I've flown formation with an F33A. Same engine, same prop, same layout, similar CG, within 100 lbs of same weight. We can't account for engine performance differences (I think mine might be stronger than his), but I was definitely faster.

Yes, I am accusing Beech of that. They built the Debonaire and made it a Bonanza because of the negative image attached to the V-tails as the "Fork tailed doctor killer". They were transitioning away from the V tail for marketing reasons. There was no way they'd put one on the 36.

Ever flown into KJAC? Once you're in the bowl, below 9K, a Baron anywhere near gross with one engine out is more or less a death sentence. You're not going anywhere but down into the terrain. If the lake is frozen, that's what I would aim for. If it ain't frozen, Highway 89, I guess?

Flown into KJAC, on average, 20 times a year for I don't know how many years. Everything from lowly singles (PIC), to twin turboprops (SIC) to a Citation X (passenger). Never in a piston twin. You could not pay me to do it. At least with a single I know I'll be meeting the terrain at less than 60knots. With a chute, a lot slower than that. In a twin, with an engine out? 100? 110?

What benefit does a second engine provide in a piston twin outside of flat midwest that a chute does not? In places like Jackson Hole, Aspen, Telluride, a second piston engine is a liability, not an asset. Until you move to something that can still climb at 800fpm on one, which means a turbo prop, you are safer in a single with a chute.

You can get APG Runaway Analysis from fltplan.com for $900/year.

I think there may be some places you can buy it by the drink if you only need it a few times a year.

The PT6 does. But, that doesn't change the dynamics of the duct. Ya, maybe 727,L-1011, or Falcon 900.

The Falcon works just fine with a duct feeding the center engine. I'm sure there's a flow loss, but it won't be much. A well designed duct is pretty efficient.

The PT6 does. But, that doesn't change the dynamics of the duct. Ya, maybe 727,L-1011, or Falcon 900.

The Falcon works just fine with a duct feeding the center engine. I'm sure there's a flow loss, but it won't be much. A well designed duct is pretty efficient.

The reversal does hurt the PT6. So does being a free turbine. I'm not sure which of those is more to blame for the inefficiency compared to the Garrets.

I can only speculate from pictures, but the SF50 duct doesn't appear to be curved. It does have a drop in it though of what appears to be 5-6". That will reduce flow, but I would't expect that to be more than a 1-2% reduction in flow rate.

Ever flown into KJAC? Once you're in the bowl, below 9K, a Baron anywhere near gross with one engine out is more or less a death sentence. You're not going anywhere but down into the terrain. If the lake is frozen, that's what I would aim for. If it ain't frozen, Highway 89, I guess?

Flown into KJAC, on average, 20 times a year for I don't know how many years. Everything from lowly singles (PIC), to twin turboprops (SIC) to a Citation X (passenger). Never in a piston twin. You could not pay me to do it. At least with a single I know I'll be meeting the terrain at less than 60knots. With a chute, a lot slower than that. In a twin, with an engine out? 100? 110?

What benefit does a second engine provide in a piston twin outside of flat midwest that a chute does not? In places like Jackson Hole, Aspen, Telluride, a second piston engine is a liability, not an asset. Until you move to something that can still climb at 800fpm on one, which means a turbo prop, you are safer in a single with a chute.

I have not read all 32 pages and maybe this has been covered. How many SF50's does Cirrus have to sell a year to break even and is this number realistic.
This might be a great idea with not enough demand.

Keep in mind at 6000lbs GWT the engine out certification rules change (Eclipse excepted) and the part 23 commuter category kicks in requiring a climb gradient on one engine.

But they aren't prevented.

It is reasonable to look for technical answers to that problem. Cirrus did and found one. You can argue it's all emotion and marketing until the proverbial bovines return to their abode, but people are alive right now who would be dead without CAPS. Statistics don't kiss their kids goodnight, walk their dogs or blow out birthday candles.

Maybe they are all incredibly bad pilots. Maybe Cirrus is tampering with primal Darwinian forces of the universe and they all should be pushing up daisies.

I think the SF50 is a marginal idea at best, but parachutes for light airplanes flown by non-professional pilots are a very good idea.

Mike,

I think the jet engine is a little more efficient than it seems. Would you look at my numbers below and see if you agree?



If we look at a 300KTAS cruise speed, we're traveling at about 506 feet per second. 1 HP is defined as 550 foot pounds per second. Therefore one pound of thrust at 300KTAS is equal to 506/550 or 0.92 HP. If the TSFC is about 0.48 lbs/lbf/hr the "equivalent" BSFC would be about 0.48/.92 or 0.52 lbs/hp/hr.

A BSFC 0.52 is certainly worse than a piston, but doesn't seem so bad overall.

Take care,
David

I would assume as a basis for certification, the cabin will have to bleed slowly enough to keep a <15k cabin altitude until the plane (under the chute) can descend to that level).

At Sea level, yes. At 25K, with only 37% of the air density, it's only 47 GPH ( and less thrust.. but apparently still enough to get the SF50 to 300 ktas)

And I thought this was about the SF50. But it kept growing and growing, so I checked in.

Gotta start somewhere:

Statistically, it can be shown it hasn't.

Corvalis, an extremely similar aircraft in all respects but the chute, has half the ACTUAL fatal accident rate, never mind all the fatal situations the SR chute supposedly "saved" people from.

Nate, heads up, Ciholas is actually Crandall disguised as an MU2 pilot

go get em