Mostly regulatory.

Has to do with pressurization redundancy to go higher. Hard to do that with one engine, so much so that the simplest thing is to hang two engines if you want to go higher.

Also, one engine has configuration penalties that limit performance versus a plane with two. There's just no good place to have one jet engine versus two on pylons. This is why an Eclipse with less total thrust and the same weight climbs much better than the SF50, more efficient engine placement.

Mike C.

If it’s regulatory how does Epic get away with higher?

The regs state a performance criteria for maintaining cabin altitude for some time limit after a failure, so you can nibble into the low 30s by having a tight cabin instead of showing redundancy that would enable FL410.

As the airplanes age, cabins tend not to be as tight and thus they probably don't meet the test criteria any more, arbitrary as it is.

Mike C.

Yet these guys are confident their SE Jet will be certified to FL410. I wonder how.
https://www.stratosaircraft.com/certified-aircraft
I'm not privy to their plans, but it's possible that automated systems to detect pressurization failures and automatically descend will provide an equivalent level of safety to satisfy the FAA.

What's also interesting about this plane is the panel. They show G3X touch EFIS displays, but those are not the "jet" version of the aftermarket Garmin EFIS. It's the G600txi.

Having said that, I like the panel configuration because it's modular and can be more easily updated in the future.

Ignorance enables aspirations beyond reality.


Hasn't in the past.

You will note that not a single company that makes jets proposed an SEJ because they know the rules and the problems. Such projects only come from companies who haven't done it, and only one reached the finish line (with a Chinese bailout).

The very first SEJ project, the failed Gulfstream Peregrine, was the first and last attempt any established jet maker ever made into the SEJ territory.

Mike C.

And past success breeds confidence. These are many of the same people who got the SETP Epic certified to FL350. It's not their first rodeo.And no SE turbine had been certified to FL350, until Epic did it.Au contraire, how could you forget the Eclipse 400? They not only proposed it, they built a prototype and flew it. https://en.wikipedia.org/wiki/Eclipse_400

Au contraire, how could you forget the Eclipse 400? They not only proposed it, they built a prototype and flew it.

Let's look at the tape.Eclipse certainly made jets at the time, and they certainly proposed the 400, they even accepted deposits on it.

Myth: BUSTED