Subject: New Fighter Series--McDonnell F-3 Demon (1 of 4)

From: [email-masked]
Date: 13 Apr 94 16:33:57 GMT

>From [email-masked]

The McDonnell F3H Demon had its origin in a Request for Proposal issued 
by the US Navy Bureau of Aeronautics on May 21, 1948 for a 
carrier-based interceptor.  In the RFP, the Navy was looking for a 
carrier-based interceptor with a performance equal or superior to that 
of the most advanced land-based fighters then entering service.  

The F3H design effort at McDonnell was led by Richard Deagen.  At that 
time, the Navy was pushing the Westinghouse-designed afterburning J40 
turbojet as the powerplant of choice for its next generation of 
advanced warplanes.  Yielding to Navy pressure, McDonnell departed 
from its previous design philosophy of using twin-engined 
configurations and decided to adopt a single J40 as the powerplant for 
its entry, which was designated Model 58 by the company.  The Model 58 
called for a single-engine, single-seat day fighter with lateral air 
intakes and a 45-degree sweptback wing and tail surfaces.  

Eleven competitors submitted designs in response to the RFP, among 
them being McDonnell's Model 58.  In December of 1948, the McDonnell 
design was declared the winner of the competition, and on January 3, 
1949 an initial Letter of Intent was issued covering the initial 
design.  The designation XF3H-1 was assigned.  

The competing Douglas design called for a delta-winged carrier-based 
aircraft.  It was also to be powered by the J40 engine.  It came in 
second in the competition, and was deemed sufficiently promising that 
the Navy issued a contract for two prototypes under the designation 
XF4D-1.  

A mockup of the XF3H-1 was inspected between July 13 and 15, 1949.  
Following some redesign in order to save weight, two XF3H-1s were 
ordered on September 30, 1949.  

The F3H had originally been proposed strictly as a day fighter.  While 
the XF3H-1 prototypes were under construction, the Navy changed its 
mind and directed that production versions of the Demon be designed as 
general-purpose all-weather fighters.  The designation of this 
production version was to be F3H-1N.  

A modified F3H-1N mockup incorporating these changes was inspected in 
July of 1951.  Work on the two prototypes was not affected, as they 
were seen simply as aerodynamic test vehicles rather than operational 
test aircraft.  However, the sudden change in direction did delay the 
Demon program significantly.  

In the summer of 1951, the first XF3H-1 (BuNo 125444) was finally 
ready for its first flight.  Since the intended 9200 lb.s.t.  
afterburning Westinghouse J40-WE-8 was not yet available for 
installation, a non-afterburning 5600 lb.s.t. XJ40-WE-6 was fitted in 
its place.  The XF3H-1 took off on its maiden flight on August 7, 
1951, Robert M. Edholm being at the controls.  The second prototype 
(BuNo 125445) followed in January of 1952.  

The J40 turbojet proved to be totally unreliable during flight 
testing.  In August of 1952, the first prototype was damaged in a 
landing accident following an inflight engine failure.  Both 
prototypes were temporarily grounded on two occasions because of 
engine problems.  In addition, early flight testing turned up problems 
with poor forward visibility, an excessively-slow roll rate, and 
inadequate lateral stability.  A redesign of the nose section on 
production models cured the visibilty problem.  The roll rate problem 
was cured by moving the ailerons further inboard, with a corresponding 
decrease in the length and area of the trailing-edge flaps.  The 
lateral stability was improved by removing the wing fence from each 
outboard wing panel.  An autopilot was added.  

The second prototype was fitted with a 10,500 lb.s.t. afterburning 
J40-WE-8 in January of 1953.  This engine did not prove to be any more 
reliable than the non-afterburning WE-6.  This aircraft was used for 
preliminary evaluation tests at the Naval Air Test Center at Patuxent, 
Maryland beginning in August of 1953.  In October of 1953, the second 
XF3H-1 was used for initial carrier trials aboard the USS *Coral Sea* 
(CVA-43).  These trials were fairly successful, but there were some 
problems with low visibility during carrier approach and landing.  

The first XF3H-1 was lost in a crash on March 18, 1954, following an 
inflight engine explosion.  The second prototype was permanently 
grounded shortly thereafter.  It was later shipped to the Naval Air 
Development Center at Johnsville, Pennsylvania to be used in barrier 
engagement tests.  
 
Serials of XF3H-1:

125444/125445		McDonnell XF3H-1 Demon

Sources:

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

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

  The World Guide to Combat Planes, William Green, Macdonald, 1966. 

  McDonnell Douglas Aircraft Since 1920, Rene J. Francillon,
  Naval Institute Press, 1990.

Joe Baugher		AT&T Bell Laboratories   	
263 Shuman Boulevard 		Naperville, Illinois 60566-7050