The Convair XP5Y-1 prototype in 1950. It first flew on 18 April 1950 at San Diego and crashed in 1953.
Convair received a request from the United States Navy in 1945 for the design of a large flying boat using new technology developed during World War II, especially the laminar flow wing and still-developing turboprop technology. Their response was the Model 117. It was a large high-wing flying boat with Allison T40 engines driving six-bladed contra-rotating propellers. It had a sleek body with a single-step hull and a slender high-lift wing with fixed floats. The Navy ordered two prototypes on 27 May 1946. Designated XP5Y-1, the first aircraft first flew on 18 April 1950 at San Diego. In August the aircraft set a turboprop endurance record of eight hours six minutes. The Navy decided not to proceed with the patrol boat version, instead directing that the design should be developed into a passenger and cargo aircraft.
One of the XP5Y-1 prototypes was lost in a non-fatal accident on 15 July 1953, while design and development continued on the passenger and cargo version of the aircraft. The transport and cargo version was designated the R3Y-1 Tradewind and first flew on 25 February 1954. Major changes were the removal of all armament and of the tailplane dihederal, the addition of a 10 ft (3.05 m) port-side access hatch, and redesigned engine nacelles to accept improved T40-A-10 engines. Cabin soundproofing and air conditioning were added for pressurized accommodation for 103 passengers or 24 tons of cargo. As a medevac aircraft, 92 stretcher cases could be carried.
R3Y-2 variant loading a tractor
A total of eleven aircraft were built. The first two prototypes built were in P5Y configuration, armed with 8,000 lb (3,600 kg) of munitions (bombs, mines, depth charges, torpedoes) and five pairs of 20 mm cannon in fore and aft side emplacements and a tail turret. The next five were built as R3Y-1 aircraft, intended for troop transport and inflight refueling tanker service. The final six were built as the R3Y-2 variant with a lifting nose and high cockpit (similar in concept to the C-5 Galaxy's nose and cockpit) for heavier transport and landing-ship duties.
The front-loading R3Y-2 aircraft with a hinged nose and high cockpit were intended to be a Flying LST (landing craft). In practice, it was discovered that it was almost impossible for the pilots to hold the aircraft steady and nose on to the beach while the aircraft was loaded or unloaded.[1] The aircraft were converted into tankers for the inflight refueling role. They had a short service life due to unsolvable reliability problems of their Allison T40 turboprop engines, a fate common to most T40-powered aircraft, such as the Douglas A2D Skyshark attack aircraft.
Operational serviceedit
R3Y-2 Tradewind refuels a record four fighters in flight, 1956
The R3Y set a transcontinental seaplane record of 403 mph (649 km/h) in 1954 by utilizing the speed of high-altitude jetstream winds. This record still stands.
After service trials the aircraft were delivered to a U.S. Navy air transport squadron, VR-2, on 31 March 1956. Problems with the engine/propeller combination led to the ending of Tradewind operations and the unit was disbanded on 16 April 1958.
The six R3Y-2s were converted into four-point in-flight tankers using the probe-and-drogue method. In September 1956 one example was the first aircraft to successfully refuel four others simultaneously in flight in 1956, refueling four Grumman F9F Cougars.
The program was halted after thirteen aircraft were built, the reason being the unreliability of the Allison T-40 turboprops. The crash of one of the two XP5Y-1 aircraft was judged due to catastrophic engine failure; when little progress was made with the engine problems, the Navy halted the program. Subsequently, three more aircraft were lost through engine failures, and the Navy gave up on the T-40 and aircraft powered by it. All the P5Y and R3Y aircraft were grounded in 1958 and subsequently broken up.
Transport aircraft for the United States Navy with side loading door, 5 built.
R3Y-2
Assault transport aircraft for the USN with shorter nose incorporating an upward-opening loading door, later converted to four-point tankers for probe-and-drogue operations, six built.
^An episode of Expedition Unknown, which first aired in January 2024, featured a search for the only remaining (not scrapped) XP5Y-1, which crashed in 1953 off the California coast.[2][3]
Sourcesedit
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. ISBN0-942612-34-5.
^"Hunt for the Secret Seaplane". discovery.com. January 2024. Retrieved January 6, 2024.
^Sims, Sean (April 8, 2019). "The Short, Storied History of the Convair XP5Y/R3Y Tradewind". thehangardeck. Retrieved January 6, 2024.
^Ginter, Steve (1996). Naval Fighters #34 : Convair XP5Y-1 & R3Y-1/-2 Tradewind (1st ed.). Simi Valley CA: S. Ginter. ISBN0942612345.
External linksedit
Wikimedia Commons has media related to Convair R3Y Tradewind.
World's First Turboprop Flying Boat, July 1950, Popular Science article with photos of XP5Y-1
January 01, 1970
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The Convair R3Y Tradewind was an American 1950s turboprop powered flying boat designed and built by Convair R3Y Tradewind An R3Y 1 Tradewind low over San Francisco Bay near NAS Alameda Role transport flying boat Manufacturer Convair First flight 22 February 1954 R3Y 1 Introduction 1956 R3Y 1 Retired 1958 Primary user United States Navy Number built 11 R3Y amp 2 P5Y Contents 1 Design and development 2 Operational service 3 Variants 4 Operators 5 Specifications R3Y 1 6 See also 7 Notes 8 Sources 9 References 10 External linksDesign and development edit nbsp The Convair XP5Y 1 prototype in 1950 It first flew on 18 April 1950 at San Diego and crashed in 1953 Convair received a request from the United States Navy in 1945 for the design of a large flying boat using new technology developed during World War II especially the laminar flow wing and still developing turboprop technology Their response was the Model 117 It was a large high wing flying boat with Allison T40 engines driving six bladed contra rotating propellers It had a sleek body with a single step hull and a slender high lift wing with fixed floats The Navy ordered two prototypes on 27 May 1946 Designated XP5Y 1 the first aircraft first flew on 18 April 1950 at San Diego In August the aircraft set a turboprop endurance record of eight hours six minutes The Navy decided not to proceed with the patrol boat version instead directing that the design should be developed into a passenger and cargo aircraft One of the XP5Y 1 prototypes was lost in a non fatal accident on 15 July 1953 while design and development continued on the passenger and cargo version of the aircraft The transport and cargo version was designated the R3Y 1 Tradewind and first flew on 25 February 1954 Major changes were the removal of all armament and of the tailplane dihederal the addition of a 10 ft 3 05 m port side access hatch and redesigned engine nacelles to accept improved T40 A 10 engines Cabin soundproofing and air conditioning were added for pressurized accommodation for 103 passengers or 24 tons of cargo As a medevac aircraft 92 stretcher cases could be carried nbsp R3Y 2 variant loading a tractor A total of eleven aircraft were built The first two prototypes built were in P5Y configuration armed with 8 000 lb 3 600 kg of munitions bombs mines depth charges torpedoes and five pairs of 20 mm cannon in fore and aft side emplacements and a tail turret The next five were built as R3Y 1 aircraft intended for troop transport and inflight refueling tanker service The final six were built as the R3Y 2 variant with a lifting nose and high cockpit similar in concept to the C 5 Galaxy s nose and cockpit for heavier transport and landing ship duties The front loading R3Y 2 aircraft with a hinged nose and high cockpit were intended to be a Flying LST landing craft In practice it was discovered that it was almost impossible for the pilots to hold the aircraft steady and nose on to the beach while the aircraft was loaded or unloaded 1 The aircraft were converted into tankers for the inflight refueling role They had a short service life due to unsolvable reliability problems of their Allison T40 turboprop engines a fate common to most T40 powered aircraft such as the Douglas A2D Skyshark attack aircraft Operational service edit nbsp R3Y 2 Tradewind refuels a record four fighters in flight 1956 The R3Y set a transcontinental seaplane record of 403 mph 649 km h in 1954 by utilizing the speed of high altitude jetstream winds This record still stands After service trials the aircraft were delivered to a U S Navy air transport squadron VR 2 on 31 March 1956 Problems with the engine propeller combination led to the ending of Tradewind operations and the unit was disbanded on 16 April 1958 The six R3Y 2s were converted into four point in flight tankers using the probe and drogue method In September 1956 one example was the first aircraft to successfully refuel four others simultaneously in flight in 1956 refueling four Grumman F9F Cougars The program was halted after thirteen aircraft were built the reason being the unreliability of the Allison T 40 turboprops The crash of one of the two XP5Y 1 aircraft was judged due to catastrophic engine failure when little progress was made with the engine problems the Navy halted the program Subsequently three more aircraft were lost through engine failures and the Navy gave up on the T 40 and aircraft powered by it All the P5Y and R3Y aircraft were grounded in 1958 and subsequently broken up Variants editXP5Y 1 Prototype patrol flying boat two built a R3Y 1 Transport aircraft for the United States Navy with side loading door 5 built R3Y 2 Assault transport aircraft for the USN with shorter nose incorporating an upward opening loading door later converted to four point tankers for probe and drogue operations six built Operators edit nbsp United States United States United States NavySpecifications R3Y 1 edit nbsp 3 view line drawing of the Convair XP5Y 1 Data from Naval Fighters 34 Convair XP5Y 1 amp R3Y 1 2 Tradewind 4 General characteristicsCrew 7 flight crew cabin crew loadmasters Capacity 80 pax 72 litter patients with 8 medical staff R3Y 2 103 pax 92 litter patients with 12 medical staff dd dd dd Length 139 ft 8 3 in 42 578 m R3Y 2 141 ft 1 7 in 43 m dd dd dd Wingspan 145 ft 9 7 in 44 442 m Width 12 ft 6 in 3 81 m maximum hull beam Height 49 ft 0 in 14 94 m keel to fin tip 51 ft 5 2 in 16 m on beaching gear dd dd dd Wing area 2 100 7 sq ft 195 16 m2 Aspect ratio 10 Airfoil root NACA 1420 Mid span NACA 4417 tip NACA 4412 average thickness 18 Gross weight 145 500 lb 65 998 kg Max takeoff weight 165 000 lb 74 843 kg Landing weight 136 739 lb 62 024 kg with maximum cargo Fuel capacity 66 000 lb 29 937 kg Powerplant 4 Allison T40 A 10 turboprop engines 5 332 shp 3 976 kW each Propellers 6 bladed Aeroproducts 15 ft 4 6 m diameter contra rotating fully feathering reversible propellers Performance Maximum speed 299 kn 344 mph 554 km h at 21 000 ft 6 401 m at MTOW 308 kn 354 mph 570 km h at 23 000 ft 7 010 m at normal gross weight dd dd dd Cruise speed 300 kn 350 mph 560 km h average at 29 000 34 200 ft 8 839 10 424 m Stall speed 98 kn 113 mph 181 km h at MTOW power off 89 4 kn 102 9 mph 165 6 km h at 136 739 lb 62 024 kg power off 87 5 kn 100 7 mph 162 1 km h at 136 739 lb 62 024 kg with approach power dd dd dd Range 2 420 nmi 2 780 mi 4 480 km Combat range 1 240 nmi 1 430 mi 2 300 km Service ceiling 30 300 ft 9 200 m at MTOW Rate of climb 1 910 ft min 9 7 m s at MTOW Time to altitude 20 000 ft 6 096 m in 12 minutes 18 seconds at MTOW 30 000 ft 9 144 m in 43 minutes 12 seconds dd dd dd Wing loading 78 5 lb sq ft 383 kg m2 at MTOW Power mass 0 1293 hp lb 0 2126 kW kg at MTOW Take off time 50 seconds in calm sea conditions at MTOWSee also editAircraft of comparable role configuration and era Martin JRM Mars Martin P6M SeaMaster Related lists List of United States Navy aircraft designations pre 1962 List of flying boats and floatplanesNotes edit An episode of Expedition Unknown which first aired in January 2024 featured a search for the only remaining not scrapped XP5Y 1 which crashed in 1953 off the California coast 2 3 Sources editDoor 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 amp 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 1992References edit Ginter 1996 p 94 Hunt for the Secret Seaplane discovery com January 2024 Retrieved January 6 2024 Sims Sean April 8 2019 The Short Storied History of the Convair XP5Y R3Y Tradewind thehangardeck Retrieved January 6 2024 Ginter Steve 1996 Naval Fighters 34 Convair XP5Y 1 amp R3Y 1 2 Tradewind 1st ed Simi Valley CA S Ginter ISBN 0942612345 External links edit nbsp Wikimedia Commons has media related to Convair R3Y Tradewind Convair R3Y Tradewind articles and publications World s First Turboprop Flying Boat July 1950 Popular Science article with photos of XP5Y 1 Retrieved from https en wikipedia org w index php title Convair R3Y Tradewind amp oldid 1199478653, wikipedia, wiki, book, books, library,
