If what you say is true, the Ted Smith screwed up the design of every airplane he ever did, including the Aerostar. Why would he do that since he was all about performance?

Why does every Boeing and Airbus lack V tails?

Why does virtually every high performance aircraft lack V tails?

V tails are more drag, particularly on something like a jet with a wide speed envelope that requires substantial trim changes. They also fail to take advantage of the main wing down flow to convert that to useable thrust.

Mike C.

Thanks Jim! You are correct......this has gone around in circles and I'm out of breath but yes the point is the Cirrus is more to insure which I stated before Mike had his broker spend a couple of hours to validate what I stated.

My bad, I thought your point was they were the same.

Apologies.

Mike C.

My bad, I thought your point was they were the same.

Apologies.

Mike C.

Look at the size of those tails!

And to top it off, they weren't big enough, so they ADDED ventral fins, too! And those also cause drag since they are fixed and can't be aligned to the airflow for all valid CG and airspeed regimes. The SF50 is really an X tail, with FOUR junctions! If junctions cause drag, then this airplane has it.

(Ignore the tube out the back, that's a spin chute, won't be on the delivered airplanes.)

Mike C.

Yes, it surely does look pretty cool...

If what you say is true, the Ted Smith screwed up the design of every airplane he ever did, including the Aerostar. Why would he do that since he was all about performance?

Why does every Boeing and Airbus lack V tails?

Why does virtually every high performance aircraft lack V tails?

V tails are more drag, particularly on something like a jet with a wide speed envelope that requires substantial trim changes. They also fail to take advantage of the main wing down flow to convert that to useable thrust.

Mike C.

V tail is not a new idea. It is a very old idea that is well understood.

BTW, Honda is not the first with the engine pylon on top of the wing, check out:

http://en.wikipedia.org/wiki/VFW-Fokker_614

Very few aviation ideas are truly new. Many of the old lessons have to be relearned.


SF50 is supposed to be simple, right?


I doubt that, but in any case, the SF50 is part 23.


The strakes were not on the original prototype but were soon added. This suggests they found out they needed MORE tail, possibly due to poor stability in turbulence.

It will be interesting to see how the SF50 performs in turbulence, something V tails are notorious for not handling well.

One thing that I've noticed is a lack of articles from people who have actually flown in the Cirrus jet (either the prototype or the conforming airframes). Makes me wonder how many of the deposit holders have flown in the jet or bought just based on the mock up.

Usually at this stage (within a year of certification or so we have been told), the aviation press has a lot of first hand flight reports. Those seem absent here. Anybody have a link to any flight reports?

Mike C.

I agree that this is curious. I would have thought at least some journalists would have flown one and written something about it.

Side comment: It's pretty interesting how tail strakes seem to be an add on to many jets. It's almost like even current state of the art CFD does not seem to address longitudinal stability as well as needed. Just a casual observation.

Mike,

The control complexity I was referencing was in the engineering, not in the user interface design. As you probably know, the simpler the user interface which may be broadly utilized generally you will have significantly more complicated engineering / design considerations.

Hopefully without the having the accompanying actual mechanical complexity.

Tim

I agree that this is curious. I would have thought at least some journalists would have flown one and written something about it.

I know that aircraft manufacturers sometimes allow the press to fly planes before the certification process is complete. The articles I read about the Mustang from a few years ago are an example. It is interesting that Cirrus hasn't done that. I could argue that it shows concern about problems and I can also argue that it may build some mystique for the plane building up to its certification and release. Who knows?

I'm not one of those who is going to fork over money to anyone for something I can't see and experience first hand. And, in fact, the final design of a lot of the airplane isn't either finished or released yet. For example the interior and interior options are unknown. I hope they improve them frankly because the mock up looks cheap and uncomfortable.

But, with my experience with Cirrus as background, I think when the final product is released it will be high quality and surprise a lot of people. Perhaps even Mike!

By now someone at Cirrus is already watching this thread and you're probably WAY down the list of people they want to demo it to

I don't know the etiquette about posting first-time in a long thread, I hope some general observations are OK.

There's a characterisation of Cirrus buyers and potential SF buyers in parts of this thread which I think is somewhat false: the idea they are kind-of moronic, with more money than sense, choosing airplanes on false grounds of safety (the chute) or "coolness : ease to fly ratio".

I personally don't like the SR series much. I have never understood why anyone would buy a new one rather than spend the money on a vastly superior used airplane. But thousands of people do.

I have never come across the "Cirrus-buying moron" archetype. The owners I know are the kind of intelligent, sensible people I guess we all think we are. The renters I know are just like all the other sensible pilots who rent airplanes.

The main differences are, I think, preferences about modern design, buying new, and buying something relatively simple rather than maximally capable. My own preference has meant I've never owned an airplane less than 30 years old. But thousands of Cirrus buyers have different preferences.

On the chute, my sense is that perhaps the main benefit Cirrus buyers perceive is passenger/spouse comfort. However "irrational", this is a real benefit. Personally, I'd rather have the extra payload. But I don't translate my preferences and weightings of an attribute into a "truth" others have to adhere to.

On the technical merit of the SF50, I agree, it is mediocre. The speed-range-payload are "OK" - plenty of personal airplanes have elements of that performance. The bad fuel efficiency is the one thing that would worry me most about its success. Combine the two, and it's perhaps the least capable airplane one could spend $2m on.

But that's how I think about it. The Cirrus market clearly shows that there is a completely different set of buyer preferences. For example, I have never understood why anyone would buy a new SR22 (fully loaded nearing $900k I think) over a lightly used Malibu. But thousands of pilots have chosen the SR22 and I imagine "simplicity" in flying is a factor (fixed gear, no pressurisation).

This concept of flying simplicity I think is a subtle and diffuse and complex one. Of course, any airplane which is single-pilot certified is something, in principle, most pilots could train for. But there is a cadre of pilots comfortable in an SR22 for whom the next step up is something they are apprehensive about in terms of the "pilot demands"; both in training and in the practicalities of remaining proficient. I have a feeling that the compromises built into the SF50 (lower speeds, lower max altitude, single jet) will make it a more accessible airplane for a certain cadre of pilots.
Compare it for example, to the Meridian.
- no prop control (or overhaul...)
- no torque roll
- FADEC, so much less worry over starts and limits after start
That doesn't sound like a long list, but my feeling is that it only takes a few elements to push a turbine type from the right to the wrong side of comfortable for the target market of buyers. I think some of the posts in this thread under estimate that.

Have a good Xmas all,
Vasa