Hello, today I would like to suggest the Convair XP5Y-1 Tradewind. This is basically a follow-up of my previous suggestion of the Martin XPB2M-1 Mars that I’ve reposted a while back. As both planes has similar origin story and ended up as a transport aircraft, in addition of being a humongous flying boat. Though the Tradewind distinguished itself from the Mars by its powerful turboprop engines and its defensive armaments of ten 20 mm autocannons.
The XP5Y-1 in-flight.
With the end of World War II in 1945, the United States has gained many knowledge and technological advancements as a result of the war, including the aviation section. Because of this, the United States Navy (USN) has decided to revisit the concept of long range maritime patrol/bomber flying boat that was put on hold during the war, as they sought to explore the concept of “sea bases” doctrine where aircrafts and units could be operated independently far away from the bases.
To achive this, the USN has invited various aircraft companies to develop a new patrol aircraft using new technologies. One of these was the Convair (formerly Consolidated Vultee) company, which has extensive experience in developing maritime aircraft and flying boats. As Convair viewed that the new jet engine technologies were not vital for the role of a patrol aircraft, they chose to settle on developing a large patrol bomber powered by turboprop engines instead. After the design was approved in 1946, two prototypes were ordered by the USN and was designated as the XP5Y-1 Tradewind. This peculiar non-threatening name is due to the USN has also planned to develop a cargo/transport version of the plane as well.
Side profile of the XP5Y-1. Note the dummy turrets on the cheek and waist position.
The XP5Y-1 Tradewind is a high-wing flying boat with sleek design. Powered by four Allisson T40 turboprop engines turning four sets of three-bladed contra propelllers, the plane can reach a top speed of 625 km/h despite its massive weight of 63 tons. As range are the main priorities, the payload of the XP5Y-1 is a modest 8,000 lbs (3,629 kg) of bombs and sea mines.
Design drawings of the XP5Y-1’s profile, including its defensive armaments and protection.
For an aircraft of its type, the XP5Y-1 has an incredible protection for its crews. The plane is armed with a staggering ten 20 mm autocannons (source does not specify the exact model of the cannon, though it’s most likely a derivative of the M2/3 autocannons in use with the USN at that time) mounted in five twin remote-controlled turrets. With a pair of the turrets placed on the cheek and waist position, and the other placed on the tail turret. The pilots and gunners are protected by some armor plates. Meanwhile, the plane also has some armor plates covering the engine and has a self-sealing fuel tanks.
The XP5Y-1 preparaing for its maiden flight at San Diego bay, 18 April 1950.
The Tradewind made its first flight on 18 April 1950 at San Diego bay, California. While the plane proved to have overall decent flight performance, it was plagued with the engine reliability issue as with the other aircrafts outfitted with the T40 engines. Nevertheless, the plane managed to set the endurance flight record for turboprop aircraft at that time, at 8 hours and 6 minutes.
However, due to a combination of engine problems, in addition to the USN has started to gain interests in the rivalling jet-powered Martin P6M SeaMaster due to it offering twice the speed and payload compared to the XP5Y-1 while being significantly more reliable. The US navy has decided to terminate the project for the combat version of the Tradewind. The remaining orders of the P5Y were thus allocated to a transport derivative of it later named the R3Y. The non-fatal crash of the first XP5Y-1 in 1953 effectively sealed the fate of the project. The R3Y version would go on to serve for only two years from 1956 to 1958 before being pulled out of service due to the engine issue shared with other T40-equipped aircraft
Crew: 10; 2 pilots, 5 gunners, and 3 relief crews/bombardiers
Length: 38.99 m
Wingspan: 44.75 m
Height: 14.05 m
Wing area: 195.27 m2
Empty weight: 23,440 kg
Takeoff weight: 56,020 kg
Max. takeoff weight: 63,675 kg
Powerplant: 4 × Allisson T40 turboprop engines, 5,100 hp each
Maximum speed: 625 km/h
Cruise speed: 360 km/h
Range: 4,480 km
Service ceiling: 12,000 m
Climb rate: 16.67 m/s
Defensive: 10 × 20 mm autocannons (possibly M2/3 autocannons) mounted in five twin turrets. With a pair at the cheek and waist, and a single turret at the tail.
Suspended: Up to 3,629 kg of bombs, sea mines, and torpedoes.
Convair R3Y Tradewind - Wikipedia
Convair P5Y Tradewind
Door, Robert F. “Beyond the Frontiers: Convair R3Y Tradewind ‘The Flying LST’” Wings of Fame, Volume 18, December 1999, Aerospace Publishing, ISSN 1361-2034
Ginter, Steve. Convair XP5Y-1 & R3Y-1/2 Tradewind. Simi Valley, Calif.: Ginter Books, 1996. ISBN 0-942612-34-5.
Gunston, Bill. “Turbo Tradewind” Aeroplane Monthly, Volume 20, Issue 01, 1992
Popular Science - Google Books