Northrop F-5 Freedom Fighter
From Scramble - The Aviation Magazine
|Northrop F-5 Freedom Fighter|
|Role||Multi role fighter|
|First Flight||31 July 1963|
Northrop developed a lightweight jet fighter in 1953, the N-102 Fang, with the experiences in Korea in mind. Eventually this would be the basis for the N-156F in 1956 and a trainer version, the N-156T. The US Navy withdrew from the project, but the US Air Force continued its support. The trainer N-156T made its first flight as the X-38 on 10 April 1959. The fighter version, the N-156F, made its first flight 30 July 1959, reaching Mach 1 in the process. All N-156 and subsequent F-5 versions were powered by General Electric J85 turbojets, which had originally been intended as the engine for the McDonnell ADM-20 Quail decoy drone. The F-5 was armed with twin Pontiac Pontiac M39 20 mm guns.
The trainer version proved an instant success and, as the T-38 Talon, 1189 were built. But the US Air Force showed no interest in the fighter version, although it financed 3 prototypes. But this fighter showed a lot of promise as an export fighter to the US Allies. The aircraft was simple and cheap. The N-156 was improved and made its first flight as the F-5A 31 July 1963. The trainer version of the F-5, the F-5B made its first flight 24 February 1964. The F-5 had an improved landing gear, enabling it to operate from rough surfaces. Also the engines were more powerful in regard to the N-156, and seven pylons had been fitted for a heavy weapons load.
Many countries showed interest in the F-5. They were looking for a successor to the F-84 Thunderstreak and the T-33. In Canada the F-5 was license built by Canadair as the CF-5 (CF-116 with the Canadian Air Force), and with their terms and cooperation with Fokker and others, the RNlAF decided to order 75 F-5A’s en 30 F-5B’s. Parts built in the Netherlands were assembled in Canada, resulting in the NF-5A and NF-5B. An eyecatching improvement were leading edge slats, improving manoeuvrability. An arrestor hook was fitted, as was a strengthened windscreen to prevent damage from bird hits. Many of these changes and improvements later found their way into the F-5E Tiger II.
The N-156TX proposal had the engines mounted in two underwing pods and had a crew of two seated in tandem underneath a shallow canopy.
The N-156NN was a proposal for a naval version that had a configuration similar to that of the Grumman F9F and was intended for use from US Navy escort carriers and similar-sized ships such as those operated by the Royal Navy. The mothballing of the Navy's fleet of escort carriers effectively killed off the N-156NN. Northrop company designation PD-2706.
The N-156F drew heavily on the design of the N-156T (T-38). Like the T-38, the low-mounted thin wings had almost equal taper on the leading and trailing edges, and featured no dihedral or anhedral and no incidence. The N-156F wing differed from that of the T-38 in having a forward-angled fillet or leading-edge extension (LEX) at each root, which had a sweep of 60 degrees. In contrast to the N-156T, the wing of the N-156F featured continuous-hinge flaps on the leading edges of full-depth honeycomb construction. Hydraulically-powered sealed-gap ailerons were provided at approximately mid-span, with light alloy single-slotted flaps inboard. The electrically-operated leading edge slats and trailing edge flaps had three positions. For take-off and landing, both leading and trailing edge flaps were fully extended, while droop alone was used for manoeuvring at speeds below 300 mph. The leading edge droop was locked slightly extended whenever the landing gear was extended. The N-156F had larger intakes than those of the N-165T in anticipation of the use of larger engines with greater air mass flow. It also featured a square-shaped air intake splitter plate, with a perforated section just inside the intake to bleed away any remaining boundary layer airflow. Eventually developed into F-5 Freedom Fighter.
Two-seat advanced trainer version based on the N-156F, powered by a pair of General Electric J85 turbojets grouped closely together in the rear fuselage and fed by a pair of lateral air intakes on the sides of the lower fuselage. Company designator PD-2789D, later designated N-156T. Eventually leading to T-38 Talon.
Dual seater, leading to F-5B.
Camera nose, swappable for the standard nose, without losing gun armament. Eventually developed in RF-5.
Carrier version developed from N-156NN. Larger wing, more fuel, greater payload, strengthened arrestor gear. Offered in 1965 to the Australian Navy as N-285B (also offered to USN)
Version using GE CF-700 aft fan engines, 6,800lb thrust.
Initial series. Static prototype designated XF-5A, three flying prototypes YF-5A. Subvariants F-5A(G) for Norway, CF-5A for Canada (local designation CF-116A), NF-5A for The Netherlands, SF-5A for Spain and VF-5A for Venezuela. Recce variants designated CF-5A(R), RF-5A, RF-5A(G), SRF-5A. Corresponding two-seaters designated YF-5B (prototype), F-5B(G), NF-5B and SF-5B. The NF version had a wing leading edge flap which improved low-speed manoeuvrability, and could carry 1,250-litre (275-imp. gal.) underwing fuel tanks. The first NF-5A was rolled out on March 5, 1969 and flew on March 24. On November 7, 1969, it flew with three others to the Netherlands. The first NF-5B flew on July 7, 1969.
Twelve F-5A aircraft modified for Skoshi Tiger combat trials in Vietnam.
Two-seat training version, designated CF-5D for Canada. Local designation CF-116D, license built by Canadair. Two-seat training version of the CF-5D for the Venezuela designated VF-5D.
F-5E/F Tiger II
28 March 1969 the prototype for the YF-5B-21 first took to the air. This two-seater had more powerful engines and many more improvements. These second generation aircraft won the competition for the successor to the old F-5s issued by the Department of Defence. These newer versions had a wider fuselage, enabling it to carry more fuel, different air intakes and an Emerson Electric AN/APQ-153 radar. In production these aircraft were given the designation F-5E Tiger II. The trainer version was designated F-5F. This also proved to be a success, within a short amount of time 1300 were ordered. The USAF had bought reasonable numbers of the F-5A, it did only buy a limited number of Tiger IIs. These served mostly with the so called ‘Aggressor’ units. These units acted as the enemy (Warsaw pact countries) aircraft during air combat training, usually in the role of the MiG-21. Switzerland was granted a license to build 98 F-5Es and 12 F-5Fs for its air force. Other orders came from Asia (both Taiwan and South Korea (as KF-5E/KF-5F)license produced the type), some Arab states and South America, but with the exception of the Swiss, no other European country ordered the Tiger. On 29 January 1979 the RF-5E Tigereye made its maiden flight. This was the photo reconnaissance version of the F-5E. Its right hand side gun was sacrificed to give room to the cameras.
F-5N Tiger II
The US Navy has used the F-5E over the years as an aggressor aircraft. These aircraft are still on the inventory, but the F-16Ns they used alongside the F-5 were retired very quickly. The need for aggressors grew and in a surprise move, the US Forces decided to buy F-5Es from the Swiss Air Force to fill this need. The aircraft purchased are the ones with low hours on the airframe, so they can still provide a lot of training to the pilots in the US Air Force, Navy and Marine Corps.
The designation F-5N is used for these ex-Swiss aircraft. It is by no means a new type, they are regular F-5Es, but the F-5N designation is used to distinguish them from the regular F-5Es in use with the US Navy. The F-5Ns, however, are flown by the US Marine Corps.
Modified F-5F for Singapore, designation also used for modified F-5E Tigris Thailand.
F-5 Tiger III
The F-5E Tiger III is an upgraded model of the F-5E Tiger II and is principally used by the Chilean Air Force for training its pilots. In 2009, the 16 F-5E Tiger III aircraft were replaced with ex-RNethAF F-16AN/BM aircraft.
Upgrade of between 40 and 50 ex-RNethAF NF-5A/B, carried out during the 2000s.
Upgrade of Brazilian F-5E/F, designated F-5EM and F-5FM respectively. Formerly designated F-5BR. Upgrades include Grifo X radar, Elisra RWR, Honeywell H-764G laser/GPS navigation system, back-up GPS, Rohde & Schwartz digital datalink, chaff/flare dispensers, Digital Air Data Computer, HOTAS, OBOGS, IFF, HMD, Martin-Baker Mk10LF ejection seat and new EFIS.
Proposals and special modifications
F-20 (F-5G) Tigershark
At first glance the F-20 Tigershark shows a lot of resemblence to its predecessor the F-5, but looks deceive. The two General Electric J85 engines were reduced to one General Electric F404-GE-100 turbofan with afterburner. An other small detail is the air intake at the base of the vertical tail plane. Its first flight as the F-5G was 30 August 1982, and the test results were excellent. Yet the US Air Force did not buy the aircraft and the US Navy eventually selected the F-16 as a successor to the F-5 in the aggressor role. The Northrop company itself had financed the project and the 1.2 billion dollar investment almost took its toll. In spite of all the promotion, no air force wanted to buy the jet. It was state of the art, the first to utilise its digital possibilities. Two of the prototypes were lost in accidents during the six year long promotional campaign. No orders were placed, and the development was cancelled at the end of the 1980s.
F-5 Shaped Sonic Boom Demonstrator
The SSBE (Shaped Sonic Boom Experiment) was formerly known as the Shaped Sonic Boom Demonstration, or SSBD, and is part of DARPA's Quiet Supersonic Platform (QSP) program. On August 27, 2003, a Northrop Grumman - modified U.S. Navy F-5E aircraft demonstrated a method to reduce the intensity of sonic booms. The nose glove extends the length of the fuselage and nearly doubles its cross-sectional area. The aircraft is a modified F-5E which has a 42.5 inch extension to the nose to make it the same length as a two seat F-5F. Besides the large fairing under the fuselage is a smaller fairing under each inlet. NASA's F-15B research testbed jet from Dryden flew in the supersonic shockwave of the F-5E in support of the test.
In 1966, Northrop began to conduct studies on a follow-on to the F-5 Freedom Fighter, with a team under Lee Begin JR, who had worked on the F-5, considering preliminary configurations for a fast, agile, lightweight air superiority fighter. In 1967, Northrop decided to follow up the preliminary concepts with more detailed design studies. Although the team's initial concepts looked much like an F-5, by 1970 they had evolved to the Northrop P-530 and featured large "leading edge root extensions" -- abbreviated as "LERX" or sometimes just "LEX", and consisted of short-span airfoil extensions forward of the wing alongside the fuselage -- plus twin tailfins, as opposed to the single tailfin of the F-5. The LERX gave better handling at high angles of attack (AOA), while the twin tailfins improved yaw stability and turn performance.
Due to the vast differences between the three major variants, these are listed below
|First flight||31 July 1963||11 August 1972||30 August 1982|
|Engine||2 x GE J85-GE-13||2 x GE J85-GE-21A||1 x GE F404-GE-400|
|Thrust||2 x 1850 kg||2 x 2268 kg||1 x 7434 kg|
|Wing span||7.83 m||8,13 m||8,53 m|
|Length||14,36 m||14,68 m||14,17 m|
|Height||3,99 m||4,08 m||4,11 m|
|Wing area||15,79 m²||17,30 m²||17,30 m²|
|Empty weight||3667 kg||4392 kg||5089 kg|
|Loaded||9397 kg||11.193 kg||11.925 kg|
|Max speed||1487 km/h||1734 km/h||2506 km/h|
|Service ceiling||15.500 m||15.500 m||16.765 m|
|Range (no external fuel)||350 km||?||555 km|
Swiss Air Force Tiger II at Emmen Air Base
Spanish Air Force SF-5A preserved in the city of Talavera
A former Dutch NF-5A seen here before its transfer to Venezuela
- An article on the Internal designations as used by the Northrop Company.