Subject: Number Thirty in the Series--The Consolidated P-30

From: [email-masked] (Joseph F Baugher)
Date: 18 Oct 92 16:18:52 GMT

>From Joseph F Baugher <[email-masked]>

The P-30 was the production version of the Consolidated Y1P-25 two-seat 
monoplane fighter which in turn had evolved from the Lockheed-Detroit 
YP-24.  It was the first aircraft to be built by Consolidated in its 
new factory at San Diego, California, after the company had relocated 
from Buffalo in 1935.  

Based on tests with the Consolidated Y1P-25, a contract for four 
production examples (33-204/207) was placed by the Army on March 1, 
1933.  For some reason, the Army decided to give the production 
version of the Y1P-25 a completely different designation, and the P-30 
number was next in line.  Overall, the P-30 was quite similar to the 
Y1P-25 which preceded it, but was powered by a different engine, a 675 
hp Curtiss V-1570-57 Conqueror with driving a two-blade constant-speed 
propeller.  In addition, the undercarriage was simplified and the 
cockpit canopy was revised.  At the same time, four similar A-11 
attack versions (Ser Nos 33-308/311) were ordered.  These were to be 
powered by V-1570-59 engines without superchargers, since high 
altitude performance was not considered important for an attack plane.  

Tests of the P-30 began in January of 1934.  Although the Army was 
generally pleased with the performance of the P-30 (especially with 
its high-altitude performance), pilots complained that the gunner who 
sat in a partly open cockpit was of limited value, as his position 
ensured that he would black out whenever maneuvering started.  Maximum 
speed was 239 mph at 15,000 feet and 194 mph at sea level.  Weights 
were 3832 lbs empty, 5092 lbs.  gross.  The P-30 could climb to 10,000 
feet in 7.6 minutes.  Range was 495 miles.  Armament was two 0.30-cal 
machine guns in the nose, plus one flexible 0.30-cal machine gun 
operated by the gunner in the rear cockpit.  

Despite misgivings about the value of the second crewman, on December 
6, 1934, 50 P-30As were ordered by the Army.  Serial were 35-001/050.  
These aircraft were redesignated PB-2A (PB for Pursuit, Biplace) 
before delivery.  The engine which powered the PB-2A was the 700 hp 
Curtiss V-1570-61, with General Electric F-2H turbosupercharger.  The 
PB-2A was equipped with a three-bladed controllable-pitch propeller.  
In addition, it carried oxygen for the crew, an absolute requirement 
for the altitudes at which the PB-2A was capable of operating.  

The first production PB-2A came off the new line at San Diego and flew 
for the first time on December 17, 1935.  The PB-2A had a maximum 
speed of 274 mph at 25,000 feet, 255.5 mph at 15,000 feet, and 214 mph 
at sea level.  It could climb to 15,000 feet in 7.78 min.  Service 
ceiling was 28,000 feet and range was 508 miles.  Weights were 4306 lb 
empty, 5643 lbs gross.  Armament consisted of two fixed 0.30-cal 
machine guns in the upper cowling synchronized to fire through the 
propeller arc, plus a single 0.30-cal machine gun operated by the 
gunner in the rear seat.  In addition, the PB-2A could carry ten 
17-pound fragmentation bombs.  

Unfortunately, the first PB-2A crashed at Wright Field in late May.  
Nevertheless, the deliveries of the PB-2A built up quite rapidly, 
being completed by July 1936.  The PB-2A initially served with the 
27th Pursuit Squadron, 1st Pursuit Group at Selfridge Field, Michigan.  
A few were also operated by that group's 94th Squadron.  In 1937, the 
1st Pursuit Group converted to Seversky P-35s and their PB-2As were 
passed on to the 33rd, 35th, and 36th Squadrons of the 8th Pursuit 
Group based at Langley Field, Virginia 

On October 17, 1936, A PB-2A flown by Lt. John M. Sterling won the 
Mitchell Trophy race at Selfridge Field at a speed of 217.5 mph.  In 
March 1937, a PB-2A reached an altitude of 39,300 feet, but high 
altitude flights were seldom performed in practice because of the 
expense, inconvenience, and discomfort of the bulky pressure suits.  

In the spring of 1939, the 8th Pursuit Group reequipped with the 
Curtiss P-36, and the 35 or so surviving PB-2As were transferred to 
Maxwell Field, Alabama.  By 1941, most were out of use.  The last one 
was donated to a ground school in March of 1942.  I don't know if any 
examples survive today.  

Although the PB-2A was not exactly one of the shining lights in 
American aviation history, it nevertheless did chalk up an impressive 
list of firsts.  The PB-2A was the only single-engined two seat 
monoplane fighter to attain operational status with the USAAC during 
the inter-war year, it was the first fighter in service with the USAAC 
to have a fully retractable undercarriage, it was the first fighter 
with a constant speed propeller, and it was the first truly successful 
application of a supercharger to an operational military aircraft.  
However, the two-seat fighter design concept was outdated by the time 
it appeared.  The idea of defending the fighter against attack from 
the year by stationing a second crew member in the rear cockpit never 
gained much support.  The penalties entailed in terms of lost speed 
and maneuverability caused by the added load seemed to be too high a 
price to pay for the addition of just one more gun.  Consequently, the 
service life of the PB-2A was quite short.  

In 1936, the USAAC held a competition for a replacement for the Boeing 
P-26 fighter.  Since the second crewman seemed to be the main drawback 
of the PB-2A, the Consolidated company thought that a single-seat 
version of their fighter might be successful in the competition.  In 
April 1936, PB-2A Ser No 35-7 was converted by Consolidated to 
single-seat configuration and entered in the USAAC competition.  It 
differed from the standard PB-2A in having the rear cockpit removed 
and the position faired over with a raised decking, but was otherwise 
quite similar to the PB-2A.  Competitors were the Seversky SEV-1XP, 
the Curtiss Model 75, and the Northrop 3A.  Unfortunately, flight 
tests revealed that the single-seat PB-2A fighter was still much too 
heavy in comparison to its competitors to make an effective fighter.  
And if that wasn't enough, the single-seat PB-2A crashed during 
testing, which permanently doomed its chances.  The ultimate winner of 
the competition was the Seversky design, which entered production as 
the P-35.  

Some of the PB-2As serving with the Army were used for tests.  PB-2A 
Ser No 35-26 was used to test a laminar flow aerofoil in 1940 with a 
new structure built over the existing wing.  

The P-33 was a proposed version of the P-30 powered by a new Pratt & 
Whitney R-1830-1 radial engine.  This project never got off the 
drawing board.  

Sources: 

  The American Fighter, Enzo Angellucci and Peter Bowers, Orion Books, 
  1987.  

  General Dynamics Aircraft And Their Predecessors, John Wegg, Naval 
  Institute Press, 1990 

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

Joe Baugher       AT&T Bell Laboratories    2000 North Naperville Road 
		  Naperville, Illinois 60566-7033.   (708) 713-4548