It doesn't have enough useful load to have "help" on board.

Mike C.

3750 lbs is the number I've seen.

Mike C.

Plastic is not as light as it used to be

Actually it's carbon fiber...

Actually it's carbon fiber...

Oh, plastic is just as light as you want it to be. But I read somewhere, and have been told this also, that with composites the FAA is assuming a 50% reduction in material strength due to defects in manufacturing. So all composite structures must be manufactured to twice the stength requirements about the usual design margins...

And that the data used to substantiate this position is from the 50s, and the FAA has no interest in updating/changing the position.

Tim

Site a reference for that.

Nobody can build composites to the tolerances sheet metal can be done, so some margin is warranted.

Mike C.

I know composites need a safety factor of 2x, rather than steel or woods 1.5x per FAA. Can't remember exactly where I read that, but it was a big subject years ago over at the Homebuilt forum.

So it weighs the same as an Eclipse? That's great considering how much larger the cabin is. An Eclipse cabin is tight. The SF50 is spacious. Go check one out.

I'd rather compromise on climb rate and have a comfortable cabin.

Those are not exclusive choices.

Put two engines on it and you would have a nice cabin and climb rate.

Mike C.

I seriously doubt that Cirrus would ever do this, but I wonder if it would viable for them to offer a slightly different version of the Cirrus Jet down the road with 2 engines. If everything you say about the benefits of having a twin jet over the single is true, then they could capture the market of people who want the "simplicity" of a single, and also the people that want great performance in a personal jet.

Those are not exclusive choices.

Put two engines on it and you would have a nice cabin and climb rate.

Mike C.

They could change to a conventional tail and call it the Debonair, too.

:P

You've assumed a twin jet would cost more.

Not clear it would.

It would not surprise me in the least to find out two PW610F engines cost the same as one FJ33-5A, when you consider *ALL* of the direct and indirect costs. Liability (both for the engine maker and the airframe maker) would be less on the twin. Twin wouldn't need complex control system mixer. Backups for systems become easier in the twin. Costs to plow the new road of SEJ certification doesn't exist for twin. And so on.

But wait, the EA550 cost more than the SF50, so doesn't that prove the point?

The present cost structure of the SF50 and Eclipse are skewed. The SF50 has not yet made it into actual production, so the pricing is likely optimistic. The EA550 isn't designed to be made in handfuls per year like it is presently, so the costing is skewed the other way. Net result, neither example represents a reliable cost point for the SEJ versus TEJ debate when you compare apples to apples.

Mike C.

I'm not assuming anything. I'm looking at available options. Nobody makes a twin SF50. This thread is about a real product that has tracks on flightaware and will be available for sale very soon. Or should I say, that is what I thought we were discussing.