From an engineering standpoint of "why twins > singles" Mike C has covered it pretty well.

In reality from an engineering standpoint, a larger single is more efficient, but less redundant. I've been up to 430 in a jet single, but again, military doesn't play by the same rules as the FAA, and we had O2 on all the time so a pressurization failure was more comfort than survival (I lost a canopy seal at 390 somewhere over western Massachusetts on climbout from KBED, that will get your attention when the cabin goes from 180 to 390).

The chute weight kills the weight advantage of a single, and the 250 limit eats all the gained engine efficiency and then some.

But, it's not just about the engineering data.

From a logic standpoint, I should want a B36TN, from a cool standpoint I want a P51D. From a wife's emotion and financial standpoint, it's looking like I'll own an older B55, TwinBo or a 310.

The question is where sales fall due to emotions and economics. The engineering of the plane is sound, and has the limitations that have been mentioned.

I agree with this on the early plane deliveries. I had to duct tape a 496 to the panel on a cross the desert trip in the Waco but I wouldn't want to do it in a jet!

But, the avionics on the airplanes that are now flying (except perhaps the doomed cheap ones that run out of airframe life in the next couple of years) are supposed to be pretty good. I'm not sure where you draw the line at upgrade version (1.5, 1.7 or later) but do you think the later avionics upgrades are dangerous, and if so, why?

There are still reports of various oddities. Things like ADC compare failures, autopilot disconnects, random glitches. There was a thread earlier this year that went into more details and those stories continue to show up.

Having an Eclipse is like having a PC with Windows 3.1. That version was just stable enough to get real work done (not like version 1 or 2), but still so buggy and clunky it drives you mad.

The Eclipse has so much that runs through the software that I am concerned about the lack of separation of functions. Sometimes you can be too integrated and I think the Eclipse is that way. When the primary and the backup systems are based on the same code base and display on the same screens, that makes me nervous.

If I flew an Eclipse, I'd want a set of backup instruments independent from the main set. Indeed, they did that with the 550 using another electronic standby system and I think you can retrofit the others.

Personally, I'd want to put an air driven AI on the panel somewhere, too. An electrical fire or lightning strike can take out all your electronics. A spinning chunk of metal is a good backup for all that. I am in the electronics design business and I can tell you that things can fail in ways no engineering would ever dream of. Call me old fashioned, I don't care, but I won't be sitting there wonder what the heck the system is doing.

Mike C.

Hi Mike-
This insurance exercise does not appear to be accurate at least as it was presented - being it is noted you have good time in type with the 182 and presumably very little if any with the SR22 - that variance in and of itself will skew the numbers more from an underwriting standpoint. That said and as I pointed out you won't pay less in an SR22 versus an equal value 182 provided all the underwriting information is identical with both (ie having equal time in type with both models). I would agree that the Cirrus might actually be a bit higher insurance in year one and as you noted would drive a formal training requirement from a CSIP. Not a comment on good versus bad just what the insurance market reality is between both airframes.

I'm not intentionally taking you out of context, just keeping the quote short.

I can't believe I forgot about one of the most popular jets of all time (which also happens to be a single):

http://en.wikipedia.org/wiki/General_Dynamics_F-16_Fighting_Falcon

Yes, I realize that it can go higher than the SF will probably ever be allowed to. But, it does lend something to the viability of a single engine turbine.

Bottom line on the SF 50 is that 28k will increase fuel burn and make it less than it could be at higher altitude. Who's to say that it doesn't get access to RVSM at some point, though? If the bleed rate of the pressure vessel is low enough, it might be certifiable to a higher altitude.

The V-tail argument was settled by Beechcraft quite a long time ago. The penalty of the larger members is negated by not having the vertical stab. I don't think the single engine creating more drag argument is viable either. Neither of us have real numbers to use for that one.

So, to go back a few pages....


Who would pick a Meridian over an SF50?

Not me.

Who would rather be a Meridian salesman over an SF50 salesman?

Not me.

Mike,

Thanks for your detailed and interesting responses to my questions a couple of pages back. I could see that aerodynamics might make two engines more efficient than one when installed on an airplane, and that the altitude restriction on single jets reduces their efficiency. I was glad to read that my instinct was not wrong, that two engines are not inherently more efficient in isolation. I had mistakenly thought you had claimed differently.

Ashley

You misread the statement. He is saying I MAY need a checkout in the 182 IF I don't have experience in it. He is NOT saying I have time in the 182.

I have equal time in both types, zero. The numbers are based on that.


He said the losses are higher for a Cirrus. That seems to be the market reality from his viewpoint and it fits with what I see.

Mike C.

F16.

The F16 is an engine nacelle where a single pilot is trapped to it. It isn't a personal airplane. In other words, they designed the airplane around the engine rather than designed the airplane around the human(s) and then find a place for the engine.

And, of course, it doesn't have to be certified by the FAA. All sorts of things are allowed for the military that you can't do for GA.


RVSM is not an issue.

Bleed of cabin won't do it.


Take a ruler to the SF50 tails surfaces and to an EA500. Numbers don't lie.


I love the "I don't know so you can't either" argument. Good thing the world doesn't work that way.

Mike C.

Mike C.

You keep mentioning tail surface area. From my very limited knowledge, intersections actually cause a lot more drag then the wetted or the cross section. As a result, the three fins on a traditional tail actually create more drag then the larger V-Tail.

Tim

Actually I didn't misread the post - he (your agent) stated "based on your experience IN a C182". That tells me he ran the pricing with noting prior experience IN a 182. He didn't say based on your experience - the Cessna 182 would be X - he said specifically IN a 182 in his comments. Splitting hairs here but I didn't misread it.

As I noted in my initial post the Cirrus is NOT less to insure than the 182 - which was the point I was making as it related to the BRS.

I specifically told him I had zero time in each aircraft.

He is saying that "based on the fact you have zero time, you MAY be required to get a check out", a warning that having 3000 hours and twin turbine time is not a pass on being checked out in a piston single (nor should it be, IMO). That is what he meant and you've taken his slightly ambiguous wording to mean something it doesn't.

In contrast, a more formal training approach will be required for the Cirrus. He was just trying to compare the two for me to know what the entrance requirements would be.


Can you produce quotes showing they are the same?

Do I actually have to get hard quotes to show you they aren't?

My agent contradicts what you said with specific numbers. Everyone is free to decide who they believe.


You chose the two aircraft to compare, not me!

Should I have him quote the Corvalis, too?

Mike C.

Love to.. as soon as I can get my hands on an SF50, I'll measure them. Do you have the measurements somewhere? You did find that range graphic they released.


We can speculate all we want, that was the point of this thread, but neither of us has numbers or a CFD model or anything that can prove it either way.

Mike, I am confused. Tom is agreeing with you, but it sounds like you are saying otherwise.

My read of his posts is agreement that the Cirrus is more expensive to insure.... (... NOT less expensive)