Mike's Flying

Mark5

Originally uploaded by Mikebert4

Now we’re getting somwhere.

This fellow did fly, and fly well. We managed to coax glide ratios of 4:1 out of it (just) and it coped with quite serious changes in wind speed/direction almost effortlessly.

If you look closely, you might well notice that it’s pretty similar to Mark4 in it’s fuselage and tail. Indeed, tis the same aircraft, only with the insane-dihedral cut down to a more acceptable 5cm or so. and longer wings added.

I apologise for the sorry state of the craft in the photos, I made the mistake of flying Mark5 before I photographed it. The nature of the construction means that after a few launches (maybe 20 or so) the joints and bends become very weak and the performance suffers. It’s somthing I’m trying to address in Mark6.

Flight of the Mark5

In fact, I’ve now brought you up to date on these here model gliders, and Mark6 is still under development, with the initial test-flights looking very promising.

The Techy Bit:

The only thing I will point out on Mark5 is somthing called gurney flaps. The trailing edge of the wing is folded down at 90º to the airflow and extending about 5mm below the wing. This increases drag (which is bad, but on a model this size, going this slow the additional drag is actually trivial), but it also increases lift. Simply put, it traps air under the wing a little bit, causing a higher pressure and hence more lift.