pipistrel sw vs CT

[hhobbit]

pipistrel sw vs CT

could some aerodynamicist explain to us how come Overview (http://www.pipistrel.si/plane/virus-sw/overview) shows a 75% cruise of 147KIAS, when they look broadly similar to CT2K, never mind the SW and LS? Is it frontal area? having flown the motor glider version, the cabin is definitely less spacious, although I would not go so far as to say it is cramped. That difference is unreal, given that power required for flight rises with the cube of the speed

[DBo]

Didn't you know that aircraft manufacturers use a specially calibrated ASI for their sales claims...

Dave

[Pilot DAR]

147KmIAS?

I have to write this second paragraph because the foregoing line triggered a message that my reply was not the required minimum 10 characters. Now it is!

[hhobbit]

eh, page 18 col 3 March Flyer quotes 145kts uncorrected. No mention of specially calibrated ASI. Still wondering. These figures are way out of line with any other aircraft that I know about with the exception of the Banbi. B ut the high Banbi figures relate to the VLA with a significantly higher loading.

[Genghis the Engineer]

It doesn't quote IAS, it just says "cruising speed".

Even money that's TAS at altitude. 147kn TAS at 10,000ft is about 126kn CAS - or about the same as you'll get out of a CT. (And a nominal 75% power at that altitude will be about full throttle.)

It's a common piece of fiction regularly seen in aircraft sales brochures - it's just that the UK microlight industry is unusually honest (usually!)

G