716X completed first flight on 7/2...

https://www.flyingmag.com/story/aircraf ... st-flight/

https://stratosaircraft.com/partner-program/

I can't wait for it to go into production. Really cool airplane.

Lurking on the Michael Ts Citation 501 threads has me intrigued buy the idea single engine JT15d jet. Half the fuel burn with still incredible performance.

Unfortunately still way outside my budget

Looks like they're still piling on the flight hours. Cool.

https://flightaware.com/live/flight/N716X/history

The Aermacchi S-211 uses a single JT15D-4D engine (2,500 lbs thrust).

Years after I started this thread and my interest has only increased. If things go well, I may even look into purchasing an experimental version before they certify.

Some interesting numbers:

Weight to Thrust Ratio: 3.0

2633 lbs usable fuel
82 gph burn at FL410
1,400 lb max payload
1,000 lb useful load max fuel
5,075 lb empty weight
8,580 lb takeoff weight

8.5 psi cabin
0.70 Mmo

Mission weight 8,580 lbs
Takeoff distance (sea level) 2,890 ft
1,500 nm IFR range
2,120 ft landing distance

22 min time to climb FL370
Service Ceiling FL410

What stood out to me with these numbers was the takeoff and landing. Takeoff of 2,900 ft at max weight. That's pretty darn good! The Epic takeoff is only ~650ft shorter.

I'm having a hard time finding negatives that would effect my decision for an Epic over the Stratos.

If there is a negative, maybe baggage space?

is this experimental?

what engines are they proposing? JT15? is it a twin?

Yes, experimental for now. It is a Pratt & Whitney Canada JT15D-5. It is not a twin. It's a single.

If certified, they expect to use a Pratt & Whitney Canada PW535E engine or a Williams FJ44-3AP.

The FAA will not certify a single engine aircraft for FL410. Lose an engine and you lose pressurization. You need two sources of pressure. I think FL310 is the max for one source. With that restriction you end up with greater fuel per mile and short range. The single engine jet has no net advantage over a twin jet flying 10,000 ft higher.

Aren't they trying to devise a solution for that to make the FAA happy?

The rule talks about cabin altitudes not going above 15,000 ft during a failure. That is really hard when flying at FL410 and your sole source of pressurized air quits.

So far, no one has certified an SEJ that high. It can be done, but the plane would likely need a second source of pressurized air. The weight, cost, and complexity of that negates the single engine advantages.

The well known solution is a second engine, which all sorts of other benefits when it comes to safety and redundancy.

When you are operating at FL410, you are a spaceship. You have 5 seconds of useful consciousness and 82% of the atmosphere is below you. Stepping out the space station airlock is only 18% worse.

Mike C.

I've heard this argument before and from what I've heard, the Stratos team has solved this issue. They have a second source, just not an engine. So, there will not be a restriction.

The Epic is allowed up to FL340 on a single so this limitation of FL310 on a single is not a thing.

The interactive cutaway shows that both the AFT and the FWD baggage spaces are unpressurized

I've heard this argument before and from what I've heard, the Stratos team has solved this issue. They have a second source, just not an engine. So, there will not be a restriction.

The Epic is allowed up to FL340 on a single so this limitation of FL310 on a single is not a thing.

What is it?

Mike C.