Scheibe SF25B versus Slingsby T61F (Venture)

[kevkdg]

Does anybody know the fundamental differences and pro's and cons of one compared with the other?

[Mechta]

Engine and spar differences (later T61s had a composite spar) are what I can find. Allegedly the Slingsby aircraft are lighter, which is the opposite of what I would have expected.

The SF25 uses a Stamo engine, whilst the T61F uses a Rollason Ardem.

The Slingsby is not much fun if you are six footish. After an hour in our club's T61 I get sore buttocks, even when sitting on a dynafoam cushion, and a bad back possibly due to the shoulder straps pushing down.

The T61 brake is ok for holding the aircraft for power checks and taxiing, but if its used as a landing brake, either the cable will pull through the clamp or the cam whcih actuates the shoes goes overcentre.

It will thermal engine off which in our club is free flying. My son had a 1hr 12min flight of which only 12 minutes had to be paid for!

Climb with two heavy crew is marginal, but our current machine with a reconditioned engine is a heck of a lot better than the one it replaced.

Several civilian and RAFGSA clubs have T61s, so if you contact them you might get someone to take you up.

If ours was a bit more comfortable I would fly in it a lot more.

I flew in what was probably an SF25B in about 1977 and that had a rope pull start handle which came out of the intrument panel, and if I remember correctly, a feathering prop. This was at Lasham (Polish Air Force Association aircraft?) so was probably intended for soaring, whereas the Air Cadets tend to only turn the engine off in the air for practiced forced landings, if their Vigilants are anything to go by, which probably explains the fixed pitch prop.

This link spells out some differences, http://www.mombu.com/aviation /civil-aviation/t-slingsby-t61-motorfalke-3810087-last.html (http://www.mombu.com/aviation%20/civil-aviation/t-slingsby-t61-motorfalke-3810087-last.html) as does wiki

[Dan Winterland]

There are several versions of the SF25, only the early ones had rope pull starts. But so did the first T61s. They are essentially the same airframe, but I think you will find the German aircraft built to a higher standard.

[chevvron]

Don't get Vigilants (Grob 109b) and Ventures (T61) confused. As regards turning the engine off, as far as I'm aware it was allowed with the Venture but there was a ban on this for Vigilants years ago (early '90s?) because it was difficult to re-start in the air, resulting in at least one 'nasty' (Binbrook?) I think it was put down to high undercowling temperatures causing the fuel (MOGAS) to vaporise in the fuel lines so it's probably been 'fixed' now.
Vigilants by the way, have a 2-speed prop operated by a 'pull' handle, but there's no in-cockpit indication of what setting you have selected!

[Mechta]

Glider Pilot Network > uk.rec.aviation.soaring > attention all T61 motorglider owners (http://uras.gliderpilot.net/?op=s2&id=30973&vt=)

This thread is well worth a read for anyone considering a T61. It appears that Slingsby have been taken over by Marshall's, who will continue to support the Firefly, but not previous aircraft.

[kevkdg]

I was considering a share in a T61F Venture, but this has made me unsure. I know not what the implications of it are!

[chevvron]

Surely if there's no company support, it could still be operated under the Permit system.

[shortstripper]

I'd love the Falke to be on an LAA permit .. No CAA survey to worry about then.

SS