Subject: Number Seventy-Three in the Series--"P-73"

From: [email-masked]
Date: 25 May 93 16:31:18 GMT

>From [email-masked]

Many authors who write about American fighter aircraft of the World 
War 2 era state categorically that there never was a fighter project 
with the designation "P-73".  For some obscure reason, this particular 
number seems to have been skipped.  The aviation historian James Fahey 
claims that the P-73 designation was deliberately omitted as a result 
of political pressure applied to the Army by the Fisher Body Division 
of the General Motors Corporation.  In 1942, Fisher was hoping to 
interest the Army in its new escort fighter design.  At that time, the 
next available Army pursuit designation was P-73, but Fisher wanted 
the Army to assign to its new escort fighter a "nice symbolic number", 
something that would sound nice in advertising copy and would make for 
memorable slogans--something like "The French 75 in World War 1, the 
Fisher P-75 in World War 2" was envisaged.  Fisher got its way and the 
Army agreed to assign the designation P-75 to its escort fighter 
project, the designations P-73 and P-74 being deliberately skipped.  

However, a few other sources maintain that there really WAS a fighter 
aircraft designated P-73 and that it actually made some test flights.  
However, it was so secret that even today there are few details 
available about it.  The P-73 was almost as mysterious in its time as 
the shadowy *Aurora* is today.  However, the reason for all this 
secrecy was not any outstanding capabilities that the P-73 might have 
had, but was a result of the neurotic personality of the owner of the 
company which produced the aircraft.  This was none other than the 
brilliant but eccentric movie tycoon, inventor, and industrialist 
Howard Hughes.  

During the Second World War, many of the projects of the Hughes 
Aircraft Company were shrouded in secrecy and were the subject of 
mysterious and convoluted political maneuverings, due in no small part 
to the bizarre personality of its owner.  Even though Howard Hughes 
and his company had been involved in several innovative aviation 
projects, the War Department found that dealing with Howard Hughes was 
a real nightmare.  He could not be relied upon to meet schedules and 
his claims about the capabilities of his aircraft were often not 
credible.  He would alternatively pressure the War Department into 
buying his aircraft right away without delay, then would withhold them 
from the government at the last minute.  He had paranoid fears about 
others stealing his ideas, at one time claiming that Lockheed had 
stolen the idea for the P-38 Lightning from him.  

Howard Hughes had always been obsessed with the setting of aviation 
records.  In the mid-1930s, he had hired the talented aeronautical 
engineer Richard Palmer to build for him a racing monoplane designed 
specifically for the purpose of setting speed records.  The product of 
this collaboration was the H-1B Racer, which took to the air for the 
first time on August 17, 1935.  On September 13, 1935, Howard Hughes 
used his H-1B racer to set a world landplane speed record of 352.388 
mph, a record which stood until 1939.  in January 1937 he used an 
altered version of his same H-1B racing aircraft to set a 
transcontinental speed record of 7 hours 28 minutes 25 seconds 
(Burbank to Newark).  

In July of 1938, Howard Hughes used a Lockheed 14-N2 twin-engined 
transport to set a round-the-world record of 91 hours 14 minutes 
flying time.  Hughes believed that this record could be bested by a 
large margin if he could design and build an aircraft dedicated to the 
task of setting long-range records.  This seems to have been the 
origin of the D-2, one of the most mysterious aircraft projects in all 
of aviation history.  Even today, fifty years after the event, few 
details and even fewer photographs or drawings of the mysterious D-2 
are publically available.  They are presumably locked away somewhere 
in the vaults of the Summa Corporation, the holding corporation for 
the Hughes empire.  

There is the possibility that Richard Palmer had begun work on the D-2 
before he left Hughes to go to work for Vultee Aircraft, but this is 
not certain.  

The D-2 project envisaged a twin-boom, twin-engined aircraft with a 
relatively small central crew nacelle.  No effort was spared to 
minimize aerodynamic drag.  The few drawings which are available show 
an aircraft with the same general configuration as the Lockheed P-38 
Lighting, although appreciably larger and heavier.  Most of the 
airframe of the D-2 was to be made of Duramold plywood, which was a 
plastic- bonded plywood molded under heat and high pressure.  
Initially, the aircraft was to have been a taildragger, but the 
landing gear was later changed to a tricycle configuration.  The main 
undercarriage units retracted rearwards into the twin booms and the 
nosewheel retraced rearwards and rotated 90 degrees to lie flat in the 
small central fuselage.  The powerplants were to have been a pair of 
Wright Tornado forty-two cylinder liquid-cooled radial engines.  

The onset of war in Europe caused all thoughts of a record-breaking 
round-the-world flight to be abandoned.  Aircraft engines and 
specialized aviation equipment urgently needed for rearmament were 
just not going to be made available for the sole purpose of setting 
records.  In order to keep his project going, in December of 1939 
Hughes offered to sell the drawings and data for the D-2 to the USAAC 
in the hopes of attracting a military contract.  He hinted that the 
design might be made into a "pursuit-type airplane", although at that 
time the D-2 had no military role envisaged.  

Hughes seems to have succeeding in interesting the Army in his 
project, since in 1940 the USAAC informed him that there was no 
objection to his purchase of a pair of Wright Tornado engines.  
However, the USAAF decided later to divert these Tornado engines to 
Lockheed for its XP-58 project, leaving Hughes without engines for his 
D-2.  Hughes was forced to switch to a pair of Pratt & Whitney 
R-2800-49s for the D-2, and these engines arrived at Hughes in March 
of 1942.  

Subsequent memos from Hughes to the Army seemed to indicate that he 
was changing his mind about the mission for the D-2.  In May of 1940, 
he was no longer referring to a "pursuit-type aircraft", but instead 
to a "Duramold bombardment aircraft".  The mission envisaged for the 
D-2 seems to have changed yet again in May 1941, the aircraft now 
being pictured as a bomber escort.  In June of 1942, the USAAF seems 
to have referred to the aircraft as the "P-73" in one communique and 
as the "XA-37" in another, indicating that there was really no clearly 
defined military role for the aircraft.  In reality, the D-2 could not 
carry enough bombs internally to make it a useful attack aircraft and 
was not sufficiently maneuverable to make it a useful fighter.  

So it seems that the designation "P-73" was reserved by the Army at 
some stage for the fighter version of the D-2, and "XA-37" for the 
attack version.  However, all of this is very murky, and it is not at 
all certain if the USAAF was ever very serious about the prospects for 
any useful military role for the Hughes aircraft.  These designations 
may have been little more than place holders.  

In early 1942, Hughes began to pressure the Army for a quick decision 
to purchase the D-2.  Responding to this pressure, on June 16, 1942, 
Lt.  Gen.  H.  H.  Arnold, Commanding General of the USAAF, ordered 
Wright Field to acquire the D-2 from Hughes for testing as a prototype 
for possible future bomber development.  However, a couple of weeks 
later, Hughes told the Army that he no longer wished to sell the D-2 
to the Army but wished instead to test it himself first.  The 
procurement of the D-2 was put on hold by the Army.  

Components for the D-2 were built by Hughes at its Culver City plant, 
and final assembly was done at Harper Dry Lake in the Mojave Desert.  
Harper Dry Lake was an exceedingly remote area in the Desert, well 
away from prying eyes.  The choice of this site was a reflection of 
Hughes' almost paranoid obsession with secrecy.  

The D-2 was built primarily of wood.  Power was provided by two 
2000-hp Pratt and Whitney R-2800-49 radials driving three-bladed 
propellers.  A hydraulic control surface boost mechanism was provided 
for elevators, rudders, and ailerons, one of the first applications of 
such a device to an aircraft.  Turbosuperchargers and cabin 
pressurization were planned, but were not yet fitted.  Crew was two or 
three.  

Initial ground trials began in the spring of 1942.  However, it soon 
became obvious that the the control forces were excessively heavy when 
the boost mechanism was not operating.  During high speed taxiing 
tests, Hughes briefly lifted the aircraft off the ground on some 30 
occasions.  These brief hops revealed some aileron instability, and 
further full-scale tests were delayed until new ailerons with broader 
chord were fitted.  

The D-2 made its first true flight on June 20, 1943.  Howard Hughes 
took it up twice that day.  Hughes noted that there were rather high 
aileron control forces and that there was a tendency to roll with 
power on and with the undercarriage retracted.  In order to correct 
these problems, Hughes increased the wingspan, but these changes did 
little to improve the flight characteristics.  

Hughes reluctantly concluded that the D-2 needed major modifications, 
including a complete redesign of the wings and a change in aerofoil 
section.  The wing center section, which was continuous through the 
fuselage nacelle, was to be revised to increase the size of the 
proposed bomb bay.  Following these changes, the aircraft was to be 
assigned the company designation D-5.  

On June of 1943, General Arnold noted that the lack of de Havilland 
Mosquito aircraft might result in an Army need for the Hughes design, 
and requested that the D-2 be flow to Bolling Field, DC.  for 
inspection.  At that time, the D-2 was undergoing modification to D-5 
configuration and wasn't going anywhere.  However, Hughes had the 
audacity to propose three separate production versions of the D-5--a 
two seat unarmed reconnaissance aircraft, a three-seat light bomber, 
and a two-seat escort fighter.  The USAAF was not impressed, and 
recommended in August of 1943 that all development of the Hughes 
D-2/D-5 be discontinued.  

In spite of the negative reception from the USAAF, Howard Hughes 
continued work on the D-2/D-5 on his own.  In November 1944, while 
still undergoing modifications to the D-5 configuration, the D-2 was 
lost in a mysterious fire.  According to Hughes, a "lightning bolt" 
struck the hangar in which it was being housed, and the aircraft was 
destroyed.  By that time, the D-2/D-5 project had evolved into the 
XF-11, which was a long- range, high-speed unarmed reconnaissance 
aircraft of all-metal construction.  It retained only the basic 
twin-boom/small central nacelle configuration of its predecessor.  

Source: 

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

  Fighters of the United States Air Force, Robert F.  Dorr and David 
  Donald, Temple Press Aerospace, 1980.  

  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