Development/Production  -  Northrop  F-5E  - Tiger

Flight 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 demon-
strated 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 manu-
factures, 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 a versionof 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.

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                                                                                                     Construction lines for Northrop F-5Es              Photos: Northrop

The 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 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.

Static 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. The aircraft was fluly combat capable (as the other prtotypes)
.

Engine malfunctions happend the same month, 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 Electric. 


                                                               frame 1    Photo: unknown
                                                         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.

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Prototype number two with Tiger painted on tail landing on 11-04-79 at Edwards AFB.                                      Northrop F-5E 11418 testing GPU-5A 30mm underbelly cannon   Photo: Northrop
Of note 30mm underfuselage gun pod                                                Photo: USAF/J. Porter

                                                                                frame 1    Photo: MBB
                                                                                               MBB Modular Dispenser System demonstration and test prototype under the fuselage of the
                                                                                               second Northrop F-5E prototype.

Thirty 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 simu-
lated. 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.

In 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 to the US Air Force between 1976 and 1981 and used at Williams AFB for training.

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Wingtip Sidewinder and LGBs underwing plus tests noseboom  
Photo: Northrop                             A little known configuration/test of second prototype Northrop F-5E 11418 with 4 Hughes
                                                                                                                                         AGM-59 Mavericks, configuration available only to SaudI Arabia.

                                                            See under the respective Air Forces pages for information regarding delivey/use of the Northrop F-5E.
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Development/Production  -  Northrop  F-5F  Tiger

                                                                                                   frame 1         Photo: Northrop
                                                                                     Sidewinder armed prototype serial 00889 on official roull-out, Hawthorne 14-08-74


No second generation conversion trainer was initially deemed 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 traine. This was combat capable and first flew on 25-09-74; it had a longer nose whiich enabled the provision of on M39 20mm cannon,
it had an Emerson AN/APQ-157 radar with dual control and display systems with the same range (ca 10miles) of the single-seater
AN/APQ-133.

Two Fiscal Year 1973 (00889/00891) were completed as two-seaters, both aircrafts first flying from Edwards AFB on 25-09-74 where they remained, undergoing several additional tests.

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   Photo: USAF              frame1
               First prototype with AIM-9J Sidewinder, testing an underwing target pod                                  Second prototype ready for armament/bombs tests in -11-76. In the backgound Northrop F-5E 11419

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 customers at 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 technicians.
   frame 1   Badge 6512 Test Sqdn       frame 1                 frame 1   Tail on show at Le Bourget
                                                First prototype F-5F 00889 at Kefkavik on the way to Le Bourget air-salon on 16-06-75 in a typical Groenland day.

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      The second prototype being prepared for spin tests on 10-11-76 at Edwards AFB.                              Weapons tests on 16-11-75 at Edwards AFB with 250 l(500?) lbs bombs and Sidewinders
      of note the extra long nose pitot tube.                                    Photo: unknown
                     
                                            See under the respective Air Forces pages for information regarding delivery/use of the Northrop F-5F

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Development/Production  -  Northrop  RF-5E  Tiger
Original Northrop plan was to provide the Tiger with limited reconnaissance capability, installing a similar nose as the RF-5A; This solution had already applied earlier to some Saudi Northrop F-5E  (see below)

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                                                                    Mix of 2 Saudi Arabian Northrop F-5E with early Northrop RF-5A nose, 2 standard Northrop F-5E
                                                                    and an air-refuelling Lockheed KC-130H
.

The solution was unsatisfying as the nose was
not effective due to the high costs and too small to accept, new, 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 as the McDonnell RF-4E for countries already opera-
ting the Tiger, a market tht was forecasted for between 100 and 150 aircrafts.


Therefore, 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.

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Northrop RF-5E 11420 seen on 14-03-79 in its original metallic colours; clearly visible the                                             Camouflaged Northrop RF-5E 11420 on a test flight.        Photo: Northrop
undernose camera windows.

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). Flight evaluation took place at the same base; the aircraft
was converted again to a pure fighter configuration by December 1979/April 1980, at the end of the evaluation.
Demonstration flights had been hold during this period to possibe non US customers: Jordan, Thailand, Korea, China/Taiwan, Saudi Arabia, Malaysia, Norway, Switzerland, Morocco and Portugal, thourgh o
nly 12 new
aircrafts were ever sold
: two bought by Malaysia and ten by Saudi Arabia


Northrop F-5E conversion to Northrop RF-5E Tiger (new standard)
Necessity 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.


                                                                                       frame 1        Photo: unknown
                                                                                    Saudi Arabian Northrop RF-5E seen in 1985 on final tests in USA

                                                                               See under the respective Air Forces pages for information regarding delivey/use of the Northrop RF-5E.
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End of Tiger production
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-seaters Tiger to 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.

                                                                                   frame 1          Photo: Northrop
                                              Final variants seen in flight: Northrop F-5F N3139Y, F-20A N4416T (both Northrop demonstrators) and Malaysian AF RF-5E M29-20.

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.
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Upgrades - Life extension of Northrop F-5E/F-5F Tigers

Upgrades
Northrop, and other US companies, had no luck in selling F-5 upgrade programs (as well as thenew light fighter(F-5G/F-20) mainly due to missing government support and late entry into the hard fought update market
for Freedom Fighters and Tigers.

frame 1         Northrop publicity

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. The pod was not adopted by any country
.

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.
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(Northrop had purchased Grumman in 1994) tried to enter the very competiteve 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.

The project was realised in partnership with the Air Force San Antonio Air Ligistics Center; stored Northrop F-5E (serial 74156) was obtained as a free loan 1994 from the US Navywas modified to represent between
April 1995 and the end of 1997 an improved version named "Tiger IV";
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 wHere it underwent a six months flight test program.

The 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 weapons 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 avionics.

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      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 at the end 1997 and re-delivered to the US Navy as no interest was shown by Air Forces.
      Costs of modifications had been
sustained by the various firms supplying the avionics. The aircraft was reconfigurated to a
      normal Northrop F-5E end of 1997.



      

           Tail emblem

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         Super Tiger...Patch


  Northrop F-5E 741568 modified as Tiger IV US Navy airframe/avionics upgrading
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New "old" US Navy Tigers
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 "Franken Tiger" (not officially), the forward fuselage being replaced by an original, refurbished US Navy aircrafts. The programm
ended on
29-04-09 with the handing over to the US Navy of the last aircraft of the first batch; additional 42 were bought by the US Navy, first delivery to St Augustine plant for modification in 2020. They will also
modified to Northrop F-5N standard.


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Last modified, ex Swiss F-5E (serial 761550) seen at the handing over ceremony at the             "Franken Tiger" Northrop F-5F 761586 roll-out on 23-04-08 at the St Augustine plant,
St Augustine plant.                                                                                                                                        the aircraft was delivered to the US Marines, colours were changed to standard camouflage.
                                                                                                                                               Photos : Northrop Grumman

Critical fatigue components were replaced. areas of the aft fuselage were refurbished, newly designed upper cockpit longerons were installed, avionics were brought up to the ๖atest 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.

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Life extension
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% for ground-attack missions.


A great number of Freedom Fighters and Tigers built between 1968 and 1989 ewre still in use with many Air Forces. This dictated the necessity to maintain and enhance the structural integrity of the airframes.

Northrop 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 offered.

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 forward fuselages.


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.