BeechTalk - BT

Username Protected · **Posted:** 24 Dec 2015, 08:50

Username Protected wrote:

Mike has addressed this eloquently in prior posts. A couple of highlights.

1) two small jet engines don't cost meaningfully less than one larger one
2) mounting one jet is aerodynamically inefficient (n/a to setp)
3) certification requirements for jet efficient altitudes require a redundant pressurization source, second engine is the cheapest way to achieve this.

1. No where has Mike posted any proof of this. Second, I know based on TP overhauls, one engine is much cheaper then two. Why would a jet be any different?
2. One time design challenge; not an on going cost.
3. Again based on the assumption of being able to go high enough. And as I posted, and Jason and many others. This is not viable in many parts of the country. Specifically, the parts of the country with the most money and GA traffic.

Tim

Username Protected · **Posted:** 24 Dec 2015, 09:06

Username Protected wrote:

Cirrus had started with a piston single that flew 100 knots at 25 GPH, would we be praising them for advancing aviation into the future?

Oh, come on! Is this sophistry really the best you can do?

Username Protected · **Posted:** 24 Dec 2015, 09:16

Username Protected wrote:

Everyone always has a better idea. But very few have the balls to put their money up to make it a reality. That's what I admire.

Sure. But whose money are you talking about?

As I understand it (mostly from https://en.wikipedia.org/wiki/Cirrus_Vision_SF50), the SF50 depositors put down about $40MM or $50MM. That wasn't enough money to go into production and the project foundered for lack of additional capital. The company was eventually sold to the Chinese firm CAIGA in 2011 for $210MM. CAIGA (wholly owned by the PRC) has fronted the SF50 development costs since then.

Username Protected · **Posted:** 24 Dec 2015, 09:50

Username Protected wrote:

This is the kind of behavior that has made America what it is and also the sort of thing that the Wright Brothers, Walter Beech, Clyde Cessna and a host of other risk taking aviation entrepreneurs did to create aviation as a practical means of travel in the first place.

You mean like Paul Moller and his flying car? We need more of that?

Look up the history of the Gulfstream Peregrine. The SEJ is NOT a new idea. This is not new territory.

The SEJ is not a "gamble", it is a bad idea, knowably bad before you start.

If Cirrus had started with a piston single that flew 100 knots at 25 GPH, would we be praising them for advancing aviation into the future?

Mike C.

Username Protected · **Posted:** 24 Dec 2015, 09:55

I bet a "knowably" bad idea will become a smashing success, and then we can start a thread of how the world is full of stupid people and they all buy Visison Jets.

Username Protected · **Posted:** 24 Dec 2015, 10:04

Does not compute!

Username Protected · **Posted:** 24 Dec 2015, 10:05

Username Protected wrote:

Why is it a bad idea? The FJ33 is a pretty efficient engine and the SETP market is doing well, why not a single engine jet?

Because the SF50 is limited to altitudes where it can't be efficient.

There are no benefits to being a single engine jet, only downsides. The concept exists only because people are applying piston think to jet design. They mistakenly think the benefits of being a single that exist for pistons and turboprops carry over to jets. They don't.

Compare an Eclipse 500 versus SF50. The EA500 goes further, faster, higher on less fuel. The EA500 has other problems, but the basic airframe and propulsion concept is not one of them.

Compare engine failure. EA500 is a slight annoyance. SF50 is a hull loss at minimum, or worse if the chute doesn't work.

If Cirrus builds roughly the same airplane, but puts two PW610s on it, and a conventional tail, that would be a winner. What they are building is a lame airplane from the start, crippled by misapplied piston think.

There is a reason Cirrus is the only SEJ vendor still around.

Mike C.

Username Protected · **Posted:** 24 Dec 2015, 10:19

Username Protected wrote:

But, planes are not sold solely on logic. Emotion in many forms plays into it.

When you are paying jet prices to fly at turboprop speeds, altitudes, and range, that can be emotional, too.

Mike C.

Username Protected · **Posted:** 24 Dec 2015, 10:25

Username Protected wrote:

2. One time design challenge; not an on going cost.

An inefficient engine setup IS an ongoing cost. Costs drag, speed, fuel.

It isn't a "design challenge", it is an intrinsic problem of SEJs, there is simply no good place to mount the engine where it is efficient.

Mike C.

Username Protected · **Posted:** 24 Dec 2015, 10:34

Username Protected wrote:

Mike , fly on piston engine between FL150 and FL250 is not a bad idea ,but fly a jet FL 250 is a bad idea ?

Yes.

Jet not like a piston.

If you put TWO engines on the SF50, it would fly higher, faster, further on less fuel. This is not theoretical, the EA500 demonstrates this clearly. Piston pilots can't understand that logic, the single/twin tradeoffs being so ingrained in their minds.

Mike C.

Username Protected · **Posted:** 24 Dec 2015, 10:41

That's BS. The EA500 is a short range airplane too.

"They" don't let you stay as high as you want for as long as you want. It's ridiculous to keep thinking that. That's OTPT.

Username Protected · **Posted:** 24 Dec 2015, 10:44

Let's say you could fly up to 410 in the SF50; what kind of performance would you see? And, would you take your family up to those hostile conditions betting on the reliability of a single air pump?

Username Protected · **Posted:** 24 Dec 2015, 10:50

Username Protected wrote:

3. Again based on the assumption of being able to go high enough. And as I posted, and Jason and many others. This is not viable in many parts of the country. Specifically, the parts of the country with the most money and GA traffic.

Username Protected · **Posted:** 24 Dec 2015, 10:51

Username Protected wrote:

When you are paying jet prices to fly at turboprop speeds, altitudes, and range, that can be emotional, too.
Mike C.

With the Vision Jet priced at around 2M, that's about the same as a new Meridian, and about half of a TBM900. In fact at that price point it will be at the bottom of the scale of SETPs. So the SF50 will be priced at TP prices with TP performance, but without having to turn a propeller. Will that make it a failure?

Username Protected · **Posted:** 24 Dec 2015, 10:53

When the plane is an enormous success, will it still be a bad idea?

Cirrus SF50