Airborne Awesomosity

Flying Boats – The Princess Is At The Other Castle

Saro_Princess_launch BBCIMG dot co dot uk

No Really Bigger Is Better

[image credit –]

In postwar Britain there was considerable money, time, and effort spent on trying to keep the colonies nearby. The Brits went to some absurd lengths to create non-stop flights to her farthest territories  utilizing aircraft such as this one.


I Think I Can, I Think I Can

As Graceful As A Flying Walrus

The British had a problem in the post war years with its once proud empire and it was one of distance. As her former territories declared independence the nation wanted to find ways to keep those that were still part of the kingdom within easy reach. To do this a competition was held to create some of the largest aircraft the world had seen.




Saunders Roe would enter the fray with the Princess. An aircraft large enough that it would have made Howard Hughes weep. Had he not been in an air conditioned hotel room keeping collections of toe nails. As is always the case range has a cost. That cost is weight which breeds complexity.


Saro_Princesses eingineer station



To create an aircraft with a five thousand mile range would require  a tremendous amount of fuel. Which requires a large structure which requires massive engines. It’s a cycle of life that feeds upon itself and has been repeated infinite times over decades.  The easiest place to start is with a flying boat. There is no issue with runway length and in an emergency you have far more options to make an unscheduled landing.

Too power this monstrosity the British decided to go with the new fangled turboprops. Which is a good solution given power, fuel usage ect. The next decision should have lead to many of the aircraft’s headaches. Due to its size and weight they went with ten engines coupled to six  propellers. If my posts have shown anything over the last year is that coupled engines are never a good idea. By the early fifties this would have been well known. Given no other choice Saunders Roe took an unproven powerplant and coupled them together. I believe that in 1952 they may have done this to prove me wrong  sixty years into the future because the engines worked fine.  The design still proved underpowered even with ten engines.



Data from Saunders and Saro Aircraft since 1917[14] British Flying Boats[15] and Flight 1952

General characteristics

  • Crew: 2 pilots, 2 flight engineers, radio operator and navigator
  • Capacity: 105 passengers in tourist and first class cabins / 137,000 lb (62,142.2 kg) disposable load
  • Length: 148 ft (45 m)
  • Wingspan: 219 ft 6 in (66.90 m) with wingtip floats retracted. 209 ft 6 in (63.86 m) floats extended.
  • Height: 55 ft 9 in (16.99 m)
  • Wing area: 5,019 sq ft (466.3 m2)
  • Airfoil: “Saro-modified Goldstein section” to “modified N.A.C.A. 4415 Series” at tip[16]
  • Empty weight: 190,000 lb (86,183 kg)
  • Gross weight: 330,000 lb (149,685 kg)
  • Max takeoff weight: 345,025 lb (156,501 kg)
  • Fuel capacity: 14,000 imp gal (63,645.3 l; 16,813.3 US gal) in four integral inner wing tanks.
  • Powerplant: 8 × Bristol Coupled-Proteus 610 Coupled turboprop engines, 2,500 hp (1,900 kW) each + 820 lbf (3.65 kN) residual thrust at 10,000 rpm at sea level.
  • Maximum continuous power: 2,050 hp (1,529 kW) + 700 lbf (3.11 kN) residual thrust at 9,500 rpm at sea level.[17]
  • Powerplant: 2 × Bristol Proteus 600 Turboprop engines, 2,500 hp (1,900 kW) each + 820 lbf (3.65 kN) residual thrust at 10,000 rpm.
  • Maximum continuous power: 2,050 hp (1,529 kW) + 700 lbf (3.11 kN) residual thrust at 9,500 rpm at sea level.[17]
  • Propellers: 4-bladed de Havilland constant speed, quick-feathering Duralumin propellers.[18], 16 ft 6 in (5.03 m) diameter


  • Maximum speed: 380 mph; 611 km/h (330 kn) at 37,000 ft (11,277.60 m)
  • Cruise speed: 360 mph (313 kn; 579 km/h) at 32,500 ft (9,906.00 m)
  • Stall speed: 113 mph; 181 km/h (98 kn) flaps and floats down
  • Range: 5,720 mi (4,971 nmi; 9,205 km)
  • Endurance: 15 hours
  • Service ceiling: 39,000 ft (11,887 m) absolute
  • Rate of climb: 1,900 ft/min (9.7 m/s) at 184 mph (296 km/h; 160 kn) at sea level



Saro_Princesses sealed seawings co dot uk


By the time the three contracted aircraft were complete, the need for them had passed. One airframe was allowed to continue test flights but the other two were cocooned never to be flown. The era of the passenger flying boat had come to an end.


  • skitter

    By the time it's painted in a livery and airborne, it doesn't seem real.
    Too cool to be a true story.

    • fodder650

      I had a pattern of posts on Flying Boats I was going to do because there is a companion land plane to the Princess that is even more unbelievable. I'm going to go post it for tomorrow then go back to the seaplanes.

      • cap'n fast


  • markus baur

    the USA once considered buying the Princess protoypes as testbeds for nuclear powered aircraft .. as even the B-36N would probalby not have been able to lift an actual propulsion reactor (it did fly with a small zero power reactor and was barly able ot get off the ground)

    • fodder650

      It was about the same time we bought the B-57 Canberra from them as well. We weren't opposed to buying Brit aircraft apparently. Shame they found all that corrosion under the tarps.