Zzz wrote:Why no retracts or penetrators? Datum 3500s are sweet! Electrical, no hydraulic lines. Summit Aircraft makes some cool penetration skis here in Oregon. Both are probably less than the cost of straight skis by the certified brands.
Seems like Alaska hasn't been getting the big snows the last 2 seasons, might be nice to have options.
Simple answers:
Penetration skis.....those tires protruding through the ski create a tremendous amount of drag. Depending on snow conditions, you may not be able to get airborne again after landing. Some are a little better than others, and on hard packed or really shallow snow, this is irrelevant. But, in any kind of deep snow, it's huge. Also, compared to straight skis, they are HEAVY, since you're lugging around a set of wheels/tires/brakes as well as the skis.
Retractables......$$$$$$$ and weight. Lots of both.
As to what type of straight skis to run, there are quite a few options out there for a ~ 2500 pound airplane. The old Federals are pretty heavy and the bottoms are pretty small, but they are hell for stout. Like, waaaaay stout. They also have tunnel bottoms, so adding UHMW to the bottoms is more problematic. If you do add UHMW, extend the plastic beyond the edges by a couple inches to increase the size of the bottoms. Frankly, the Federal 3000s are probably overkill for a 2500 pound airplane.
The Landes 2500 skis would probably work fine for this application. The Landes 3000s might be a bit big, but if the added weight doesn't scare you......
Lots of other straight skis out there. Atlee Dodge skis are good skis, and if you can find a set of really nasty ones where the wood bottoms are shot, salvage the pedestals and fabricate composite bottoms. Or, since you're E/AB, find someone with a set of the Atlee skis, and weld up copies of the pedestals. Atlees might even sell you a set of pedestals for that matter. Then you can make the skis as big as you like.
Be aware, however, that certified skis have been tested, and proven in the real world......if you aren't VERY familiar with how skis work, and you're determined to fabricate your own, very carefully copy a certified design, rather than design your own. Trust me, sometimes what appears to be a minor design change can result in some pretty ugly consequences.
But, bottom line: If you can get away with straight skis, you will likely have much better performance.
MTV