Subject: Number Eighty-Nine in the Series--Northrop F-89 Scorpion (10 of 10)

From: [email-masked]
Date: 1 Oct 93 16:55:53 GMT

>From [email-masked]

The F-89J (Model N-160) was the designation given to earlier F-89Ds 
that were modified in service to carry the Douglas MB-1 Genie 
nuclear-tipped unguided air-to-air rocket.  

Development of the Genie rocket was begun by Douglas Aircraft in 1955, 
with the Los Alamos National Laboratory being given the responsibility 
for the nuclear warhead.  The Genie rocket was unguided, relying on 
the power of its nuclear warhead rather than on guidance to ensure a 
kill.  The MB-1 Genie rocket was powered by a 36,600 pound thrust 
Thiokol TU-389 rocket motor.  Launch weight was 822 pounds, and 
maximum velocity was about Mach 3.3.  Flick-out fin-tips gave the 
Genie stability in flight and corrected for roll and gravity drop.  
The range of the Genie was about 6 miles, and the rocket was equipped 
with a W25 nuclear warhead with a 1.5-kiloton yield.  Lethal radius 
was estimated to be about 1000 feet.  

The F-89J was equipped to carry two Genies on launching rails that 
were carried on the underwing pylons.  On most F-89Js, the wingtip 
armament pods of the F-89D were removed and replaced by 600-gallon 
fuel tanks, although a few F-89Js still retained the standard F-89D 
wingtip pods.  Later, the F-89J was further modified by adding two 
additional underwing pylons on each wing located inboard of the Genie 
pylon for Falcon air-to-air missiles.  These four Falcons carried 
conventional high-explosive warheads.  

The F-89J was equipped with the Hughes MG-12 fire control system, an 
upgraded and more advanced version of the E-9 of the F-89D.  This 
system made it possible for the crew to launch the Genie while in a 
nose-up, climbing attitude, making it possible to attack bombers that 
were flying at a much higher altitude.  During an intercept, the 
Hughes fire-control system tracked the target, assigned the missile, 
commanded the pilot to arm the nuclear warhead, fired the missile, 
pulled the interceptor into a tight turn to escape the detonation, 
then triggered the nuclear warhead by remote control at the right 
moment.  

The modified F-89J became known as "Weapons System 205G".  Initial 
deliveries of the F-89J were made during November of 1956, with the 
84th Fighter Interceptor Squadron at Hamilton AFB in California bing 
the first receipient.  This squadron began standing active alerts on 
January 1, 1957.  Initially, the aircraft were armed with just one 
Genie rocket.  

The first live firing of a nuclear-tipped Genie took place on July 19, 
1957, during a series of nuclear tests known as Operation *PLUM BOB*.  
On that day, F-89J serial number 53-2547 fired an MB-1 over the Yucca 
Flats Nuclear Test Site, and the warhead was detonated at an altitude 
of 15,000 feet by a signal from the ground.  This shot, named *JOHN*, 
made the Scorpion the first interceptor in history to launch a nuclear 
weapon.  In order to prove that the Genie could safely be used over 
populated areas in the US, several Air Force officers volunteered to 
stand on the ground directly underneath the detonation point.  
Following the test, these men were apparently unharmed, although I 
suppose that one might want to check and see what happened to them in 
later years.  

There were a total of 350 F-89Ds modified to F-89J standards.  They 
were taken from the D-35 through D-75 production blocks.  These 
modifications were carried out between March of 1956 and February of 
1958.  

The first production Genie rockets arrived in the field in May of 
1957.  Approximately 3150 Genies and their associated nuclear warheads 
were manufactured between 1956 and 1963.  In 1962, the designation of 
the Genie was changed to AIR-2A.  

The F-89J, with the two nuclear Genies and the four Falcons (plus 104 
FFAR rockets when carrying F-89D pods), was the most heavily-armed 
interceptor in the USAF inventory.  However, the F-89J was destined 
for only a short service life, being replaced by the supersonic 
McDonnell F-101B Voodoo and the Convair F-106A Delta Dart starting in 
July of 1959.  The F-89Js were then transferred to the Air National 
Guard.  By 1962, some nine ANG squadrons were equipped with 
nuclear-armed F-89Js.  The F-89J remained in service with the 132nd 
FIS of the Maine ANG and the 134th FIS of the Iowa ANG until late 
1968, when they were replaced by supersonic aircraft.  

[Question: I was somewhat surprised to read that ANG units had been 
equipped with nuclear weapons.  Is this correct, or is my source in 
error? ] 

F-89J-55-NO serial number 53-2509A is currently on display at the 
Wright Patterson Air Force Base Museum.  

Sources:

  United States Military Aircraft Since 1909, Gordon Swanborough
  and Peter M. Bowers, Smithsonian, 1989.
  
  F-89 Scorpion in Action, Aircraft Number 104, Larry Davis and 
  Dave Menard, Squadron/Signal Publications, 1990.

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

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

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

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

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