Unseen 1940s airplane designs of Hughes Aircraft, part 1: the Model 19 and Model 30 maritime patrol aircraft

Ever since I was 11 years old, I've been fascinated by the life and times of Howard Hughes (1905-1976) with emphasis on the ups and downs of his life, including the H-1's history-making speed record in September 1935, the crash of the XF-11 reconnaissance aircraft on its first flight, Hughes' tenure as head of TWA (originally Transcontinental and Western Air, later Trans World Airlines), and the H-4 (HK-1) Hercules flying boat that once had the biggest wingspan of any aircraft until the Model 351 Stratolaunch's first flight in 2019 (in fact, the 2004 film The Aviator by Leonardo DiCaprio rekindled Americans' interest in Howard Hughes). However, thanks to research by Ryan Crierie (who maintains the General Staff website) and a few other aviation gurus, it is quite apparent that the Hughes Aircraft Company undertook design work on a number of miscellaneous combat and non-combat aircraft designs during the time that the H-4 was under construction. Therefore, this post will be the first in a two-part blogpost series about fixed-wing aircraft projects conceived by the Hughes Aircraft Company in the 1945-1946 period.

Three-view drawing (left) and artist's conception (right) of the Hughes Model 19 patrol bomber flying boat project of early 1945

On December 20, 1944, the US Navy's Bureau of Aeronautics initiated a requirement for a maritime patrol flying boat powered by four Pratt & Whitney R-2800 Double Wasp radial piston engines and carrying 4,000 lb (1,814 kg) of bombs, which would be used for anti-submarine warfare, anti-shipping missions, and search-and-rescue. Convair, Hughes, and Martin immediately submitted bids for this requirement, and Hughes' proposal bore the company designation Model 19. Resembling the H-4 in the shape of the wings and hull design but differing in having a squared-off vertical stabilizer, the Model 19 was 117 feet 2 in (35.71 meters) long with a wingspan of 167 feet 1 in (50.93 meters), a gross weight of 110,000 lb (49,895 kg), a top speed of 254 mph (408 km/h), an altitude of 21,000 feet (6,400 meters), and a range of 4,500 miles (7,242 km). Defensive armament comprised eight .50 caliber machine guns in four turrets (one nose turret, two waist turrets, and one tail turret), and the Model 19 could carry two 2,000 lb (907 kg) bombs or mines below the wings, and four 1,000 lb (453 kg) bombs, two 2,000 lb (907 kg) bombs, four 400 lb (181 kg) bombs, twelve 325 lb (147 kg) depth charges, or six 657 lb (298 kg) depth charges in internal weapons bays. Power was supplied by four 2,100 hp (1,544 kW) Pratt & Whitney R-2800C-14 radial piston engines, and the crew of the Model 19 comprised a pilot, co-pilot, navigator/bombardier, radio man, radar operator, flight engineer, countermeasures operator, and four gunners.

Three-view drawing (left) and desktop model (right) of the Hughes Model 30 turboprop patrol flying boat project envisaged in April 1946

As 1945 progressed, the BuAer decided that the performance parameters jotted out in the December 1944 specification for a new four-engine patrol flying boat only offered marginal improvement over that of the Consolidated PB2Y and Martin PB2M/JRM Mars, so the idea of a brand new flying boat with R-2800s was instantly abandoned and the Hughes Model 19 along with the rival Convair designs and Martin Model 225 were shelved. However, the Navy was still interested in a new flying boat able to perform the operational roles specified in the December 1944 requirement, and the development of gas turbine engines such as turbojets and turboprops prompted the BuAer to announce a new requirement on December 27, 1945 for a 165,000 lb (74,843 kg) flying boat with improved hull design and utilizing four turboprop engines in order to significantly improve performance. The same companies which had submitted bids for the December 1944 specification participated in this new competition, and in April 1946, Hughes responded to this requirement with a slightly enlarged derivative of the Model 19 with turboprop power, designated Model 30 by the company. The Model 30 design was 128 feet 8 in (39.22 meters) long with a wingspan of 181 feet 11.43 in (55.46 meters), a gross weight of 150,000 lb (68,038 kg), a range of 3,570 miles (5,745 km), and a top speed of 322 mph (518 km/h). The crew comprised a pilot, co-pilot, navigator/bombardier, radio man, radar operator, flight engineer, countermeasures operator, and four gunners, and power was provided by four 3,150 shp (2,316 kW) Westinghouse 25D (T30) turboprops. Like the Model 19, the Model 30 had eight .50 caliber machine guns in four turrets (one nose turret, two waist turrets, and one tail turret, but it utilized increased offensive armament, with four 2,000 lb (907 kg) bombs or mines carried below the wings and four 1,000 lb (453 kg) bombs, two 2,000 lb (907 kg) bombs, eight 500 lb (227 kg) bombs, twelve 325 lb (147 kg) depth charges, or six 650 lb (295 kg) depth charges carried internally.

In the end, the Hughes Model 30 and rival Martin Model 230 lost out to the Convair Model 117 on May 27, 1946, after evaluation of the competitors' proposals by the BuAer, and the winning Convair design was designated XP5Y-1, with a contract being signed on June 19 a contract was signed for two XP5Y-1 prototypes. While the Hughes and Martin designs had been deemed to have inferior performance to the XP5Y-1, the contract award to Convair meant that the Hughes company had enough financial wiggle room to complete the H-4 flying boat on its own. 

Acknowledgements

I would like to thank Tommy Thomason for sending me three-view drawings and artist's renderings of the Hughes Model 19 and Model 30 designs. I thank Ryan Crierie (owner of the General Staff website) for providing specifications of the Model 19 and Model 30 projects on the Secret Projects Forum. 

References:

Bradley, R., 2010. Convair Advanced Designs: Secret Projects from San Diego 1923-1962. North Branch, MN: Specialty Press.

Ginter, S., 1996. Convair XP5Y-1 & R3Y-1/-2 Tradewind (Naval Fighters Number 34). Simi Valley, CA: Ginter Books.