I wonder if there's a profit window in taking something like an "old Lear" and retrofitting it with modern engines and avionics. Seems like you could bypass a huge (and expensive) portion of the certification process especially if you started with a proven engine and avionics suite. The airframe itself comes with a lot of the tough stuff (pressurization, deice, flight envelope, control force, emergency backups, etc) already certified.[/quote]




Its been tried look at spirit jet. http://www.spirit-wing.com

This discusion is like watching history repeat itself. Go and reread the early articles on the eclipse. Cost of aquisition, performance, capability, the claims made before production were not deliverable .

http://www.nextantaerospace.com/images/ ... rticle.pdf

I think between certification and labor costs (not to mention even used engines) it's hard to make something that's better than the used options already out there. Nextant seems to be trying to take a old but not too old airframe and refurb it to competitive with gently used. That might be workable.

But I think refurbing totally clapped out to competing with tired but serviceable is hard trick.

Fundamental difference, the SEJ is in an entirely new territory as regards market, engineering, regulations, etc. Making a fixed gear piston single is mundane by comparison so Cirrus didn't have to blaze a new trail there.

One could argue it is a territory with a LOT of dead projects, starting all the way back to the 1980s with the Peregrine. I predict Cirrus will simply get their dried out bones deeper into the forest than others.

Mike C.

Your logic is highly flawed since it presumes all activities one starts are reasonable.

If so, we should be able to buy Moller flying cars now, and there should be 2000 Eclipses flying around.

Cirrus knows piston singles. Very little of that heritage applies to jets.


Grandfathered, you couldn't do a new design today like that. Rules changed after the SETPs were certified, partly in response to a concern that these SE planes were gong into the high flight levels.

This is also a reason why there are no new SETP designs recently. Basically a barrier to entry for other makers, which gives TBM and PC12 a market advantage because they have older heritage. Such is the ways of the FAA regulations.


Then what do you call my airplane that goes faster, burns half the fuel, goes twice as far, uses less runway, can land on ice and snow, and carries 3 times as much?

Market annihilator?

No argument claiming practical value of the SF50 is going to win. The only one that has a chance is the ego thing, and I think that is going to fail when the realities hit home.


Piston think again. That's like saying you want to dominate the pizza market with steaks. Just doesn't work, two different markets, two different approaches.

Mike C.

I don't think mike will ever get it. There is a reason companies don't let their engineers do the marketing. They'd never sell anything. From a practical stand point all kinds of good reasons can be made why it's not the best choice in almost all aspects. I think it's ugly, slow for a jet and flies too low. But I also think it will sell when and if certified. I've seen the people drooling on it at Oshkosh for years. And these were the people who can afford it.
Jason, I'm pretty sure Sam wasn't referring to segments of the whole american population in his reference to the middle group. More likely meant the middle of the upper group. Meaning you. I drive a piston so I'm lower upper?

There are not as many as you think after you eliminate the old ones (newer jet engines are significantly more efficient), the ones that are too big (FJ44 for example), and the ones not allowed to be on a single (PW600s for example).

The jet engine makers are not that excited about providing engines for SEJs and you really can't go forward unless they are onboard. Williams is the most accessible of engine makers, even working with experimental aircraft, so that's where Cirrus went.

To give you a sense of PWC's thoughts, in the PW600 series TCDS:

"The engine is approved for multiple engine installations only."

One wonders if PWC was consulted on the Eclipse EA400 concept beforehand (used a PW615F). I doubt it given the secrecy the EA400 project had at the time.

Mike C.

Wouldn't you rather have two jet engines instead of one for the SAME price?

The issue isn't SF50 versus TBM, it is SEJ versus TEJ. Piston think is so ingrained that you reflexively think the twin jet HAS to cost more. It DOESN'T.


Yes it is, it will cost you at least 1 and probably 2 people's worth of useful load.

Mike C.

The laws of physics don't allow you to optimize the jet engine such that it works well at 25K. The PLANE has to push through heavier air, so the engine POWER has to be high to do that. A jet at FL410 is ALWAYS going to be WAY more efficient. Two engines is the price of admission to the high flight levels.


You can't change the DENSITY OF AIR at FL250. Given that, no way to make FL250 an efficient jet altitude.


Actually they are about the same. Brand New King Air 90 and TBM are within 10% of each other, likewise for King Air 250 and PC-12.

People buy the single to save fuel, not for lower acquisition cost. Unfortunately, that math doesn't work for jets due to altitude limitations.

Mike C.

http://www.nextantaerospace.com/400xti/ ... rison.html

In my mind, this is a FAR better aircraft than many new ones. The BeechJet suffered from fuel thirsty engines, this fixes that and greatly increases its range and performance. The airframe is ROBUST, you can definitely tell the same engineers who designed the MU2 worked on this one.

Mike C.

The dream has been sold.

The reality comes when you have 250 lbs full fuel useful load and it burns 80 GPH to go 270 knots for only 500 nm at FL250.

Put TWO PW610F on the SF50, and now it goes 360 knots, burns 50 GPH, goes 1000 nm, carries 800 lbs, and flies at FL410.

It really is that much of a change! And that's not even considering the redundancy advantages of two engines, only looking at the performance.

Eclipse got it right when they put TWO engines on the plane. Recall that Eclipse wanted to make the CHEAPEST JET EVER, that was basically their entire mission statement. Why did they choose two engines? Because it doesn't cost more than one when you are a JET.

Mike C.

Mike,

You are missing the point. Jet engines can be tuned for optimal efficiency at any specific altitude. Does not matter how "thick" the air is, it is all thermal dynamics. In fact, at lower altitudes, with denser air you actually get more efficient engines. This is actually a result of less mechanical energy wasted on friction (the fans do not have to spin as fast to generate the same compression, and by just dealing with the lower altitudes, you reduce the variable vane complexities and the associated drag).

However, for most jets from the Mustang and up in size, the drag penalties on the airframe have far out weighed the potential savings on the jet engines. And this is a legacy think on the jet manufacturers. Just like you accuse other of piston think, you exhibit legacy jet think.

The interest in the Eclipse, and the SF50 both demonstrate like the original SR20 and SR22 there is a potential for an unmet market need in aviation. In this case a short legged jet for the owner pilot with a low pilot workload designed for the 250-750 NM range with occasional excursions farther.

I know three guys with deposits on the Cirrus SF50, all three have SR22, two of SETP (Meridian and TBM 700?). All three are planning to sell the other aircraft when they get their SF50s (running bet is either 2016 or 2017, they are down the list a bit). Reason, it fits the mission, has a chute so the wives and employees feel comfortable, has a jet, no prop so it is a "real" plane.

I now you do not see the market, and you probably would have bought a betamax while I bought a VHS. But the market will eventually tell the story, engineering will not. The only real question for Cirrus and the market, is there enough demand and can the price be low enough to create the demand. Piper said there was not enough of a market, Diamond also bowed out because investors said there is not enough money/profit. On the other side Cirrus and Eclipse have said yes, Cessna said yes with the new M2....

Time will tell.

Tim

Mike,

Jetprop has proven that people are willing to totally ignore useful load. Not too hard to find a P46T with full fuel useful under 100 lbs. Let's assume for the moment that everyone who buys an SF50 flies it 500 lbs over gross. Does that change the market dynamics in your estimation?

I think people will put up with a lot of inefficiency with a JET assuming it will perform a mission. Is the 6000# limit anything magical from an engineering standpoint or just an FAA fence?

FAA Fence, like 25K MSL.

Tim

Oshkosh tells the tale. Mob scene at Cirrus with a lot more than lookers, people EXCITED about the jet and putting down deposits. Most everyone else was dead, including Cessna with the M2, Beech with a $1.6M Baron, etc.

IMO the challenge is not engineering perfection, its PILOTS. There are plenty of good pilots in the world, they just don't have $2M plus operating expenses, so they don't count. There are also a lot of rich people in the world, they are usually busy and don't have time to fly around 300 hours a year, attend 2 weeks of training, argue for hours on pilot boards, and live aviation. They do however count and they have spoken, they want a jet that a private pilot w/IR can handle flying 50-100 hours a year. Cirrus is just the only company listening.

BTW- I have bought two new Cessna's in my life. You know how many times they asked me what I wanted in a step up aircraft? Zero.

This.. exactly. What is the step up from a good high performance single piston?

A baron? Sorry.. I'm not putting 2x fuel and 2x maintenance through it to get 10 or maybe 15 more knots.