especially when the FJ33 is likely to be made in qty while the pratt 610 is married to a failed airframe manufacturer

especially when the FJ33 is likely to be made in qty while the pratt 610 is married to a failed airframe manufacturer

for clarity, I'm squarely in the "no" camp
A lycoming O-320 vs an IO-720 - sure one is more expensive than 2 of the other
2 small turbine engines, no way
Now consider that the alleged cheaper flavor will always be a low-volume oddball.

But what do they know

Do the seatbelts require the driver the slow down to 20 MPH and have the steering wheel straight before they restrain you?

Do the seatbelts require the driver to activate them?

If both of those were true, seatbelts would save almost no one they do today.

If the chute actually covered more than a trifle of the flight envelope, then it would be more of an argument, but the SF-50 chute is so severely limited that if you are in the chute envelope, you actually aren't in much danger.

Mike C.

knowing that its not easy to do a restart at altitude; I wonder what the procedure is for the SF50? What is the highest altitude recommended? How does this compare to the optimal Chute altitude?

BTW, what is the best glide speed and range for the SF50?

(starting to sound like Monte Python in the background. "Bring Forth the Holy Hand Grenade of Antioch!" Reading from the Holy Book of Armaments, Chapter 7, Verse 2.).

I don't have the SF 50 AFM, but it probably has a restart envelope pretty close to its FL280 service ceiling. The planes I flew with Pratts had a restart envelope of about 25,000, and drifting down from normal cruise altitudes of 350 to 390 was always necessary to attempt a restart.

The Williams engines may have totally different characteristics, but another question would be what is the minimum speed for windmilling to keep the engine-driven accessories functioning.

I believe that the technology exists today to equip almost any jet or turboprop with the ability to navigate to and land at a suitable airport in an emergency (engine failure at altitude or pilot incapacitation) and I suspect that functionality would be less expensive initially and long term as well as considerably lighter than a whole airframe parachute. Probably more effective as well.

I believe that the technology exists today to equip almost any jet or turboprop with the ability to navigate to and land at a suitable airport in an emergency (engine failure at altitude or pilot incapacitation) and I suspect that functionality would be less expensive initially and long term as well as considerably lighter than a whole airframe parachute. Probably more effective as well.

Air restart envelope for the FJ33 is probably similar to the FJ44. You can use the starter or windmill start is above 230kts below 15K. With the FADEC in a windmill start you just move the throttle to cut off to reset the FADEC then back to idle. When over 230kts the engine should light off.

It's hard not to wonder how the single engine jet stacks up if the FAA raised the ceiling to say, 350...

The small Pratts can be restarted at FL200 or lower

OEM engine supply agreements are confidential, so you will never see verifiable proof of this.

However, from the Eclipse bankruptcy documents filed during proceedings (sadly, no longer accessible online), the PWC agreement showed Eclipse was getting PW610F for about $280K each.

A new FJ44-2A runs about $750K each. This is why a Williams conversion of a Citation 501SP is about $2.1M out the door, most of that is the engines.

Correct for inflation, the rough price delta is about double per engine, or two PW610F is the cost of one FJ33-5A (which is just an FJ44 in reality, it is on the FJ44 TCDS).

Further evidence is the sales price history of both the Eclipse and SF50 have been remarkably similar, so the second engine didn't affect the sales price very much.

A single larger engine will cost more per unit for being larger, for having fewer units to amortize development costs over, for having higher liability to the engine manufacturer, and for having lower future revenue for service and major engine events. Engine makers ultimately make as much money if not more from future parts and service than they do from the initial purchase.

Given 500 airframes of each type, would you rather be the engine OEM that supports 1000 engines on a twin or 500 engines on a single? For the twin, you sell twice as many engines, sell twice as many parts and service, and have basically zero liability. On the single, you sell half as many engines, sell half as many parts and service, and have a huge liability if the engine fails.

Seems like a simply choice to me, and that's reflected in the price the OEM pays to get the engine.

Mike C.

Mike,

Someone stated in another thread that your relative is an engineer for Textron/Cessna and holds patents with them. Was that fake news?