fighter in August 1962. The third prototype, designated Northrop YF-5A, was completed and flew on 31-07-63,
being fully representative of production aircrafts. Both
earlier prototypes were later brought up to YF-5A standard
Northrop - US Army trials
The US Army's wish to operate its own supportforce
led in January 1960 till July 1961 to trials for the
possible selection of a jet aircraft. This would have operated in the
Forward Air Control and the Close Air Support role operating from
uniproved airfields near front lines. Initial factory tests were held
on a grass runway at Hughes airfield, Culver City, not fare from the
Two Fiat G-91R-3s, two G-91R-4s, one G-91T-1, two Douglas A-4D-2 (A-4B) Skyhawks and the two Freedom
Fighters prototypes (59-04987/988) participated at Fort Rucker Army Base to the
Bombs armed Northrop YF-5A 94987 (without guns) in company with its competitors,
Fiat G-91R-3 and Douglas A-4B.
Soft ground trials at Pensacola in June 1961: the second Freedom Fighter prototype with
larger tires on the main and two-wheels on the front landing gear, later removed. Trials
included landing in 1300 ft/396m on grass and taking off with a maximum load in less
than 2'500 ft/762m. USAF inscription was replaced by "Army" in September 1961 for
additional tests at Pensacola NAS.
The Northrop aircraft was preferred by the Army, but the project was unfortunately cancelled due to US Air Force
Northrop F-5A / RF-5A / F-5B - Freedom Fighter
break through came on 22-10-62 when the USAF placed an order for 71 MAP
funded aircrafts, followed by a second one placed on 27-08-63 for
Fighters, to be supplied to friendly nations. It was planned to build
12 aircrafts per month, initial delivery planned
during the first quarter of 1965.
Costruction of the third prototype could be completed, works already
starting on 26-04-62, followed by the first flight on 31-07-63.
This was the first airframe to feature all seven external stores
pylons, designated Northrop YF-5A.
Production started immediately at the Hawthorne, a combined production line shared with the F-5B and Northrop T-38 trainer was capable of producing 22 aircrafts per months. The first production/fourth prototype aircraft (63-08367)
flew for the first time in October 1963 (less then a month from the
order); it joined the test program at the end of 1963, together with
the second production/fifth prototype (63-08368).
Northrop delivered the first three protypes, designated F-5A Freedom Fighter, to the Air Force by the third quarter (July-September) of Fiscal Year 1963.
On 30-06-1963 there were two active F-5A and one non-operational. First military test flight was on 14-08-63.
Category I testing took place between October 1962 and May 1965. First aircraft accepted for Category II tests by the Air Force Flight Test Center, Edwards AFB, was serial number 63-08367
on 01-02-64, performance, stability and control testing began on
30-04-64 with s/n 63-08368. Both Category II and III lasted
between February and October 1964. Tests continued till 1966; 16'000 flight hours were simulated.
An operational requirement to incorporate two 20 mm Pontiac M-39A to increase Freedom Fighter's firing power was issued in 1964 by the USAF. Only a ranging set mounted in the nose and an optical sight were at pilot's disposal for air-to-air and air-to-ground operations.
Approximately 140 USAF personnell from Tactical Air Command, Air
Training Command, Edwards AFB Flight Test Centre, together with
Northrop personnell, were involved in 1030 trials flight hours during FY 1964. Acceptance of the first Freedom Fighter by Tactical Air Command was on 30-04-64. Future Williams
AFB instructor pilots were also contemporanously trained.
Fatigue tests were carried out between 1964 and 1966 for a total of 16'000 simulated fight hours.
The third protype and the two first production examples undergoing
tests with bombs and long range tank.
Northrop showed two of its Freedom Fighters (serials 69175/176) at the le Bourget air show while transting
Europe on delivery to Iran.
Serial 69176 (with code 203 on the nose) at le Bourget on 03-06-67. Photo: unknown
See under the respective Air Forces pages for information regarding delivey/use of the Northrop F-5A.
conversion on the new fighter dictated the construction of
a two-seater, designated . This had no cannon armament but
could carry any all other armament under the wings. One two-seater per
nine single-seaters was foreseen in the two initial contracts.
First flight of this
new version was on 24-02-64 by serial 63-8438; it was declared operational already
on 30-04-64, earlier than the single-seater which was in August 1964.
Deliveries started on April 30th, 1964 to the 4441st Combat Crew Training Squadron at Williams AFB, a new USAF unit taking care of pilots belonging to the countries selected to receive the aircraft training.
Northrop F-5B 38438 with long nose pitot tube in May 1964. Photo: Northrop
Sales demonstration was undertaken by the first company demonstrator between June and September 1964 in Europe and the Middle East: Italy, Belgium, Germany and Saudi Arabia. Unfortunately it was lost during one of the las demonstration flights.
The first company demonstrator shown at Brussels-Zavestem in unusual colours on 28-06-64.
The second Northrop F-5B (serial 38445) replaced immediately the lost one.
The fourth production Northrop F-5B (serial 63-08421) with several design improvements and a more powerful GE
J-85-15 was used for 7 hours/8 missions tests at Edwards AFB between the 9th and 15-06-65;
some of these improvements were later incorporated in the development of
F-5As supplied to various Air Forces as well a being offered, without success, to Belgium.
Further engine trials took place at a later stage again on the Northrop F-5B company demonstrator with the much more powerful General Electric J-85-21,
first flown as such on 28-03-69; they
lasted five months for a total of approximately 130 flight hours. This
engine was to power the next generation Northrop F-5E Tiger.
Northrop F-5B 38445 with General Electric J-85-21 on a test flight.
mid-73 eighty-four of eighty-eight F-5B foreseen for MAP countries had
been handed over to the USAF for onward transfer, together with 13 sold
under Foreign Military Sales program (2 to Lybia, 6 to Norway, 5 to
Iran); additional 2 FMS to Jordan were to be delivered to Jordan
static tests airframe (serialled C-8123) was withdrawn from use and
transferred to the Lackland AFB for preservation where it was seen on
See under the respective Air Forces pages
for information regarding delivey/use of the Northrop F-5B.
An USA official document states tha
by September 1975 that the a Northrop reprsentative was
appointed to sell Northrop F-5s: Belgium, Denmark, France,
Germany, Italy, Luxembourg, Netherlands, Norway, Portugal and the
Necessity of a reconnaissance version for countries receiving Military Assistance Program help, was recognized by the mid 60s. An order for 13 aircrafts for Iran
was placed in October 1967, followed by the first flight in May 1968.
Tests were held the same year at Edwards AFB during the period July 1st
and August 28th with the first production aircraft (for Iran, s/n 67-21219) flying 58.8 hours in 47 test missions.
Northrop's own Northrop F-5A-15 serial 38372 was modified as RF-5A prototype in 1968,
later being modified again as F-5A-15 and used for tests.
Main difference to the fighter version was the modification of the nose
to mount four KS-92 cameras, otherwise retaining its combat
The second aircraft built (serial 89102) was demonstrated at Le Bourget air show in June 1969 before onward delivery to the Norwegian Air Force.
Photo: R.A. Scholefield
Northrop RF-5A for the Norwegian AF seen at le Bourget air show on 07-06-69.
This version was only built for US allied Air Forces; USAF never adopted it, not even for training.
See under the corresponding Air Forces pages for information regarding delivey/use of this version.
Freedom Fighter production
Monthly production rate at the Hawthorne plant was at the beginning of
1965 of ten mixed, single- and two seaters; 150 Freedom Fighters had
been handed-over to the USAF for onward delivery to the Military Assistance
Program (MAP) countries in October 1965.
By the end of Fiscal Year 1967 Northrop had produced 527 aircrafts.
Production of the F-5A came to an end in March 1972, unfortunately there are several versions regarding the exact number built.
One version states that 3 prototypes, 617 F-5A 624 production airframes have
been completed (2 modified as F-5B).
Production of the F-5B ended in
the mid-seventies, 134 200 airframes having been completed.
Production of the RF-5A ended in June 1972
having completed 89 airframes, for an total of 3 prototypes and 844 production airframes.
second version mentions the construction of 3 prototypes, 1 static
airframe and 617 production Northrop F-5A, 89 RF-5A, 134 F-5B, total
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Northrop F-5E / F-5F / RF-5E - Tiger
testing of an uprated General Electric J-85-GE-21 engine in a
highly modified Northrop F-5B started in March 1969 and
lasted till August of that year for a total of approximately 130 flying
hours; this demonstrated the availability of an engine which could
power an higher performance fighter of the family to be used mainly
air-superiority missions by nations with little technological knowledge.
Northrop made an unsolicited offer to the US Secretary of Defence/Air
Force but these wanted confirmation of the higher performance by
flight tests. The US Congress required a competition between several
manufactures, before funds would be granted covering the 1973
Fiscal Year for the so-called Advanced International Fighter programm.
Four companies answered in March 1970 to the request for proposal
placed on 26-02-70: Northrop with its F-5E; a stripped down version of its the F-4E Phantom was offered by McDonnel-Douglas, Lockheed of its F-104 Starfighter, Ling-Temco-Vought of its F-8 Crusader.
All these underwent a seven months USAF evaluation at the end of which
the Northrop F-5E was officially declared winner on 20-11-70.
A fixed price contract for 325 aircrafts was placed on 08-12-70, all funded bs Military Assistance Grant Aid;
deliveries were foreseen: 26 in Fiscal Year 1972, 71 during FY 1973, 120 in
FY 1974 and 108 in FY 1975. On November 1970 the first flight date was
set to December 1972.
The new fighter was officially named Northrop F-5E Tiger on 28-12-70.
first production F-5E was initially planned to be produced in February
1973; the aircrafts during February to October 1973 were to be used by
the USAF for tests and evaluation, for training and a few to be
delivered to Vietnam.
First four F-5Es were built on F-5 subassembly line at Hawthorne, fifth
and following aircrafts were assembled at Palmdale; these five were
foreseen to run the test program, but various modifications delayed
the completion (and increased the costs) of the programm, necessitating
the addition of a sixth aircraft to flight testing. All these aircrafts
were to be refurbished and transferred to the Air Force for operational use upon completion of the
development phase, as they actually were.
The most important difference to the Freedom Fighter was the
installation of an Emerson Electric radar, AN/APQ-153 in the early
examples, replaced by an improved search range Emerson Electric AN/APQ-159 in later examples; the double-seaters were equipped with Emerson Electric AN/APQ-157, a dual-control variant of the first radar.
engine tests were completed by May 1972, roll-out of the first
prototype took place at Hawthorne plant on 23-06-72, first
flight on 11-08-72 at Edwards AFB. An altitude of 20'000 feet was
reached during this flight.
Engine malfunctions happend the same
month, 1972 forcing suspension of flight tests between 21-09-72 and
16-12-72. Finally, the first Tiger was accepted by the Air Force on
03-08-73 for flight tests at Edwards AFB. Definitive engine
approval had been given on 25-04-73 after modifications by General
The third prototype seen at an open-day at Edwards AFB in 1973 with early Sidewinder AIM-9B
on wing tip. No tiger painted on tail.
Prototype number two with Tiger painted on tail landing on 11-04-79 at Edwards AFB.
Of note 30mm underfuselage gun pod
Northrop F-5E 11418 testing GPU-5 30mm underbelly
MBB Modular Dispenser System demonstration and test prototype under the fuselage of the
second Northrop F-5E prototype.
tousand simulated flight hours airframe fatigue tests
were completed on 22-11-75, consisting of 85% air-to-air combat and 15%
air-to-ground combat. Tests continued till 1955; 24'000 flight hours
were simulated. This brought to a redesign of the vertical stabilizer
due to failure.
Delivery of the first Tiger to the 425th Tactical Fighter Training Squadron at Williams AFB was on 06-04-73, four months ahead of schedule; Squadron's role was to train pilots of countries that had ordered Tigers.
May 1975 there were 6 Northrop F-5E undergoing tests by the Joint Test
Force (Northrop /USAF) at Edwards AFB; they participated from this Air Base to the development of special features for non-US customers.
Northrop showed its new
product at the le Bourget air show in June 1975
with the presence of one Northrop F-5E, serial 01467 code 51.
All prototypes were transferred between 1976 and 1981 to the US Air Force and used at Williams AFB for training.
See under the respective Air Forces pages for information regarding delivey/use of the Northrop F-5E.
Northrop F-5F Tiger
No second generation conversion trainer was initially deemed to be necessary
in view of the
modest number of single-seater thought to be sold;
the Northrop F-5B would take care of training new pilots. Increasing
number of Tigers sold dictated the development and production of the
next generation trainer.
Two Fiscal Year 1973 (00889/00891) were
completed as two-seaters, both aircrafts first flew from
Edwards AFB on 25-09-74 where they remained, undergoing several tests.
Photos: collection The Northrop F-5 Enthusiast
The first prototype F-5F 00889 at Kefkavik on the way to demostration at
Le Bourget air-salon on 16-06-75 in a typical Groenland day.
Demostration flights, eg. Le Bourget Air Show in June 1975, were performed as well
as armament and target tug tests from Edwards AFB for foreign customersat least until
November 1976. These tests were taken care by the 6512nd Test Squadron, 6510th
Test Wing/Air Force Flight Test Center-Edwards AFB in conjunction with Northrop
Badge 6512 Test Squadron.
The second prototype being prepared for spin tests on 10-11-76 at Edwards AFB;
of note the extra long nose pitot tube.
See under the respective Air Forces pages for information regarding delivey/use of the Northrop F-5F.
Northrop RF-5E Tiger Eye
Original Northrop plan was to provide
the Tiger with limited
reconnaissance capability installing a similar nose as the RF-5A had.
This solution had already applied earlier to some Saudi Northrop F-5E
but was unsatisfying as the nose was too small to accept latest
reconnaissance equipment; the company decided therefore to go (using
company funds) for a new
design carrying sensors as cameras or infrared systems on quick-change pallets inside the lengthened, strengthened, wider nose. It would have similar capacity
the McDonnell RF-4E for countries already operating the Tiger, a market for between 100 and 150 aircrafts was forecasted.
An alternative possibility to convert Northrop F-5E Tigers fighter into
reconnaissance aircrafts was not considered by Northrop as not effective due to
the high costs.
One of the Northrop F-5E
Tiger prototypes (74-01420) was leased back from USAF to be converted as prototype and first flown as RF-5E on 29-01-79 from Edwards AFB's Air Force Flight Test Center.
Flight evaluation took
place at the same base; the aircraft was converted again to fighter
configuration by December 1979/April 1980,
at the end of the evaluation. Demonstration flights were hold during
this period to possibe non US customers: Jordan, Thailand, Korea,
China/Taiwan, Saudi Arabia, Malaysia, Norway, Switzerland, Morocco and
Northrop RF-5E 11420 seen on 14-03-79 in its original metallic colours; clearly visible the
undernose camera windows.
Camouflaged Northrop RF-5E 11420 on a test flight. Photo: Northrop
It was shown also at the Le Bourget (France) show in June 1979
but the sales were disappointing mainly due to the high cost (50% more
than the fighter). Only 12 aircrafts were sold: two bought by Malaysia and ten by Saudi
for a reconnaissance version of the Tiger was still felt in Asia
beginning of the 1990s; Singapore initiated a programm to locally
convert eight Northrop F-5E to reconnaissance aircrafts by STAerospace in 1991, delivered in 1994. The same company converted seven Republic of China (Taiwan) Northrop F-5E to the reconnainsance version with initial delivery in August 1997.
See under the respective Air Forces pages for information regarding delivey/use of the Northrop RF-5E.
Northrop F-5G / F-20 Tigershark
third generation of the
Northrop product with the latest airframe, engines, radar
and avionic features was studied beginning mid-70s, keeping in mind the same requirements as the previous versions: low cost, ruggedness and ease of operation.
The study ended with the construction of the Northrop F-5G,
later redesignated F-20, first flown on 30-08-82.
It had little connonality with the earlier version, though initially designated in the F-5 range
Politics first blocked the sale of this fighter;
authorisation to sell the more advanced,
expensive and complicated General Dyna-
mics F-16 abroad in 1983 gave the death
the project. Three airframes had
been built, two of which were lost
an additional airframe was only partially
completed. Presence of the fighter at Edwards AFB with the 6512 Test Wing
was from 10-04-84 till April 1985.
By 1986 Northrop
had incurred in a loss of
USD 1,2 billion, when
No further details of this third F-5 generation
fighter are included as this is outside the
scope of this study.
The third prototype, N4467I, in a spectatular
End of Northrop production
of F-5E, F-5F Tiger variants was completed on 16-01-87 with the
hand-over at Northrop's Palmdale plant of two single-seater Tiger to the
Bahrain. These were not the last as five additional Northrop F-5E and 3 F-5E were assembled from spare parts for Singapore by the beginning of July 1989, almost to underline the vitality of the design.
Final variants seen in flight: Northrop F-5F N3139Y, F-20A N4416T (both Northrop demonstrators)
and Malaysian AF RF-5E M29-20.
The exact number of Tiger built is 953 divided in 4 prototypes built at Hawthorne, 941 at Palmdale and 8 at Mojave (from spare parts); exactly how many of each type is not known.There are several versions: F-5E 792/793 RF-5E 12, F-5F 146
(F-5E 786, 793, F-5F 140,147 Who can help?).
A total of around 2'160 aircrafts of all variants were built by Northrop or built under licence abroad,
an enormous success in consideration that the aircraft was not originally taken in consideration by the US Air Force.
Northrop's Tiger upgrades/life extension
and other US companies, had no luck in selling F-5 upgrade programs,
mainly due to missing government support (F-5G/F-20) and
late entry into the hard fought update market for Freedom Fighters and Tigers.
The second Northrop F-5E prototype was used at Edwards AFB, starting from November 1982,
for trials of the Northrop AN/ALQ-171(V) pod-mounted Conformal
Countermeasures System, partially paid by the Swiss government. This pod fitted around the underfuselage pylon,
allowing the pylon to carry external fuel or ordnance. The
prototype completed a nine flights demonstration program at Edwards AFB
that included aircraft handling and jamming capabilities; additional
tests were held beginning 1983 at the USAF Electronic Warfare
Environment Simulator at Fort Worth, completed in June 1983.
Another upgrade trial took place in 1985, when an Emerson APG-69 was installed in a
Swiss double-seater (J-3209); the aircraft was demonstrated at the Le
Bourget Air Show in June 1985 without any sales success. Another radar set was installed on a USAF 425th Squadron Northrop F-5F and completed 200 test missions at Williams AFB.
One Tiger was tested in 1991 at Fallon NAS with an
Westinghouse APG-66 radar, but the radar was again not adopted by any Air Force.
(Northrop had purchased Grumman in 1994) tried to
enter the upgrade market at the end of 1993 with an avionics upgrade in
order to establish the Northrop F-5s as a lead-in trainer to the
General Dynamics F-16.
One of the 127 Sqns, serial 741568 code 46, was modified to represent an improved aircraft named Tiger IV from 20-04-95 to the end of 1997.
initial 12 flights concentrated on evaluating air-to-air modes of the
Westinghous APG-66 pulse-Doppler radar, doubling the detection range,
after which the aircraft was grounded for a software upgrade. A furter
seven flights tested air-to-ground radar modes of the integrated
weapon-system and delivery. This version was offered in several possible packages; costs were lowered using
components already in use in various other aircrafts. Main packages
included 1 or 2 Bendix Multifunction Displays as used by the Taiwanese
IDF, a GEC Head Up Display as used by the F-16, an
Westinghouse APG-66 radar, an INS, HOTAS control and many other
features; one cannon had to be removed to allow space for the new
aircraft was reconfigurated to a normal Northrop F-5E end of 1997, and
re-delivred to the US Navy, as no interest was shown by the various Air
Forces. Cost of the
modifications had been sustained by the various firms supplying the
Northrop F-5E 741568 modified as Tiger IV
The project was realised in partnership with the Air Force San Antonio
Air Ligistics Center; stored Northrop F-5E (serial 741568) was obtained as a free loan in 1994 from the US Navy, avionics companies supplied their products, NorthropGrumman
made a structural upgrade. The first flight of the modified aircraft
took place on 20-04-95 from Los Angeles International Airport,
transferring directly to Edwards AFB were it underwent on a six months test
The project had no luck, though partial modifications, according to the client's wishes were offered; the aircraft was modified back to the original version in 1998.
US Navy airframe/avionics modifications
Worn-out US Navy Tiger airframes needed to be replaced by the beginning of the 2000 years. Several options were taken into consideration; a modification/upgrade program
by Norair, involving initially 32, later 44 former low-time (an average
of 2'500 flight/hours) Swiss Northrop F-5E, was selected.
The program started in 2003 (with the delivery of airframes from Emmen, Switzerland): 41 were modified at St Augustine's Manufacturing and Flight Test Center as upgraded single-seaters with the designation Northrop
F-5N, three were converted as double-seaters, keeping the designation
F-5F, the forward fuselage being replaced by an original, refurbished US Navy one. The programm ended on 29-04-09
with the handing over to the US Navy of the last aircraft.
critical components were replaced. areas of the aft fuselage were
refurbished, newly designed upper cockpit longerons were installed,
avionics were brought up to present standard, aircrafts were completely
rewired, the liquid oxygen system was replaced by a gaseous one,
anti-skid brakes were added. The conversion lasting approximately five months with the cost of around USD 1m each.
Tiger" Northrop F-5F 761586 roll-out on 23-04-08 at the St Augustine plant,
the aircraft was
delivered to the US Marines, colours were changed to standard camouflage.
Photo: Northrop Grumman
Last modified ex Swiss F-5E (serial
761550) seen at the handing over ceremony at the St Augustine plant.
Photo: Northrop Grumman
A first increase in service life to 8'000 hours (the Northrop F-5E anf F-5F were
originally cleared for a service life of 4'000 flying hours) was granted in 1977 following thorough tests on a complete
Northrop F-5E airframe. The new clearance was given in the assumption
of 85 percent of flights in air-combat and 15 percent for ground-attack missions.
A great number of Freedom Fighters and Tigers built between 1968 and 1989 are
still in use with many Air Forces. This dictated the necessity to
maintain and enhance the structural integrity of the airframes.
Grumman was selected in 1995 to manufacture 14 new wings, upper and
lower cockpit/dorsal longerons, fuselage bulkheads and other parts for
foreign Northrop RF-5A, F-5A, F-5B, F-5E, F-5Fs; the company
contemporanously expanded its spare parts business providing a
"one-stop" team for
total support of the fighters. Upgrade retrofit kits, including INS/GPS
navigation system, antiskid brakes, an onboard oxygen-generating system
to reduce costs compared to the early liquid oxygen system were also
The role of the Tiger switched in
the world more and more to that of a lead-in trainer; the company
offered (without success) in mid 90's a conversion kit to convert
single-seaters F-5E to double-seaters F-5F with new manufactured
Beginning of 2005 Northrop developed a new system support plan in order to enable the users
to obtain part of the necessary structure and other spare parts from another company. A teaming
agreement was signed on 04-05-10 with the Swiss company RUAG
Aviation to provide worldwide sustainment and life cycle logistics, as well as modifications and upgrade programs, to countries flying the F-5 Tiger. RUAG is the prime support provider for the Swiss Air Force and other F-5 operators.