Subject: Number Eighty-Four in the Series--Republic F-84 Thunderstreak (12 of 13)

From: [email-masked]
Date: 30 Jul 93 16:38:43 GMT

>From [email-masked]

One of the weaknesses of early jet fighters was their limited range and 
endurance.  The FICON (FIghter CONveyor) project was an early 1950s 
attempt to extend the range of fighter and reconnaissance jets by 
having them operate as parasites from B-36 bombers.  

On January 19, 1951, Convair was ordered to modify an RB-36F bomber 
(serial number 49-2707) to carry and recover a modified F-84E.  The 
modified RB-36F was redesignated GRB-36F.  The bomb bay of the GRB-36F 
was extensively modified, and the usual bomb racks were replaced by a 
retractable H-shaped cradle.  F-84E serial number 49-2115 was modified 
to carry a hook on the upper nose ahead of its cockpit.  The F-84E was 
to fly up underneath the B-36 and use its hook to engage a slot in the 
cradle.  The cradle would then rotate down over the fuselage of the 
F-84E and engage hardpoints on the rear fuselage.  Once attached, the 
F-84E would be pulled upward and nestle underneath the belly of the 
GRB-36F.  

The GRB-36F/F-84E combination began its first retrieval and launch 
tests on January 9, 1952.  The first complete cycle of retrieve, 
retraction, and launch took place on April 23, 1952.  

In 1953, the original YRF-84F 51-1828 was modified and tested for the 
hook up in flight with a B-36.  It had a hook on the nose ahead of the 
cockpit for engaging the H-shaped trapeze lowered from the B-36, and 
had a set of hardpoints on the rear fuselage for attachment of the 
aircraft to the trapeze once it was engaged.  In addition, the 
tailplane of the modified YRF-84F was sharply canted downwards in 
order to clear the bottom of the B-36 during launch and recovery.  The 
conventional landing gear of the YRF-84F was retained.  This aircraft 
was redesignated GRF-84F.  

The success of the tests with the F-84E and the GRF-84F led to a USAF 
order that 25 RF-84F reconnaissance aircraft be modified to operate as 
parasite aircraft.  These aircraft were redesignated RF-84K.  Serials 
were 52-7254/7278.  Ten B-36D bombers were ordered modified to act as 
motherships, these aircraft being redesignated GRB-36D.  

Ten GRB-36Ds with cradles for RF-84Ks were delivered to SAC in 
February/March of 1955.  In a typical mission, they were to carry the 
RF-84K out to a 2810-mile radius and launch the parasite at an 
altitude of 25,000 feet.  After completion of the mission, the RF-84K 
would be recovered by the GRB-36D and returned to base.  

The GRB-36D motherships saw limited service with the 99th Strategic 
Reconnaissance Wing based at Fairchild AFB, operating in a team with 
RF-84Ks of the 91st Strategic Reconnaissance Squadron based at nearby 
Larson AFB.  Operations with the 91st Strategic Reconnaissance 
Squadron's Thunderflashes continued until the spring of 1956, when 
they were quietly abandoned.  In retrospect, it seems that the 
withdrawal of the GRB-36G/RF-84K combination from service coincided 
with the introduction of the U-2 spyplane into service.  

When visiting the Wright Patterson Air Force Base Museum in June of 
1992, I noted that the YRF-84F is on display there.  However, I have 
its tail number listed as being 92430, which must be wrong.  

Sources:

  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.

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

  The Republic F-84F Thunderstreak, Ray Wagner, Profile Publications, 1966.

  General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute
  Press, 1990.

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