Twotter vs. Casa 212.
Now before I go any further, and excluding certification, and sticking to the apples and apples as it were, the Casa 212 is a very good machine, it is powered by TPE 331’s, very high power output from a very compact engine, that for its power output use’s somewhat less fuel than a PT6 of comparable ESHP:
The Casa 212 has a lot less ground clearance than the Otter, I was told when I did an evaluation of the Casa that it could not be equipped with Mid to High floatation tires, but it can be operated on Snow/Ice and assorted surfaces & strips, thus its stuck with the limiting issue of ground clearance compared to the Otter. (Maybe some one can tell me why it cannot be fitted with floatation tires)
The Otter you can bounce it on/off water as well.
The Casa has a great utility advantage over the Otter with its rear door.
Now lets deal with my statement of hanging a pair of Pt 6’s on it?
The TPE 331 series are fixed shaft engines as opposed to free turbines.
The 331 series require prop spinning on shut down to prevent “shaft set”. the Pt6 is totally immune from this.
The 331 requires a lot more cranking Amps’ from a battery due to its fixed shaft, and having to swing the inertia and mass of the prop, than what the Free turbine of the Pt 6 does, put them in a cold climate, and you will always have issues of cold batteries on both machines, but the Pt 6 can be “milked” if down on Amps, ( Up to a point), I have heard of chaps getting away with starts at as low as 11-12 %, down on the ice with the Twotter.
Where as the Casa has been grounded due not being able to get enough out of the battery.
Now take the PT 6 to a hot and dusty climate, i.e. the desert, or to a tropical climate with coral dust & salt spray, it will keep going and not “overly object” to the climate, the same can not be said for the 331, it is heavier on maintenance to keep it in service, it just plain does not like the dust:
I am not saying that either is good for either engine, but the Pt 6 is a lot less “bothered” by it all.
i.e. “in the bush”, the Pt 6 is a lot more maintenance friendly than its counterpart: ( My opinion)
On the other hand where you operate both types of engines in a clean climate, with ground power readily available, they both give outstanding service.
One could say that the Pt 6 is more versatile when it comes to climatically different & remote area’s, this is my opinion and belief from my experience.
Now “IF” the CASA had PT 6’s on it, and it could be fitted with mid to high floatation gear, with the rear ramp/door, it would without any doubt be a far better machine than the Otter, for a start it would carry just short of 30 punters over a similar distance for almost the same operating cost as the Otter, into and out of , just a bit more runway than what the Otter requires:
But not on/off the big blue wet thing.
Chr's
H/Snort.
