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HISTORY
and the advent of the MiG-21 made it necessary
to arm America’s allies with sufficiently powerful
aircraft capable of air combat. Therefore, the
International Fighter Aircraft (IFA) program
was announced, for which Northrop prepared
a thorough modernization of the F-5A.
The prototype designated F-5A-21 received more
powerful GE J85-21 engines, each with a maximum
thrust of 19.12 kN (4,300 lbs). These, together with
the need for more voluminous fuel tanks, required
a lengthening and widening of the fuselage.
The wings received an increase in area by way
of the addition of the LERX, or Leading Edge Root
Extension, which improved the maneuverability of
the aircraft. Modeled after the Canadian license
built and modified CF-5, a two-position front
landing gear was introduced. In the extended
position, the wing angle of attack was de facto
increased and thus the take-off run was shortened.
Another significant change was the installation
of the Emerson Electric AN/APQ-153 fire control
radar, which significantly expanded the possibilities
of combat use against aerial targets. It was also
possible to install other avionics equipment
according to customer requirements
The first F-5E, as the aircraft was now designated,
took to the air on August 11, 1972, and a two-seat
variant designated F-5F was also developed.
It flew for the first time on September 25, 1974 and
received an extended nose, which, unlike the F-5B,
allowed for the installation of at least one cannon.
The two-seat version received the Emerson
AN/APQ-157 radar, which was a development of the
AN/APQ-153 intended for two-seat aircraft with
dual controls. Both radars have the same range of
approximately 18 km (11 miles).
Following the Skoshi Tiger program, the F-5E
was named ‘Tiger II’ and the Williams Based 425th
TFS received its first aircraft on April 6, 1973.
This unit was reactivated in 1969 and tasked with
training Vietnamese personnel for the F-5A and
subsequently the F-5E. After the US withdrew
from Vietnam, it continued to train personnel from
countries that purchased the F-5E/F. The unit
continued in this mission until 1989, when sales of
the Tiger II were discontinued.
An RF-5E ‘Tigereye’ reconnaissance version was
also developed, with appropriate equipment in the
nose displacing the radar and one of the cannons.
Subsequent upgrades to the F-5E included the
Emerson AN/APG-69 radar, which was a successor
to the AN/APQ-159, however most users chose
not to use this option for financial reasons.
The exception was the Swiss Air Force and USAF
aggressor squadrons.
Continuous Improvements
The F-5E underwent a number of upgrades, the
most significant of which was the introduction
of the new Emerson AN/APQ-159 radar with
a range of about 36 km (22 miles), replacing the
original AN/APQ-153. A similar radar upgrade
was also proposed for the F-5F, with a derivative
AN/APQ-159 type to replace the AN/APQ-157.
However, this upgrade was not implemented.
In total, Northrop produced 792 F-5Es, 140
F-5Fs and a dozen RF-5Es. Other aircraft were
assembled overseas from components supplied
by Northrop. In Malaysia, 56 were manufactured in
this way, in Switzerland 90, in South Korea 68 and
in Taiwan, 308.
Various versions of the F-5 remain in service with
several air forces. Singapore has approximately
49 modernized and redesignated F-5S (single-seat)
and F-5T (two-seat) aircraft. The upgrade includes
a new GRIFO radar, upgraded cockpits with multi-
function displays and compatibility with the Rafael
Python and AIM-120 AMRAAM air-to-air missiles.
With the help of Elbit, modernization programs
were implemented in Chile and Brazil. Called
the F-5 Plus, the Chilean upgrade included the
new Elta 2032 radar and other improvements.
The Brazilian program, the result being designated
F-5M (Modernized), is armed with Python
Vs coupled with the DASH helmet system and the
new GRIFO radar, cockpit displays and navigation
electronics. Brazilian F-5Ms can also carry Israeli
Derby missiles.
Aggressors
No branch of the US military uses the F-5 in
combat, but this type has proven itself very well
in the role of enemy aircraft for advanced pilot
training. It is operationally very efficient, the price
per flight hour is roughly one-third that of the
F/A-18, and it has similar dimensions to the MiG-21.
F-5Es served with the US Air Force from 1975
to 1990, the Marine Corps purchased former USAF
aircraft in 1989, and the US Navy operated F-5Es at
The Naval Fighter Weapons School at NAS Miramar,
with VF-127, VF- 43 and VF-45. ‘Top Gun’ received
a total of ten F-5Es and three F-5Fs for the enemy
aircraft role.
The F-5E/F was gradually renewed and
modernized, including machines bought from
Switzerland. These were designated F-5N after
modernization and received upgraded avionics
and other improvements. Gradually they received
enlarged LERXs and also a new radome, nicknamed
‘sharknose’ for its flatter shape. This was introduced
primarily to improve flight characteristics at high
angles of attack and to improve spin recovery.
Switzerland sold a portion of their F-5E/Fs to the United States, retaining the rest to this day. Photo: Wikimedia
A trio of F-5Es of the 527th TFTS operating in 1983 out of RAF Alconbury. Photo: USAF
INFO Eduard
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March 2024