Subject: Number 105 in the Series--Republic F-105 Thunderchief (8 of 9)

From: [email-masked]
Date: 16 Feb 94 17:34:01 GMT

>From [email-masked]

The F-105F was a two-seat combat proficiency trainer version of the 
F-105D.  The two crew members were seated in tandem ejector seats 
underneath separate clamshell-type canopies.  The cockpits were 
provided with dual controls.  The fuselage of the F-105F was about 
five feet longer than that of the F-105D and the tail fin and rudder 
were taller and larger in area.  A transfer system in the F-105F 
allowed each crew member to monitor or control all or any of the 
aircraft's subsystems.  The F-105F was nearly 2000 pounds heavier than 
the F-105D, and it retained many of the features of the D, including 
the retractable midair refuelling probe.  Although originally intended 
as an advanced trainer, the F-105F retained the full combat capability 
of the single-seat F-105D, including the all-weather R-14D radar 
system.  It had a performance that was within a couple of a percent of 
that of the F-105D.  

The maiden flight of the first F-105D (62-4412) was on June 11, 1963.  It 
reached a speed of Mach 1.15 on this flight.  Service introduction was 
in December of 1963 with the 4520th Combat Crew Training Wing based at 
Nellis AFB and with the 4th Tactical Fighter Wing based at 
Seymour-Johnson AFB.  

143 F-105Fs were built in the years 1963 to 1964.  These aircraft were 
actually originally ordered as single-seat F-105Ds, but before they
could be built the Air Force specified that they be delivered as
two-seat F-105Fs.  No Thunderchiefs were actually procured as F-105Fs
from the beginning.  

The delivery of the last F-105F (63-8366) in 1964 marked the end of 
Thunderchief production.  Later on in the 'sixties, the mounting losses
of F-105s in combat over Vietnam led the Air Force to give some 
consideration to reopening the F-105 production line, but nothing
ever came of the idea.  The closing down of Thunderchief production
marked the end of the line for Republic Aviation as a manufacturer
of fighter aircraft.  

The F-105F is primarily remembered today for its role as a Wild Weasel 
aircraft, a type of aircraft originally designed for the suppression 
of North Vietnamese surface-to-air missile radar sites.  When American 
bombing raids against North Vietnam began in 1964, combat losses of US 
aircraft began to mount alarmingly.  Many of these losses were caused 
by the increasingly effective use by the North Vietnamese of 
radar-guided surface-to-air missiles.  Someone in the USAF got the 
bright idea that the best way to defeat the surface-to-air missile 
threat would be to destroy or otherwise shut down their guidance 
radars, leaving enemy missile sites effectively blind and impotent.  

The first Wild Weasel aircraft were North American F-100F Super Sabre 
two-seat fighter-bombers which were modified in 1965 for the role of 
identifying, marking, and attacking North Vietnamese SAM sites, 
particularly their radar installations.  They were fitted with special 
equipment designed to detect enemy radar emissions and to determine 
the location of their transmitters.  Once the sites were located and 
identified, fighter-bombers accompanying the F-100F aircraft would 
then attack the target with iron bombs.  The project was given the 
name *Wild Weasel*, after the fierce little mammal which has a 
reputation of being so fearless that it pursues its prey into its very 
den.  

The F-100F Wild Weasel I program claimed credit for nine confirmed SAM 
radar kills.  An undetermined number of other enemy radars were forced 
off the air as a result of Wild Weasel I activities.  

After the F-100F two-seaters had proven the feasibility of the general 
concept, the same sort of adaptation was made to the vastly more 
capable F-105F two-seater.  86 F-105Fs were selected for modification 
as Wild Weasel III aircraft, which was over half the total F-105F 
production.  The electronic weapons officer in the rear seat of the 
Wild Weasel F-105F operated a battery of sophisticated electronic 
equipment which was capable of detecting the emissions from enemy 
radars and determining the exact location of their sources.  Once these 
sites were identified, the F-105F could attack them with a battery of 
AGM-45A Shrike antiradar missiles, which were designed to home in on 
an enemy radar transmission and follow it all the way to its source 
and destroy it.  The Wild Weasel F-105F could also carry powerful 
jamming equipment which was designed to confuse the enemy radar 
installation or to misdirect any surface-to-air missiles that might be 
launched.  Alternatively, the F-105F crew could direct other aircraft 
toward the missile sites, which would be attacked by iron bombs or 
cannon fire.  

The first F-105F Wild Weasel III missions were flown in 1966.  In a 
typical mission, a Wild Weasel F-105F would accompany each flight of 
two or four F-105Ds.  This helped to cut the loss rates tremendously.  

North Vietnamese MiG-17 and MiG-21 fighters were also a menace, and 
many a bombed-up Thunderchief fell to the guns and missiles of these 
aircraft.  In order to counter the MiG threat, a few F-105Fs were 
modified to carry QRC-128 VHF jammers that were intended to block 
communications between MiG pilots and their ground controllers.  
The North Vietnamese were trained in Soviet tactics, which called
for rigid ground control of airborne interceptors.  When communication
was cut, tactics usually called for the MiG pilots to return to base. 
The code name for this project was *Combat Martin*.  Six of these planes 
were later returned to their original configuration and were 
eventually brought into the Wild Weasel III program.  

Several F-105Fs were modified under the *Commando Nail* program with 
improved R-14A radar which made it possible to achieve sharper target 
definition.  In addition, the pilot's weapons release switch was 
modified to enable the rear seat pilot to control bomb release.  
*Commando Nail* F-105Fs flew numerous hazardous all-weather low-level 
bombing missions over North Vietnam, the first of these being on April 
26, 1967.  Six of these *Commando Nail* F-105Fs were later returned to 
their original configurations and were brought into the Wild Weasel 
III program 

Throughout the Southeast Asia War, the F-105F was repeatedly modified 
to meet changing conditions.  They were equipped with armor plating, 
backup flight control systems, X-band beacons, new radar altimeters, 
and AN/ASG-19 Thunderstick gun bombsights which provided for automatic 
or manual and blind or visual weapons delivery, with automatic or 
manually-controlled weapons release.  The pilot ejector seat was 
improved, and AN/APR-25(U)-26(V) radar homing and warning (RHAW)
antennae were added to the tip of the vertical fin.  Several F-105Fs 
were equipped with a combat camera mounted in a protrusion on the lower 
nose just behind the radome.  Most F-105Fs were fitted in the field
with ram air scoops on the rear fuselage to address an afterburner 
cooling problem which had resulted in some engine fires.

Although the last F-105D was withdrawn from Southeast Asia in October 
of 1970, the two-seat F-105F Wild Weasel remained in Southeast Asia 
until the end of US involvement in Vietnam.  However, they were 
gradually replaced in their Wild Weasel role by the McDonnell F-4G 
Wild Weasel IV.  Their final wartime role was as an escort for 
high-flying B-52s during the Linebacker I and Linebacker II 
operations, which culminated in the Christmas 1972 offensive against 
Hanoi that finally forced the North Vietnamese to the conference 
table.  

Surviving F-105Fs from Vietnam were transferred to the Air National 
Guard as they were replaced in Air Force service by F-4Gs.  In 1971, 
the Air National Guard received its first 8 F-105Fs.  By mid-1973, 
only 17 F-105Fs remained in service, 5 with the Air Force and 12 with 
the ANG.  Several examples served with the 508th TFG and with the 
Georgia Air National Guard until 1981, when the last Thunderchiefs
were finally retired.

Serial of the F-105F: 

62-4412/4447 	Republic F-105F Thunderchief 
63-8260/8366 	Republic F-105F Thunderchief 

Specification of the F-105F Thunderchief: 

One Pratt & Whitney J75-P-19W turbojet, rated at 17,200 lb.s.t. dry 
and 26,500 lb.s.t. with afterburner.  Maximum speed: 1386 mph at 
38,000 feet (Mach 2.1), 876 mph at sea level (Mach 1.15).  Initial 
climb rate was 34,500 feet per minute (at 39,350 pounds).  Combat 
radius was 740 miles with 8 750-pound bombs.  Total internal fuel
capacity was 1160 US gallons in seven tanks (including 25 gallons in
the fuel lines).  The internal weapons bay can accommodate a
390-US gallon guel tank in place of the "special store".  The
fuel load can be further augmented by two 450 US-gallon drop tanks
on the inner underwing pylons and an additional 450 or 600 US gallon
drop tank carried on a pylon underneath the fuselage, bringing total
maximum fuel capacity to 3100 US gallons.  
Dimensions: wingspan 34 feet 11 1/4 inches, length 69 
feet 7 1/3 inches, height 20 feet 2 inches, wing area 385 square feet.  
Weights: 40,073 pounds loaded (clean), 54,027 pounds maximum takeoff.  
Armed with one 20-mm M61A1 rotary cannon with 1029 rounds.  Up to 
8,000 pounds of ordinance could be carried in the internal weapons 
bay.  In addition, a further 6000 pounds of ordinance could be carried 
on external weapons racks (four underneath the wings, one underneath 
the fuselage).  Typical weapons load include 16 750-pound bombs, 9 
LAU-3/A or LAU-18/A rocket pods, or four AIM-9B Sidewinder infrared 
homing missiles in the intercept role 

Sources:

  The Illustrated Encyclopedia of Aircraft Armament, Bill Gunston,   
  Orion, 1988.

  United States Military Aircraft Since 1909, Gordon Swanborough and
  Peter M. Bowers, Smithsonian, 1989.

  The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987.

  Fighters of the United States Air Force, Robert F. Dorr and
  David Donald, Temple Press Aerospace, 1990.

  American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday,
  1982.

  Post-World War II Fighters, 1945-1973, Marcelle Size Knaack,
  Office of Air Force History, 1986. 

  The World Guide to Combat Planes, William Green, MacDonald, London, 1966

  The World's Fighting Planes, William Green, Doubleday, 1964.

  The Aircraft of the World, William Green and Gerald Pollinger, Doubleday,
  1965.

  The Thunder Factory, Joshua Stoff, Motorbooks, 1990.

  F-105 Thunderchief in Detail and Scale, Bert Kinzey, Kalmbach Books,
  1993.

Joe Baugher		AT&T Bell Laboratories   	
2000 North Naperville Road      Naperville, Illinois 60566-7033