The Northrop F-5 "Freedom Fighter" / "Tiger"

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The F-5 is a lightweight, easy-to-fly, simple-to-maintain, and (relatively) cheap supersonic fighter. Today, this versatile aircraft serves in the air force inventories of 27 countries. It is a lightweight, easy-to-fly, simple-to-maintain, and (relatively) cheap supersonic fighter that was selected in the early 1960's for use by underdeveloped countries as part of the U.S. Military Assistance Program (MAP).

Its origins can be traced to design studies begun by Northrop in the mid-19501s. The development of the Northrop F-5 began in 1954 when a Northrop team toured Europe and Asia to examine the defense needs of NATO and SEATO countries. A 1955 company design study for a lightweight supersonic fighter that would be relatively inexpensive, easy to maintain, and capable of operating out of short runways. Development proceeded along two lines.

The Air Force did not initially look favorably upon the proposal, since it did not need for a lightweight fighter. However, it did need a new trainer to replace the Lockheed T-33, and in June of 1956 the Air Force announced that it was going to acquire the trainer version, the T-38 Talon. In response to this USAF requirement for a supersonic trainer, the two-place T-38 Talon was produced. First flight took place on April 10, 1959, and eventually 1189 of these aircraft were manufactured for use by the USAF, the Navy, NASA, and the Federal Republic of Germany. Most of these were delivered by the mid-1960's. In addition to its trainer and pilot proficiency roles, the T-38 was flown for a number of years by the USAF Thunderbird exhibition team.

First flight of the prototype of the fighter version of the aircraft, designated F-5, occurred in July 1959. On April 25, 1962, the Department of Defense announced that it had chosen the aircraft for its Military Assistance Program (MAP). America's NATO and SEATO allies would now be able to acquire a supersonic warplane of world-class quality at a reasonable cost. On August 9, 1962 the aircraft was given the official designation of F-5A Freedom Fighter. Later known as the Tiger, initial deliveries of the F-5 were made to Iran in January 1965. Attracted by its performance, reliability, and low cost (in 1972, the cost of an F-5 was about one-third that of an F-4), other countries outside MAP soon began buying the F-5.

Optimized for the air-to-ground role, the F-5A had only a very limited air-to-air capability, and was not equipped with a fire-control radar. The F-5B was the two-seat version of the F-5A. It was generally similar to the single-seat F-5A but had two seats in tandem for dual fighter/trainer duties.

The F-5 was originally designed as a daytime, air-to-air fighter, but it has also been extensively used as a ground-attack aircraft. Photoreconnaissance versions of the F-5 have also been produced. Armament for the air-to-air combat role consists of two 20-mm cannons and two Sidewinder missiles. Radius of a typical air combat mission with this armament and external fuel tanks is 375 miles, and average mission speed is 541 miles per hour. In the ground-attack mode, about 7000 pounds of external ordnance may be carried. Evaluated in Vietnam by the USAF, the F-5 was later used by Vietnamese forces. Never a part of the USAF tactical forces, it has been used as an aggressor aircraft to represent a hostile fighter in simulated combat with U.S. fighters. Some of the characteristics of the F-5 resemble those of the Soviet-built MIG-21 in certain altitude ranges.

In configuration the F-5 is a low-wing monoplane equipped with an all-moving horizontal tall mounted in the low position; the fuselage is carefully contoured in accordance with the transonic area rule. Small side-mounted inlets supply air for the two General Electric J85 afterburning turbojet engines. The 4.8-percent-thick wing has 24 sweepback at the quarter chord line. The wing trailing edge is nearly straight, giving a trapezoidal shape to the planform. Lateral control is provided by small ailerons located near midsemispan; single-slotted high-lift flaps extend from the inboard end of the ailerons to the sides of the fuselage. Leading-edge flaps are used to improve maneuvering performance. These flaps are not incorporated in the wings of the T-38. Speed brakes are mounted on the bottom of the fuselage. Turning performance is enhanced by an aileron-rudder interconnect system, and handling characteristics are improved by artificial damping about the pitch and yaw axes. The F-5 is reported to have good handling characteristics and, in contrast with the F-4, does not have a propensity for entering unintentional spins.

Although all F-5A production was intended for MAP, in October 1965, the USAF "borrowed" 12 combat-ready F-5As from MAP supplies and sent them to Vietnem with the 4503rd Tactical Fighter Wing for operational service trials. This program was given the code name of *Skoshi Tiger" ("little" Tiger). and it was during this tour of duty that the F-5 picked up its Tiger nickname. Evaluated in Vietnam by the USAF, the F-5 was later used by Vietnamese forces.

On November 20, 1970, the Northrop entry was declared the winner of the IFA (International Fighter Aircraft) to be the F-5A/B's successor. The emphasis was be on the air-superiority role for nations faced with threats from opponents operating late-generation MiG-21s. An order was placed for five development and 325 production aircraft. In January of 1971, it was reclassified as F-5E. The aircraft came to be known as Tiger II.

The F-5E is a small, light aircraft. Its design gross weight of 15 745 pounds is only about 30 percent of the 53 848-pound design gross weight of the F-4. In performance, the F-5 has a Mach 1.51 capability at about 36000 feet and a sea-level rate of climb of 28 536 feet per minute - a good performance but not comparable with that of the F-4. Certainly, the load-carrying capability of the F-5 is much less than that of the larger aircraft.

Never a part of the USAF tactical forces, it has been used as an aggressor aircraft to represent a hostile fighter in simulated combat with U.S. fighters. Some of the characteristics of the F-5 resemble those of the Soviet-built MIG-21 in certain altitude ranges. The US Navy Fighter Weapons School (the so-called "Top Gun" school) at NAS Miramar acquired a total of ten F-5Es and three F-5Fs for dissimilar air combat training. Because of the F-5's characteristics, which were similar to the MiG-21, was used as 'agressor' aircraft, equipping the FWS and VF-126 at NAS Miramar, plus VF-43 at NAS Oceana. All three units later disposed of their Tiger IIs in favor of the General Dynamics F-16N. These Tiger IIs were passed on to VF-95 at NAS Key West and VFA-127 at NAS Fallon. During FY 1996, VFC-13 moved from NAS Miramar, CA, to NAS Fallon, NV, and transitioned from 12 F/A-18 to 25 F-5 aircraft. VFC-13's flight hour program increased to offset the scheduled decommissioning of the two remaining Active Component adversary squadrons, VF-45 and VFA-127. This transition to the F-5 adversary aircraft provided Active and Reserve Navy pilots with air-to-air combat training at significant savings to the taxpayer. Recent estimates show that the F-5 can be operated at one third of what it costs to operate an F/A-18.

F-5 Freedom Fighter / Tiger
Specifications
	F-5A Freedom Figher	F-5E Tiger II
Engines	Two General Electric J85-GE-13 turbojets, rated at 2720 lb.s.t., 4080 lb.s.t. with afterburning.	Two General Electric J85-GE-21A turbojets, 5000 lb.s.t. with afterburning.
Maximum speed	925 mph (Mach 1.4) at 36,000 feet. Maximum cruising speed: 640 mph (Mach 0.97) at 36,000 feet	Maximum cruising speed without afterburning: Mach 0.98 at 36,000 feet.
Service ceiling	50,500 feet.	51,800 feet
Range	with maximum fuel -- 1387 miles. Combat radius with maximum payload -- 195 miles Combat radius with maximum fuel and two 530-pound bombs 558 miles.	with maximum fuel -- 1543 miles Combat radius with maximum fuel and 2 Sidewinder missiles -- 656 miles.
wingspan	25 feet 3 inches,	26 feet 8 inches
length	47 feet 2 inches,	48 feet 2 inches
height	13 feet 2 inches,	13 feet 4 inches
wing area	170 square feet.	186 square feet
Weights:	8085 pounds empty, 11,477 pounds combat, 13,433 pounds gross, 20,677 pounds maximum takeoff	9683 pounds empty, 13,350 pounds combat, 15,745 pounds gross, 24,676 pounds maximum takeoff.
Armament	two 20-mm cannon in the fuselage nose. Two AIM-9 Sidewinderat the wingtips Five pylons carry up to 6200 pounds of ordinance or fuel tanks loads can include four air-to-air missiles, Bullpup air-to-surface missiles, bombs, up to 20 unguided rockets, or external fuel tanks.	two 20-mm M39A2 cannon with 280 rpg two AIM-9 Sidewinder missiles at wingtips Five pylons can carry up to 7000 pounds of ordnance or fuel

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F-5A Freedom Fighter

F-5E Tiger II

F-5F Tiger II

The F-5E aircraft is a fixed wing, supersonic aircraft armed with two 20mm guns and two sidewinder AIM-9 air-to-air missiles. The aircraft is an improved model of an existing system and is essentially an off-the-shelf procurement. It was designed for use by allies primarily as an air superiority fighter for local air defense with a secondary air-to-ground capability. These were procured in small numbers by the US Air Force and Navy for their "Top Gun" / Air Combat Maneuvering schools, as performance - and size - wise they were a close match for the very numerous MiG-21. Being cheaper and easier to maintain than the F-15 and F-16 type aircraft, many US allies also purchased these upgraded aircraft, as well.

The F-5E is a single-seated twin engine aircraft. There is one underfuselage and four under-wing pylons for missiles, bombs, and rocket packs. The F-5E is indeed a small, light aircraft. Its design gross weight of 15,745 pounds is only about 30 percent of the 53 848-pound design gross weight of the F-4. In performance, the F-5 has a Mach 1.51 capability at about 36000 feet and a sea-level rate of climb of 28 536 feet per minute - a good performance but not comparable with that of the F-4. Certainly, the load-carrying capability of the F-5 is much less than that of the larger aircraft. The F-5E comes equipped with an Emerson AN/APQ-159 radar.

The F-5E Tiger II was a greatly improved version of the earlier F-5A Freedom Fighter. Redesigned as a highly maneuverable, lightweight and inexpensive air superiority fighter, the E model featured an air-to-air fire control radar system and a lead computing gunsight. More powerful J85 engines required the fuselage to be both widened and lengthened. The forward wing root was redesigned to give the "Tiger II" wing its characteristic triple delta shape.

In December 1970, Northrop Grumman began development and production on the F-5A-21, an aircraft design that emphasized maneuverability rather than high speed and was officially reclassified as the F-5E. Originally, Northop Corporation, Aircraft Division began working on an improved F-5 as a private venture. Further development in aerodynamics and engines led to the F-5E and F (the C designation going to those aircraft used in the Skoshi Tiger tests.) On December 8, 1970, Northrop was awarded a fixed-price incentive contract for engineering development and production of the 1?-5E airframe. The contruct award price was $415.6 million, if all five fiscal year options were exercised for 325 aircraft. SPO records showed a June 30, 1972, estimate for the total 325 aircraft program to be $705.6 million. This was an increase of $8.3 million over the total program estimate (MASF, MAP, FMS--325 aircraft) as of June 30, 1971. The first flight of the F-5E was on Aug. 11, 1972.

The General Electric Company was awarded a cost-plus-incentive-fee contract on March 1, 1971, for engine development. On May 20, 1971, a letter contract was executed by the Air Force to preserve the engine procurement schedule. This letter contract was definitized as a fixed price redeterminable contract on September 17, 1971. The aggregate initial tlcvelopment and production contracts was $9.086 million. As of June 30, 1972, the aggregate of these contracts was $53.287 million resulting from quantity increase to meet schedule requirements.

By 1975 Northrop's F-5E air superiority fighter had successfully completed a comprehensive Aircraft Structural Integrity Program (ASIP), including a flight flutter and flight loads survey program, and a static test and fatigue test program. The primary objective of the ASIP master Plan was to insure that the aircraft's structural design would operate satisfactorily when subjected to the conditions associated with air-to-air combat and air-to-ground weapon delivery in peacetime and in hostile environments. The F-5E fatigue program was formulated during a transition phase of fundamental change in USAF Aircraft Structural Integrity Program Philosophy. Therefore, this program was primarily structured to meet existing requirements while utilizing state-of-the-art techniques in fatigue analysis and fracture mechanics.

The first USAF unit to receive the aircraft was the 425th TFS at Williams Air Force Base, Ariz., responsible for training foreign pilots in the F-5 aircraft. The most well-known use of the "Tiger II" was as an aggressor aircraft at the USAF Fighter Weapons School, Nellis Air Force Base, Nev. The 425th Tactical Fighter Training Squadron was reactivated at Williams AFB, Ariz., on Oct. 15, 1969 and was assigned to the 58th Tactical Fighter Training Wing at Luke AFB, Ariz. The squadron's new mission was to train aircrews from friendly nations to fly and fight in the F-5. The first F-5E Tiger II was delivered to the 425th April 6, 1973. The 425 TFTS was reassigned to the 405th Tactical Training Wing as of Aug. 29, 1979 and the unit was activated at Luke. In June 1989, the squadron's F-5 training program terminated after having produced 1,499 graduates. The 425th was inactivated Sept. 1, 1989.

The aggressor pilots of the 64th Fighter Weapons Squadron were trained in Soviet tactics and used the Es to similate MiG-21s for training USAF pilots in aerial combat skills. Eventually, aggressor squadrons were formed at RAF Alconbury, U.K., and Clark AB, PI, for training USAF pilots stationed overseas along with pilots of friendly foreign nations. The Aggressors were established with the mission to provide realistic, enemy oriented, dissimilar air combat tactics training for United States Air Force fighter units. They accomplished this mission since 1973 with first the Northrop T-38 and later the Northrop F-5E. The F-5E is an acceptable simulator of the Soviet built MIG-21 Fishbed which was originally produced in the early 1960's.

The 527th Tactical Fighter Training Aggressor Squadron, flying F-5E “Tiger IIs,” activated at RAF Alconbury on 01 April 1976. The squadron provided combat training to North Atlantic Treaty Organization forces by teaching and demonstrating soviet air tactics-under the title of Dissimilar Air Combat Tactics. The 527th flew the first “Aggressor” sortie from RAF Alconbury in May 1976. [During 1988, two squadrons of A-10A “Thunderbolt IIs,” the 509th and 511th Tactical Fighter Squadrons, arrived from RAF Bentwaters/Woodbridge, and as the A-10s arrived, the 527th Aggressor Squadron moved to RAF Bentwaters.]

In 1977, the bulk of two major air-to-air tests were flown on an instrumented air combat maneuvering range north of Nellis Air Force Base, Nevada: the Air Intercept Missile Evaluation (AIMVAL) and the Air Combat Evaluation (ACEVAL). These tests pitted "Blue Force" F-15s and F-14s against "Red Force" F-5Es, chosen to simulate the Soviet-built MiG-21. AIMVAL’s test matrix included Blue-versus-Red force ratios of 1-v-1 (one F-15 or F-14 versus one F-5E), 1-v-2, 2-v-2, and 2-v-4, and called for 540 valid engagements involving 1,800 sorties. ACEVAL’s test matrix added 2-v-1, 4-v-2, and 4-v-4 trials to the four force ratios used in AIMVAL and required a total of 360 valid engagements involving 1,488 sorties. The results of AIMVAL/ACEVAL were highly controversial at the time -- "superior" Blue fighters, avionics, and missiles had not dominated Blue-Red exchange ratios nearly as much as had been expected. This confirmed past combat experience, especially its implication that situation awareness explained why people were shot down four times out of five.

By the 1980s the Russian air combat threat has changed into a more sophisticated fighter force, including modern Soviet air combat fighters such as the MIG-23 Flogger, MIG-31 Foxhound, MIG-29 Fulcrum, and SU-27 Flanker. The F-5E was not an acceptable simulator for any of these aircraft, though an upgraded F-5E with an improved radar could serve a part-task simulator for only the MIG-23 Flogger.

Prior to the deactivation of the 65th Aggressor Squadron in 1989, the pilots flew the F-5E Tiger II. The squadron flew more than 250,000 sorties in more than 1,000 training deployments in the U.S. and overseas.

The F-5 aircraft provides air to air combat training to graduate level pilots and carrier air wings at 3 locations in the continental United States. Program Manager Air 207 (PMA207) is delegated authority and is ultimately responsible and accountable to the Commander, Naval Air Systems Command (COMNAVAIRSYSCOM). PMA207 has been tasked by COMNAVAIRSYSCOM to provide contract maintenance, logistics management, and administration in support of this mission.

	SITE		UNIT		T/M/S	QNTY.

	NAS Fallon	VFC-13		F-5E/F/N	   15
	MCAS Yuma		VMF 401		F-5/F/N	   12
	NAS Key West	VFC-111	   	F-5/F/N	   20

The aircraft are configured with Tactical Air Combat Training System (TACTS) pods, AIM-9 captive missiles, and external fuel tank as required. Heads Up Display (HUD), video camera, and various Electronic Countermeasures (ECM) equipment may be incorporated into the F-5. It is inherent in meeting mission commitments that operational aircraft are available for flight. In order to meet squadron mission flight requirements, a Ready For Tasking (RFT)rate of 80% is required for the flight schedule. RFT is defined as an aircraft ready for a specific event on the daily flight schedule. The rate is computed as a percentage of total aircraft in reporting. The aircraft will routinely deploy to other USN/USAF/USMC bases for unit training missions while continuing to operate at home base.

VC-13 was redesignated as FIGHTER SQUADRON COMPOSITE THIRTEEN (VFC-13) on April 22, 1988, in recognition of the squadron's more focused role of fleet adversary support. In 1988, the "Saints" transitioned to the A-4F "Super Fox", a more powerful and capable version of the Skyhawk. In October 1993, VFC-13 transitioned to the single-seat, two engine F/A-18 "Hornet". Budget cuts associated with the post cold war "right sizing" of the Navy resulted in the squadron transitioning to the F-5E/F Tigher II and relocating to NAS Fallon, NV in March of 1996. NAS Fallon, the "Saints" new home, is the primary location for all Navy carrier-based tactical aircrew training. VFC-13 adversary pilots work closely with the Naval Strike and Air Warefare Center (NSAWC) to provide the best air combat training possible.

Activated in 1986, VMFT-401 is the Marine Corps’ only aggressor squadron, utilizing the flight characteristics and appearance of the F-5E Tiger and their other aircraft, the F-5N Tiger II, to mimic various types of threat aircraft. This enables other Marines to stay prepared for any air-to-air combat situations that may arise.

The F-5 Tiger II is used by the Navy and Marine Corps at Naval Air Station Fallon, NV, and Marine Corps Air Station Yuma, AZ, in the adversary mission. Thirty-two single-seat F-5E and four F-5F aircraft performed well since being introduced into this very demanding role in 1975. A strain survey and fatigue life assessment completed in 1998 indicated the aircraft could remain in service for another 15 years through FY15. This, combined with interest from the Chief of Naval Operations to continue the F-5 as the backbone of the adversary force, prompted the development of “Tiger 2015”. Tiger 2015 is a strategy developed to ensure the continued safe, reliable, and cost effective service of the aircraft to FY15 and beyond. It consists of a multi-faceted approach, combining a mix of component replacements, avionics upgrades, and additional testing and analysis to ensure the aircraft will reach the FY15 objective.

The F-5F two-seat trainer variant retains full combat capability. The fuselage was lengthened by 1.02 meters (3 feet 4 inches). Development was approved by the USAF in early 1974, and the first flight was on 25 September 1974. In summer 1976, the first of 118 aircraft was delivered. The Brazilian export version incorporates a large dorsal fin to accommodate an ADF antenna. The F-5Fs exported to the Royal Saudi air force featured a Litton LN-33 INS and IFR capability.

A laser device enables aircrews of the F-5F jet fighter to pinpoint ground targets for laser-homing weapons. Senior research assistant Lee Wofford adjust the device, called a laser designator, at Hughes Aircraft Company's electro-optical and data systems group, Culver City, CA. The compact laser designator is part of a Laser Target Designator System (LTDS) that is designed to fit the narrow space between the back seat and the left side of the F-5F fuselage. In operation, the observer sights a target through an optical telescope and fires the laser designator. The beam passes through the aircraft canopy to the target and is reflected like a beacon. Laser-homing weapons sense the reflected laser light and guide themselves to the target. Hughes produced the laser designator in the late 1970s for Northrop Corporation, prime contractor for the LTDS, which are manufactured for foreign military sales.

When an aircraft rolls off the production line, it's expected to be in service for a certain number of flight hours, which constitutes the "fatigue life" of the airframe. This fatigue life projection assumes a certain usage pattern for the aircraft, in terms of the type and quantity of maneuvers it performs while in service. The Naval Air Systems Command (NavAir) keeps track of the usage pattern of the planes, and that information is used to determine how quickly the airframe fatigue life is being expended. In the mid-1990s the algorithms used by NavAir to monitor F-5 fatigue life expended (FLE) were updated. The new algorithms were used with recent analytical loads data from Northrop to calculate the fatigue life remaining to the fleet of F-5 aircraft, which unfortunately resulted in a significant life reduction from what had previously been expected.

As of 1999 the Taiwan Air Force (TAF) had about 70,000 personnel and over 400 combat aircraft. The current inventory includes approximately 180 older F-5E/F fighters and over 100 more modern Indigenous Defense Fighters (IDFs). In 1982, the year in which the Second Force Modernization Program was launched, the ROK began producing F-5F fighter-bombers in a joint venture with the US contractor Northrop.

DCMA AIMO – St. Augustine’s Aviation Program Team, located at Northrop Grumman’s St. Augustine Manufacturing Center, oversees a complex mix of active, reserve and international contracts. Their responsibilities include the monitoring of the Swiss upgrade of excess F-5E/F Tigers to a U.S. Navy Reserve/U.S. Marine Corps Reserve F-5N configuration.

F-5E upgrades are offered by several companies including IAI, which upgraded Chile's aircraft with the Elta M-2032 radar, new avionics, HUD, and HOTAS. A staged upgrade program with similar features is offered by Northrop Grumman.

References

Testing may give F-5E longer lease on life Tester February 26, 1997 -- Recently, the algorithms used by NavAir to monitor F-5 fatigue life expended (FLE) were updated. The new algorithms unfortunately resulted in a significant life reduction from what had previously been expected.

Northrop F-5 Joe Baugher's American Military Aircraft Encyclopedia



F-5A Freedom Fighter	F-5C Tiger	F-5D Tiger II

F-5 Freedom Fighter / Tiger

F-5A Freedom Fighter

F-5E Tiger II

F-5F Tiger II

References