evansb
Post 4
Note that most Vickers Viscount 700-series have tapered tips and Viscount 800 series have squared-off tips. The photo below shows an early BEA 700-series Viscount with experimental high-speed tips.
Very interested as I'm doing some research into various the various Viscount blades. The change from taper, or "Needle" blades to square-tipped, or "Paddle" blades, took place when the Dart 510 was introduced for the Capital and CAA orders. There are also 3 variations in the square-tipped "Paddle" props, including the "Trapezoidal" blade fitted to the Dart 525 but I'm still bottoming them out!
Regarding the blades in the photo, known as "Cutlass" blades, these were fitted to the 2 Dart-Daks which did route/turboprop proving flights round Europe and to the early Viscount 701s and 708s for BEA and Air France with Dart 505's fitted. They had copper leading edges riveted on and there were, by all acounts, reliability issues with the blades + they were expensive to repair.
As the Dart 506 was introduced, so too was the "Needle" blade. The early 701's and 708's also had their engines upgraded to the Dart 506 and the "Cutlass" blades vanished with the Dart 505's. The upgrade often took place 2 engines at a time so, for a while, the 701's and 708's could be seen sporting 2 "Cutlass" and 2 "Needle" props. Later production 701's and 708's went straight to Dart 506's so they only flew with "Needle" blades.
Interestingly, I have not seen any record of the Viscount prototypes with "Cutlass" blades, the first flight appearing to be with non-standard "Needle"-type blades. I believe the Darts were also earlier, 504's if I recall. Anyway, if anyone has anything on Viscount blades, particularly details on the at least 3 versions of the "Paddle" blades, or comments on the above, it would be great to hear from you.
Cheers,
H 'n' H