I was still feeling a bit sore about my bouncy landing at Malbec on Friday and was browsing the internet yesterday when I came across the following video on Youtube.
The pilot of the aircraft involved, a Zenair 701 with slats, the design on which the Savannah was based, was described on the web site where I found it as being ‘an experienced test pilot’. But just watch it through until he lands at around 3 mins 09.
What I was researching were the landing characteristics of slatted wings (like those on my Savannah) and it seems that when you’re flaring in the approach and the angle of attack is increasing, you need to keep some power on otherwise the drag from the slats increases to the point when the aircraft just drops. That’s OK so long as you’re close to the ground and that’s how you achieve a really STOL landing, but not so good if you’re still some way up. Like this guy was.
He was a pretty hefty bloke anyway (it was shot in the USA, the country of large portions…) and he hit from quite a height having cut the engine over the runway threshold. It’s amazing to me given how much the undercarriage bent (remember, this is a thick bar of aluminium!) that the aircraft just shrugged it off and carried on with its landing roll with no ill effects, but it shows that I had nothing to worry about following my own much softer departure outside the preferred bounds of the landing envelope!
But, more seriously, what this does show is that even an experienced pilot can be caught out by the flying characteristics of a wing design and that I’d do as well to do my own ‘research’ with the Savannah on an airfield with plenty of runway to play with before I start trying to become the STOL king of Plazac.
Interestingly enough, I found that the slats add hardly anything to the performance of the Savannah wing and can be removed, even leaving the brackets in place, and vortex generators added without the need to fit ICP’s own VG kit that includes a new longer and thinner leading edge. The thorough research done by the first person who did it, in Australia in about 2008 and whose idea was subsequently copied by ICP showed that the performance difference between the ‘unofficial’ and ‘official’ wing designs is negligible, although, of course, the cost isn’t. Both wings achieve the same benefits in fuel consumption, higher cruise speed, more nose-down attitude in the cruise and smoother landing characteristics. Food for thought.