United States Air Force
 
                THIS IS A WIDELY KNOWN SUBJECT - ONLY THE MOST IMPORTANT DETAILS ARE REPORTED

 
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                                   Last update 27-06-22

                        Data written in blue are subject to confirmation.

OPERATIONS
 
                  Sparrow Hawk program
In mid-December 1964, the US Air Force established Project Sparrow Hawk, a high priority requirement to evaluate light attack aircrafts, Grumman A-6A (retired later from evaluation), Duglas A-4C (replaced by A-4E)
and Northrop F-5A, in the tactical mission environment. The object of the test was to determine the capability of these aircraft to perform close air support. Tactical Air Command conducted the test at Eglin AFB in
Florida, with Air Training Command (ATC) providing T-38 aircrew transition and ground crew training. The Air Staff also directed ATC to coordinate with TAC training requirements. By 30 June 1965, Air Training
Command had completed its support of Sparrow Hawk; Skoshi Tiger was started the next month.

The Sparrow Hawk program confirmed that the Freedom Fighter was a capable fighter-bomber, though US Defence Secretary was not enthusiastic about supplying jets to South Vietnam. Unfortunately
1 Northrop F-5A had been lost in the meantime (on 24-06-65) while flying mock air combat with its wingman.

                                     Skoshi Tiger program
Freedom Fighters were initially foreseen to be delivered to Military Assistance Program entitled countries plus those buying the aircraft under Foreign Military Sales, but, due to heavy attrition in Vietnam and quick avai-
lability, the Air Force requested the acquisition of 200 examples to be used in Southeast Asia. In July 1965 only a combat evaluation, officially to last from 23-10-65 till 09-03-66, was approved by the US Department of
Defence after. The name of the project was derivered from the Japanese: "Sukoshi Tiger/Small Tiger" and.

The program was planned to be divided in several phases: the first being to attack targets not far from Bien Hoa, the second was to move the unit to Da Nang AFB (in the North of the country) for local targets and the
third to return to Bien Hoa AFB with very intensive  operations.

Immediate action was started to initiate preparations after approval by the US Department of Defence for a Vietnam inland evaluation.

3rd Tactical Fighter Wing - Bien Hoa AFB 4503rd Tactical Fighter Squadron(Provisional)                                               - Bien Hoa AFB

4503rd Tactical Training Squadron (Provisional)
Five Northrop F-5A-15 and seven F-5A-20 originally destined to Military Assistance Plan countries were withdrawn from MAP and assigned to the for the tests especially formed 4503rd Tactical Fighter Squadron
(Provisional) formed the same month (26 or 29-07-65) at Williams AFB. The aircrafts were officially redesigned Northrop F-5C (though some kept the F-5A painted under the cockpit) after having been modified at
Northrop's Palmdale plant by adding a removable, non retractable air-refuelling probe on the left side, 90 lbs of external armour plates under the cockpit to protect the pilot and under the engine, as well as jetti-
sonable stores pylons. South-East Asia camouflage was added, additional maintenance was to performed in order to ensure the integrity of the aircrafts.
Seven pilots and several technicians (all volounteer, former Sparrow Hawk program personnell) had already started 50 hours trials on the Freedom Fighter on July 22nd. Initial, successful trials were accomplished
within four-day with sessions of armament (cannon, bomb, rockets) and air-refuelling exercises, even "soft" field trials at Eglin AFB.

            
Northrop F-5C (see a-a refuelling probe) serial 13315 rocket and underwing SUU-7 dispenser          Serial 66-09139 already modified to Northrop F-5C standard, with air-refuelling probe left-hand site.
night test at Palmadale AFB.
                                                                       Photo: USAF
                                                                                                Air refuelling exercise during the test period in USA.

Intensive training (foreseen to last six months but completed in six weeks) anticipated the departure by 12 Northrop F-5 from Williams AFB to the Republic of Vietnam, Bien Hoa AFB, on 20-10-65. Eight in-flight
refuelling enabled an six hours non-stop flight to Hickham AFB (Hawaii); the next day in 7.5 hours to Andersen AFB  (Guam) with 5 in-flight refuelling, stopping at Wake and Midway Islands. The final leg was on
23-10-65 to Clark AFB (Philippines) and Bien Hoa AFB in 5 hours with 3 air-refuelling. Two Freedom Fighters were attended by one Boeing KC-135 tanker; they landed at their destination in two waves.


                                                                       Photo: USAF
                                                                                   Northrop F-5 13314 -  Arrival ceremony at Bien Hoa AFB 23-10-65

Fast operational readiness was shown, when, 4 hours later, two aircrafts attacked targets not far from their new home base with their cannons and four 500lbs bombs each. The first two months fighters flew
mainly within 40 miles from Bien Hoa AFB, venturing seldom farther away.

The Squadron operated as an independent unit till 21-11-65, when it was attached to the Bien Hoa AFB based 3rd Tactical Fighter Wing which had moved in on from USA 08-11-65 from USA with its North American
F-100D/F-100F. Four Pacic AF and four F-5As were available at Bien Hoa AB with each an average of 169/188 flight hours from arrival in October 1965 till 31 December 1965, increased to 203 in the first semester
of 1966. The overall (USA and Vietnam) average availability during FY 1966 was 22 aircrafts.
 
End of December 1965 saw the conclusion of the phase one: operations in the South of the country. The review of it was mixed: some preferred the Douglas A-1 Skyraider as it carried a larger load and loitered
a longer time on the target. Pilots and ground crews were enthusiast about the Nothrop plane. Twelve aircrafts flew twenty-four sorties a day, possible were twice that; it was easy to maintain, though minior equip-
ment problems surfaced. The 20-mm machineguns were not holding up. Aircraft engines, damaged by debris sucked in from expended ammunition and rockets, had to be replaced, on the average, after every
26 hours of flying. The same debris scratched and smoked the plane's canopy, making it difficult for the pilot to see, especially when it rained. Most of the logistic and planning totals worked out in the States for
the experiment had to be multiplied by a factor of four or five for operations in Vietnam.
The unit delivered over 3'000'000 lbs of ordnance. An quite impressive record, with only one loss on 16-12-65. Eight aircrafts was the availability on hand during the fourth Fiscal Year quarter, ending 31-12-65.

                                                                   
                                                      Three replacement Northrop F-5C on delivery/refuelling flight in 1967, followed by a camouflaged Lockhheed F-104

Planned phase two, moving to Da Nang AFB (Northern part of the country) and operating against strongly defended targets and, possibly in air-combats, started on 03-01-66.
Operations into the near People's Republic of Vietnam were foreseen, but a general moratorium of bombing North Vietnam blocked this part of the program. Attacks against targets in Laos,
particularly against Ho Chi Minh Trail traffic, were flown as an alternative; air-refuelling was needed for these attacks. This evaluation phase ended on 30-01-66; the Freedom Fighter had
flown almost 400 sorties, destructed six bridges.

                                                                    
                                                                                    Line up of 8 Northrop F-5C at Da Nang AFB    Photo:  R.R.D.

Phase 3, back to Bien Hoa AFB, the test re-started on 02-02-66. Maximum effort was to support the III Army Corps (Vietnamese Army and US Army). It was a short (21 days) but, purposely, very intensive period:
348 combat sorties were flown by the Squadrons' pilots (six planes five times each  day); 26 bunkers and 21 sampans were destroyed in addition to ground attacks with cannons,
rockets,   napalm, Mk.82 and M117 bombs.   Maintenance proficiency increased to the point where ground crews were changing engines in less than two hours.

Phase 4 The planes returned to da Nang AFB on 20-02-66, though the test was scheduled to end on that day. Bad weather drove them away from Laos on the first week for the first week but improved weather
conditions as of the 01-03-66 allowed them to operate for the first time above the Demilitared Zone (border South/North Vietnam) for high altitude escort against MiGs and for the ground attacking role, ending
this phase on 08-03-66 when the aircrafts returned to Bien Hoa AFB. The plane wase judged capable of serivce in Vietnam; during this phase 176 combat sorties with the expenditure of almost 6'000 20 mm
cannon rounds and 543 Mk.117 were flown. Air superiority and escort missions, armed with 2 AIM-9B Sidewinder, were conducted over northern Laos. No loss but several small arms damages were reported,
repairable within a short time. Two aircrafts were held in the third quarter of Fiscal Year 1966.

                                                                                            Photo: unknown
                                                                  Norrthrop F-5C serial 13332 with bombs, fuselage tank and in flight refuelling probe equipped

                                                                                            Photo: unknown
                                                                               An armed Northrop F-5C during a foggy day waiting for the next mission

              Photos: USAF    
Serials 38424, 38429, 13317 seen at Bien Hoa AFB on 31-01-66; 38429 has an Mk.82 bomb underwing.                                             Northrop F-5C 38428 releasing 500 lbs bombs.

                                                                                     Photo: unknown
                                                                                        Unknown serial Northrop F-5C equipped with two napalm tanks.                                                                

Freedom Fighter evaluation was completed on 08-03-66 when the Squadron ended its provisional status to become a regular Squadron.

10th Fighter Commando Squadron                                                  - Bien Hoa AFB

March 8th, 1966 saw the birth of the short-lived 10th Fighter Commando Squadron. The Squadron remained at Bien Hoa AFB. Unit establishment was authorised to increase to 18 aircrafts, 7 additional aircrafts,
whose refuelling booms were removed on arrival, were transferred to Bien Hoa by March 1966. All other in-flight refuelling booms had been in the meantime removed, officially as the Republic of Vietnam had no
tankers, unofficially in order to avoid Republic of Vietnam fighters to enter North Vietnamese airspace. Five Northrop F-5A were available between January 1st and March 31st 1966, four between April 1st and
June 30th 1966. Northrop F-5C availabilty between 01-04-66 and 30-06-66 was six.

Freedom fighter could go relatively unscathed through enemy anti-aircraft fire due to its small size and strong airframe, but at the end of 1966 Vietnamese troops introduced quadruple ZSU-57 57mm a-a guns,
which were then responsible for several damaged airframes.

                        Photo: via Jessie
        Northrop F-5C 1332 seen at Binh Tuy          Photo: Stu Brennan                                           This photo shows how intens combat activity was is shown on an Northrop F-5, photo taken at Bien Hoa AB.
                                                                                                                                               Pilot probably on exchange tour; the Bear is part of the Marines VMA-223 badge.

Statistics for the period from the 08-03/04- to 17-04-67 showed that there had been 7'321/9447 combat sorties, 7'537 hours had been flown with only 81 aborts (missions interrupted), 17 Freedom Fighters had
received battle damage, 8 aircrafts had been lost. Used ordnance: 9'777 napalm canisters, 875 GBU bombs, 11'589 GP bombs and 778'566 20mm rounds shot. This munition was expended during close support,
against enemy supply routes (roads/trails/sampans). All this was achieved with the loss of 6 aircrafts due to ground fire and 2 due to engine failure.
Pressures from the Vietnamese government reached its goal: a supersonic jet fighter for the Republic of Vietnam Air Force:  former 10th Fighter Commando Squadron's Freedom Fighters. Training of Vietnamese flying
and maintenance personnel by the Bien Hoa Squadron started in October 1966.

According to an official USA paper there were at the end of USA Fiscal Year 1966 (30-09-66) 11 Northrop F-5 in Southern Vietnam;12  F-5A/Cs were turned over to the Republic of Vietnam AF on 17-04-67 at
Bien Hoa on deactivation of the USAF Squadron, and officially accepted by South Vietnam on 01-06-67. Some 10th Air Commando Squadron pilots and technical personnel remained at Bien Hoa as instructors.
Evaluation results
A team of 33 person performed the combat evaluation; comparisation data regarding performance, weapons delivery accuracy,  maintainability, reliability, maneuverability, survivability and vulnerability were initially
supplied by MxcDonnell F-4s based in Thailand, Bien Hoa based North American F-100s Super Sabre and Lockheed F-104s Starfighter till they were based at Da Nang.

Combat losses were given as 1 aircraft in 1965, 6 in1966, while operational losses were 1 in 1966 and 1 in 1967.

One weakness of the aircraft was known from the very beginning: its short range compared to other fighter-bombers operated in Vietnam (McDonnell F-105, McDonnell F-4 and North American F-100); the average
radious of action with 2 fully armed, 560 rounds, 20mm cannons, 2 Mk.82 500lbs or 2 Mk.117 750lbs general purpose bombs and 2 napalm canisters (finned or unfinned) was officially given in 1966 as 120 nautical
miles. Help to overcome this shortage was given by tanker support.

                                                                         Photo: USAF
                                   Four Mk.117 750 lbs bombs armed Northrop F-5Cs 38428 waiting to be in-flight refuelled by an KC-135, nearest aircraft is serial 13315.

                                                                          Photo: Frank Emory
                                                                                     Northrop F-5C loaded with Napalm and 500 lbs Mk82 Snakeye bombs.

Cluster bombs were also used.  Accuracy of strikes were confirmed by Forward Air Controllers (FAC): the F-5s became quickly the favourite FAC ground-attack aircraft.

Ease of maintenance was extreme, engine changes in minimal time, battle damage very low due to to the small size. Problems rectified during this period included: stores separation from pylons (sometimes damaging
the airframe) and pylons separation, debris from firing the cannons which caused Foreign Objects Damage to the engine. Rain posed windscreen problems during cannon firing and slow flight. Some pilots wishes
were introduced on the Northrop F-5E (albeit not on Skoshi Tiger aircrafts): shorter take-off run, more powerful engine, a tail hook, a computing gunsight. Total missions were 2'664 causing only 42 aborts.

                                                                             Photo: unknown
                                                                          Aerial view of Bien Hoa Northrop F-5C bins, next to North American F-100s.

Final evaluation report mentioned that the Freedom Fighter had a better reliability than the North American F-100, a much better than the McDonnell F-4 (most capable aircraft), but was an only good to complement
these, not to substitute them in the tactical air operations.
The Northrop F-5A recorded in Vietnam 1551 hours of combat in 1638 flights; these represented 3083 bomb deliveries, 3369 ground gunnery passes, 131 rocket deliveries, 1360 napalm deliveries and 110 CBU
deliveries.

The US Air Force stopped considering buying the Northrop F-5 and finally bought the Ling-Temco-Vught A-7 Corsair, its preferred aircraft from the very beginning.

Additional Vietnam War details can be found in the book "F-5 Tigers over Vietnam" by J. Tambini, the magazines: "Wings of Fame" volume 5, "World Air Power Journal" volume 25 Summer 1996, "Air Enthusiast" No 105
May/June 2003 and others.